Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 16.11.21 11:45, Oleksandr Andrushchenko wrote:
Hi, Geert!
On 16.11.21 11:36, Geert Uytterhoeven wrote:
Hi Oleksandr,
On Thu, Oct 28, 2021 at 8:15 AM Oleksandr Andrushchenko
wrote:
From: Oleksandr Andrushchenko
Xen-pciback driver was designed to be built for x86 only. But it
can also be used by other architectures, e.g. Arm.
Currently PCI backend implements multiple functionalities at a time,
such as:
1. It is used as a database for assignable PCI devices, e.g. xl
pci-assignable-{add|remove|list} manipulates that list. So, whenever
the toolstack needs to know which PCI devices can be passed through
it reads that from the relevant sysfs entries of the pciback.
2. It is used to hold the unbound PCI devices list, e.g. when passing
through a PCI device it needs to be unbound from the relevant device
driver and bound to pciback (strictly speaking it is not required
that the device is bound to pciback, but pciback is again used as a
database of the passed through PCI devices, so we can re-bind the
devices back to their original drivers when guest domain shuts down)
3. Device reset for the devices being passed through
4. Para-virtualised use-cases support
The para-virtualised part of the driver is not always needed as some
architectures, e.g. Arm or x86 PVH Dom0, are not using backend-frontend
model for PCI device passthrough.
For such use-cases make the very first step in splitting the
xen-pciback driver into two parts: Xen PCI stub and PCI PV backend
drivers.
For that add new configuration options CONFIG_XEN_PCI_STUB and
CONFIG_XEN_PCIDEV_STUB, so the driver can be limited in its
functionality, e.g. no support for para-virtualised scenario.
x86 platform will continue using CONFIG_XEN_PCIDEV_BACKEND for the
fully featured backend driver.
Signed-off-by: Oleksandr Andrushchenko
Signed-off-by: Anastasiia Lukianenko
Reviewed-by: Stefano Stabellini
Reviewed-by: Juergen Gross
Thanks for your patch, which is now commit a67efff28832a597
("xen-pciback: allow compiling on other archs than x86")
in v5.16-rc1.
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -181,10 +181,34 @@ config SWIOTLB_XEN
select DMA_OPS
select SWIOTLB
+config XEN_PCI_STUB
+ bool
+
+config XEN_PCIDEV_STUB
+ tristate "Xen PCI-device stub driver"
+ depends on PCI && !X86 && XEN
+ depends on XEN_BACKEND
+ select XEN_PCI_STUB
+ default m
Please note that this means "default y" if CONFIG_MODULES=n.
Perhaps this should be "default m if MODULES" instead?
I don't really have strong opinion on this and will let Xen maintainers
speak: @Boris, @Juergen what's your preference here?
TBH, I don't have any.
All other backends have no "default" line, so maybe the cleanest
solution would be to remove the "default" lines for XEN_PCIDEV_STUB
and XEN_PCIDEV_BACKEND, too?
+ help
+ The PCI device stub driver provides limited version of the PCI
+ device backend driver without para-virtualized support for guests.
+ If you select this to be a module, you will need to make sure no
+ other driver has bound to the device(s) you want to make visible to
+ other guests.
+
+ The "hide" parameter (only applicable if backend driver is compiled
+ into the kernel) allows you to bind the PCI devices to this module
+ from the default device drivers. The argument is the list of PCI BDFs:
+ xen-pciback.hide=(03:00.0)(04:00.0)
+
+ If in doubt, say m.
+
config XEN_PCIDEV_BACKEND
tristate "Xen PCI-device backend driver"
depends on PCI && X86 && XEN
depends on XEN_BACKEND
+ select XEN_PCI_STUB
default m
help
The PCI device backend driver allows the kernel to export arbitrary
Juergen
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Re: [PATCH] xen-pciback: allow compiling on other archs than x86
Hi, Geert!
On 16.11.21 11:36, Geert Uytterhoeven wrote:
> Hi Oleksandr,
>
> On Thu, Oct 28, 2021 at 8:15 AM Oleksandr Andrushchenko
> wrote:
>> From: Oleksandr Andrushchenko
>>
>> Xen-pciback driver was designed to be built for x86 only. But it
>> can also be used by other architectures, e.g. Arm.
>>
>> Currently PCI backend implements multiple functionalities at a time,
>> such as:
>> 1. It is used as a database for assignable PCI devices, e.g. xl
>> pci-assignable-{add|remove|list} manipulates that list. So, whenever
>> the toolstack needs to know which PCI devices can be passed through
>> it reads that from the relevant sysfs entries of the pciback.
>> 2. It is used to hold the unbound PCI devices list, e.g. when passing
>> through a PCI device it needs to be unbound from the relevant device
>> driver and bound to pciback (strictly speaking it is not required
>> that the device is bound to pciback, but pciback is again used as a
>> database of the passed through PCI devices, so we can re-bind the
>> devices back to their original drivers when guest domain shuts down)
>> 3. Device reset for the devices being passed through
>> 4. Para-virtualised use-cases support
>>
>> The para-virtualised part of the driver is not always needed as some
>> architectures, e.g. Arm or x86 PVH Dom0, are not using backend-frontend
>> model for PCI device passthrough.
>>
>> For such use-cases make the very first step in splitting the
>> xen-pciback driver into two parts: Xen PCI stub and PCI PV backend
>> drivers.
>>
>> For that add new configuration options CONFIG_XEN_PCI_STUB and
>> CONFIG_XEN_PCIDEV_STUB, so the driver can be limited in its
>> functionality, e.g. no support for para-virtualised scenario.
>> x86 platform will continue using CONFIG_XEN_PCIDEV_BACKEND for the
>> fully featured backend driver.
>>
>> Signed-off-by: Oleksandr Andrushchenko
>> Signed-off-by: Anastasiia Lukianenko
>> Reviewed-by: Stefano Stabellini
>> Reviewed-by: Juergen Gross
> Thanks for your patch, which is now commit a67efff28832a597
> ("xen-pciback: allow compiling on other archs than x86")
> in v5.16-rc1.
>
>> --- a/drivers/xen/Kconfig
>> +++ b/drivers/xen/Kconfig
>> @@ -181,10 +181,34 @@ config SWIOTLB_XEN
>> select DMA_OPS
>> select SWIOTLB
>>
>> +config XEN_PCI_STUB
>> + bool
>> +
>> +config XEN_PCIDEV_STUB
>> + tristate "Xen PCI-device stub driver"
>> + depends on PCI && !X86 && XEN
>> + depends on XEN_BACKEND
>> + select XEN_PCI_STUB
>> + default m
> Please note that this means "default y" if CONFIG_MODULES=n.
> Perhaps this should be "default m if MODULES" instead?
I don't really have strong opinion on this and will let Xen maintainers
speak: @Boris, @Juergen what's your preference here?
>
>> + help
>> + The PCI device stub driver provides limited version of the PCI
>> + device backend driver without para-virtualized support for guests.
>> + If you select this to be a module, you will need to make sure no
>> + other driver has bound to the device(s) you want to make visible to
>> + other guests.
>> +
>> + The "hide" parameter (only applicable if backend driver is compiled
>> + into the kernel) allows you to bind the PCI devices to this module
>> + from the default device drivers. The argument is the list of PCI
>> BDFs:
>> + xen-pciback.hide=(03:00.0)(04:00.0)
>> +
>> + If in doubt, say m.
>> +
>> config XEN_PCIDEV_BACKEND
>> tristate "Xen PCI-device backend driver"
>> depends on PCI && X86 && XEN
>> depends on XEN_BACKEND
>> + select XEN_PCI_STUB
>> default m
>> help
>>The PCI device backend driver allows the kernel to export
>> arbitrary
> Gr{oetje,eeting}s,
>
> Geert
Thank you,
Oleksandr
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 --
> ge...@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like
> that.
> -- Linus Torvalds
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
Hi Oleksandr,
On Thu, Oct 28, 2021 at 8:15 AM Oleksandr Andrushchenko
wrote:
> From: Oleksandr Andrushchenko
>
> Xen-pciback driver was designed to be built for x86 only. But it
> can also be used by other architectures, e.g. Arm.
>
> Currently PCI backend implements multiple functionalities at a time,
> such as:
> 1. It is used as a database for assignable PCI devices, e.g. xl
>pci-assignable-{add|remove|list} manipulates that list. So, whenever
>the toolstack needs to know which PCI devices can be passed through
>it reads that from the relevant sysfs entries of the pciback.
> 2. It is used to hold the unbound PCI devices list, e.g. when passing
>through a PCI device it needs to be unbound from the relevant device
>driver and bound to pciback (strictly speaking it is not required
>that the device is bound to pciback, but pciback is again used as a
>database of the passed through PCI devices, so we can re-bind the
>devices back to their original drivers when guest domain shuts down)
> 3. Device reset for the devices being passed through
> 4. Para-virtualised use-cases support
>
> The para-virtualised part of the driver is not always needed as some
> architectures, e.g. Arm or x86 PVH Dom0, are not using backend-frontend
> model for PCI device passthrough.
>
> For such use-cases make the very first step in splitting the
> xen-pciback driver into two parts: Xen PCI stub and PCI PV backend
> drivers.
>
> For that add new configuration options CONFIG_XEN_PCI_STUB and
> CONFIG_XEN_PCIDEV_STUB, so the driver can be limited in its
> functionality, e.g. no support for para-virtualised scenario.
> x86 platform will continue using CONFIG_XEN_PCIDEV_BACKEND for the
> fully featured backend driver.
>
> Signed-off-by: Oleksandr Andrushchenko
> Signed-off-by: Anastasiia Lukianenko
> Reviewed-by: Stefano Stabellini
> Reviewed-by: Juergen Gross
Thanks for your patch, which is now commit a67efff28832a597
("xen-pciback: allow compiling on other archs than x86")
in v5.16-rc1.
> --- a/drivers/xen/Kconfig
> +++ b/drivers/xen/Kconfig
> @@ -181,10 +181,34 @@ config SWIOTLB_XEN
> select DMA_OPS
> select SWIOTLB
>
> +config XEN_PCI_STUB
> + bool
> +
> +config XEN_PCIDEV_STUB
> + tristate "Xen PCI-device stub driver"
> + depends on PCI && !X86 && XEN
> + depends on XEN_BACKEND
> + select XEN_PCI_STUB
> + default m
Please note that this means "default y" if CONFIG_MODULES=n.
Perhaps this should be "default m if MODULES" instead?
> + help
> + The PCI device stub driver provides limited version of the PCI
> + device backend driver without para-virtualized support for guests.
> + If you select this to be a module, you will need to make sure no
> + other driver has bound to the device(s) you want to make visible to
> + other guests.
> +
> + The "hide" parameter (only applicable if backend driver is compiled
> + into the kernel) allows you to bind the PCI devices to this module
> + from the default device drivers. The argument is the list of PCI
> BDFs:
> + xen-pciback.hide=(03:00.0)(04:00.0)
> +
> + If in doubt, say m.
> +
> config XEN_PCIDEV_BACKEND
> tristate "Xen PCI-device backend driver"
> depends on PCI && X86 && XEN
> depends on XEN_BACKEND
> + select XEN_PCI_STUB
> default m
> help
> The PCI device backend driver allows the kernel to export arbitrary
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
Please ignore this patch in favor of "RESEND PATCH v6" due to
a warning reported by kernel test robot :
I love your patch! Perhaps something to improve:
[auto build test WARNING on xen-tip/linux-next]
[also build test WARNING on linux/master linus/master v5.15-rc7 next-20211028]
[cannot apply to helgaas-pci/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url:https://github.com/0day-ci/linux/commits/Oleksandr-Andrushchenko/xen-pciback-allow-compiling-on-other-archs-than-x86/20211028-141523
base:https://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git linux-next
config: arm64-defconfig (attached as .config)
compiler: aarch64-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
wgethttps://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross
-O ~/bin/make.cross
chmod +x ~/bin/make.cross
#https://github.com/0day-ci/linux/commit/085a7279d0d85497688bc5be9a1f00ab2cce02ae
git remote add linux-reviewhttps://github.com/0day-ci/linux
git fetch --no-tags linux-review
Oleksandr-Andrushchenko/xen-pciback-allow-compiling-on-other-archs-than-x86/20211028-141523
git checkout 085a7279d0d85497688bc5be9a1f00ab2cce02ae
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross
ARCH=arm64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot
All warnings (new ones prefixed by >>):
>> drivers/xen/pci.c:279:5: warning: no previous prototype for
>> 'xen_find_device_domain_owner' [-Wmissing-prototypes]
279 | int xen_find_device_domain_owner(struct pci_dev *dev)
| ^~~~
>> drivers/xen/pci.c:293:5: warning: no previous prototype for
>> 'xen_register_device_domain_owner' [-Wmissing-prototypes]
293 | int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t
domain)
| ^~~~
>> drivers/xen/pci.c:315:5: warning: no previous prototype for
>> 'xen_unregister_device_domain_owner' [-Wmissing-prototypes]
315 | int xen_unregister_device_domain_owner(struct pci_dev *dev)
| ^~
vim +/xen_find_device_domain_owner +279 drivers/xen/pci.c
278
> 279 int xen_find_device_domain_owner(struct pci_dev *dev)
280 {
281 struct xen_device_domain_owner *owner;
282 int domain = -ENODEV;
283
284 spin_lock(&dev_domain_list_spinlock);
285 owner = find_device(dev);
286 if (owner)
287 domain = owner->domain;
288 spin_unlock(&dev_domain_list_spinlock);
289 return domain;
290 }
291 EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
292
> 293 int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t
domain)
294 {
295 struct xen_device_domain_owner *owner;
296
297 owner = kzalloc(sizeof(struct xen_device_domain_owner),
GFP_KERNEL);
298 if (!owner)
299 return -ENODEV;
300
301 spin_lock(&dev_domain_list_spinlock);
302 if (find_device(dev)) {
303 spin_unlock(&dev_domain_list_spinlock);
304 kfree(owner);
305 return -EEXIST;
306 }
307 owner->domain = domain;
308 owner->dev = dev;
309 list_add_tail(&owner->list, &dev_domain_list);
310 spin_unlock(&dev_domain_list_spinlock);
311 return 0;
312 }
313 EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
314
> 315 int xen_unregister_device_domain_owner(struct pci_dev *dev)
On 28.10.21 09:13, Oleksandr Andrushchenko wrote:
> From: Oleksandr Andrushchenko
>
> Xen-pciback driver was designed to be built for x86 only. But it
> can also be used by other architectures, e.g. Arm.
>
> Currently PCI backend implements multiple functionalities at a time,
> such as:
> 1. It is used as a database for assignable PCI devices, e.g. xl
> pci-assignable-{add|remove|list} manipulates that list. So, whenever
> the toolstack needs to know which PCI devices can be passed through
> it reads that from the relevant sysfs entries of the pciback.
> 2. It is used to hold the unbound PCI devices list, e.g. when passing
> through a PCI device it needs to be unbound from the relevant device
> driver and bound to pciback (strictly speaking it is not required
> that the device is bound to pciback, but pciback is again used as a
> database of the passed through PCI devices, so we can re-bind the
> devices back to their original drivers when guest domain shuts down)
> 3. Device reset for the devices being passed through
> 4. Para-virtualised use-cases support
>
>
[PATCH] xen-pciback: allow compiling on other archs than x86
From: Oleksandr Andrushchenko
Xen-pciback driver was designed to be built for x86 only. But it
can also be used by other architectures, e.g. Arm.
Currently PCI backend implements multiple functionalities at a time,
such as:
1. It is used as a database for assignable PCI devices, e.g. xl
pci-assignable-{add|remove|list} manipulates that list. So, whenever
the toolstack needs to know which PCI devices can be passed through
it reads that from the relevant sysfs entries of the pciback.
2. It is used to hold the unbound PCI devices list, e.g. when passing
through a PCI device it needs to be unbound from the relevant device
driver and bound to pciback (strictly speaking it is not required
that the device is bound to pciback, but pciback is again used as a
database of the passed through PCI devices, so we can re-bind the
devices back to their original drivers when guest domain shuts down)
3. Device reset for the devices being passed through
4. Para-virtualised use-cases support
The para-virtualised part of the driver is not always needed as some
architectures, e.g. Arm or x86 PVH Dom0, are not using backend-frontend
model for PCI device passthrough.
For such use-cases make the very first step in splitting the
xen-pciback driver into two parts: Xen PCI stub and PCI PV backend
drivers.
For that add new configuration options CONFIG_XEN_PCI_STUB and
CONFIG_XEN_PCIDEV_STUB, so the driver can be limited in its
functionality, e.g. no support for para-virtualised scenario.
x86 platform will continue using CONFIG_XEN_PCIDEV_BACKEND for the
fully featured backend driver.
Signed-off-by: Oleksandr Andrushchenko
Signed-off-by: Anastasiia Lukianenko
Reviewed-by: Stefano Stabellini
Reviewed-by: Juergen Gross
---
Changes since v5:
- rebased
Changes since v4:
- squashed two patches
- simplified Makefile
Changes since v3:
- Fix >>32 shift for 32-bit architectures
Changes since v2:
- swap the patch order
Since v1:
- Do not move pci_xen_initial_domain as it is x86 specific
---
arch/x86/include/asm/xen/pci.h | 19 --
arch/x86/pci/xen.c | 76 +
drivers/xen/Kconfig | 24 +++
drivers/xen/Makefile| 2 +-
drivers/xen/pci.c | 75
drivers/xen/xen-pciback/Makefile| 7 ++
drivers/xen/xen-pciback/conf_space_header.c | 8 ++-
drivers/xen/xen-pciback/pci_stub.c | 3 +-
drivers/xen/xen-pciback/pciback.h | 5 ++
drivers/xen/xen-pciback/xenbus.c| 8 ++-
include/xen/pci.h | 28
11 files changed, 155 insertions(+), 100 deletions(-)
create mode 100644 include/xen/pci.h
diff --git a/arch/x86/include/asm/xen/pci.h b/arch/x86/include/asm/xen/pci.h
index 4557f7cb0fa6..9015b888edd6 100644
--- a/arch/x86/include/asm/xen/pci.h
+++ b/arch/x86/include/asm/xen/pci.h
@@ -22,25 +22,6 @@ static inline int __init pci_xen_initial_domain(void)
return -1;
}
#endif
-#ifdef CONFIG_XEN_DOM0
-int xen_find_device_domain_owner(struct pci_dev *dev);
-int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain);
-int xen_unregister_device_domain_owner(struct pci_dev *dev);
-#else
-static inline int xen_find_device_domain_owner(struct pci_dev *dev)
-{
- return -1;
-}
-static inline int xen_register_device_domain_owner(struct pci_dev *dev,
- uint16_t domain)
-{
- return -1;
-}
-static inline int xen_unregister_device_domain_owner(struct pci_dev *dev)
-{
- return -1;
-}
-#endif
#if defined(CONFIG_PCI_MSI)
#if defined(CONFIG_PCI_XEN)
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 5debe4ac6f81..12da00558631 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -23,6 +23,7 @@
#include
#include
+#include
#include
#include
#include
@@ -585,78 +586,3 @@ int __init pci_xen_initial_domain(void)
}
#endif
-#ifdef CONFIG_XEN_DOM0
-
-struct xen_device_domain_owner {
- domid_t domain;
- struct pci_dev *dev;
- struct list_head list;
-};
-
-static DEFINE_SPINLOCK(dev_domain_list_spinlock);
-static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
-
-static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
-{
- struct xen_device_domain_owner *owner;
-
- list_for_each_entry(owner, &dev_domain_list, list) {
- if (owner->dev == dev)
- return owner;
- }
- return NULL;
-}
-
-int xen_find_device_domain_owner(struct pci_dev *dev)
-{
- struct xen_device_domain_owner *owner;
- int domain = -ENODEV;
-
- spin_lock(&dev_domain_list_spinlock);
- owner = find_device(dev);
- if (owner)
- domain = owner->domain;
- spin_unlock(&dev_domain_list_spinlock);
- return domain;
-}
-EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
-
-int xen_regis
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 21.09.21 23:44, Stefano Stabellini wrote:
> On Tue, 21 Sep 2021, Oleksandr Andrushchenko wrote:
>> On 21.09.21 10:09, Juergen Gross wrote:
>>> On 21.09.21 09:00, Oleksandr Andrushchenko wrote:
On 21.09.21 09:49, Juergen Gross wrote:
> On 21.09.21 08:38, Oleksandr Andrushchenko wrote:
>> On 21.09.21 09:07, Juergen Gross wrote:
>>> On 21.09.21 07:51, Oleksandr Andrushchenko wrote:
On 21.09.21 08:20, Juergen Gross wrote:
> On 21.09.21 01:16, Stefano Stabellini wrote:
>> On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
>>> On 20.09.21 14:30, Juergen Gross wrote:
On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
> Hello, Stefano!
>
> On 18.09.21 00:45, Stefano Stabellini wrote:
>> Hi Oleksandr,
>>
>> Why do you want to enable pciback on ARM? Is it only to
>> "disable" a PCI
>> device in Dom0 so that it can be safely assigned to a DomU?
> Not only that
>> I am asking because actually I don't think we want to enable the
>> PV PCI
>> backend feature of pciback on ARM, right? That would clash with
>> the PCI
>> assignment work you have been doing in Xen. They couldn't both
>> work at
>> the same time.
> Correct, it is not used
>> If we only need pciback to "park" a device in Dom0, wouldn't it
>> be
>> possible and better to use pci-stub instead?
> Not only that, so pci-stub is not enough
>
> The functionality which is implemented by the pciback and the
> toolstack
> and which is relevant/missing/needed for ARM:
>
> 1. pciback is used as a database for assignable PCI devices, e.g.
> xl
> pci-assignable-{add|remove|list} manipulates that list.
> So, whenever the
> toolstack needs to know which PCI devices can be passed
> through it reads
> that from the relevant sysfs entries of the pciback.
>
> 2. pciback is used to hold the unbound PCI devices, e.g. when
> passing through
> a PCI device it needs to be unbound from the relevant
> device driver and bound
> to pciback (strictly speaking it is not required that
> the device is bound to
> pciback, but pciback is again used as a database of the
> passed through PCI
> devices, so we can re-bind the devices back to their
> original drivers when
> guest domain shuts down)
>
> 3. Device reset
>
> We have previously discussed on xen-devel ML possible solutions
> to that as from the
> above we see that pciback functionality is going to be only
> partially used on Arm.
>
> Please see [1] and [2]:
>
> 1. It is not acceptable to manage the assignable list in Xen
> itself
>
> 2. pciback can be split into two parts: PCI assignable/bind/reset
> handling and
> the rest like vPCI etc.
>
> 3. pcifront is not used on Arm
It is neither in x86 PVH/HVM guests.
>>> Didn't know that, thank you for pointing
> So, limited use of the pciback is one of the bricks used to
> enable PCI passthrough
> on Arm. It was enough to just re-structure the driver and have it
> run on Arm to achieve
> all the goals above.
>
> If we still think it is desirable to break the pciback driver
> into "common" and "pcifront specific"
> parts then it can be done, yet the patch is going to be the very
> first brick in that building.
Doing this split should be done, as the pcifront specific part
could be
omitted on x86, too, in case no PV guests using PCI passthrough
have to
be supported.
>>> Agree, that the final solution should have the driver split
> So, I think this patch is still going to be needed besides which
> direction we take.
Some kind of this patch, yes. It might look different in case the
split
is done first.
I don't mind doing it in either sequence.
>>> With this patch we have Arm on the same page as the above mentioned
>>> x86 guests,
>>>
>>> e.g. the driver has unused code, but yet allows Arm to function now.
>>>
>>> At this stage
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On Tue, 21 Sep 2021, Oleksandr Andrushchenko wrote:
> On 21.09.21 10:09, Juergen Gross wrote:
> > On 21.09.21 09:00, Oleksandr Andrushchenko wrote:
> >>
> >> On 21.09.21 09:49, Juergen Gross wrote:
> >>> On 21.09.21 08:38, Oleksandr Andrushchenko wrote:
>
> On 21.09.21 09:07, Juergen Gross wrote:
> > On 21.09.21 07:51, Oleksandr Andrushchenko wrote:
> >>
> >> On 21.09.21 08:20, Juergen Gross wrote:
> >>> On 21.09.21 01:16, Stefano Stabellini wrote:
> On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
> > On 20.09.21 14:30, Juergen Gross wrote:
> >> On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
> >>> Hello, Stefano!
> >>>
> >>> On 18.09.21 00:45, Stefano Stabellini wrote:
> Hi Oleksandr,
>
> Why do you want to enable pciback on ARM? Is it only to
> "disable" a PCI
> device in Dom0 so that it can be safely assigned to a DomU?
> >>> Not only that
>
> I am asking because actually I don't think we want to enable the
> PV PCI
> backend feature of pciback on ARM, right? That would clash with
> the PCI
> assignment work you have been doing in Xen. They couldn't both
> work at
> the same time.
> >>> Correct, it is not used
>
> If we only need pciback to "park" a device in Dom0, wouldn't it
> be
> possible and better to use pci-stub instead?
> >>>
> >>> Not only that, so pci-stub is not enough
> >>>
> >>> The functionality which is implemented by the pciback and the
> >>> toolstack
> >>> and which is relevant/missing/needed for ARM:
> >>>
> >>> 1. pciback is used as a database for assignable PCI devices, e.g.
> >>> xl
> >>> pci-assignable-{add|remove|list} manipulates that list.
> >>> So, whenever the
> >>> toolstack needs to know which PCI devices can be passed
> >>> through it reads
> >>> that from the relevant sysfs entries of the pciback.
> >>>
> >>> 2. pciback is used to hold the unbound PCI devices, e.g. when
> >>> passing through
> >>> a PCI device it needs to be unbound from the relevant
> >>> device driver and bound
> >>> to pciback (strictly speaking it is not required that
> >>> the device is bound to
> >>> pciback, but pciback is again used as a database of the
> >>> passed through PCI
> >>> devices, so we can re-bind the devices back to their
> >>> original drivers when
> >>> guest domain shuts down)
> >>>
> >>> 3. Device reset
> >>>
> >>> We have previously discussed on xen-devel ML possible solutions
> >>> to that as from the
> >>> above we see that pciback functionality is going to be only
> >>> partially used on Arm.
> >>>
> >>> Please see [1] and [2]:
> >>>
> >>> 1. It is not acceptable to manage the assignable list in Xen
> >>> itself
> >>>
> >>> 2. pciback can be split into two parts: PCI assignable/bind/reset
> >>> handling and
> >>> the rest like vPCI etc.
> >>>
> >>> 3. pcifront is not used on Arm
> >>
> >> It is neither in x86 PVH/HVM guests.
> > Didn't know that, thank you for pointing
> >>
> >>> So, limited use of the pciback is one of the bricks used to
> >>> enable PCI passthrough
> >>> on Arm. It was enough to just re-structure the driver and have it
> >>> run on Arm to achieve
> >>> all the goals above.
> >>>
> >>> If we still think it is desirable to break the pciback driver
> >>> into "common" and "pcifront specific"
> >>> parts then it can be done, yet the patch is going to be the very
> >>> first brick in that building.
> >>
> >> Doing this split should be done, as the pcifront specific part
> >> could be
> >> omitted on x86, too, in case no PV guests using PCI passthrough
> >> have to
> >> be supported.
> > Agree, that the final solution should have the driver split
> >>
> >>> So, I think this patch is still going to be needed besides which
> >>> direction we take.
> >>
> >> Some kind of this patch, yes. It might look different in case the
> >> split
> >> is done first.
> >>
> >> I don't mind doing it in either sequence.
> >>
> > With this patch we have Arm on the same page as the above mentioned
> > x86 guests,
> >
> > e.g. the driver has unused code, b
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 21.09.21 10:54, Juergen Gross wrote:
> On 17.09.21 15:01, Oleksandr Andrushchenko wrote:
>> From: Oleksandr Andrushchenko
>>
>> Xen-pciback driver was designed to be built for x86 only. But it
>> can also be used by other architectures, e.g. Arm.
>> Re-structure the driver in a way that it can be built for other
>> platforms as well.
>>
>> Signed-off-by: Oleksandr Andrushchenko
>> Signed-off-by: Anastasiia Lukianenko
>>
>> ---
>> Tested on Arm and x86.
>> ---
>> arch/x86/include/asm/xen/pci.h | 24 --
>> arch/x86/pci/xen.c | 74 +
>> drivers/xen/Kconfig | 2 +-
>> drivers/xen/events/events_base.c | 1 +
>> drivers/xen/pci.c | 75 ++
>> drivers/xen/xen-pciback/pci_stub.c | 3 +-
>> drivers/xen/xen-pciback/xenbus.c | 2 +-
>> include/xen/pci.h | 34 ++
>> 8 files changed, 115 insertions(+), 100 deletions(-)
>> create mode 100644 include/xen/pci.h
>>
>> diff --git a/arch/x86/include/asm/xen/pci.h b/arch/x86/include/asm/xen/pci.h
>> index 3506d8c598c1..9ff7b49bca08 100644
>> --- a/arch/x86/include/asm/xen/pci.h
>> +++ b/arch/x86/include/asm/xen/pci.h
>> @@ -14,30 +14,6 @@ static inline int pci_xen_hvm_init(void)
>> return -1;
>> }
>> #endif
>> -#if defined(CONFIG_XEN_DOM0)
>> -int __init pci_xen_initial_domain(void);
>
> Why are you removing this prototype? It is X86 specific.
Indeed it is. Will not remove it form x86 code
>
>> -int xen_find_device_domain_owner(struct pci_dev *dev);
>> -int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain);
>> -int xen_unregister_device_domain_owner(struct pci_dev *dev);
>> -#else
>> -static inline int __init pci_xen_initial_domain(void)
>> -{
>> - return -1;
>> -}
>> -static inline int xen_find_device_domain_owner(struct pci_dev *dev)
>> -{
>> - return -1;
>> -}
>> -static inline int xen_register_device_domain_owner(struct pci_dev *dev,
>> - uint16_t domain)
>> -{
>> - return -1;
>> -}
>> -static inline int xen_unregister_device_domain_owner(struct pci_dev *dev)
>> -{
>> - return -1;
>> -}
>> -#endif
>> #if defined(CONFIG_PCI_MSI)
>> #if defined(CONFIG_PCI_XEN)
>> diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
>> index 3d41a09c2c14..4a45b0bf9ae4 100644
>> --- a/arch/x86/pci/xen.c
>> +++ b/arch/x86/pci/xen.c
>> @@ -23,6 +23,7 @@
>> #include
>> #include
>> +#include
>> #include
>> #include
>> #include
>> @@ -583,77 +584,4 @@ int __init pci_xen_initial_domain(void)
>> }
>> return 0;
>> }
>> -
>> -struct xen_device_domain_owner {
>> - domid_t domain;
>> - struct pci_dev *dev;
>> - struct list_head list;
>> -};
>> -
>> -static DEFINE_SPINLOCK(dev_domain_list_spinlock);
>> -static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
>> -
>> -static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
>> -{
>> - struct xen_device_domain_owner *owner;
>> -
>> - list_for_each_entry(owner, &dev_domain_list, list) {
>> - if (owner->dev == dev)
>> - return owner;
>> - }
>> - return NULL;
>> -}
>> -
>> -int xen_find_device_domain_owner(struct pci_dev *dev)
>> -{
>> - struct xen_device_domain_owner *owner;
>> - int domain = -ENODEV;
>> -
>> - spin_lock(&dev_domain_list_spinlock);
>> - owner = find_device(dev);
>> - if (owner)
>> - domain = owner->domain;
>> - spin_unlock(&dev_domain_list_spinlock);
>> - return domain;
>> -}
>> -EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
>> -
>> -int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
>> -{
>> - struct xen_device_domain_owner *owner;
>> -
>> - owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
>> - if (!owner)
>> - return -ENODEV;
>> -
>> - spin_lock(&dev_domain_list_spinlock);
>> - if (find_device(dev)) {
>> - spin_unlock(&dev_domain_list_spinlock);
>> - kfree(owner);
>> - return -EEXIST;
>> - }
>> - owner->domain = domain;
>> - owner->dev = dev;
>> - list_add_tail(&owner->list, &dev_domain_list);
>> - spin_unlock(&dev_domain_list_spinlock);
>> - return 0;
>> -}
>> -EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
>> -
>> -int xen_unregister_device_domain_owner(struct pci_dev *dev)
>> -{
>> - struct xen_device_domain_owner *owner;
>> -
>> - spin_lock(&dev_domain_list_spinlock);
>> - owner = find_device(dev);
>> - if (!owner) {
>> - spin_unlock(&dev_domain_list_spinlock);
>> - return -ENODEV;
>> - }
>> - list_del(&owner->list);
>> - spin_unlock(&dev_domain_list_spinlock);
>> - kfree(owner);
>> - return 0;
>> -}
>> -EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
>> #endif
>> diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
>> index a37eb52fb401..057ddf61ef61 100644
>> --- a/drivers/xen/Kconfig
>> +++ b/drive
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 17.09.21 15:01, Oleksandr Andrushchenko wrote:
From: Oleksandr Andrushchenko
Xen-pciback driver was designed to be built for x86 only. But it
can also be used by other architectures, e.g. Arm.
Re-structure the driver in a way that it can be built for other
platforms as well.
Signed-off-by: Oleksandr Andrushchenko
Signed-off-by: Anastasiia Lukianenko
---
Tested on Arm and x86.
---
arch/x86/include/asm/xen/pci.h | 24 --
arch/x86/pci/xen.c | 74 +
drivers/xen/Kconfig| 2 +-
drivers/xen/events/events_base.c | 1 +
drivers/xen/pci.c | 75 ++
drivers/xen/xen-pciback/pci_stub.c | 3 +-
drivers/xen/xen-pciback/xenbus.c | 2 +-
include/xen/pci.h | 34 ++
8 files changed, 115 insertions(+), 100 deletions(-)
create mode 100644 include/xen/pci.h
diff --git a/arch/x86/include/asm/xen/pci.h b/arch/x86/include/asm/xen/pci.h
index 3506d8c598c1..9ff7b49bca08 100644
--- a/arch/x86/include/asm/xen/pci.h
+++ b/arch/x86/include/asm/xen/pci.h
@@ -14,30 +14,6 @@ static inline int pci_xen_hvm_init(void)
return -1;
}
#endif
-#if defined(CONFIG_XEN_DOM0)
-int __init pci_xen_initial_domain(void);
Why are you removing this prototype? It is X86 specific.
-int xen_find_device_domain_owner(struct pci_dev *dev);
-int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain);
-int xen_unregister_device_domain_owner(struct pci_dev *dev);
-#else
-static inline int __init pci_xen_initial_domain(void)
-{
- return -1;
-}
-static inline int xen_find_device_domain_owner(struct pci_dev *dev)
-{
- return -1;
-}
-static inline int xen_register_device_domain_owner(struct pci_dev *dev,
- uint16_t domain)
-{
- return -1;
-}
-static inline int xen_unregister_device_domain_owner(struct pci_dev *dev)
-{
- return -1;
-}
-#endif
#if defined(CONFIG_PCI_MSI)
#if defined(CONFIG_PCI_XEN)
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 3d41a09c2c14..4a45b0bf9ae4 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -23,6 +23,7 @@
#include
#include
+#include
#include
#include
#include
@@ -583,77 +584,4 @@ int __init pci_xen_initial_domain(void)
}
return 0;
}
-
-struct xen_device_domain_owner {
- domid_t domain;
- struct pci_dev *dev;
- struct list_head list;
-};
-
-static DEFINE_SPINLOCK(dev_domain_list_spinlock);
-static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
-
-static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
-{
- struct xen_device_domain_owner *owner;
-
- list_for_each_entry(owner, &dev_domain_list, list) {
- if (owner->dev == dev)
- return owner;
- }
- return NULL;
-}
-
-int xen_find_device_domain_owner(struct pci_dev *dev)
-{
- struct xen_device_domain_owner *owner;
- int domain = -ENODEV;
-
- spin_lock(&dev_domain_list_spinlock);
- owner = find_device(dev);
- if (owner)
- domain = owner->domain;
- spin_unlock(&dev_domain_list_spinlock);
- return domain;
-}
-EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
-
-int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
-{
- struct xen_device_domain_owner *owner;
-
- owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
- if (!owner)
- return -ENODEV;
-
- spin_lock(&dev_domain_list_spinlock);
- if (find_device(dev)) {
- spin_unlock(&dev_domain_list_spinlock);
- kfree(owner);
- return -EEXIST;
- }
- owner->domain = domain;
- owner->dev = dev;
- list_add_tail(&owner->list, &dev_domain_list);
- spin_unlock(&dev_domain_list_spinlock);
- return 0;
-}
-EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
-
-int xen_unregister_device_domain_owner(struct pci_dev *dev)
-{
- struct xen_device_domain_owner *owner;
-
- spin_lock(&dev_domain_list_spinlock);
- owner = find_device(dev);
- if (!owner) {
- spin_unlock(&dev_domain_list_spinlock);
- return -ENODEV;
- }
- list_del(&owner->list);
- spin_unlock(&dev_domain_list_spinlock);
- kfree(owner);
- return 0;
-}
-EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
#endif
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index a37eb52fb401..057ddf61ef61 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -182,7 +182,7 @@ config SWIOTLB_XEN
config XEN_PCIDEV_BACKEND
tristate "Xen PCI-device backend driver"
- depends on PCI && X86 && XEN
+ depends on PCI && XEN
depends on XEN_BACKEND
default m
help
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/e
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 21.09.21 10:09, Juergen Gross wrote:
> On 21.09.21 09:00, Oleksandr Andrushchenko wrote:
>>
>> On 21.09.21 09:49, Juergen Gross wrote:
>>> On 21.09.21 08:38, Oleksandr Andrushchenko wrote:
On 21.09.21 09:07, Juergen Gross wrote:
> On 21.09.21 07:51, Oleksandr Andrushchenko wrote:
>>
>> On 21.09.21 08:20, Juergen Gross wrote:
>>> On 21.09.21 01:16, Stefano Stabellini wrote:
On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
> On 20.09.21 14:30, Juergen Gross wrote:
>> On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
>>> Hello, Stefano!
>>>
>>> On 18.09.21 00:45, Stefano Stabellini wrote:
Hi Oleksandr,
Why do you want to enable pciback on ARM? Is it only to "disable"
a PCI
device in Dom0 so that it can be safely assigned to a DomU?
>>> Not only that
I am asking because actually I don't think we want to enable the
PV PCI
backend feature of pciback on ARM, right? That would clash with
the PCI
assignment work you have been doing in Xen. They couldn't both
work at
the same time.
>>> Correct, it is not used
If we only need pciback to "park" a device in Dom0, wouldn't it be
possible and better to use pci-stub instead?
>>>
>>> Not only that, so pci-stub is not enough
>>>
>>> The functionality which is implemented by the pciback and the
>>> toolstack
>>> and which is relevant/missing/needed for ARM:
>>>
>>> 1. pciback is used as a database for assignable PCI devices, e.g. xl
>>> pci-assignable-{add|remove|list} manipulates that list.
>>> So, whenever the
>>> toolstack needs to know which PCI devices can be passed
>>> through it reads
>>> that from the relevant sysfs entries of the pciback.
>>>
>>> 2. pciback is used to hold the unbound PCI devices, e.g. when
>>> passing through
>>> a PCI device it needs to be unbound from the relevant
>>> device driver and bound
>>> to pciback (strictly speaking it is not required that the
>>> device is bound to
>>> pciback, but pciback is again used as a database of the
>>> passed through PCI
>>> devices, so we can re-bind the devices back to their
>>> original drivers when
>>> guest domain shuts down)
>>>
>>> 3. Device reset
>>>
>>> We have previously discussed on xen-devel ML possible solutions to
>>> that as from the
>>> above we see that pciback functionality is going to be only
>>> partially used on Arm.
>>>
>>> Please see [1] and [2]:
>>>
>>> 1. It is not acceptable to manage the assignable list in Xen itself
>>>
>>> 2. pciback can be split into two parts: PCI assignable/bind/reset
>>> handling and
>>> the rest like vPCI etc.
>>>
>>> 3. pcifront is not used on Arm
>>
>> It is neither in x86 PVH/HVM guests.
> Didn't know that, thank you for pointing
>>
>>> So, limited use of the pciback is one of the bricks used to enable
>>> PCI passthrough
>>> on Arm. It was enough to just re-structure the driver and have it
>>> run on Arm to achieve
>>> all the goals above.
>>>
>>> If we still think it is desirable to break the pciback driver into
>>> "common" and "pcifront specific"
>>> parts then it can be done, yet the patch is going to be the very
>>> first brick in that building.
>>
>> Doing this split should be done, as the pcifront specific part could
>> be
>> omitted on x86, too, in case no PV guests using PCI passthrough have
>> to
>> be supported.
> Agree, that the final solution should have the driver split
>>
>>> So, I think this patch is still going to be needed besides which
>>> direction we take.
>>
>> Some kind of this patch, yes. It might look different in case the
>> split
>> is done first.
>>
>> I don't mind doing it in either sequence.
>>
> With this patch we have Arm on the same page as the above mentioned
> x86 guests,
>
> e.g. the driver has unused code, but yet allows Arm to function now.
>
> At this stage of PCI passthrough on Arm it is yet enough. Long term,
> when
>
> the driver gets split, Arm will benefit from that split too, but
> unfortunately I do not
>
> have enough bandwidth for that piece of wo
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 21.09.21 09:00, Oleksandr Andrushchenko wrote:
On 21.09.21 09:49, Juergen Gross wrote:
On 21.09.21 08:38, Oleksandr Andrushchenko wrote:
On 21.09.21 09:07, Juergen Gross wrote:
On 21.09.21 07:51, Oleksandr Andrushchenko wrote:
On 21.09.21 08:20, Juergen Gross wrote:
On 21.09.21 01:16, Stefano Stabellini wrote:
On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
On 20.09.21 14:30, Juergen Gross wrote:
On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
Hello, Stefano!
On 18.09.21 00:45, Stefano Stabellini wrote:
Hi Oleksandr,
Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
device in Dom0 so that it can be safely assigned to a DomU?
Not only that
I am asking because actually I don't think we want to enable the PV PCI
backend feature of pciback on ARM, right? That would clash with the PCI
assignment work you have been doing in Xen. They couldn't both work at
the same time.
Correct, it is not used
If we only need pciback to "park" a device in Dom0, wouldn't it be
possible and better to use pci-stub instead?
Not only that, so pci-stub is not enough
The functionality which is implemented by the pciback and the toolstack
and which is relevant/missing/needed for ARM:
1. pciback is used as a database for assignable PCI devices, e.g. xl
pci-assignable-{add|remove|list} manipulates that list. So, whenever
the
toolstack needs to know which PCI devices can be passed through it
reads
that from the relevant sysfs entries of the pciback.
2. pciback is used to hold the unbound PCI devices, e.g. when passing through
a PCI device it needs to be unbound from the relevant device driver
and bound
to pciback (strictly speaking it is not required that the device is
bound to
pciback, but pciback is again used as a database of the passed through
PCI
devices, so we can re-bind the devices back to their original drivers
when
guest domain shuts down)
3. Device reset
We have previously discussed on xen-devel ML possible solutions to that as from
the
above we see that pciback functionality is going to be only partially used on
Arm.
Please see [1] and [2]:
1. It is not acceptable to manage the assignable list in Xen itself
2. pciback can be split into two parts: PCI assignable/bind/reset handling and
the rest like vPCI etc.
3. pcifront is not used on Arm
It is neither in x86 PVH/HVM guests.
Didn't know that, thank you for pointing
So, limited use of the pciback is one of the bricks used to enable PCI
passthrough
on Arm. It was enough to just re-structure the driver and have it run on Arm to
achieve
all the goals above.
If we still think it is desirable to break the pciback driver into "common" and
"pcifront specific"
parts then it can be done, yet the patch is going to be the very first brick in
that building.
Doing this split should be done, as the pcifront specific part could be
omitted on x86, too, in case no PV guests using PCI passthrough have to
be supported.
Agree, that the final solution should have the driver split
So, I think this patch is still going to be needed besides which direction we
take.
Some kind of this patch, yes. It might look different in case the split
is done first.
I don't mind doing it in either sequence.
With this patch we have Arm on the same page as the above mentioned x86 guests,
e.g. the driver has unused code, but yet allows Arm to function now.
At this stage of PCI passthrough on Arm it is yet enough. Long term, when
the driver gets split, Arm will benefit from that split too, but unfortunately
I do not
have enough bandwidth for that piece of work at the moment.
That's fair and I don't want to scope-creep this simple patch asking for
an enormous rework. At the same time I don't think we should enable the
whole of pciback on ARM because it would be erroneous and confusing.
As the first stage before the driver is split or ifdef's used - can we take the
patch
as is now? In either way we chose this needs to be done, e.g. enable compiling
for other architectures and common code move.
Fine with me in principle. I need to take a more thorough look
at the patch, though.
Of course
I am wonder if there is a simple:
if (!xen_pv_domain())
return;
That we could add in a couple of places in pciback to stop it from
initializing the parts we don't care about. Something along these lines
(untested and probably incomplete).
What do you guys think?
Uh no, not in this way, please. This will kill pci passthrough on x86
with dom0 running as PVH. I don't think this is working right now, but
adding more code making it even harder to work should be avoided.
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index da34ce85dc88..991ba0a9b359 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -15,6 +15,7 @@
#include
#include
#include
+#include
#incl
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 21.09.21 09:49, Juergen Gross wrote:
> On 21.09.21 08:38, Oleksandr Andrushchenko wrote:
>>
>> On 21.09.21 09:07, Juergen Gross wrote:
>>> On 21.09.21 07:51, Oleksandr Andrushchenko wrote:
On 21.09.21 08:20, Juergen Gross wrote:
> On 21.09.21 01:16, Stefano Stabellini wrote:
>> On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
>>> On 20.09.21 14:30, Juergen Gross wrote:
On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
> Hello, Stefano!
>
> On 18.09.21 00:45, Stefano Stabellini wrote:
>> Hi Oleksandr,
>>
>> Why do you want to enable pciback on ARM? Is it only to "disable" a
>> PCI
>> device in Dom0 so that it can be safely assigned to a DomU?
> Not only that
>>
>> I am asking because actually I don't think we want to enable the PV
>> PCI
>> backend feature of pciback on ARM, right? That would clash with the
>> PCI
>> assignment work you have been doing in Xen. They couldn't both work
>> at
>> the same time.
> Correct, it is not used
>>
>> If we only need pciback to "park" a device in Dom0, wouldn't it be
>> possible and better to use pci-stub instead?
>
> Not only that, so pci-stub is not enough
>
> The functionality which is implemented by the pciback and the
> toolstack
> and which is relevant/missing/needed for ARM:
>
> 1. pciback is used as a database for assignable PCI devices, e.g. xl
> pci-assignable-{add|remove|list} manipulates that list. So,
> whenever the
> toolstack needs to know which PCI devices can be passed
> through it reads
> that from the relevant sysfs entries of the pciback.
>
> 2. pciback is used to hold the unbound PCI devices, e.g. when passing
> through
> a PCI device it needs to be unbound from the relevant device
> driver and bound
> to pciback (strictly speaking it is not required that the
> device is bound to
> pciback, but pciback is again used as a database of the
> passed through PCI
> devices, so we can re-bind the devices back to their original
> drivers when
> guest domain shuts down)
>
> 3. Device reset
>
> We have previously discussed on xen-devel ML possible solutions to
> that as from the
> above we see that pciback functionality is going to be only partially
> used on Arm.
>
> Please see [1] and [2]:
>
> 1. It is not acceptable to manage the assignable list in Xen itself
>
> 2. pciback can be split into two parts: PCI assignable/bind/reset
> handling and
> the rest like vPCI etc.
>
> 3. pcifront is not used on Arm
It is neither in x86 PVH/HVM guests.
>>> Didn't know that, thank you for pointing
> So, limited use of the pciback is one of the bricks used to enable
> PCI passthrough
> on Arm. It was enough to just re-structure the driver and have it run
> on Arm to achieve
> all the goals above.
>
> If we still think it is desirable to break the pciback driver into
> "common" and "pcifront specific"
> parts then it can be done, yet the patch is going to be the very
> first brick in that building.
Doing this split should be done, as the pcifront specific part could be
omitted on x86, too, in case no PV guests using PCI passthrough have to
be supported.
>>> Agree, that the final solution should have the driver split
> So, I think this patch is still going to be needed besides which
> direction we take.
Some kind of this patch, yes. It might look different in case the split
is done first.
I don't mind doing it in either sequence.
>>> With this patch we have Arm on the same page as the above mentioned x86
>>> guests,
>>>
>>> e.g. the driver has unused code, but yet allows Arm to function now.
>>>
>>> At this stage of PCI passthrough on Arm it is yet enough. Long term,
>>> when
>>>
>>> the driver gets split, Arm will benefit from that split too, but
>>> unfortunately I do not
>>>
>>> have enough bandwidth for that piece of work at the moment.
>>
>> That's fair and I don't want to scope-creep this simple patch asking for
>> an enormous rework. At the same time I don't think we should enable the
>> whole of pciback on ARM because it would be erroneous and confusing.
As the first stage before the driver is split or ifdef's used - can we
take the patch
a
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 21.09.21 08:38, Oleksandr Andrushchenko wrote:
On 21.09.21 09:07, Juergen Gross wrote:
On 21.09.21 07:51, Oleksandr Andrushchenko wrote:
On 21.09.21 08:20, Juergen Gross wrote:
On 21.09.21 01:16, Stefano Stabellini wrote:
On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
On 20.09.21 14:30, Juergen Gross wrote:
On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
Hello, Stefano!
On 18.09.21 00:45, Stefano Stabellini wrote:
Hi Oleksandr,
Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
device in Dom0 so that it can be safely assigned to a DomU?
Not only that
I am asking because actually I don't think we want to enable the PV PCI
backend feature of pciback on ARM, right? That would clash with the PCI
assignment work you have been doing in Xen. They couldn't both work at
the same time.
Correct, it is not used
If we only need pciback to "park" a device in Dom0, wouldn't it be
possible and better to use pci-stub instead?
Not only that, so pci-stub is not enough
The functionality which is implemented by the pciback and the toolstack
and which is relevant/missing/needed for ARM:
1. pciback is used as a database for assignable PCI devices, e.g. xl
pci-assignable-{add|remove|list} manipulates that list. So, whenever the
toolstack needs to know which PCI devices can be passed through it reads
that from the relevant sysfs entries of the pciback.
2. pciback is used to hold the unbound PCI devices, e.g. when passing through
a PCI device it needs to be unbound from the relevant device driver and
bound
to pciback (strictly speaking it is not required that the device is
bound to
pciback, but pciback is again used as a database of the passed through
PCI
devices, so we can re-bind the devices back to their original drivers
when
guest domain shuts down)
3. Device reset
We have previously discussed on xen-devel ML possible solutions to that as from
the
above we see that pciback functionality is going to be only partially used on
Arm.
Please see [1] and [2]:
1. It is not acceptable to manage the assignable list in Xen itself
2. pciback can be split into two parts: PCI assignable/bind/reset handling and
the rest like vPCI etc.
3. pcifront is not used on Arm
It is neither in x86 PVH/HVM guests.
Didn't know that, thank you for pointing
So, limited use of the pciback is one of the bricks used to enable PCI
passthrough
on Arm. It was enough to just re-structure the driver and have it run on Arm to
achieve
all the goals above.
If we still think it is desirable to break the pciback driver into "common" and
"pcifront specific"
parts then it can be done, yet the patch is going to be the very first brick in
that building.
Doing this split should be done, as the pcifront specific part could be
omitted on x86, too, in case no PV guests using PCI passthrough have to
be supported.
Agree, that the final solution should have the driver split
So, I think this patch is still going to be needed besides which direction we
take.
Some kind of this patch, yes. It might look different in case the split
is done first.
I don't mind doing it in either sequence.
With this patch we have Arm on the same page as the above mentioned x86 guests,
e.g. the driver has unused code, but yet allows Arm to function now.
At this stage of PCI passthrough on Arm it is yet enough. Long term, when
the driver gets split, Arm will benefit from that split too, but unfortunately
I do not
have enough bandwidth for that piece of work at the moment.
That's fair and I don't want to scope-creep this simple patch asking for
an enormous rework. At the same time I don't think we should enable the
whole of pciback on ARM because it would be erroneous and confusing.
As the first stage before the driver is split or ifdef's used - can we take the
patch
as is now? In either way we chose this needs to be done, e.g. enable compiling
for other architectures and common code move.
Fine with me in principle. I need to take a more thorough look
at the patch, though.
Of course
I am wonder if there is a simple:
if (!xen_pv_domain())
return;
That we could add in a couple of places in pciback to stop it from
initializing the parts we don't care about. Something along these lines
(untested and probably incomplete).
What do you guys think?
Uh no, not in this way, please. This will kill pci passthrough on x86
with dom0 running as PVH. I don't think this is working right now, but
adding more code making it even harder to work should be avoided.
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index da34ce85dc88..991ba0a9b359 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -15,6 +15,7 @@
#include
#include
#include
+#include
#include "pciback.h"
#define INVALID_EVTCHN_IRQ (-1)
@@ -685,8 +686,12 @@ static int xen_pcibk_xenbus_prob
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 21.09.21 09:07, Juergen Gross wrote:
> On 21.09.21 07:51, Oleksandr Andrushchenko wrote:
>>
>> On 21.09.21 08:20, Juergen Gross wrote:
>>> On 21.09.21 01:16, Stefano Stabellini wrote:
On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
> On 20.09.21 14:30, Juergen Gross wrote:
>> On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
>>> Hello, Stefano!
>>>
>>> On 18.09.21 00:45, Stefano Stabellini wrote:
Hi Oleksandr,
Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
device in Dom0 so that it can be safely assigned to a DomU?
>>> Not only that
I am asking because actually I don't think we want to enable the PV PCI
backend feature of pciback on ARM, right? That would clash with the PCI
assignment work you have been doing in Xen. They couldn't both work at
the same time.
>>> Correct, it is not used
If we only need pciback to "park" a device in Dom0, wouldn't it be
possible and better to use pci-stub instead?
>>>
>>> Not only that, so pci-stub is not enough
>>>
>>> The functionality which is implemented by the pciback and the toolstack
>>> and which is relevant/missing/needed for ARM:
>>>
>>> 1. pciback is used as a database for assignable PCI devices, e.g. xl
>>> pci-assignable-{add|remove|list} manipulates that list. So,
>>> whenever the
>>> toolstack needs to know which PCI devices can be passed through
>>> it reads
>>> that from the relevant sysfs entries of the pciback.
>>>
>>> 2. pciback is used to hold the unbound PCI devices, e.g. when passing
>>> through
>>> a PCI device it needs to be unbound from the relevant device
>>> driver and bound
>>> to pciback (strictly speaking it is not required that the device
>>> is bound to
>>> pciback, but pciback is again used as a database of the passed
>>> through PCI
>>> devices, so we can re-bind the devices back to their original
>>> drivers when
>>> guest domain shuts down)
>>>
>>> 3. Device reset
>>>
>>> We have previously discussed on xen-devel ML possible solutions to that
>>> as from the
>>> above we see that pciback functionality is going to be only partially
>>> used on Arm.
>>>
>>> Please see [1] and [2]:
>>>
>>> 1. It is not acceptable to manage the assignable list in Xen itself
>>>
>>> 2. pciback can be split into two parts: PCI assignable/bind/reset
>>> handling and
>>> the rest like vPCI etc.
>>>
>>> 3. pcifront is not used on Arm
>>
>> It is neither in x86 PVH/HVM guests.
> Didn't know that, thank you for pointing
>>
>>> So, limited use of the pciback is one of the bricks used to enable PCI
>>> passthrough
>>> on Arm. It was enough to just re-structure the driver and have it run
>>> on Arm to achieve
>>> all the goals above.
>>>
>>> If we still think it is desirable to break the pciback driver into
>>> "common" and "pcifront specific"
>>> parts then it can be done, yet the patch is going to be the very first
>>> brick in that building.
>>
>> Doing this split should be done, as the pcifront specific part could be
>> omitted on x86, too, in case no PV guests using PCI passthrough have to
>> be supported.
> Agree, that the final solution should have the driver split
>>
>>> So, I think this patch is still going to be needed besides which
>>> direction we take.
>>
>> Some kind of this patch, yes. It might look different in case the split
>> is done first.
>>
>> I don't mind doing it in either sequence.
>>
> With this patch we have Arm on the same page as the above mentioned x86
> guests,
>
> e.g. the driver has unused code, but yet allows Arm to function now.
>
> At this stage of PCI passthrough on Arm it is yet enough. Long term, when
>
> the driver gets split, Arm will benefit from that split too, but
> unfortunately I do not
>
> have enough bandwidth for that piece of work at the moment.
That's fair and I don't want to scope-creep this simple patch asking for
an enormous rework. At the same time I don't think we should enable the
whole of pciback on ARM because it would be erroneous and confusing.
>>
>> As the first stage before the driver is split or ifdef's used - can we take
>> the patch
>> as is now? In either way we chose this needs to be done, e.g. enable
>> compiling
>> for other architectures and common code move.
>
> Fine with me in principle. I need to take a more thorough look
> at the patch, though.
Of course
>
>>
I am wonder if there is a simple:
if (!xen_pv_domain())
return;
That we could add in a couple of places in pciback to st
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 21.09.21 07:51, Oleksandr Andrushchenko wrote:
On 21.09.21 08:20, Juergen Gross wrote:
On 21.09.21 01:16, Stefano Stabellini wrote:
On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
On 20.09.21 14:30, Juergen Gross wrote:
On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
Hello, Stefano!
On 18.09.21 00:45, Stefano Stabellini wrote:
Hi Oleksandr,
Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
device in Dom0 so that it can be safely assigned to a DomU?
Not only that
I am asking because actually I don't think we want to enable the PV PCI
backend feature of pciback on ARM, right? That would clash with the PCI
assignment work you have been doing in Xen. They couldn't both work at
the same time.
Correct, it is not used
If we only need pciback to "park" a device in Dom0, wouldn't it be
possible and better to use pci-stub instead?
Not only that, so pci-stub is not enough
The functionality which is implemented by the pciback and the toolstack
and which is relevant/missing/needed for ARM:
1. pciback is used as a database for assignable PCI devices, e.g. xl
pci-assignable-{add|remove|list} manipulates that list. So, whenever the
toolstack needs to know which PCI devices can be passed through it reads
that from the relevant sysfs entries of the pciback.
2. pciback is used to hold the unbound PCI devices, e.g. when passing through
a PCI device it needs to be unbound from the relevant device driver and
bound
to pciback (strictly speaking it is not required that the device is
bound to
pciback, but pciback is again used as a database of the passed through
PCI
devices, so we can re-bind the devices back to their original drivers
when
guest domain shuts down)
3. Device reset
We have previously discussed on xen-devel ML possible solutions to that as from
the
above we see that pciback functionality is going to be only partially used on
Arm.
Please see [1] and [2]:
1. It is not acceptable to manage the assignable list in Xen itself
2. pciback can be split into two parts: PCI assignable/bind/reset handling and
the rest like vPCI etc.
3. pcifront is not used on Arm
It is neither in x86 PVH/HVM guests.
Didn't know that, thank you for pointing
So, limited use of the pciback is one of the bricks used to enable PCI
passthrough
on Arm. It was enough to just re-structure the driver and have it run on Arm to
achieve
all the goals above.
If we still think it is desirable to break the pciback driver into "common" and
"pcifront specific"
parts then it can be done, yet the patch is going to be the very first brick in
that building.
Doing this split should be done, as the pcifront specific part could be
omitted on x86, too, in case no PV guests using PCI passthrough have to
be supported.
Agree, that the final solution should have the driver split
So, I think this patch is still going to be needed besides which direction we
take.
Some kind of this patch, yes. It might look different in case the split
is done first.
I don't mind doing it in either sequence.
With this patch we have Arm on the same page as the above mentioned x86 guests,
e.g. the driver has unused code, but yet allows Arm to function now.
At this stage of PCI passthrough on Arm it is yet enough. Long term, when
the driver gets split, Arm will benefit from that split too, but unfortunately
I do not
have enough bandwidth for that piece of work at the moment.
That's fair and I don't want to scope-creep this simple patch asking for
an enormous rework. At the same time I don't think we should enable the
whole of pciback on ARM because it would be erroneous and confusing.
As the first stage before the driver is split or ifdef's used - can we take the
patch
as is now? In either way we chose this needs to be done, e.g. enable compiling
for other architectures and common code move.
Fine with me in principle. I need to take a more thorough look
at the patch, though.
I am wonder if there is a simple:
if (!xen_pv_domain())
return;
That we could add in a couple of places in pciback to stop it from
initializing the parts we don't care about. Something along these lines
(untested and probably incomplete).
What do you guys think?
Uh no, not in this way, please. This will kill pci passthrough on x86
with dom0 running as PVH. I don't think this is working right now, but
adding more code making it even harder to work should be avoided.
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index da34ce85dc88..991ba0a9b359 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -15,6 +15,7 @@
#include
#include
#include
+#include
#include "pciback.h"
#define INVALID_EVTCHN_IRQ (-1)
@@ -685,8 +686,12 @@ static int xen_pcibk_xenbus_probe(struct xenbus_device
*dev,
const struct xenbus_device_id *id)
{
int err = 0;
- struc
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 21.09.21 08:20, Juergen Gross wrote:
> On 21.09.21 01:16, Stefano Stabellini wrote:
>> On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
>>> On 20.09.21 14:30, Juergen Gross wrote:
On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
> Hello, Stefano!
>
> On 18.09.21 00:45, Stefano Stabellini wrote:
>> Hi Oleksandr,
>>
>> Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
>> device in Dom0 so that it can be safely assigned to a DomU?
> Not only that
>>
>> I am asking because actually I don't think we want to enable the PV PCI
>> backend feature of pciback on ARM, right? That would clash with the PCI
>> assignment work you have been doing in Xen. They couldn't both work at
>> the same time.
> Correct, it is not used
>>
>> If we only need pciback to "park" a device in Dom0, wouldn't it be
>> possible and better to use pci-stub instead?
>
> Not only that, so pci-stub is not enough
>
> The functionality which is implemented by the pciback and the toolstack
> and which is relevant/missing/needed for ARM:
>
> 1. pciback is used as a database for assignable PCI devices, e.g. xl
> pci-assignable-{add|remove|list} manipulates that list. So,
> whenever the
> toolstack needs to know which PCI devices can be passed through it
> reads
> that from the relevant sysfs entries of the pciback.
>
> 2. pciback is used to hold the unbound PCI devices, e.g. when passing
> through
> a PCI device it needs to be unbound from the relevant device driver
> and bound
> to pciback (strictly speaking it is not required that the device is
> bound to
> pciback, but pciback is again used as a database of the passed
> through PCI
> devices, so we can re-bind the devices back to their original
> drivers when
> guest domain shuts down)
>
> 3. Device reset
>
> We have previously discussed on xen-devel ML possible solutions to that
> as from the
> above we see that pciback functionality is going to be only partially
> used on Arm.
>
> Please see [1] and [2]:
>
> 1. It is not acceptable to manage the assignable list in Xen itself
>
> 2. pciback can be split into two parts: PCI assignable/bind/reset
> handling and
> the rest like vPCI etc.
>
> 3. pcifront is not used on Arm
It is neither in x86 PVH/HVM guests.
>>> Didn't know that, thank you for pointing
> So, limited use of the pciback is one of the bricks used to enable PCI
> passthrough
> on Arm. It was enough to just re-structure the driver and have it run on
> Arm to achieve
> all the goals above.
>
> If we still think it is desirable to break the pciback driver into
> "common" and "pcifront specific"
> parts then it can be done, yet the patch is going to be the very first
> brick in that building.
Doing this split should be done, as the pcifront specific part could be
omitted on x86, too, in case no PV guests using PCI passthrough have to
be supported.
>>> Agree, that the final solution should have the driver split
> So, I think this patch is still going to be needed besides which
> direction we take.
Some kind of this patch, yes. It might look different in case the split
is done first.
I don't mind doing it in either sequence.
>>> With this patch we have Arm on the same page as the above mentioned x86
>>> guests,
>>>
>>> e.g. the driver has unused code, but yet allows Arm to function now.
>>>
>>> At this stage of PCI passthrough on Arm it is yet enough. Long term, when
>>>
>>> the driver gets split, Arm will benefit from that split too, but
>>> unfortunately I do not
>>>
>>> have enough bandwidth for that piece of work at the moment.
>>
>> That's fair and I don't want to scope-creep this simple patch asking for
>> an enormous rework. At the same time I don't think we should enable the
>> whole of pciback on ARM because it would be erroneous and confusing.
As the first stage before the driver is split or ifdef's used - can we take the
patch
as is now? In either way we chose this needs to be done, e.g. enable compiling
for other architectures and common code move.
>>
>> I am wonder if there is a simple:
>>
>> if (!xen_pv_domain())
>> return;
>>
>> That we could add in a couple of places in pciback to stop it from
>> initializing the parts we don't care about. Something along these lines
>> (untested and probably incomplete).
>>
>> What do you guys think?
>
> Uh no, not in this way, please. This will kill pci passthrough on x86
> with dom0 running as PVH. I don't think this is working right now, but
> adding more code making it even harder to work should be avoided.
>
>> diff --git a/drivers/xen/xen-pciback/xenbus.c
>> b/drivers/xen/xen-pciback/x
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 21.09.21 01:16, Stefano Stabellini wrote:
On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
On 20.09.21 14:30, Juergen Gross wrote:
On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
Hello, Stefano!
On 18.09.21 00:45, Stefano Stabellini wrote:
Hi Oleksandr,
Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
device in Dom0 so that it can be safely assigned to a DomU?
Not only that
I am asking because actually I don't think we want to enable the PV PCI
backend feature of pciback on ARM, right? That would clash with the PCI
assignment work you have been doing in Xen. They couldn't both work at
the same time.
Correct, it is not used
If we only need pciback to "park" a device in Dom0, wouldn't it be
possible and better to use pci-stub instead?
Not only that, so pci-stub is not enough
The functionality which is implemented by the pciback and the toolstack
and which is relevant/missing/needed for ARM:
1. pciback is used as a database for assignable PCI devices, e.g. xl
pci-assignable-{add|remove|list} manipulates that list. So, whenever the
toolstack needs to know which PCI devices can be passed through it reads
that from the relevant sysfs entries of the pciback.
2. pciback is used to hold the unbound PCI devices, e.g. when passing through
a PCI device it needs to be unbound from the relevant device driver and
bound
to pciback (strictly speaking it is not required that the device is bound
to
pciback, but pciback is again used as a database of the passed through PCI
devices, so we can re-bind the devices back to their original drivers when
guest domain shuts down)
3. Device reset
We have previously discussed on xen-devel ML possible solutions to that as from
the
above we see that pciback functionality is going to be only partially used on
Arm.
Please see [1] and [2]:
1. It is not acceptable to manage the assignable list in Xen itself
2. pciback can be split into two parts: PCI assignable/bind/reset handling and
the rest like vPCI etc.
3. pcifront is not used on Arm
It is neither in x86 PVH/HVM guests.
Didn't know that, thank you for pointing
So, limited use of the pciback is one of the bricks used to enable PCI
passthrough
on Arm. It was enough to just re-structure the driver and have it run on Arm to
achieve
all the goals above.
If we still think it is desirable to break the pciback driver into "common" and
"pcifront specific"
parts then it can be done, yet the patch is going to be the very first brick in
that building.
Doing this split should be done, as the pcifront specific part could be
omitted on x86, too, in case no PV guests using PCI passthrough have to
be supported.
Agree, that the final solution should have the driver split
So, I think this patch is still going to be needed besides which direction we
take.
Some kind of this patch, yes. It might look different in case the split
is done first.
I don't mind doing it in either sequence.
With this patch we have Arm on the same page as the above mentioned x86 guests,
e.g. the driver has unused code, but yet allows Arm to function now.
At this stage of PCI passthrough on Arm it is yet enough. Long term, when
the driver gets split, Arm will benefit from that split too, but unfortunately
I do not
have enough bandwidth for that piece of work at the moment.
That's fair and I don't want to scope-creep this simple patch asking for
an enormous rework. At the same time I don't think we should enable the
whole of pciback on ARM because it would be erroneous and confusing.
I am wonder if there is a simple:
if (!xen_pv_domain())
return;
That we could add in a couple of places in pciback to stop it from
initializing the parts we don't care about. Something along these lines
(untested and probably incomplete).
What do you guys think?
Uh no, not in this way, please. This will kill pci passthrough on x86
with dom0 running as PVH. I don't think this is working right now, but
adding more code making it even harder to work should be avoided.
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index da34ce85dc88..991ba0a9b359 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -15,6 +15,7 @@
#include
#include
#include
+#include
#include "pciback.h"
#define INVALID_EVTCHN_IRQ (-1)
@@ -685,8 +686,12 @@ static int xen_pcibk_xenbus_probe(struct xenbus_device
*dev,
const struct xenbus_device_id *id)
{
int err = 0;
- struct xen_pcibk_device *pdev = alloc_pdev(dev);
+ struct xen_pcibk_device *pdev;
+
+ if (!xen_pv_domain())
+ return 0;
+ pdev = alloc_pdev(dev);
This hunk isn't needed, as with bailing out of xen_pcibk_xenbus_register
early will result in xen_pcibk_xenbus_probe never being called.
if (pdev == NULL) {
err = -ENOMEM;
xenbus_dev
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
Hi, Stefano!
On 21.09.21 02:16, Stefano Stabellini wrote:
> On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
>> On 20.09.21 14:30, Juergen Gross wrote:
>>> On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
Hello, Stefano!
On 18.09.21 00:45, Stefano Stabellini wrote:
> Hi Oleksandr,
>
> Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
> device in Dom0 so that it can be safely assigned to a DomU?
Not only that
> I am asking because actually I don't think we want to enable the PV PCI
> backend feature of pciback on ARM, right? That would clash with the PCI
> assignment work you have been doing in Xen. They couldn't both work at
> the same time.
Correct, it is not used
> If we only need pciback to "park" a device in Dom0, wouldn't it be
> possible and better to use pci-stub instead?
Not only that, so pci-stub is not enough
The functionality which is implemented by the pciback and the toolstack
and which is relevant/missing/needed for ARM:
1. pciback is used as a database for assignable PCI devices, e.g. xl
pci-assignable-{add|remove|list} manipulates that list. So, whenever
the
toolstack needs to know which PCI devices can be passed through it
reads
that from the relevant sysfs entries of the pciback.
2. pciback is used to hold the unbound PCI devices, e.g. when passing
through
a PCI device it needs to be unbound from the relevant device driver
and bound
to pciback (strictly speaking it is not required that the device is
bound to
pciback, but pciback is again used as a database of the passed
through PCI
devices, so we can re-bind the devices back to their original
drivers when
guest domain shuts down)
3. Device reset
We have previously discussed on xen-devel ML possible solutions to that as
from the
above we see that pciback functionality is going to be only partially used
on Arm.
Please see [1] and [2]:
1. It is not acceptable to manage the assignable list in Xen itself
2. pciback can be split into two parts: PCI assignable/bind/reset handling
and
the rest like vPCI etc.
3. pcifront is not used on Arm
>>> It is neither in x86 PVH/HVM guests.
>> Didn't know that, thank you for pointing
So, limited use of the pciback is one of the bricks used to enable PCI
passthrough
on Arm. It was enough to just re-structure the driver and have it run on
Arm to achieve
all the goals above.
If we still think it is desirable to break the pciback driver into
"common" and "pcifront specific"
parts then it can be done, yet the patch is going to be the very first
brick in that building.
>>> Doing this split should be done, as the pcifront specific part could be
>>> omitted on x86, too, in case no PV guests using PCI passthrough have to
>>> be supported.
>> Agree, that the final solution should have the driver split
So, I think this patch is still going to be needed besides which direction
we take.
>>> Some kind of this patch, yes. It might look different in case the split
>>> is done first.
>>>
>>> I don't mind doing it in either sequence.
>>>
>> With this patch we have Arm on the same page as the above mentioned x86
>> guests,
>>
>> e.g. the driver has unused code, but yet allows Arm to function now.
>>
>> At this stage of PCI passthrough on Arm it is yet enough. Long term, when
>>
>> the driver gets split, Arm will benefit from that split too, but
>> unfortunately I do not
>>
>> have enough bandwidth for that piece of work at the moment.
> That's fair and I don't want to scope-creep this simple patch asking for
> an enormous rework. At the same time I don't think we should enable the
> whole of pciback on ARM because it would be erroneous and confusing.
>
> I am wonder if there is a simple:
>
> if (!xen_pv_domain())
> return;
>
> That we could add in a couple of places in pciback to stop it from
> initializing the parts we don't care about. Something along these lines
> (untested and probably incomplete).
>
> What do you guys think?
I think that it needs to be an additional patch and the PV check seems
reasonable to me. We need to check if gating only part of the initialization
with xen_pv_domain is just enough, e.g. if the rest of the code is ok that
something was not initialized and won't be touched at run-time.
Let's see what other think about the approach
>
>
> diff --git a/drivers/xen/xen-pciback/xenbus.c
> b/drivers/xen/xen-pciback/xenbus.c
> index da34ce85dc88..991ba0a9b359 100644
> --- a/drivers/xen/xen-pciback/xenbus.c
> +++ b/drivers/xen/xen-pciback/xenbus.c
> @@ -15,6 +15,7 @@
> #include
> #include
> #include
> +#include
> #include "pciback.h"
>
> #define INVALID_EVTCHN_IRQ (-1)
>
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On Mon, 20 Sep 2021, Oleksandr Andrushchenko wrote:
> On 20.09.21 14:30, Juergen Gross wrote:
> > On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
> >> Hello, Stefano!
> >>
> >> On 18.09.21 00:45, Stefano Stabellini wrote:
> >>> Hi Oleksandr,
> >>>
> >>> Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
> >>> device in Dom0 so that it can be safely assigned to a DomU?
> >> Not only that
> >>>
> >>> I am asking because actually I don't think we want to enable the PV PCI
> >>> backend feature of pciback on ARM, right? That would clash with the PCI
> >>> assignment work you have been doing in Xen. They couldn't both work at
> >>> the same time.
> >> Correct, it is not used
> >>>
> >>> If we only need pciback to "park" a device in Dom0, wouldn't it be
> >>> possible and better to use pci-stub instead?
> >>
> >> Not only that, so pci-stub is not enough
> >>
> >> The functionality which is implemented by the pciback and the toolstack
> >> and which is relevant/missing/needed for ARM:
> >>
> >> 1. pciback is used as a database for assignable PCI devices, e.g. xl
> >> pci-assignable-{add|remove|list} manipulates that list. So, whenever
> >> the
> >> toolstack needs to know which PCI devices can be passed through it
> >> reads
> >> that from the relevant sysfs entries of the pciback.
> >>
> >> 2. pciback is used to hold the unbound PCI devices, e.g. when passing
> >> through
> >> a PCI device it needs to be unbound from the relevant device driver
> >> and bound
> >> to pciback (strictly speaking it is not required that the device is
> >> bound to
> >> pciback, but pciback is again used as a database of the passed
> >> through PCI
> >> devices, so we can re-bind the devices back to their original drivers
> >> when
> >> guest domain shuts down)
> >>
> >> 3. Device reset
> >>
> >> We have previously discussed on xen-devel ML possible solutions to that as
> >> from the
> >> above we see that pciback functionality is going to be only partially used
> >> on Arm.
> >>
> >> Please see [1] and [2]:
> >>
> >> 1. It is not acceptable to manage the assignable list in Xen itself
> >>
> >> 2. pciback can be split into two parts: PCI assignable/bind/reset handling
> >> and
> >> the rest like vPCI etc.
> >>
> >> 3. pcifront is not used on Arm
> >
> > It is neither in x86 PVH/HVM guests.
> Didn't know that, thank you for pointing
> >
> >> So, limited use of the pciback is one of the bricks used to enable PCI
> >> passthrough
> >> on Arm. It was enough to just re-structure the driver and have it run on
> >> Arm to achieve
> >> all the goals above.
> >>
> >> If we still think it is desirable to break the pciback driver into
> >> "common" and "pcifront specific"
> >> parts then it can be done, yet the patch is going to be the very first
> >> brick in that building.
> >
> > Doing this split should be done, as the pcifront specific part could be
> > omitted on x86, too, in case no PV guests using PCI passthrough have to
> > be supported.
> Agree, that the final solution should have the driver split
> >
> >> So, I think this patch is still going to be needed besides which direction
> >> we take.
> >
> > Some kind of this patch, yes. It might look different in case the split
> > is done first.
> >
> > I don't mind doing it in either sequence.
> >
> With this patch we have Arm on the same page as the above mentioned x86
> guests,
>
> e.g. the driver has unused code, but yet allows Arm to function now.
>
> At this stage of PCI passthrough on Arm it is yet enough. Long term, when
>
> the driver gets split, Arm will benefit from that split too, but
> unfortunately I do not
>
> have enough bandwidth for that piece of work at the moment.
That's fair and I don't want to scope-creep this simple patch asking for
an enormous rework. At the same time I don't think we should enable the
whole of pciback on ARM because it would be erroneous and confusing.
I am wonder if there is a simple:
if (!xen_pv_domain())
return;
That we could add in a couple of places in pciback to stop it from
initializing the parts we don't care about. Something along these lines
(untested and probably incomplete).
What do you guys think?
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index da34ce85dc88..991ba0a9b359 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -15,6 +15,7 @@
#include
#include
#include
+#include
#include "pciback.h"
#define INVALID_EVTCHN_IRQ (-1)
@@ -685,8 +686,12 @@ static int xen_pcibk_xenbus_probe(struct xenbus_device
*dev,
const struct xenbus_device_id *id)
{
int err = 0;
- struct xen_pcibk_device *pdev = alloc_pdev(dev);
+ struct xen_pcibk_device *pdev;
+
+ if (!xen_pv_domain())
+ return 0;
+ pdev = alloc_pdev(dev);
if (pdev == NULL) {
err = -ENOMEM;
xenb
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
Hello, Juergen!
On 20.09.21 14:30, Juergen Gross wrote:
> On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
>> Hello, Stefano!
>>
>> On 18.09.21 00:45, Stefano Stabellini wrote:
>>> Hi Oleksandr,
>>>
>>> Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
>>> device in Dom0 so that it can be safely assigned to a DomU?
>> Not only that
>>>
>>> I am asking because actually I don't think we want to enable the PV PCI
>>> backend feature of pciback on ARM, right? That would clash with the PCI
>>> assignment work you have been doing in Xen. They couldn't both work at
>>> the same time.
>> Correct, it is not used
>>>
>>> If we only need pciback to "park" a device in Dom0, wouldn't it be
>>> possible and better to use pci-stub instead?
>>
>> Not only that, so pci-stub is not enough
>>
>> The functionality which is implemented by the pciback and the toolstack
>> and which is relevant/missing/needed for ARM:
>>
>> 1. pciback is used as a database for assignable PCI devices, e.g. xl
>> pci-assignable-{add|remove|list} manipulates that list. So, whenever the
>> toolstack needs to know which PCI devices can be passed through it reads
>> that from the relevant sysfs entries of the pciback.
>>
>> 2. pciback is used to hold the unbound PCI devices, e.g. when passing through
>> a PCI device it needs to be unbound from the relevant device driver and
>> bound
>> to pciback (strictly speaking it is not required that the device is
>> bound to
>> pciback, but pciback is again used as a database of the passed through
>> PCI
>> devices, so we can re-bind the devices back to their original drivers
>> when
>> guest domain shuts down)
>>
>> 3. Device reset
>>
>> We have previously discussed on xen-devel ML possible solutions to that as
>> from the
>> above we see that pciback functionality is going to be only partially used
>> on Arm.
>>
>> Please see [1] and [2]:
>>
>> 1. It is not acceptable to manage the assignable list in Xen itself
>>
>> 2. pciback can be split into two parts: PCI assignable/bind/reset handling
>> and
>> the rest like vPCI etc.
>>
>> 3. pcifront is not used on Arm
>
> It is neither in x86 PVH/HVM guests.
Didn't know that, thank you for pointing
>
>> So, limited use of the pciback is one of the bricks used to enable PCI
>> passthrough
>> on Arm. It was enough to just re-structure the driver and have it run on Arm
>> to achieve
>> all the goals above.
>>
>> If we still think it is desirable to break the pciback driver into "common"
>> and "pcifront specific"
>> parts then it can be done, yet the patch is going to be the very first brick
>> in that building.
>
> Doing this split should be done, as the pcifront specific part could be
> omitted on x86, too, in case no PV guests using PCI passthrough have to
> be supported.
Agree, that the final solution should have the driver split
>
>> So, I think this patch is still going to be needed besides which direction
>> we take.
>
> Some kind of this patch, yes. It might look different in case the split
> is done first.
>
> I don't mind doing it in either sequence.
>
With this patch we have Arm on the same page as the above mentioned x86 guests,
e.g. the driver has unused code, but yet allows Arm to function now.
At this stage of PCI passthrough on Arm it is yet enough. Long term, when
the driver gets split, Arm will benefit from that split too, but unfortunately
I do not
have enough bandwidth for that piece of work at the moment.
>
> Juergen
Thank you,
Oleksandr
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
On 20.09.21 07:23, Oleksandr Andrushchenko wrote:
Hello, Stefano!
On 18.09.21 00:45, Stefano Stabellini wrote:
Hi Oleksandr,
Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
device in Dom0 so that it can be safely assigned to a DomU?
Not only that
I am asking because actually I don't think we want to enable the PV PCI
backend feature of pciback on ARM, right? That would clash with the PCI
assignment work you have been doing in Xen. They couldn't both work at
the same time.
Correct, it is not used
If we only need pciback to "park" a device in Dom0, wouldn't it be
possible and better to use pci-stub instead?
Not only that, so pci-stub is not enough
The functionality which is implemented by the pciback and the toolstack
and which is relevant/missing/needed for ARM:
1. pciback is used as a database for assignable PCI devices, e.g. xl
pci-assignable-{add|remove|list} manipulates that list. So, whenever the
toolstack needs to know which PCI devices can be passed through it reads
that from the relevant sysfs entries of the pciback.
2. pciback is used to hold the unbound PCI devices, e.g. when passing through
a PCI device it needs to be unbound from the relevant device driver and
bound
to pciback (strictly speaking it is not required that the device is bound
to
pciback, but pciback is again used as a database of the passed through PCI
devices, so we can re-bind the devices back to their original drivers when
guest domain shuts down)
3. Device reset
We have previously discussed on xen-devel ML possible solutions to that as from
the
above we see that pciback functionality is going to be only partially used on
Arm.
Please see [1] and [2]:
1. It is not acceptable to manage the assignable list in Xen itself
2. pciback can be split into two parts: PCI assignable/bind/reset handling and
the rest like vPCI etc.
3. pcifront is not used on Arm
It is neither in x86 PVH/HVM guests.
So, limited use of the pciback is one of the bricks used to enable PCI
passthrough
on Arm. It was enough to just re-structure the driver and have it run on Arm to
achieve
all the goals above.
If we still think it is desirable to break the pciback driver into "common" and
"pcifront specific"
parts then it can be done, yet the patch is going to be the very first brick in
that building.
Doing this split should be done, as the pcifront specific part could be
omitted on x86, too, in case no PV guests using PCI passthrough have to
be supported.
So, I think this patch is still going to be needed besides which direction we
take.
Some kind of this patch, yes. It might look different in case the split
is done first.
I don't mind doing it in either sequence.
Juergen
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Re: [PATCH] xen-pciback: allow compiling on other archs than x86
Hello, Stefano!
On 18.09.21 00:45, Stefano Stabellini wrote:
> Hi Oleksandr,
>
> Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
> device in Dom0 so that it can be safely assigned to a DomU?
Not only that
>
> I am asking because actually I don't think we want to enable the PV PCI
> backend feature of pciback on ARM, right? That would clash with the PCI
> assignment work you have been doing in Xen. They couldn't both work at
> the same time.
Correct, it is not used
>
> If we only need pciback to "park" a device in Dom0, wouldn't it be
> possible and better to use pci-stub instead?
Not only that, so pci-stub is not enough
The functionality which is implemented by the pciback and the toolstack
and which is relevant/missing/needed for ARM:
1. pciback is used as a database for assignable PCI devices, e.g. xl
pci-assignable-{add|remove|list} manipulates that list. So, whenever the
toolstack needs to know which PCI devices can be passed through it reads
that from the relevant sysfs entries of the pciback.
2. pciback is used to hold the unbound PCI devices, e.g. when passing through
a PCI device it needs to be unbound from the relevant device driver and
bound
to pciback (strictly speaking it is not required that the device is bound to
pciback, but pciback is again used as a database of the passed through PCI
devices, so we can re-bind the devices back to their original drivers when
guest domain shuts down)
3. Device reset
We have previously discussed on xen-devel ML possible solutions to that as from
the
above we see that pciback functionality is going to be only partially used on
Arm.
Please see [1] and [2]:
1. It is not acceptable to manage the assignable list in Xen itself
2. pciback can be split into two parts: PCI assignable/bind/reset handling and
the rest like vPCI etc.
3. pcifront is not used on Arm
So, limited use of the pciback is one of the bricks used to enable PCI
passthrough
on Arm. It was enough to just re-structure the driver and have it run on Arm to
achieve
all the goals above.
If we still think it is desirable to break the pciback driver into "common" and
"pcifront specific"
parts then it can be done, yet the patch is going to be the very first brick in
that building.
So, I think this patch is still going to be needed besides which direction we
take.
Hope this sheds some light,
Oleksandr
>
>
> On Fri, 17 Sep 2021, Oleksandr Andrushchenko wrote:
>> From: Oleksandr Andrushchenko
>>
>> Xen-pciback driver was designed to be built for x86 only. But it
>> can also be used by other architectures, e.g. Arm.
>> Re-structure the driver in a way that it can be built for other
>> platforms as well.
>>
>> Signed-off-by: Oleksandr Andrushchenko
>> Signed-off-by: Anastasiia Lukianenko
>>
>> ---
>> Tested on Arm and x86.
>> ---
>> arch/x86/include/asm/xen/pci.h | 24 --
>> arch/x86/pci/xen.c | 74 +
>> drivers/xen/Kconfig| 2 +-
>> drivers/xen/events/events_base.c | 1 +
>> drivers/xen/pci.c | 75 ++
>> drivers/xen/xen-pciback/pci_stub.c | 3 +-
>> drivers/xen/xen-pciback/xenbus.c | 2 +-
>> include/xen/pci.h | 34 ++
>> 8 files changed, 115 insertions(+), 100 deletions(-)
>> create mode 100644 include/xen/pci.h
>>
>> diff --git a/arch/x86/include/asm/xen/pci.h b/arch/x86/include/asm/xen/pci.h
>> index 3506d8c598c1..9ff7b49bca08 100644
>> --- a/arch/x86/include/asm/xen/pci.h
>> +++ b/arch/x86/include/asm/xen/pci.h
>> @@ -14,30 +14,6 @@ static inline int pci_xen_hvm_init(void)
>> return -1;
>> }
>> #endif
>> -#if defined(CONFIG_XEN_DOM0)
>> -int __init pci_xen_initial_domain(void);
>> -int xen_find_device_domain_owner(struct pci_dev *dev);
>> -int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain);
>> -int xen_unregister_device_domain_owner(struct pci_dev *dev);
>> -#else
>> -static inline int __init pci_xen_initial_domain(void)
>> -{
>> -return -1;
>> -}
>> -static inline int xen_find_device_domain_owner(struct pci_dev *dev)
>> -{
>> -return -1;
>> -}
>> -static inline int xen_register_device_domain_owner(struct pci_dev *dev,
>> - uint16_t domain)
>> -{
>> -return -1;
>> -}
>> -static inline int xen_unregister_device_domain_owner(struct pci_dev *dev)
>> -{
>> -return -1;
>> -}
>> -#endif
>>
>> #if defined(CONFIG_PCI_MSI)
>> #if defined(CONFIG_PCI_XEN)
>> diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
>> index 3d41a09c2c14..4a45b0bf9ae4 100644
>> --- a/arch/x86/pci/xen.c
>> +++ b/arch/x86/pci/xen.c
>> @@ -23,6 +23,7 @@
>>
>> #include
>> #include
>> +#include
>> #include
>> #include
>> #include
>> @@ -583,77 +584,4 @@ int __init pci_xen_initial_domain(void)
>> }
>> return 0;
>> }
>> -
>> -struct xen_device_domain_owner {
>> -d
Re: [PATCH] xen-pciback: allow compiling on other archs than x86
Hi Oleksandr,
Why do you want to enable pciback on ARM? Is it only to "disable" a PCI
device in Dom0 so that it can be safely assigned to a DomU?
I am asking because actually I don't think we want to enable the PV PCI
backend feature of pciback on ARM, right? That would clash with the PCI
assignment work you have been doing in Xen. They couldn't both work at
the same time.
If we only need pciback to "park" a device in Dom0, wouldn't it be
possible and better to use pci-stub instead?
On Fri, 17 Sep 2021, Oleksandr Andrushchenko wrote:
> From: Oleksandr Andrushchenko
>
> Xen-pciback driver was designed to be built for x86 only. But it
> can also be used by other architectures, e.g. Arm.
> Re-structure the driver in a way that it can be built for other
> platforms as well.
>
> Signed-off-by: Oleksandr Andrushchenko
> Signed-off-by: Anastasiia Lukianenko
>
> ---
> Tested on Arm and x86.
> ---
> arch/x86/include/asm/xen/pci.h | 24 --
> arch/x86/pci/xen.c | 74 +
> drivers/xen/Kconfig| 2 +-
> drivers/xen/events/events_base.c | 1 +
> drivers/xen/pci.c | 75 ++
> drivers/xen/xen-pciback/pci_stub.c | 3 +-
> drivers/xen/xen-pciback/xenbus.c | 2 +-
> include/xen/pci.h | 34 ++
> 8 files changed, 115 insertions(+), 100 deletions(-)
> create mode 100644 include/xen/pci.h
>
> diff --git a/arch/x86/include/asm/xen/pci.h b/arch/x86/include/asm/xen/pci.h
> index 3506d8c598c1..9ff7b49bca08 100644
> --- a/arch/x86/include/asm/xen/pci.h
> +++ b/arch/x86/include/asm/xen/pci.h
> @@ -14,30 +14,6 @@ static inline int pci_xen_hvm_init(void)
> return -1;
> }
> #endif
> -#if defined(CONFIG_XEN_DOM0)
> -int __init pci_xen_initial_domain(void);
> -int xen_find_device_domain_owner(struct pci_dev *dev);
> -int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain);
> -int xen_unregister_device_domain_owner(struct pci_dev *dev);
> -#else
> -static inline int __init pci_xen_initial_domain(void)
> -{
> - return -1;
> -}
> -static inline int xen_find_device_domain_owner(struct pci_dev *dev)
> -{
> - return -1;
> -}
> -static inline int xen_register_device_domain_owner(struct pci_dev *dev,
> -uint16_t domain)
> -{
> - return -1;
> -}
> -static inline int xen_unregister_device_domain_owner(struct pci_dev *dev)
> -{
> - return -1;
> -}
> -#endif
>
> #if defined(CONFIG_PCI_MSI)
> #if defined(CONFIG_PCI_XEN)
> diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
> index 3d41a09c2c14..4a45b0bf9ae4 100644
> --- a/arch/x86/pci/xen.c
> +++ b/arch/x86/pci/xen.c
> @@ -23,6 +23,7 @@
>
> #include
> #include
> +#include
> #include
> #include
> #include
> @@ -583,77 +584,4 @@ int __init pci_xen_initial_domain(void)
> }
> return 0;
> }
> -
> -struct xen_device_domain_owner {
> - domid_t domain;
> - struct pci_dev *dev;
> - struct list_head list;
> -};
> -
> -static DEFINE_SPINLOCK(dev_domain_list_spinlock);
> -static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
> -
> -static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
> -{
> - struct xen_device_domain_owner *owner;
> -
> - list_for_each_entry(owner, &dev_domain_list, list) {
> - if (owner->dev == dev)
> - return owner;
> - }
> - return NULL;
> -}
> -
> -int xen_find_device_domain_owner(struct pci_dev *dev)
> -{
> - struct xen_device_domain_owner *owner;
> - int domain = -ENODEV;
> -
> - spin_lock(&dev_domain_list_spinlock);
> - owner = find_device(dev);
> - if (owner)
> - domain = owner->domain;
> - spin_unlock(&dev_domain_list_spinlock);
> - return domain;
> -}
> -EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
> -
> -int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
> -{
> - struct xen_device_domain_owner *owner;
> -
> - owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
> - if (!owner)
> - return -ENODEV;
> -
> - spin_lock(&dev_domain_list_spinlock);
> - if (find_device(dev)) {
> - spin_unlock(&dev_domain_list_spinlock);
> - kfree(owner);
> - return -EEXIST;
> - }
> - owner->domain = domain;
> - owner->dev = dev;
> - list_add_tail(&owner->list, &dev_domain_list);
> - spin_unlock(&dev_domain_list_spinlock);
> - return 0;
> -}
> -EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
> -
> -int xen_unregister_device_domain_owner(struct pci_dev *dev)
> -{
> - struct xen_device_domain_owner *owner;
> -
> - spin_lock(&dev_domain_list_spinlock);
> - owner = find_device(dev);
> - if (!owner) {
> - spin_unlock(&dev_domain_list_spinlock);
> - return -ENODEV;
> - }
> - list_del(&owner->list);
> - spin_un
[PATCH] xen-pciback: allow compiling on other archs than x86
From: Oleksandr Andrushchenko
Xen-pciback driver was designed to be built for x86 only. But it
can also be used by other architectures, e.g. Arm.
Re-structure the driver in a way that it can be built for other
platforms as well.
Signed-off-by: Oleksandr Andrushchenko
Signed-off-by: Anastasiia Lukianenko
---
Tested on Arm and x86.
---
arch/x86/include/asm/xen/pci.h | 24 --
arch/x86/pci/xen.c | 74 +
drivers/xen/Kconfig| 2 +-
drivers/xen/events/events_base.c | 1 +
drivers/xen/pci.c | 75 ++
drivers/xen/xen-pciback/pci_stub.c | 3 +-
drivers/xen/xen-pciback/xenbus.c | 2 +-
include/xen/pci.h | 34 ++
8 files changed, 115 insertions(+), 100 deletions(-)
create mode 100644 include/xen/pci.h
diff --git a/arch/x86/include/asm/xen/pci.h b/arch/x86/include/asm/xen/pci.h
index 3506d8c598c1..9ff7b49bca08 100644
--- a/arch/x86/include/asm/xen/pci.h
+++ b/arch/x86/include/asm/xen/pci.h
@@ -14,30 +14,6 @@ static inline int pci_xen_hvm_init(void)
return -1;
}
#endif
-#if defined(CONFIG_XEN_DOM0)
-int __init pci_xen_initial_domain(void);
-int xen_find_device_domain_owner(struct pci_dev *dev);
-int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain);
-int xen_unregister_device_domain_owner(struct pci_dev *dev);
-#else
-static inline int __init pci_xen_initial_domain(void)
-{
- return -1;
-}
-static inline int xen_find_device_domain_owner(struct pci_dev *dev)
-{
- return -1;
-}
-static inline int xen_register_device_domain_owner(struct pci_dev *dev,
- uint16_t domain)
-{
- return -1;
-}
-static inline int xen_unregister_device_domain_owner(struct pci_dev *dev)
-{
- return -1;
-}
-#endif
#if defined(CONFIG_PCI_MSI)
#if defined(CONFIG_PCI_XEN)
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 3d41a09c2c14..4a45b0bf9ae4 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -23,6 +23,7 @@
#include
#include
+#include
#include
#include
#include
@@ -583,77 +584,4 @@ int __init pci_xen_initial_domain(void)
}
return 0;
}
-
-struct xen_device_domain_owner {
- domid_t domain;
- struct pci_dev *dev;
- struct list_head list;
-};
-
-static DEFINE_SPINLOCK(dev_domain_list_spinlock);
-static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
-
-static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
-{
- struct xen_device_domain_owner *owner;
-
- list_for_each_entry(owner, &dev_domain_list, list) {
- if (owner->dev == dev)
- return owner;
- }
- return NULL;
-}
-
-int xen_find_device_domain_owner(struct pci_dev *dev)
-{
- struct xen_device_domain_owner *owner;
- int domain = -ENODEV;
-
- spin_lock(&dev_domain_list_spinlock);
- owner = find_device(dev);
- if (owner)
- domain = owner->domain;
- spin_unlock(&dev_domain_list_spinlock);
- return domain;
-}
-EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
-
-int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
-{
- struct xen_device_domain_owner *owner;
-
- owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
- if (!owner)
- return -ENODEV;
-
- spin_lock(&dev_domain_list_spinlock);
- if (find_device(dev)) {
- spin_unlock(&dev_domain_list_spinlock);
- kfree(owner);
- return -EEXIST;
- }
- owner->domain = domain;
- owner->dev = dev;
- list_add_tail(&owner->list, &dev_domain_list);
- spin_unlock(&dev_domain_list_spinlock);
- return 0;
-}
-EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
-
-int xen_unregister_device_domain_owner(struct pci_dev *dev)
-{
- struct xen_device_domain_owner *owner;
-
- spin_lock(&dev_domain_list_spinlock);
- owner = find_device(dev);
- if (!owner) {
- spin_unlock(&dev_domain_list_spinlock);
- return -ENODEV;
- }
- list_del(&owner->list);
- spin_unlock(&dev_domain_list_spinlock);
- kfree(owner);
- return 0;
-}
-EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
#endif
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index a37eb52fb401..057ddf61ef61 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -182,7 +182,7 @@ config SWIOTLB_XEN
config XEN_PCIDEV_BACKEND
tristate "Xen PCI-device backend driver"
- depends on PCI && X86 && XEN
+ depends on PCI && XEN
depends on XEN_BACKEND
default m
help
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index a78704ae3618..35493ff0d146 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@
