Re: [Qemu-devel] [PATCH qemu v3] RFC: vfio-pci: Allow mmap of MSIX BAR
On Wed, 24 Jan 2018 16:30:04 +0100
Auger Eric wrote:
> Hi Alex,
> On 24/01/18 16:02, Alex Williamson wrote:
> > On Wed, 24 Jan 2018 15:13:06 +0100
> > Auger Eric wrote:
> >
> >> Hi Alex,
> >> On 23/01/18 20:55, Alex Williamson wrote:
> >>> On Tue, 23 Jan 2018 16:34:34 +0100
> >>> Auger Eric wrote:
> >>>
> Hi Alexey,
> On 23/01/18 02:22, Alexey Kardashevskiy wrote:
> > This makes use of a new VFIO_REGION_INFO_CAP_MSIX_MAPPABLE capability
> > which tells that a region with MSIX data can be mapped entirely, i.e.
> > the VFIO PCI driver won't prevent MSIX vectors area from being mapped.
> >
> > With this change, all BARs are mapped in a single chunk and MSIX vectors
> > are emulated on top unless the machine requests not to by defining and
> > enabling a new "vfio-no-msix-emulation" property. At the moment only
> > sPAPR machine does so - it prohibits MSIX emulation and does not allow
> > enabling it as it does not define the "set" callback for the new
> > property;
> > the new property also does not appear in "-machine pseries,help".
> >
> > If MSIX vectors section is not aligned to the page size, the KVM memory
> > listener does not register it with the KVM as a memory slot and MSIX is
> > emulated by QEMU as before. This may create MMIO RAM memory sections
> > with
> > an address or/and a size not aligned which will make vfio_dma_map()
> > fail;
> > to address this, this makes treats such failures as non-fatal.
> >
> > This requires the kernel change - "vfio-pci: Allow mapping MSIX BAR" -
> > for the new capability: https://www.spinics.net/lists/kvm/msg160282.html
> >
> > Signed-off-by: Alexey Kardashevskiy
> > ---
> > Changes:
> > v3:
> > * vfio_listener_region_add() won't make qemu exit if failed on MMIO MR
> >
> > ---
> > include/hw/vfio/vfio-common.h | 1 +
> > linux-headers/linux/vfio.h| 5 +
> > hw/ppc/spapr.c| 7 +++
> > hw/vfio/common.c | 19 +++
> > hw/vfio/pci.c | 10 ++
> > 5 files changed, 42 insertions(+)
> >
> > diff --git a/include/hw/vfio/vfio-common.h
> > b/include/hw/vfio/vfio-common.h
> > index f3a2ac9..927d600 100644
> > --- a/include/hw/vfio/vfio-common.h
> > +++ b/include/hw/vfio/vfio-common.h
> > @@ -171,6 +171,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int
> > index,
> > struct vfio_region_info **info);
> > int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
> > uint32_t subtype, struct vfio_region_info
> > **info);
> > +bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int
> > region);
> > #endif
> > extern const MemoryListener vfio_prereg_listener;
> >
> > diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
> > index 4312e96..b45182e 100644
> > --- a/linux-headers/linux/vfio.h
> > +++ b/linux-headers/linux/vfio.h
> > @@ -301,6 +301,11 @@ struct vfio_region_info_cap_type {
> > #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
> > #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
> >
> > +/*
> > + * The MSIX mappable capability informs that MSIX data of a BAR can be
> > mmapped.
> > + */
> > +#define VFIO_REGION_INFO_CAP_MSIX_MAPPABLE 3
> > +
> > /**
> > * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
> > * struct vfio_irq_info)
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index d1acfe8..5ff43ce 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -2789,6 +2789,11 @@ static void
> > spapr_set_modern_hotplug_events(Object *obj, bool value,
> > spapr->use_hotplug_event_source = value;
> > }
> >
> > +static bool spapr_get_msix_emulation(Object *obj, Error **errp)
> > +{
> > +return true;
> > +}
> > +
> > static char *spapr_get_resize_hpt(Object *obj, Error **errp)
> > {
> > sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
> > @@ -2870,6 +2875,8 @@ static void spapr_instance_init(Object *obj)
> > object_property_set_description(obj, "vsmt",
> > "Virtual SMT: KVM behaves as if
> > this were"
> > " the host's SMT mode",
> > &error_abort);
> > +object_property_add_bool(obj, "vfio-no-msix-emulation",
> > + spapr_get_msix_emulation, NULL, NULL);
> > }
> >
> > static void spapr_machine_finalizefn(Object *obj)
> > diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> > index b77be3a..842c5b2 100644
> > --- a/hw/vfio/common.c
> > +++ b/hw/vfio/common.c
>
Re: [Qemu-devel] [PATCH qemu v3] RFC: vfio-pci: Allow mmap of MSIX BAR
Hi Alex,
On 24/01/18 16:02, Alex Williamson wrote:
> On Wed, 24 Jan 2018 15:13:06 +0100
> Auger Eric wrote:
>
>> Hi Alex,
>> On 23/01/18 20:55, Alex Williamson wrote:
>>> On Tue, 23 Jan 2018 16:34:34 +0100
>>> Auger Eric wrote:
>>>
Hi Alexey,
On 23/01/18 02:22, Alexey Kardashevskiy wrote:
> This makes use of a new VFIO_REGION_INFO_CAP_MSIX_MAPPABLE capability
> which tells that a region with MSIX data can be mapped entirely, i.e.
> the VFIO PCI driver won't prevent MSIX vectors area from being mapped.
>
> With this change, all BARs are mapped in a single chunk and MSIX vectors
> are emulated on top unless the machine requests not to by defining and
> enabling a new "vfio-no-msix-emulation" property. At the moment only
> sPAPR machine does so - it prohibits MSIX emulation and does not allow
> enabling it as it does not define the "set" callback for the new property;
> the new property also does not appear in "-machine pseries,help".
>
> If MSIX vectors section is not aligned to the page size, the KVM memory
> listener does not register it with the KVM as a memory slot and MSIX is
> emulated by QEMU as before. This may create MMIO RAM memory sections with
> an address or/and a size not aligned which will make vfio_dma_map() fail;
> to address this, this makes treats such failures as non-fatal.
>
> This requires the kernel change - "vfio-pci: Allow mapping MSIX BAR" -
> for the new capability: https://www.spinics.net/lists/kvm/msg160282.html
>
> Signed-off-by: Alexey Kardashevskiy
> ---
> Changes:
> v3:
> * vfio_listener_region_add() won't make qemu exit if failed on MMIO MR
>
> ---
> include/hw/vfio/vfio-common.h | 1 +
> linux-headers/linux/vfio.h| 5 +
> hw/ppc/spapr.c| 7 +++
> hw/vfio/common.c | 19 +++
> hw/vfio/pci.c | 10 ++
> 5 files changed, 42 insertions(+)
>
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index f3a2ac9..927d600 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -171,6 +171,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int
> index,
> struct vfio_region_info **info);
> int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
> uint32_t subtype, struct vfio_region_info
> **info);
> +bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int
> region);
> #endif
> extern const MemoryListener vfio_prereg_listener;
>
> diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
> index 4312e96..b45182e 100644
> --- a/linux-headers/linux/vfio.h
> +++ b/linux-headers/linux/vfio.h
> @@ -301,6 +301,11 @@ struct vfio_region_info_cap_type {
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG(3)
>
> +/*
> + * The MSIX mappable capability informs that MSIX data of a BAR can be
> mmapped.
> + */
> +#define VFIO_REGION_INFO_CAP_MSIX_MAPPABLE 3
> +
> /**
> * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
> * struct vfio_irq_info)
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index d1acfe8..5ff43ce 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2789,6 +2789,11 @@ static void spapr_set_modern_hotplug_events(Object
> *obj, bool value,
> spapr->use_hotplug_event_source = value;
> }
>
> +static bool spapr_get_msix_emulation(Object *obj, Error **errp)
> +{
> +return true;
> +}
> +
> static char *spapr_get_resize_hpt(Object *obj, Error **errp)
> {
> sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
> @@ -2870,6 +2875,8 @@ static void spapr_instance_init(Object *obj)
> object_property_set_description(obj, "vsmt",
> "Virtual SMT: KVM behaves as if this
> were"
> " the host's SMT mode",
> &error_abort);
> +object_property_add_bool(obj, "vfio-no-msix-emulation",
> + spapr_get_msix_emulation, NULL, NULL);
> }
>
> static void spapr_machine_finalizefn(Object *obj)
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index b77be3a..842c5b2 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -530,6 +530,10 @@ static void vfio_listener_region_add(MemoryListener
> *listener,
> return;
>
> fail:
> +if (memory_region_is_ram_device(section->mr)) {
> +error_report("failed to vfio_dma_map. pci p2p may not work");
> +return;
> +}
Re: [Qemu-devel] [PATCH qemu v3] RFC: vfio-pci: Allow mmap of MSIX BAR
On Wed, 24 Jan 2018 15:13:06 +0100
Auger Eric wrote:
> Hi Alex,
> On 23/01/18 20:55, Alex Williamson wrote:
> > On Tue, 23 Jan 2018 16:34:34 +0100
> > Auger Eric wrote:
> >
> >> Hi Alexey,
> >> On 23/01/18 02:22, Alexey Kardashevskiy wrote:
> >>> This makes use of a new VFIO_REGION_INFO_CAP_MSIX_MAPPABLE capability
> >>> which tells that a region with MSIX data can be mapped entirely, i.e.
> >>> the VFIO PCI driver won't prevent MSIX vectors area from being mapped.
> >>>
> >>> With this change, all BARs are mapped in a single chunk and MSIX vectors
> >>> are emulated on top unless the machine requests not to by defining and
> >>> enabling a new "vfio-no-msix-emulation" property. At the moment only
> >>> sPAPR machine does so - it prohibits MSIX emulation and does not allow
> >>> enabling it as it does not define the "set" callback for the new property;
> >>> the new property also does not appear in "-machine pseries,help".
> >>>
> >>> If MSIX vectors section is not aligned to the page size, the KVM memory
> >>> listener does not register it with the KVM as a memory slot and MSIX is
> >>> emulated by QEMU as before. This may create MMIO RAM memory sections with
> >>> an address or/and a size not aligned which will make vfio_dma_map() fail;
> >>> to address this, this makes treats such failures as non-fatal.
> >>>
> >>> This requires the kernel change - "vfio-pci: Allow mapping MSIX BAR" -
> >>> for the new capability: https://www.spinics.net/lists/kvm/msg160282.html
> >>>
> >>> Signed-off-by: Alexey Kardashevskiy
> >>> ---
> >>> Changes:
> >>> v3:
> >>> * vfio_listener_region_add() won't make qemu exit if failed on MMIO MR
> >>>
> >>> ---
> >>> include/hw/vfio/vfio-common.h | 1 +
> >>> linux-headers/linux/vfio.h| 5 +
> >>> hw/ppc/spapr.c| 7 +++
> >>> hw/vfio/common.c | 19 +++
> >>> hw/vfio/pci.c | 10 ++
> >>> 5 files changed, 42 insertions(+)
> >>>
> >>> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> >>> index f3a2ac9..927d600 100644
> >>> --- a/include/hw/vfio/vfio-common.h
> >>> +++ b/include/hw/vfio/vfio-common.h
> >>> @@ -171,6 +171,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int
> >>> index,
> >>> struct vfio_region_info **info);
> >>> int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
> >>> uint32_t subtype, struct vfio_region_info
> >>> **info);
> >>> +bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int
> >>> region);
> >>> #endif
> >>> extern const MemoryListener vfio_prereg_listener;
> >>>
> >>> diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
> >>> index 4312e96..b45182e 100644
> >>> --- a/linux-headers/linux/vfio.h
> >>> +++ b/linux-headers/linux/vfio.h
> >>> @@ -301,6 +301,11 @@ struct vfio_region_info_cap_type {
> >>> #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
> >>> #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG(3)
> >>>
> >>> +/*
> >>> + * The MSIX mappable capability informs that MSIX data of a BAR can be
> >>> mmapped.
> >>> + */
> >>> +#define VFIO_REGION_INFO_CAP_MSIX_MAPPABLE 3
> >>> +
> >>> /**
> >>> * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
> >>> * struct vfio_irq_info)
> >>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> >>> index d1acfe8..5ff43ce 100644
> >>> --- a/hw/ppc/spapr.c
> >>> +++ b/hw/ppc/spapr.c
> >>> @@ -2789,6 +2789,11 @@ static void spapr_set_modern_hotplug_events(Object
> >>> *obj, bool value,
> >>> spapr->use_hotplug_event_source = value;
> >>> }
> >>>
> >>> +static bool spapr_get_msix_emulation(Object *obj, Error **errp)
> >>> +{
> >>> +return true;
> >>> +}
> >>> +
> >>> static char *spapr_get_resize_hpt(Object *obj, Error **errp)
> >>> {
> >>> sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
> >>> @@ -2870,6 +2875,8 @@ static void spapr_instance_init(Object *obj)
> >>> object_property_set_description(obj, "vsmt",
> >>> "Virtual SMT: KVM behaves as if this
> >>> were"
> >>> " the host's SMT mode",
> >>> &error_abort);
> >>> +object_property_add_bool(obj, "vfio-no-msix-emulation",
> >>> + spapr_get_msix_emulation, NULL, NULL);
> >>> }
> >>>
> >>> static void spapr_machine_finalizefn(Object *obj)
> >>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> >>> index b77be3a..842c5b2 100644
> >>> --- a/hw/vfio/common.c
> >>> +++ b/hw/vfio/common.c
> >>> @@ -530,6 +530,10 @@ static void vfio_listener_region_add(MemoryListener
> >>> *listener,
> >>> return;
> >>>
> >>> fail:
> >>> +if (memory_region_is_ram_device(section->mr)) {
> >>> +error_report("failed to vfio_dma_map. pci p2p may not work");
> >>> +return;
> >>> +}
> >>
> >> I don't think this is an acceptable solution as
Re: [Qemu-devel] [PATCH qemu v3] RFC: vfio-pci: Allow mmap of MSIX BAR
Hi Alex,
On 23/01/18 20:55, Alex Williamson wrote:
> On Tue, 23 Jan 2018 16:34:34 +0100
> Auger Eric wrote:
>
>> Hi Alexey,
>> On 23/01/18 02:22, Alexey Kardashevskiy wrote:
>>> This makes use of a new VFIO_REGION_INFO_CAP_MSIX_MAPPABLE capability
>>> which tells that a region with MSIX data can be mapped entirely, i.e.
>>> the VFIO PCI driver won't prevent MSIX vectors area from being mapped.
>>>
>>> With this change, all BARs are mapped in a single chunk and MSIX vectors
>>> are emulated on top unless the machine requests not to by defining and
>>> enabling a new "vfio-no-msix-emulation" property. At the moment only
>>> sPAPR machine does so - it prohibits MSIX emulation and does not allow
>>> enabling it as it does not define the "set" callback for the new property;
>>> the new property also does not appear in "-machine pseries,help".
>>>
>>> If MSIX vectors section is not aligned to the page size, the KVM memory
>>> listener does not register it with the KVM as a memory slot and MSIX is
>>> emulated by QEMU as before. This may create MMIO RAM memory sections with
>>> an address or/and a size not aligned which will make vfio_dma_map() fail;
>>> to address this, this makes treats such failures as non-fatal.
>>>
>>> This requires the kernel change - "vfio-pci: Allow mapping MSIX BAR" -
>>> for the new capability: https://www.spinics.net/lists/kvm/msg160282.html
>>>
>>> Signed-off-by: Alexey Kardashevskiy
>>> ---
>>> Changes:
>>> v3:
>>> * vfio_listener_region_add() won't make qemu exit if failed on MMIO MR
>>>
>>> ---
>>> include/hw/vfio/vfio-common.h | 1 +
>>> linux-headers/linux/vfio.h| 5 +
>>> hw/ppc/spapr.c| 7 +++
>>> hw/vfio/common.c | 19 +++
>>> hw/vfio/pci.c | 10 ++
>>> 5 files changed, 42 insertions(+)
>>>
>>> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
>>> index f3a2ac9..927d600 100644
>>> --- a/include/hw/vfio/vfio-common.h
>>> +++ b/include/hw/vfio/vfio-common.h
>>> @@ -171,6 +171,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int
>>> index,
>>> struct vfio_region_info **info);
>>> int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
>>> uint32_t subtype, struct vfio_region_info
>>> **info);
>>> +bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int
>>> region);
>>> #endif
>>> extern const MemoryListener vfio_prereg_listener;
>>>
>>> diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
>>> index 4312e96..b45182e 100644
>>> --- a/linux-headers/linux/vfio.h
>>> +++ b/linux-headers/linux/vfio.h
>>> @@ -301,6 +301,11 @@ struct vfio_region_info_cap_type {
>>> #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
>>> #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
>>>
>>> +/*
>>> + * The MSIX mappable capability informs that MSIX data of a BAR can be
>>> mmapped.
>>> + */
>>> +#define VFIO_REGION_INFO_CAP_MSIX_MAPPABLE 3
>>> +
>>> /**
>>> * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
>>> * struct vfio_irq_info)
>>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>>> index d1acfe8..5ff43ce 100644
>>> --- a/hw/ppc/spapr.c
>>> +++ b/hw/ppc/spapr.c
>>> @@ -2789,6 +2789,11 @@ static void spapr_set_modern_hotplug_events(Object
>>> *obj, bool value,
>>> spapr->use_hotplug_event_source = value;
>>> }
>>>
>>> +static bool spapr_get_msix_emulation(Object *obj, Error **errp)
>>> +{
>>> +return true;
>>> +}
>>> +
>>> static char *spapr_get_resize_hpt(Object *obj, Error **errp)
>>> {
>>> sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
>>> @@ -2870,6 +2875,8 @@ static void spapr_instance_init(Object *obj)
>>> object_property_set_description(obj, "vsmt",
>>> "Virtual SMT: KVM behaves as if this
>>> were"
>>> " the host's SMT mode", &error_abort);
>>> +object_property_add_bool(obj, "vfio-no-msix-emulation",
>>> + spapr_get_msix_emulation, NULL, NULL);
>>> }
>>>
>>> static void spapr_machine_finalizefn(Object *obj)
>>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>>> index b77be3a..842c5b2 100644
>>> --- a/hw/vfio/common.c
>>> +++ b/hw/vfio/common.c
>>> @@ -530,6 +530,10 @@ static void vfio_listener_region_add(MemoryListener
>>> *listener,
>>> return;
>>>
>>> fail:
>>> +if (memory_region_is_ram_device(section->mr)) {
>>> +error_report("failed to vfio_dma_map. pci p2p may not work");
>>> +return;
>>> +}
>>
>> I don't think this is an acceptable solution as it produces plenty of
>> errors such as
>>
>> qemu-system-aarch64: VFIO_MAP_DMA: -22
>> qemu-system-aarch64: vfio_dma_map(0x30a7ab90, 0x80, 0x2000,
>> 0xfffd79a0) = -22 (Invalid argument)
>
> This much of the error above could be avoided by looking at the type1
> page size bitmap before tryin
Re: [Qemu-devel] [PATCH qemu v3] RFC: vfio-pci: Allow mmap of MSIX BAR
On Tue, 23 Jan 2018 16:34:34 +0100
Auger Eric wrote:
> Hi Alexey,
> On 23/01/18 02:22, Alexey Kardashevskiy wrote:
> > This makes use of a new VFIO_REGION_INFO_CAP_MSIX_MAPPABLE capability
> > which tells that a region with MSIX data can be mapped entirely, i.e.
> > the VFIO PCI driver won't prevent MSIX vectors area from being mapped.
> >
> > With this change, all BARs are mapped in a single chunk and MSIX vectors
> > are emulated on top unless the machine requests not to by defining and
> > enabling a new "vfio-no-msix-emulation" property. At the moment only
> > sPAPR machine does so - it prohibits MSIX emulation and does not allow
> > enabling it as it does not define the "set" callback for the new property;
> > the new property also does not appear in "-machine pseries,help".
> >
> > If MSIX vectors section is not aligned to the page size, the KVM memory
> > listener does not register it with the KVM as a memory slot and MSIX is
> > emulated by QEMU as before. This may create MMIO RAM memory sections with
> > an address or/and a size not aligned which will make vfio_dma_map() fail;
> > to address this, this makes treats such failures as non-fatal.
> >
> > This requires the kernel change - "vfio-pci: Allow mapping MSIX BAR" -
> > for the new capability: https://www.spinics.net/lists/kvm/msg160282.html
> >
> > Signed-off-by: Alexey Kardashevskiy
> > ---
> > Changes:
> > v3:
> > * vfio_listener_region_add() won't make qemu exit if failed on MMIO MR
> >
> > ---
> > include/hw/vfio/vfio-common.h | 1 +
> > linux-headers/linux/vfio.h| 5 +
> > hw/ppc/spapr.c| 7 +++
> > hw/vfio/common.c | 19 +++
> > hw/vfio/pci.c | 10 ++
> > 5 files changed, 42 insertions(+)
> >
> > diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> > index f3a2ac9..927d600 100644
> > --- a/include/hw/vfio/vfio-common.h
> > +++ b/include/hw/vfio/vfio-common.h
> > @@ -171,6 +171,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int
> > index,
> > struct vfio_region_info **info);
> > int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
> > uint32_t subtype, struct vfio_region_info
> > **info);
> > +bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int
> > region);
> > #endif
> > extern const MemoryListener vfio_prereg_listener;
> >
> > diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
> > index 4312e96..b45182e 100644
> > --- a/linux-headers/linux/vfio.h
> > +++ b/linux-headers/linux/vfio.h
> > @@ -301,6 +301,11 @@ struct vfio_region_info_cap_type {
> > #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
> > #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
> >
> > +/*
> > + * The MSIX mappable capability informs that MSIX data of a BAR can be
> > mmapped.
> > + */
> > +#define VFIO_REGION_INFO_CAP_MSIX_MAPPABLE 3
> > +
> > /**
> > * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
> > * struct vfio_irq_info)
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index d1acfe8..5ff43ce 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -2789,6 +2789,11 @@ static void spapr_set_modern_hotplug_events(Object
> > *obj, bool value,
> > spapr->use_hotplug_event_source = value;
> > }
> >
> > +static bool spapr_get_msix_emulation(Object *obj, Error **errp)
> > +{
> > +return true;
> > +}
> > +
> > static char *spapr_get_resize_hpt(Object *obj, Error **errp)
> > {
> > sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
> > @@ -2870,6 +2875,8 @@ static void spapr_instance_init(Object *obj)
> > object_property_set_description(obj, "vsmt",
> > "Virtual SMT: KVM behaves as if this
> > were"
> > " the host's SMT mode", &error_abort);
> > +object_property_add_bool(obj, "vfio-no-msix-emulation",
> > + spapr_get_msix_emulation, NULL, NULL);
> > }
> >
> > static void spapr_machine_finalizefn(Object *obj)
> > diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> > index b77be3a..842c5b2 100644
> > --- a/hw/vfio/common.c
> > +++ b/hw/vfio/common.c
> > @@ -530,6 +530,10 @@ static void vfio_listener_region_add(MemoryListener
> > *listener,
> > return;
> >
> > fail:
> > +if (memory_region_is_ram_device(section->mr)) {
> > +error_report("failed to vfio_dma_map. pci p2p may not work");
> > +return;
> > +}
>
> I don't think this is an acceptable solution as it produces plenty of
> errors such as
>
> qemu-system-aarch64: VFIO_MAP_DMA: -22
> qemu-system-aarch64: vfio_dma_map(0x30a7ab90, 0x80, 0x2000,
> 0xfffd79a0) = -22 (Invalid argument)
This much of the error above could be avoided by looking at the type1
page size bitmap before trying to perform the mapping.
> qemu-system-aarch64: failed to vfio
Re: [Qemu-devel] [PATCH qemu v3] RFC: vfio-pci: Allow mmap of MSIX BAR
Hi Alexey,
On 23/01/18 02:22, Alexey Kardashevskiy wrote:
> This makes use of a new VFIO_REGION_INFO_CAP_MSIX_MAPPABLE capability
> which tells that a region with MSIX data can be mapped entirely, i.e.
> the VFIO PCI driver won't prevent MSIX vectors area from being mapped.
>
> With this change, all BARs are mapped in a single chunk and MSIX vectors
> are emulated on top unless the machine requests not to by defining and
> enabling a new "vfio-no-msix-emulation" property. At the moment only
> sPAPR machine does so - it prohibits MSIX emulation and does not allow
> enabling it as it does not define the "set" callback for the new property;
> the new property also does not appear in "-machine pseries,help".
>
> If MSIX vectors section is not aligned to the page size, the KVM memory
> listener does not register it with the KVM as a memory slot and MSIX is
> emulated by QEMU as before. This may create MMIO RAM memory sections with
> an address or/and a size not aligned which will make vfio_dma_map() fail;
> to address this, this makes treats such failures as non-fatal.
>
> This requires the kernel change - "vfio-pci: Allow mapping MSIX BAR" -
> for the new capability: https://www.spinics.net/lists/kvm/msg160282.html
>
> Signed-off-by: Alexey Kardashevskiy
> ---
> Changes:
> v3:
> * vfio_listener_region_add() won't make qemu exit if failed on MMIO MR
>
> ---
> include/hw/vfio/vfio-common.h | 1 +
> linux-headers/linux/vfio.h| 5 +
> hw/ppc/spapr.c| 7 +++
> hw/vfio/common.c | 19 +++
> hw/vfio/pci.c | 10 ++
> 5 files changed, 42 insertions(+)
>
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index f3a2ac9..927d600 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -171,6 +171,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index,
> struct vfio_region_info **info);
> int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
> uint32_t subtype, struct vfio_region_info
> **info);
> +bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int
> region);
> #endif
> extern const MemoryListener vfio_prereg_listener;
>
> diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
> index 4312e96..b45182e 100644
> --- a/linux-headers/linux/vfio.h
> +++ b/linux-headers/linux/vfio.h
> @@ -301,6 +301,11 @@ struct vfio_region_info_cap_type {
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG(3)
>
> +/*
> + * The MSIX mappable capability informs that MSIX data of a BAR can be
> mmapped.
> + */
> +#define VFIO_REGION_INFO_CAP_MSIX_MAPPABLE 3
> +
> /**
> * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
> * struct vfio_irq_info)
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index d1acfe8..5ff43ce 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2789,6 +2789,11 @@ static void spapr_set_modern_hotplug_events(Object
> *obj, bool value,
> spapr->use_hotplug_event_source = value;
> }
>
> +static bool spapr_get_msix_emulation(Object *obj, Error **errp)
> +{
> +return true;
> +}
> +
> static char *spapr_get_resize_hpt(Object *obj, Error **errp)
> {
> sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
> @@ -2870,6 +2875,8 @@ static void spapr_instance_init(Object *obj)
> object_property_set_description(obj, "vsmt",
> "Virtual SMT: KVM behaves as if this
> were"
> " the host's SMT mode", &error_abort);
> +object_property_add_bool(obj, "vfio-no-msix-emulation",
> + spapr_get_msix_emulation, NULL, NULL);
> }
>
> static void spapr_machine_finalizefn(Object *obj)
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index b77be3a..842c5b2 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -530,6 +530,10 @@ static void vfio_listener_region_add(MemoryListener
> *listener,
> return;
>
> fail:
> +if (memory_region_is_ram_device(section->mr)) {
> +error_report("failed to vfio_dma_map. pci p2p may not work");
> +return;
> +}
I don't think this is an acceptable solution as it produces plenty of
errors such as
qemu-system-aarch64: VFIO_MAP_DMA: -22
qemu-system-aarch64: vfio_dma_map(0x30a7ab90, 0x80, 0x2000,
0xfffd79a0) = -22 (Invalid argument)
qemu-system-aarch64: failed to vfio_dma_map. pci p2p may not work
testing context is: aarch64 + Mellanox CX-4 PF where we still try to map
the BAR0 area [0 - 0x2000] before the MSI-X table which is not aligned
with the host 64kB page.
Region 0: Memory at 804 (64-bit, prefetchable) [size=32M]
Capabilities: [9c] MSI-X: Enable+ Count=64 Masked-
Vector table: BAR=0 offset=2000
PBA: BAR=0 offset=3
[Qemu-devel] [PATCH qemu v3] RFC: vfio-pci: Allow mmap of MSIX BAR
This makes use of a new VFIO_REGION_INFO_CAP_MSIX_MAPPABLE capability
which tells that a region with MSIX data can be mapped entirely, i.e.
the VFIO PCI driver won't prevent MSIX vectors area from being mapped.
With this change, all BARs are mapped in a single chunk and MSIX vectors
are emulated on top unless the machine requests not to by defining and
enabling a new "vfio-no-msix-emulation" property. At the moment only
sPAPR machine does so - it prohibits MSIX emulation and does not allow
enabling it as it does not define the "set" callback for the new property;
the new property also does not appear in "-machine pseries,help".
If MSIX vectors section is not aligned to the page size, the KVM memory
listener does not register it with the KVM as a memory slot and MSIX is
emulated by QEMU as before. This may create MMIO RAM memory sections with
an address or/and a size not aligned which will make vfio_dma_map() fail;
to address this, this makes treats such failures as non-fatal.
This requires the kernel change - "vfio-pci: Allow mapping MSIX BAR" -
for the new capability: https://www.spinics.net/lists/kvm/msg160282.html
Signed-off-by: Alexey Kardashevskiy
---
Changes:
v3:
* vfio_listener_region_add() won't make qemu exit if failed on MMIO MR
---
include/hw/vfio/vfio-common.h | 1 +
linux-headers/linux/vfio.h| 5 +
hw/ppc/spapr.c| 7 +++
hw/vfio/common.c | 19 +++
hw/vfio/pci.c | 10 ++
5 files changed, 42 insertions(+)
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index f3a2ac9..927d600 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -171,6 +171,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index,
struct vfio_region_info **info);
int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
uint32_t subtype, struct vfio_region_info **info);
+bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int region);
#endif
extern const MemoryListener vfio_prereg_listener;
diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
index 4312e96..b45182e 100644
--- a/linux-headers/linux/vfio.h
+++ b/linux-headers/linux/vfio.h
@@ -301,6 +301,11 @@ struct vfio_region_info_cap_type {
#define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
#define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
+/*
+ * The MSIX mappable capability informs that MSIX data of a BAR can be mmapped.
+ */
+#define VFIO_REGION_INFO_CAP_MSIX_MAPPABLE 3
+
/**
* VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
* struct vfio_irq_info)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index d1acfe8..5ff43ce 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -2789,6 +2789,11 @@ static void spapr_set_modern_hotplug_events(Object *obj,
bool value,
spapr->use_hotplug_event_source = value;
}
+static bool spapr_get_msix_emulation(Object *obj, Error **errp)
+{
+return true;
+}
+
static char *spapr_get_resize_hpt(Object *obj, Error **errp)
{
sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
@@ -2870,6 +2875,8 @@ static void spapr_instance_init(Object *obj)
object_property_set_description(obj, "vsmt",
"Virtual SMT: KVM behaves as if this were"
" the host's SMT mode", &error_abort);
+object_property_add_bool(obj, "vfio-no-msix-emulation",
+ spapr_get_msix_emulation, NULL, NULL);
}
static void spapr_machine_finalizefn(Object *obj)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index b77be3a..842c5b2 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -530,6 +530,10 @@ static void vfio_listener_region_add(MemoryListener
*listener,
return;
fail:
+if (memory_region_is_ram_device(section->mr)) {
+error_report("failed to vfio_dma_map. pci p2p may not work");
+return;
+}
/*
* On the initfn path, store the first error in the container so we
* can gracefully fail. Runtime, there's not much we can do other
@@ -1387,6 +1391,21 @@ int vfio_get_dev_region_info(VFIODevice *vbasedev,
uint32_t type,
return -ENODEV;
}
+bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int region)
+{
+struct vfio_region_info *info = NULL;
+bool ret = false;
+
+if (!vfio_get_region_info(vbasedev, region, &info)) {
+if (vfio_get_region_info_cap(info, cap_type)) {
+ret = true;
+}
+g_free(info);
+}
+
+return ret;
+}
+
/*
* Interfaces for IBM EEH (Enhanced Error Handling)
*/
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 359a8f1..a96ece6 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -1289,6 +1289,11 @@ static void vfio_pci_fixup_msix_region(VFIOPCIDevice
*vdev)
off_t start, end;
VFIORegion *region = &vdev->bars[vdev->msix->tabl
