[KVM-AUTOTEST PATCH] KVM test: kvm_vm.py: don't require pci_assignable to be defined
Currently to disable PCI device assignment pci_assignable must be explicitly
set to "no". This patch allows it to remain undefined (and adds a warning
message and a comment).
Signed-off-by: Michael Goldish
---
client/tests/kvm/kvm_vm.py | 47 +--
1 files changed, 23 insertions(+), 24 deletions(-)
diff --git a/client/tests/kvm/kvm_vm.py b/client/tests/kvm/kvm_vm.py
index af45a81..78cbb16 100755
--- a/client/tests/kvm/kvm_vm.py
+++ b/client/tests/kvm/kvm_vm.py
@@ -502,49 +502,48 @@ class VM:
self.uuid = f.read().strip()
f.close()
-if not params.get("pci_assignable") == "no":
-pa_type = params.get("pci_assignable")
+# Assign a PCI assignable device
+self.pci_assignable = None
+pa_type = params.get("pci_assignable")
+if pa_type in ["vf", "pf", "mixed"]:
pa_devices_requested = params.get("devices_requested")
# Virtual Functions (VF) assignable devices
if pa_type == "vf":
-pa_driver = params.get("driver")
-pa_driver_option = params.get("driver_option")
-self.pci_assignable = kvm_utils.PciAssignable(type=pa_type,
-driver=pa_driver,
-driver_option=pa_driver_option,
-devices_requested=pa_devices_requested)
+self.pci_assignable = kvm_utils.PciAssignable(
+type=pa_type,
+driver=params.get("driver"),
+driver_option=params.get("driver_option"),
+devices_requested=pa_devices_requested)
# Physical NIC (PF) assignable devices
elif pa_type == "pf":
-pa_device_names = params.get("device_names")
-self.pci_assignable = kvm_utils.PciAssignable(type=pa_type,
- names=pa_device_names,
-
devices_requested=pa_devices_requested)
+self.pci_assignable = kvm_utils.PciAssignable(
+type=pa_type,
+names=params.get("device_names"),
+devices_requested=pa_devices_requested)
# Working with both VF and PF
elif pa_type == "mixed":
-pa_device_names = params.get("device_names")
-pa_driver = params.get("driver")
-pa_driver_option = params.get("driver_option")
-self.pci_assignable = kvm_utils.PciAssignable(type=pa_type,
-driver=pa_driver,
-driver_option=pa_driver_option,
-names=pa_device_names,
-devices_requested=pa_devices_requested)
+self.pci_assignable = kvm_utils.PciAssignable(
+type=pa_type,
+driver=params.get("driver"),
+driver_option=params.get("driver_option"),
+names=params.get("device_names"),
+devices_requested=pa_devices_requested)
self.pa_pci_ids = self.pci_assignable.request_devs()
if self.pa_pci_ids:
-logging.debug("Successfuly assigned devices: %s" %
+logging.debug("Successfuly assigned devices: %s",
self.pa_pci_ids)
else:
logging.error("No PCI assignable devices were assigned "
"and 'pci_assignable' is defined to %s "
- "on your config file. Aborting VM creation."
%
+ "on your config file. Aborting VM creation.",
pa_type)
return False
-else:
-self.pci_assignable = None
+elif pa_type and pa_type != "no":
+logging.warn("Unsupported pci_assignable type: %s", pa_type)
# Make qemu command
qemu_command = self.make_qemu_command()
--
1.5.4.1
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Re: porting fixes regarding kvm-clock and lost irqs to stable qemu-kvm 0.12.4
Am 05.06.2010 um 03:34 schrieb Faidon Liambotis:
> Hi,
>
> Peter Lieven wrote:
>> i was looking for a generic way to disable it in the hypervisor
>> without the need to touch every guests kernel commandline.
>> this would be easy revertible once its all working as expected.
> This is a huge hack but for the same reason I've made an LD_PRELOAD
> wrapper that wraps ioctl masking the hsot kernel's kvmclock feature from
> userspace kvm. I'll be happy to share it if you're interested.
i would be grateful if you can sent it to me offlist. however, i came up with
this hack,
that seems to work also:
diff -ur qemu-kvm-0.12.4.orig/qemu-kvm-x86.c qemu-kvm-0.12.4/qemu-kvm-x86.c
--- qemu-kvm-0.12.4.orig/qemu-kvm-x86.c 2010-05-09 13:05:19.0 +0200
+++ qemu-kvm-0.12.4/qemu-kvm-x86.c 2010-06-02 18:18:53.0 +0200
@@ -1240,7 +1240,7 @@
int feature;
} para_features[] = {
#ifdef KVM_CAP_CLOCKSOURCE
- { KVM_CAP_CLOCKSOURCE, KVM_FEATURE_CLOCKSOURCE },
+// { KVM_CAP_CLOCKSOURCE, KVM_FEATURE_CLOCKSOURCE },
#endif
#ifdef KVM_CAP_NOP_IO_DELAY
{ KVM_CAP_NOP_IO_DELAY, KVM_FEATURE_NOP_IO_DELAY },
>
> Works like a charm, migration has worken reliably with qemu-kvm 0.11.3 +
> the wrapper.
>
> Regards,
> Faidon
> --
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>
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Re: [RFC PATCH v7 11/19] Use callback to deal with skb_release_data() specially.
Le samedi 05 juin 2010 à 18:14 +0800, xiaohui@intel.com a écrit :
> From: Xin Xiaohui
>
> If buffer is external, then use the callback to destruct
> buffers.
>
> Signed-off-by: Xin Xiaohui
> Signed-off-by: Zhao Yu
> Reviewed-by: Jeff Dike
> ---
> net/core/skbuff.c | 11 +++
> 1 files changed, 11 insertions(+), 0 deletions(-)
>
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index 37587f0..418457c 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -385,6 +385,11 @@ static void skb_clone_fraglist(struct sk_buff *skb)
>
> static void skb_release_data(struct sk_buff *skb)
> {
> + /* check if the skb has external buffers, we have use destructor_arg
> + * here to indicate
> + */
> + struct skb_external_page *ext_page = skb_shinfo(skb)->destructor_arg;
> +
Oh well. This is v7 of your series, and nobody complained yet ?
This is a new cache miss on a _critical_ path.
> if (!skb->cloned ||
> !atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1,
> &skb_shinfo(skb)->dataref)) {
> @@ -397,6 +402,12 @@ static void skb_release_data(struct sk_buff *skb)
> if (skb_has_frags(skb))
> skb_drop_fraglist(skb);
>
> + /* if the skb has external buffers, use destructor here,
> + * since after that skb->head will be kfree, in case skb->head
> + * from external buffer cannot use kfree to destroy.
> + */
Why not deferring here the access to skb_shinfo(skb)->destructor_arg ?
> + if (dev_is_mpassthru(skb->dev) && ext_page && ext_page->dtor)
> + ext_page->dtor(ext_page);
> kfree(skb->head);
> }
> }
if (dev_is_mpassthru(skb->dev)) {
struct skb_external_page *ext_page =
skb_shinfo(skb)->destructor_arg;
if (ext_page && ext_page->dtor)
ext_page->dtor(ext_page);
}
destructor_arg should me moved before frags[] if you really want to use it.
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index bf243fc..b136d90 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -202,10 +202,11 @@ struct skb_shared_info {
*/
atomic_tdataref;
- skb_frag_t frags[MAX_SKB_FRAGS];
/* Intermediate layers must ensure that destructor_arg
* remains valid until skb destructor */
void * destructor_arg;
+
+ skb_frag_t frags[MAX_SKB_FRAGS];
};
/* We divide dataref into two halves. The higher 16 bits hold references
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Re: [RFC PATCH v7 08/19] Make __alloc_skb() to get external buffer.
Le samedi 05 juin 2010 à 18:14 +0800, xiaohui@intel.com a écrit : > From: Xin Xiaohui > child->fclone = SKB_FCLONE_UNAVAILABLE; > } > + /* Record the external buffer info in this field. It's not so good, > + * but we cannot find another place easily. > + */ > + shinfo->destructor_arg = ext_page; > + Yes this is a big problem, its basically using a cache line that was not touched before. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [RFC PATCH v7 03/19] Export 2 func for device to assign/deassign new strucure
Le samedi 05 juin 2010 à 18:14 +0800, xiaohui@intel.com a écrit :
> From: Xin Xiaohui
>
> Signed-off-by: Xin Xiaohui
> Signed-off-by: Zhao Yu
> Reviewed-by: Jeff Dike
> ---
> include/linux/netdevice.h |3 +++
> net/core/dev.c| 28
> 2 files changed, 31 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index bae725c..efb575a 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1592,6 +1592,9 @@ extern gro_result_t napi_frags_finish(struct
> napi_struct *napi,
> gro_result_t ret);
> extern struct sk_buff * napi_frags_skb(struct napi_struct *napi);
> extern gro_result_t napi_gro_frags(struct napi_struct *napi);
> +extern int netdev_mp_port_attach(struct net_device *dev,
> + struct mpassthru_port *port);
> +extern void netdev_mp_port_detach(struct net_device *dev);
>
> static inline void napi_free_frags(struct napi_struct *napi)
> {
> diff --git a/net/core/dev.c b/net/core/dev.c
> index f769098..ecbb6b1 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -2469,6 +2469,34 @@ void netif_nit_deliver(struct sk_buff *skb)
> rcu_read_unlock();
> }
>
> +/* Export two functions to assign/de-assign mp_port pointer
> + * to a net device.
> + */
> +
> +int netdev_mp_port_attach(struct net_device *dev,
> + struct mpassthru_port *port)
> +{
> + /* locked by mp_mutex */
> + if (rcu_dereference(dev->mp_port))
> + return -EBUSY;
> +
Please... this is bogus...
Try with following config settings :
CONFIG_PROVE_LOCKING=y
CONFIG_PROVE_RCU=y
CONFIG_PROVE_RCU_REPEATEDLY=y
> + rcu_assign_pointer(dev->mp_port, port);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(netdev_mp_port_attach);
> +
> +void netdev_mp_port_detach(struct net_device *dev)
> +{
> + /* locked by mp_mutex */
> + if (!rcu_dereference(dev->mp_port))
> + return;
same problem here
> +
> + rcu_assign_pointer(dev->mp_port, NULL);
> + synchronize_rcu();
> +}
> +EXPORT_SYMBOL(netdev_mp_port_detach);
> +
> /**
> * netif_receive_skb - process receive buffer from network
> * @skb: buffer to process
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RE: Hey...... Buy an email list of up to 50,000 customers!
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[RFC PATCH v7 04/19] Add a ndo_mp_port_prep pointer to net_device_ops.
From: Xin Xiaohui
If the driver want to allocate external buffers,
then it can export it's capability, as the skb
buffer header length, the page length can be DMA, etc.
The external buffers owner may utilize this.
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
include/linux/netdevice.h |4
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index efb575a..183c786 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -707,6 +707,10 @@ struct net_device_ops {
int (*ndo_fcoe_get_wwn)(struct net_device *dev,
u64 *wwn, int type);
#endif
+#if defined(CONFIG_MEDIATE_PASSTHRU) || defined(CONFIG_MEDIATE_PASSTHRU_MODULE)
+ int (*ndo_mp_port_prep)(struct net_device *dev,
+ struct mpassthru_port *port);
+#endif
};
/*
--
1.5.4.4
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[RFC PATCH v7 05/19] Add a function make external buffer owner to query capability.
From: Xin Xiaohui
The external buffer owner can use the functions to get
the capability of the underlying NIC driver.
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
include/linux/netdevice.h |2 +
net/core/dev.c| 51 +
2 files changed, 53 insertions(+), 0 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 183c786..31d9c4a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1599,6 +1599,8 @@ extern gro_result_t napi_gro_frags(struct
napi_struct *napi);
extern int netdev_mp_port_attach(struct net_device *dev,
struct mpassthru_port *port);
extern void netdev_mp_port_detach(struct net_device *dev);
+extern int netdev_mp_port_prep(struct net_device *dev,
+ struct mpassthru_port *port);
static inline void napi_free_frags(struct napi_struct *napi)
{
diff --git a/net/core/dev.c b/net/core/dev.c
index ecbb6b1..37b389a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2497,6 +2497,57 @@ void netdev_mp_port_detach(struct net_device *dev)
}
EXPORT_SYMBOL(netdev_mp_port_detach);
+/* To support meidate passthru(zero-copy) with NIC driver,
+ * we'd better query NIC driver for the capability it can
+ * provide, especially for packet split mode, now we only
+ * query for the header size, and the payload a descriptor
+ * may carry. If a driver does not use the API to export,
+ * then we may try to use a default value, currently,
+ * we use the default value from an IGB driver. Now,
+ * it's only called by mpassthru device.
+ */
+#if defined(CONFIG_MEDIATE_PASSTHRU) || defined(CONFIG_MEDIATE_PASSTHRU_MODULE)
+int netdev_mp_port_prep(struct net_device *dev,
+ struct mpassthru_port *port)
+{
+ int rc;
+ int npages, data_len;
+ const struct net_device_ops *ops = dev->netdev_ops;
+
+ /* needed by packet split */
+
+ if (ops->ndo_mp_port_prep) {
+ rc = ops->ndo_mp_port_prep(dev, port);
+ if (rc)
+ return rc;
+ } else {
+ /* If the NIC driver did not report this,
+* then we try to use default value.
+*/
+ port->hdr_len = 128;
+ port->data_len = 2048;
+ port->npages = 1;
+ }
+
+ if (port->hdr_len <= 0)
+ goto err;
+
+ npages = port->npages;
+ data_len = port->data_len;
+ if (npages <= 0 || npages > MAX_SKB_FRAGS ||
+ (data_len < PAGE_SIZE * (npages - 1) ||
+data_len > PAGE_SIZE * npages))
+ goto err;
+
+ return 0;
+err:
+ dev_warn(&dev->dev, "invalid page constructor parameters\n");
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(netdev_mp_port_prep);
+#endif
+
/**
* netif_receive_skb - process receive buffer from network
* @skb: buffer to process
--
1.5.4.4
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[RFC PATCH v7 06/19] Add a function to indicate if device use external buffer.
From: Xin Xiaohui
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
include/linux/netdevice.h |5 +
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 31d9c4a..0cb78f4 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1602,6 +1602,11 @@ extern void netdev_mp_port_detach(struct net_device
*dev);
extern int netdev_mp_port_prep(struct net_device *dev,
struct mpassthru_port *port);
+static inline bool dev_is_mpassthru(struct net_device *dev)
+{
+ return (dev && dev->mp_port);
+}
+
static inline void napi_free_frags(struct napi_struct *napi)
{
kfree_skb(napi->skb);
--
1.5.4.4
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[RFC PATCH v7 08/19] Make __alloc_skb() to get external buffer.
From: Xin Xiaohui
Add a dev parameter to __alloc_skb(), skb->data
points to external buffer, recompute skb->head,
maintain shinfo of the external buffer, record
external buffer info into destructor_arg field.
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
__alloc_skb() cleanup by
Jeff Dike
include/linux/skbuff.h |7 ---
net/core/skbuff.c | 43 +--
2 files changed, 41 insertions(+), 9 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 281a1c0..5ff8c27 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -442,17 +442,18 @@ extern void kfree_skb(struct sk_buff *skb);
extern void consume_skb(struct sk_buff *skb);
extern void __kfree_skb(struct sk_buff *skb);
extern struct sk_buff *__alloc_skb(unsigned int size,
- gfp_t priority, int fclone, int node);
+ gfp_t priority, int fclone,
+ int node, struct net_device *dev);
static inline struct sk_buff *alloc_skb(unsigned int size,
gfp_t priority)
{
- return __alloc_skb(size, priority, 0, -1);
+ return __alloc_skb(size, priority, 0, -1, NULL);
}
static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
gfp_t priority)
{
- return __alloc_skb(size, priority, 1, -1);
+ return __alloc_skb(size, priority, 1, -1, NULL);
}
extern int skb_recycle_check(struct sk_buff *skb, int skb_size);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index fbdb1f1..38d19d0 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -161,7 +161,8 @@ EXPORT_SYMBOL(skb_under_panic);
* @fclone: allocate from fclone cache instead of head cache
* and allocate a cloned (child) skb
* @node: numa node to allocate memory on
- *
+ * @dev: a device owns the skb if the skb try to get external buffer.
+ * otherwise is NULL.
* Allocate a new &sk_buff. The returned buffer has no headroom and a
* tail room of size bytes. The object has a reference count of one.
* The return is the buffer. On a failure the return is %NULL.
@@ -170,12 +171,13 @@ EXPORT_SYMBOL(skb_under_panic);
* %GFP_ATOMIC.
*/
struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
- int fclone, int node)
+ int fclone, int node, struct net_device *dev)
{
struct kmem_cache *cache;
struct skb_shared_info *shinfo;
struct sk_buff *skb;
- u8 *data;
+ u8 *data = NULL;
+ struct skb_external_page *ext_page = NULL;
cache = fclone ? skbuff_fclone_cache : skbuff_head_cache;
@@ -185,8 +187,23 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t
gfp_mask,
goto out;
size = SKB_DATA_ALIGN(size);
- data = kmalloc_node_track_caller(size + sizeof(struct skb_shared_info),
- gfp_mask, node);
+
+ /* If the device wants to do mediate passthru(zero-copy),
+* the skb may try to get external buffers from outside.
+* If fails, then fall back to alloc buffers from kernel.
+*/
+ if (dev && dev->mp_port) {
+ ext_page = netdev_alloc_external_page(dev, skb, size);
+ if (ext_page) {
+ data = ext_page->start;
+ size = ext_page->size;
+ }
+ }
+
+ if (!data)
+ data = kmalloc_node_track_caller(
+ size + sizeof(struct skb_shared_info),
+ gfp_mask, node);
if (!data)
goto nodata;
@@ -208,6 +225,15 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t
gfp_mask,
skb->mac_header = ~0U;
#endif
+ /* If the skb get external buffers sucessfully, since the shinfo is
+* at the end of the buffer, we may retain the shinfo once we
+* need it sometime.
+*/
+ if (ext_page) {
+ skb->head = skb->data - NET_IP_ALIGN - NET_SKB_PAD;
+ memcpy(ext_page->ushinfo, skb_shinfo(skb),
+ sizeof(struct skb_shared_info));
+ }
/* make sure we initialize shinfo sequentially */
shinfo = skb_shinfo(skb);
atomic_set(&shinfo->dataref, 1);
@@ -231,6 +257,11 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t
gfp_mask,
child->fclone = SKB_FCLONE_UNAVAILABLE;
}
+ /* Record the external buffer info in this field. It's not so good,
+* but we cannot find another place easily.
+*/
+ shinfo->destructor_arg = ext_page;
+
out:
return skb;
nodata:
@@ -259,7 +290,7 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
int node = dev->dev.parent ? dev_to_node(
[RFC PATCH v7 09/19] Ignore room skb_reserve() when device is using external buffer.
From: Xin Xiaohui
Make the skb->data and skb->head from external buffer
to be consistent, we ignore the room reserved by driver
for kernel skb.
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
include/linux/skbuff.h |9 +
1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 5ff8c27..193b259 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1200,6 +1200,15 @@ static inline int skb_tailroom(const struct sk_buff *skb)
*/
static inline void skb_reserve(struct sk_buff *skb, int len)
{
+ /* Since skb_reserve() is only for an empty buffer,
+* and when the skb is getting external buffer, we cannot
+* retain the external buffer has the same reserved space
+* in the header which kernel allocatd skb has, so have to
+* ignore this. And we have recorded the external buffer
+* info in the destructor_arg field, so use it as indicator.
+*/
+ if (skb_shinfo(skb)->destructor_arg)
+ return;
skb->data += len;
skb->tail += len;
}
--
1.5.4.4
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[RFC PATCH v7 10/19] Don't do skb recycle, if device use external buffer.
From: Xin Xiaohui Signed-off-by: Xin Xiaohui Signed-off-by: Zhao Yu Reviewed-by: Jeff Dike --- net/core/skbuff.c |6 ++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 38d19d0..37587f0 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -553,6 +553,12 @@ int skb_recycle_check(struct sk_buff *skb, int skb_size) if (skb_shared(skb) || skb_cloned(skb)) return 0; + /* if the device wants to do mediate passthru, the skb may +* get external buffer, so don't recycle +*/ + if (dev_is_mpassthru(skb->dev)) + return 0; + skb_release_head_state(skb); shinfo = skb_shinfo(skb); atomic_set(&shinfo->dataref, 1); -- 1.5.4.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[RFC PATCH v7 12/19] Add a hook to intercept external buffers from NIC driver.
From: Xin Xiaohui
The hook is called in netif_receive_skb().
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
net/core/dev.c | 35 +++
1 files changed, 35 insertions(+), 0 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index 37b389a..dc2f225 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2548,6 +2548,37 @@ err:
EXPORT_SYMBOL(netdev_mp_port_prep);
#endif
+#if defined(CONFIG_MEDIATE_PASSTHRU) || defined(CONFIG_MEDIATE_PASSTHRU_MODULE)
+/* Add a hook to intercept mediate passthru(zero-copy) packets,
+ * and insert it to the socket queue owned by mp_port specially.
+ */
+static inline struct sk_buff *handle_mpassthru(struct sk_buff *skb,
+ struct packet_type **pt_prev,
+ int *ret,
+ struct net_device *orig_dev)
+{
+ struct mpassthru_port *mp_port = NULL;
+ struct sock *sk = NULL;
+
+ if (!dev_is_mpassthru(skb->dev))
+ return skb;
+ mp_port = skb->dev->mp_port;
+
+ if (*pt_prev) {
+ *ret = deliver_skb(skb, *pt_prev, orig_dev);
+ *pt_prev = NULL;
+ }
+
+ sk = mp_port->sock->sk;
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_state_change(sk);
+
+ return NULL;
+}
+#else
+#define handle_mpassthru(skb, pt_prev, ret, orig_dev) (skb)
+#endif
+
/**
* netif_receive_skb - process receive buffer from network
* @skb: buffer to process
@@ -2629,6 +2660,10 @@ int netif_receive_skb(struct sk_buff *skb)
ncls:
#endif
+ /* To intercept mediate passthru(zero-copy) packets here */
+ skb = handle_mpassthru(skb, &pt_prev, &ret, orig_dev);
+ if (!skb)
+ goto out;
skb = handle_bridge(skb, &pt_prev, &ret, orig_dev);
if (!skb)
goto out;
--
1.5.4.4
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[RFC PATCH v7 15/19] Add basic funcs and ioctl to mp device.
From: Xin Xiaohui
The ioctl is used by mp device to bind an underlying
NIC, it will query hardware capability and declare the
NIC to use external buffers.
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
memory leak fixed,
kconfig made,
do_unbind() made,
mp_chr_ioctl() cleanup
by Jeff Dike
drivers/vhost/mpassthru.c | 681 +
1 files changed, 681 insertions(+), 0 deletions(-)
create mode 100644 drivers/vhost/mpassthru.c
diff --git a/drivers/vhost/mpassthru.c b/drivers/vhost/mpassthru.c
new file mode 100644
index 000..25e2f3e
--- /dev/null
+++ b/drivers/vhost/mpassthru.c
@@ -0,0 +1,681 @@
+/*
+ * MPASSTHRU - Mediate passthrough device.
+ * Copyright (C) 2009 ZhaoYu, XinXiaohui, Dike, Jeffery G
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#define DRV_NAME"mpassthru"
+#define DRV_DESCRIPTION "Mediate passthru device driver"
+#define DRV_COPYRIGHT "(C) 2009 ZhaoYu, XinXiaohui, Dike, Jeffery G"
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#include
+
+/* Uncomment to enable debugging */
+/* #define MPASSTHRU_DEBUG 1 */
+
+#ifdef MPASSTHRU_DEBUG
+static int debug;
+
+#define DBG if (mp->debug) printk
+#define DBG1 if (debug == 2) printk
+#else
+#define DBG(a...)
+#define DBG1(a...)
+#endif
+
+#define COPY_THRESHOLD (L1_CACHE_BYTES * 4)
+#define COPY_HDR_LEN (L1_CACHE_BYTES < 64 ? 64 : L1_CACHE_BYTES)
+
+struct frag {
+ u16 offset;
+ u16 size;
+};
+
+struct page_info {
+ struct list_headlist;
+ int header;
+ /* indicate the actual length of bytes
+* send/recv in the external buffers
+*/
+ int total;
+ int offset;
+ struct page *pages[MAX_SKB_FRAGS+1];
+ struct skb_frag_struct frag[MAX_SKB_FRAGS+1];
+ struct sk_buff *skb;
+ struct page_ctor*ctor;
+
+ /* The pointer relayed to skb, to indicate
+* it's a external allocated skb or kernel
+*/
+ struct skb_external_pageext_page;
+ struct skb_shared_info ushinfo;
+
+#define INFO_READ 0
+#define INFO_WRITE 1
+ unsignedflags;
+ unsignedpnum;
+
+ /* It's meaningful for receive, means
+* the max length allowed
+*/
+ size_t len;
+
+ /* The fields after that is for backend
+* driver, now for vhost-net.
+*/
+
+ struct kiocb*iocb;
+ unsigned intdesc_pos;
+ struct iovechdr[MAX_SKB_FRAGS + 2];
+ struct ioveciov[MAX_SKB_FRAGS + 2];
+};
+
+static struct kmem_cache *ext_page_info_cache;
+
+struct page_ctor {
+ struct list_headreadq;
+ int wq_len;
+ int rq_len;
+ spinlock_t read_lock;
+ /* record the locked pages */
+ int lock_pages;
+ struct rlimit o_rlim;
+ struct net_device *dev;
+ struct mpassthru_port port;
+};
+
+struct mp_struct {
+ struct mp_file *mfile;
+ struct net_device *dev;
+ struct page_ctor*ctor;
+ struct socket socket;
+
+#ifdef MPASSTHRU_DEBUG
+ int debug;
+#endif
+};
+
+struct mp_file {
+ atomic_t count;
+ struct mp_struct *mp;
+ struct net *net;
+};
+
+struct mp_sock {
+ struct sock sk;
+ struct mp_struct*mp;
+};
+
+static int mp_dev_change_flags(struct net_device *dev, unsigned flags)
+{
+ int ret = 0;
+
+ rtnl_lock();
+ ret = dev_change_flags(dev, flags);
+ rtnl_unlock();
+
+ if (ret < 0)
+ printk(KERN_ERR "failed to change dev state of %s", dev->name);
+
+ return ret;
+}
+
+static int page_ctor_attach(struct mp_struct *mp)
+{
+ int rc;
+ struct page_ctor *ctor;
+ struct net_device *dev = mp->dev;
+
+ /* locked by mp_mutex */
+ if (rcu_dereference(mp->ctor))
+ return -EBU
[RFC PATCH v7 13/19] To skip GRO if buffer is external currently.
From: Xin Xiaohui
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
net/core/dev.c |4
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index dc2f225..6c6b2fe 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2787,6 +2787,10 @@ enum gro_result dev_gro_receive(struct napi_struct
*napi, struct sk_buff *skb)
if (skb_is_gso(skb) || skb_has_frags(skb))
goto normal;
+ /* currently GRO is not supported by mediate passthru */
+ if (dev_is_mpassthru(skb->dev))
+ goto normal;
+
rcu_read_lock();
list_for_each_entry_rcu(ptype, head, list) {
if (ptype->type != type || ptype->dev || !ptype->gro_receive)
--
1.5.4.4
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[RFC PATCH v7 16/19] Manipulate external buffers in mp device.
From: Xiaohui Xin
How external buffer comes from, how to destroy.
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
drivers/vhost/mpassthru.c | 253 -
1 files changed, 251 insertions(+), 2 deletions(-)
diff --git a/drivers/vhost/mpassthru.c b/drivers/vhost/mpassthru.c
index 25e2f3e..8c48898 100644
--- a/drivers/vhost/mpassthru.c
+++ b/drivers/vhost/mpassthru.c
@@ -161,6 +161,39 @@ static int mp_dev_change_flags(struct net_device *dev,
unsigned flags)
return ret;
}
+/* The main function to allocate external buffers */
+static struct skb_external_page *page_ctor(struct mpassthru_port *port,
+ struct sk_buff *skb, int npages)
+{
+ int i;
+ unsigned long flags;
+ struct page_ctor *ctor;
+ struct page_info *info = NULL;
+
+ ctor = container_of(port, struct page_ctor, port);
+
+ spin_lock_irqsave(&ctor->read_lock, flags);
+ if (!list_empty(&ctor->readq)) {
+ info = list_first_entry(&ctor->readq, struct page_info, list);
+ list_del(&info->list);
+ }
+ spin_unlock_irqrestore(&ctor->read_lock, flags);
+ if (!info)
+ return NULL;
+
+ for (i = 0; i < info->pnum; i++) {
+ get_page(info->pages[i]);
+ info->frag[i].page = info->pages[i];
+ info->frag[i].page_offset = i ? 0 : info->offset;
+ info->frag[i].size = port->npages > 1 ? PAGE_SIZE :
+ port->data_len;
+ }
+ info->skb = skb;
+ info->ext_page.frags = info->frag;
+ info->ext_page.ushinfo = &info->ushinfo;
+ return &info->ext_page;
+}
+
static int page_ctor_attach(struct mp_struct *mp)
{
int rc;
@@ -186,7 +219,7 @@ static int page_ctor_attach(struct mp_struct *mp)
dev_hold(dev);
ctor->dev = dev;
- ctor->port.ctor = NULL;
+ ctor->port.ctor = page_ctor;
ctor->port.sock = &mp->socket;
ctor->lock_pages = 0;
rc = netdev_mp_port_attach(dev, &ctor->port);
@@ -252,11 +285,66 @@ static int set_memlock_rlimit(struct page_ctor *ctor, int
resource,
return 0;
}
+static void relinquish_resource(struct page_ctor *ctor)
+{
+ if (!(ctor->dev->flags & IFF_UP) &&
+ !(ctor->wq_len + ctor->rq_len))
+ printk(KERN_INFO "relinquish_resource\n");
+}
+
+static void mp_ki_dtor(struct kiocb *iocb)
+{
+ struct page_info *info = (struct page_info *)(iocb->private);
+ int i;
+
+ if (info->flags == INFO_READ) {
+ for (i = 0; i < info->pnum; i++) {
+ if (info->pages[i]) {
+ set_page_dirty_lock(info->pages[i]);
+ put_page(info->pages[i]);
+ }
+ }
+ info->skb->destructor = NULL;
+ kfree_skb(info->skb);
+ info->ctor->rq_len--;
+ } else
+ info->ctor->wq_len--;
+ /* Decrement the number of locked pages */
+ info->ctor->lock_pages -= info->pnum;
+ kmem_cache_free(ext_page_info_cache, info);
+ relinquish_resource(info->ctor);
+
+ return;
+}
+
+static struct kiocb *create_iocb(struct page_info *info, int size)
+{
+ struct kiocb *iocb = NULL;
+
+ iocb = info->iocb;
+ if (!iocb)
+ return iocb;
+ iocb->ki_flags = 0;
+ iocb->ki_users = 1;
+ iocb->ki_key = 0;
+ iocb->ki_ctx = NULL;
+ iocb->ki_cancel = NULL;
+ iocb->ki_retry = NULL;
+ iocb->ki_iovec = NULL;
+ iocb->ki_eventfd = NULL;
+ iocb->ki_pos = info->desc_pos;
+ iocb->ki_nbytes = size;
+ iocb->ki_dtor(iocb);
+ iocb->private = (void *)info;
+ iocb->ki_dtor = mp_ki_dtor;
+
+ return iocb;
+}
+
static int page_ctor_detach(struct mp_struct *mp)
{
struct page_ctor *ctor;
struct page_info *info;
- struct kiocb *iocb = NULL;
int i;
/* locked by mp_mutex */
@@ -268,11 +356,17 @@ static int page_ctor_detach(struct mp_struct *mp)
for (i = 0; i < info->pnum; i++)
if (info->pages[i])
put_page(info->pages[i]);
+ create_iocb(info, 0);
+ ctor->rq_len--;
kmem_cache_free(ext_page_info_cache, info);
}
+
+ relinquish_resource(ctor);
+
set_memlock_rlimit(ctor, RLIMIT_MEMLOCK,
ctor->o_rlim.rlim_cur,
ctor->o_rlim.rlim_max);
+
netdev_mp_port_detach(ctor->dev);
dev_put(ctor->dev);
@@ -320,6 +414,161 @@ static void mp_put(struct mp_file *mfile)
mp_detach(mfile->mp);
}
+/* The callback to destruct the external buffers or skb */
+static void page_dtor(struct skb_external_page *ext_page)
+{
+ struct page_info *info;
+ struct
[RFC PATCH v7 17/19] Export proto_ops to vhost-net driver.
From: Xin Xiaohui
Currently, vhost-net is only user to the mp device.
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
drivers/vhost/mpassthru.c | 295 -
1 files changed, 290 insertions(+), 5 deletions(-)
diff --git a/drivers/vhost/mpassthru.c b/drivers/vhost/mpassthru.c
index 8c48898..23755ba 100644
--- a/drivers/vhost/mpassthru.c
+++ b/drivers/vhost/mpassthru.c
@@ -414,6 +414,11 @@ static void mp_put(struct mp_file *mfile)
mp_detach(mfile->mp);
}
+static void iocb_tag(struct kiocb *iocb)
+{
+ iocb->ki_flags = 1;
+}
+
/* The callback to destruct the external buffers or skb */
static void page_dtor(struct skb_external_page *ext_page)
{
@@ -449,7 +454,7 @@ static void page_dtor(struct skb_external_page *ext_page)
* Queue the notifier to wake up the backend driver
*/
- create_iocb(info, info->total);
+ iocb_tag(info->iocb);
sk = ctor->port.sock->sk;
sk->sk_write_space(sk);
@@ -569,8 +574,288 @@ failed:
return NULL;
}
+static void mp_sock_destruct(struct sock *sk)
+{
+ struct mp_struct *mp = container_of(sk, struct mp_sock, sk)->mp;
+ kfree(mp);
+}
+
+static void mp_sock_state_change(struct sock *sk)
+{
+ if (sk_has_sleeper(sk))
+ wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN);
+}
+
+static void mp_sock_write_space(struct sock *sk)
+{
+ if (sk_has_sleeper(sk))
+ wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT);
+}
+
+static void mp_sock_data_ready(struct sock *sk, int coming)
+{
+ struct mp_struct *mp = container_of(sk, struct mp_sock, sk)->mp;
+ struct page_ctor *ctor = NULL;
+ struct sk_buff *skb = NULL;
+ struct page_info *info = NULL;
+ struct ethhdr *eth;
+ struct kiocb *iocb = NULL;
+ int len, i;
+
+ struct virtio_net_hdr hdr = {
+ .flags = 0,
+ .gso_type = VIRTIO_NET_HDR_GSO_NONE
+ };
+
+ ctor = rcu_dereference(mp->ctor);
+ if (!ctor)
+ return;
+
+ while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+ if (skb_shinfo(skb)->destructor_arg) {
+ info = container_of(skb_shinfo(skb)->destructor_arg,
+ struct page_info, ext_page);
+ info->skb = skb;
+ if (skb->len > info->len) {
+ mp->dev->stats.rx_dropped++;
+ DBG(KERN_INFO "Discarded truncated rx packet: "
+ " len %d > %zd\n", skb->len, info->len);
+ info->total = skb->len;
+ goto clean;
+ } else {
+ eth = eth_hdr(skb);
+ skb_push(skb, ETH_HLEN);
+ info->total = skb->len;
+ }
+ } else {
+ /* The skb composed with kernel buffers
+* in case external buffers are not sufficent.
+* The case should be rare.
+*/
+ unsigned long flags;
+ int i;
+ info = NULL;
+
+ spin_lock_irqsave(&ctor->read_lock, flags);
+ if (!list_empty(&ctor->readq)) {
+ info = list_first_entry(&ctor->readq,
+ struct page_info, list);
+ list_del(&info->list);
+ }
+ spin_unlock_irqrestore(&ctor->read_lock, flags);
+ if (!info) {
+ DBG(KERN_INFO
+ "No external buffer avaliable %p\n",
+ skb);
+ skb_queue_head(&sk->sk_receive_queue,
+ skb);
+ break;
+ }
+ info->skb = skb;
+ eth = eth_hdr(skb);
+ skb_push(skb, ETH_HLEN);
+ info->total = skb->len;
+ skb_copy_datagram_iovec(skb, 0, info->iov, skb->len);
+ }
+
+ len = memcpy_toiovec(info->hdr, (unsigned char *)&hdr,
+ sizeof hdr);
+ if (len) {
+ DBG(KERN_INFO
+ "Unable to write vnet_hdr at addr %p: %d\n",
+ info->hdr->iov_base, len);
+ goto clean;
+ }
+
+ iocb = create_iocb(info, skb->len + sizeof(hdr));
+ continue;
+
+clean:
+ kfree_skb(skb);
+ for
[RFC PATCH v7 00/19] Provide a zero-copy method on KVM virtio-net.
We provide an zero-copy method which driver side may get external buffers to DMA. Here external means driver don't use kernel space to allocate skb buffers. Currently the external buffer can be from guest virtio-net driver. The idea is simple, just to pin the guest VM user space and then let host NIC driver has the chance to directly DMA to it. The patches are based on vhost-net backend driver. We add a device which provides proto_ops as sendmsg/recvmsg to vhost-net to send/recv directly to/from the NIC driver. KVM guest who use the vhost-net backend may bind any ethX interface in the host side to get copyless data transfer thru guest virtio-net frontend. patch 01-13:net core changes. patch 14-18:new device as interface to mantpulate external buffers. patch 19: for vhost-net. The guest virtio-net driver submits multiple requests thru vhost-net backend driver to the kernel. And the requests are queued and then completed after corresponding actions in h/w are done. For read, user space buffers are dispensed to NIC driver for rx when a page constructor API is invoked. Means NICs can allocate user buffers from a page constructor. We add a hook in netif_receive_skb() function to intercept the incoming packets, and notify the zero-copy device. For write, the zero-copy deivce may allocates a new host skb and puts payload on the skb_shinfo(skb)->frags, and copied the header to skb->data. The request remains pending until the skb is transmitted by h/w. Here, we have ever considered 2 ways to utilize the page constructor API to dispense the user buffers. One:Modify __alloc_skb() function a bit, it can only allocate a structure of sk_buff, and the data pointer is pointing to a user buffer which is coming from a page constructor API. Then the shinfo of the skb is also from guest. When packet is received from hardware, the skb->data is filled directly by h/w. What we have done is in this way. Pros: We can avoid any copy here. Cons: Guest virtio-net driver needs to allocate skb as almost the same method with the host NIC drivers, say the size of netdev_alloc_skb() and the same reserved space in the head of skb. Many NIC drivers are the same with guest and ok for this. But some lastest NIC drivers reserves special room in skb head. To deal with it, we suggest to provide a method in guest virtio-net driver to ask for parameter we interest from the NIC driver when we know which device we have bind to do zero-copy. Then we ask guest to do so. Two:Modify driver to get user buffer allocated from a page constructor API(to substitute alloc_page()), the user buffer are used as payload buffers and filled by h/w directly when packet is received. Driver should associate the pages with skb (skb_shinfo(skb)->frags). For the head buffer side, let host allocates skb, and h/w fills it. After that, the data filled in host skb header will be copied into guest header buffer which is submitted together with the payload buffer. Pros: We could less care the way how guest or host allocates their buffers. Cons: We still need a bit copy here for the skb header. We are not sure which way is the better here. This is the first thing we want to get comments from the community. We wish the modification to the network part will be generic which not used by vhost-net backend only, but a user application may use it as well when the zero-copy device may provides async read/write operations later. We have got comments from Michael. And he said the first method will break the compatiblity of virtio-net driver and may complicate the qemu live migration. Currently, we tried to ignore the skb_reserve() if the device is doing zero-copy. Then guest virtio-net driver wil not changed. So we now continue to go with the first way. But comments about the two ways are still appreicated. We provide multiple submits and asynchronous notifiicaton to vhost-net too. Our goal is to improve the bandwidth and reduce the CPU usage. Exact performance data will be provided later. But for simple test with netperf, we found bindwidth up and CPU % up too, but the bindwidth up ratio is much more than CPU % up ratio. What we have not done yet: packet split support To support GRO Performance tuning what we have done in v1: polish the RCU usage deal with write logging in asynchroush mode in vhost add notifier block for mp device rename page_ctor to mp_port in netdevice.h to make it looks generic add mp_dev_change_flags() for mp device to change NIC state add CONIFG_VHOST_MPASSTHRU to limit the usage when module is not load a small fix for missing dev_put when fail usin
[RFC PATCH v7 19/19] Provides multiple submits and asynchronous notifications.
From: Xin Xiaohui
The vhost-net backend now only supports synchronous send/recv
operations. The patch provides multiple submits and asynchronous
notifications. This is needed for zero-copy case.
Signed-off-by: Xin Xiaohui
---
drivers/vhost/net.c | 255 -
drivers/vhost/vhost.c | 120 +--
drivers/vhost/vhost.h | 14 +++
3 files changed, 333 insertions(+), 56 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 9777583..9a0d162 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -24,6 +24,8 @@
#include
#include
#include
+#include
+#include
#include
@@ -45,10 +47,13 @@ enum vhost_net_poll_state {
VHOST_NET_POLL_STOPPED = 2,
};
+static struct kmem_cache *notify_cache;
+
struct vhost_net {
struct vhost_dev dev;
struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX];
struct vhost_poll poll[VHOST_NET_VQ_MAX];
+ struct kmem_cache *cache;
/* Tells us whether we are polling a socket for TX.
* We only do this when socket buffer fills up.
* Protected by tx vq lock. */
@@ -93,11 +98,146 @@ static void tx_poll_start(struct vhost_net *net, struct
socket *sock)
net->tx_poll_state = VHOST_NET_POLL_STARTED;
}
+struct kiocb *notify_dequeue(struct vhost_virtqueue *vq)
+{
+ struct kiocb *iocb = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vq->notify_lock, flags);
+ if (!list_empty(&vq->notifier)) {
+ iocb = list_first_entry(&vq->notifier,
+ struct kiocb, ki_list);
+ list_del(&iocb->ki_list);
+ }
+ spin_unlock_irqrestore(&vq->notify_lock, flags);
+ return iocb;
+}
+
+static void handle_iocb(struct kiocb *iocb)
+{
+ struct vhost_virtqueue *vq = iocb->private;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vq->notify_lock, flags);
+ list_add_tail(&iocb->ki_list, &vq->notifier);
+ spin_unlock_irqrestore(&vq->notify_lock, flags);
+}
+
+static int is_async_vq(struct vhost_virtqueue *vq)
+{
+ return (vq->link_state == VHOST_VQ_LINK_ASYNC);
+}
+
+static void handle_async_rx_events_notify(struct vhost_net *net,
+ struct vhost_virtqueue *vq,
+ struct socket *sock)
+{
+ struct kiocb *iocb = NULL;
+ struct vhost_log *vq_log = NULL;
+ int rx_total_len = 0;
+ unsigned int head, log, in, out;
+ int size;
+
+ if (!is_async_vq(vq))
+ return;
+
+ if (sock->sk->sk_data_ready)
+ sock->sk->sk_data_ready(sock->sk, 0);
+
+ vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
+ vq->log : NULL;
+
+ while ((iocb = notify_dequeue(vq)) != NULL) {
+ vhost_add_used_and_signal(&net->dev, vq,
+ iocb->ki_pos, iocb->ki_nbytes);
+ size = iocb->ki_nbytes;
+ head = iocb->ki_pos;
+ rx_total_len += iocb->ki_nbytes;
+
+ if (iocb->ki_dtor)
+ iocb->ki_dtor(iocb);
+ kmem_cache_free(net->cache, iocb);
+
+ /* when log is enabled, recomputing the log info is needed,
+* since these buffers are in async queue, and may not get
+* the log info before.
+*/
+ if (unlikely(vq_log)) {
+ if (!log)
+ __vhost_get_vq_desc(&net->dev, vq, vq->iov,
+ ARRAY_SIZE(vq->iov),
+ &out, &in, vq_log,
+ &log, head);
+ vhost_log_write(vq, vq_log, log, size);
+ }
+ if (unlikely(rx_total_len >= VHOST_NET_WEIGHT)) {
+ vhost_poll_queue(&vq->poll);
+ break;
+ }
+ }
+}
+
+static void handle_async_tx_events_notify(struct vhost_net *net,
+ struct vhost_virtqueue *vq)
+{
+ struct kiocb *iocb = NULL;
+ struct list_head *entry, *tmp;
+ unsigned long flags;
+ int tx_total_len = 0;
+
+ if (!is_async_vq(vq))
+ return;
+ spin_lock_irqsave(&vq->notify_lock, flags);
+ list_for_each_safe(entry, tmp, &vq->notifier) {
+ iocb = list_entry(entry,
+struct kiocb, ki_list);
+ if (!iocb->ki_flags)
+ continue;
+ list_del(&iocb->ki_list);
+ vhost_add_used_and_signal(&net->dev, vq,
+ iocb->ki_pos, 0);
+ tx_total_len += iocb->ki_nbytes;
+
+ if (iocb->ki_dtor)
+ iocb->ki_dtor(iocb);
+
+
[RFC PATCH v7 18/19] Add a kconfig entry and make entry for mp device.
From: Xin Xiaohui Signed-off-by: Xin Xiaohui Reviewed-by: Jeff Dike --- drivers/vhost/Kconfig | 10 ++ drivers/vhost/Makefile |2 ++ 2 files changed, 12 insertions(+), 0 deletions(-) diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig index e4e2fd1..a6b8cbf 100644 --- a/drivers/vhost/Kconfig +++ b/drivers/vhost/Kconfig @@ -9,3 +9,13 @@ config VHOST_NET To compile this driver as a module, choose M here: the module will be called vhost_net. +config MEDIATE_PASSTHRU + tristate "mediate passthru network driver (EXPERIMENTAL)" + depends on VHOST_NET + ---help--- + zerocopy network I/O support, we call it as mediate passthru to + be distiguish with hardare passthru. + + To compile this driver as a module, choose M here: the module will + be called mpassthru. + diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile index 72dd020..c18b9fc 100644 --- a/drivers/vhost/Makefile +++ b/drivers/vhost/Makefile @@ -1,2 +1,4 @@ obj-$(CONFIG_VHOST_NET) += vhost_net.o vhost_net-y := vhost.o net.o + +obj-$(CONFIG_MEDIATE_PASSTHRU) += mpassthru.o -- 1.5.4.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[RFC PATCH v7 14/19] Add header file for mp device.
From: Xin Xiaohui
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
include/linux/mpassthru.h | 25 +
1 files changed, 25 insertions(+), 0 deletions(-)
create mode 100644 include/linux/mpassthru.h
diff --git a/include/linux/mpassthru.h b/include/linux/mpassthru.h
new file mode 100644
index 000..ba8f320
--- /dev/null
+++ b/include/linux/mpassthru.h
@@ -0,0 +1,25 @@
+#ifndef __MPASSTHRU_H
+#define __MPASSTHRU_H
+
+#include
+#include
+
+/* ioctl defines */
+#define MPASSTHRU_BINDDEV _IOW('M', 213, int)
+#define MPASSTHRU_UNBINDDEV_IO('M', 214)
+
+#ifdef __KERNEL__
+#if defined(CONFIG_MEDIATE_PASSTHRU) || defined(CONFIG_MEDIATE_PASSTHRU_MODULE)
+struct socket *mp_get_socket(struct file *);
+#else
+#include
+#include
+struct file;
+struct socket;
+static inline struct socket *mp_get_socket(struct file *f)
+{
+ return ERR_PTR(-EINVAL);
+}
+#endif /* CONFIG_MEDIATE_PASSTHRU */
+#endif /* __KERNEL__ */
+#endif /* __MPASSTHRU_H */
--
1.5.4.4
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[RFC PATCH v7 11/19] Use callback to deal with skb_release_data() specially.
From: Xin Xiaohui
If buffer is external, then use the callback to destruct
buffers.
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
net/core/skbuff.c | 11 +++
1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 37587f0..418457c 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -385,6 +385,11 @@ static void skb_clone_fraglist(struct sk_buff *skb)
static void skb_release_data(struct sk_buff *skb)
{
+ /* check if the skb has external buffers, we have use destructor_arg
+* here to indicate
+*/
+ struct skb_external_page *ext_page = skb_shinfo(skb)->destructor_arg;
+
if (!skb->cloned ||
!atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1,
&skb_shinfo(skb)->dataref)) {
@@ -397,6 +402,12 @@ static void skb_release_data(struct sk_buff *skb)
if (skb_has_frags(skb))
skb_drop_fraglist(skb);
+ /* if the skb has external buffers, use destructor here,
+* since after that skb->head will be kfree, in case skb->head
+* from external buffer cannot use kfree to destroy.
+*/
+ if (dev_is_mpassthru(skb->dev) && ext_page && ext_page->dtor)
+ ext_page->dtor(ext_page);
kfree(skb->head);
}
}
--
1.5.4.4
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[RFC PATCH v7 07/19] Add interface to get external buffers.
From: Xin Xiaohui
Currently, it can get external buffers from mp device.
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
include/linux/skbuff.h | 12
net/core/skbuff.c | 16
2 files changed, 28 insertions(+), 0 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index cf309c9..281a1c0 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1519,6 +1519,18 @@ static inline void netdev_free_page(struct net_device
*dev, struct page *page)
__free_page(page);
}
+extern struct skb_external_page *netdev_alloc_external_pages(
+ struct net_device *dev,
+ struct sk_buff *skb, int npages);
+
+static inline struct skb_external_page *netdev_alloc_external_page(
+ struct net_device *dev,
+ struct sk_buff *skb, unsigned int size)
+{
+ return netdev_alloc_external_pages(dev, skb,
+ DIV_ROUND_UP(size, PAGE_SIZE));
+}
+
/**
* skb_clone_writable - is the header of a clone writable
* @skb: buffer to check
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 93c4e06..fbdb1f1 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -278,6 +278,22 @@ struct page *__netdev_alloc_page(struct net_device *dev,
gfp_t gfp_mask)
}
EXPORT_SYMBOL(__netdev_alloc_page);
+struct skb_external_page *netdev_alloc_external_pages(struct net_device *dev,
+ struct sk_buff *skb, int npages)
+{
+ struct mpassthru_port *port;
+ struct skb_external_page *ext_page = NULL;
+
+ port = rcu_dereference(dev->mp_port);
+ if (!port)
+ goto out;
+ WARN_ON(npages > port->npages);
+ ext_page = port->ctor(port, skb, npages);
+out:
+ return ext_page;
+}
+EXPORT_SYMBOL(netdev_alloc_external_pages);
+
void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
int size)
{
--
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[RFC PATCH v7 02/19] Add a new struct for device to manipulate external buffer.
From: Xin Xiaohui
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
include/linux/netdevice.h | 19 ++-
1 files changed, 18 insertions(+), 1 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index fa8b476..bae725c 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -530,6 +530,22 @@ struct netdev_queue {
unsigned long tx_dropped;
} cacheline_aligned_in_smp;
+/* Add a structure in structure net_device, the new field is
+ * named as mp_port. It's for mediate passthru (zero-copy).
+ * It contains the capability for the net device driver,
+ * a socket, and an external buffer creator, external means
+ * skb buffer belongs to the device may not be allocated from
+ * kernel space.
+ */
+struct mpassthru_port {
+ int hdr_len;
+ int data_len;
+ int npages;
+ unsignedflags;
+ struct socket *sock;
+ struct skb_external_page *(*ctor)(struct mpassthru_port *,
+ struct sk_buff *, int);
+};
/*
* This structure defines the management hooks for network devices.
@@ -952,7 +968,8 @@ struct net_device {
struct macvlan_port *macvlan_port;
/* GARP */
struct garp_port*garp_port;
-
+ /* mpassthru */
+ struct mpassthru_port *mp_port;
/* class/net/name entry */
struct device dev;
/* space for optional device, statistics, and wireless sysfs groups */
--
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[RFC PATCH v7 01/19] Add a new structure for skb buffer from external.
From: Xin Xiaohui
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
include/linux/skbuff.h | 12
1 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 124f90c..cf309c9 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -203,6 +203,18 @@ struct skb_shared_info {
void * destructor_arg;
};
+/* The structure is for a skb which skb->data may point to
+ * an external buffer, which is not allocated from kernel space.
+ * Since the buffer is external, then the shinfo or frags are
+ * also extern too. It also contains a destructor for itself.
+ */
+struct skb_external_page {
+ u8 *start;
+ int size;
+ struct skb_frag_struct *frags;
+ struct skb_shared_info *ushinfo;
+ void(*dtor)(struct skb_external_page *);
+};
/* We divide dataref into two halves. The higher 16 bits hold references
* to the payload part of skb->data. The lower 16 bits hold references to
* the entire skb->data. A clone of a headerless skb holds the length of
--
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[RFC PATCH v7 03/19] Export 2 func for device to assign/deassign new strucure
From: Xin Xiaohui
Signed-off-by: Xin Xiaohui
Signed-off-by: Zhao Yu
Reviewed-by: Jeff Dike
---
include/linux/netdevice.h |3 +++
net/core/dev.c| 28
2 files changed, 31 insertions(+), 0 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index bae725c..efb575a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1592,6 +1592,9 @@ extern gro_result_t napi_frags_finish(struct
napi_struct *napi,
gro_result_t ret);
extern struct sk_buff *napi_frags_skb(struct napi_struct *napi);
extern gro_result_tnapi_gro_frags(struct napi_struct *napi);
+extern int netdev_mp_port_attach(struct net_device *dev,
+struct mpassthru_port *port);
+extern void netdev_mp_port_detach(struct net_device *dev);
static inline void napi_free_frags(struct napi_struct *napi)
{
diff --git a/net/core/dev.c b/net/core/dev.c
index f769098..ecbb6b1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2469,6 +2469,34 @@ void netif_nit_deliver(struct sk_buff *skb)
rcu_read_unlock();
}
+/* Export two functions to assign/de-assign mp_port pointer
+ * to a net device.
+ */
+
+int netdev_mp_port_attach(struct net_device *dev,
+ struct mpassthru_port *port)
+{
+ /* locked by mp_mutex */
+ if (rcu_dereference(dev->mp_port))
+ return -EBUSY;
+
+ rcu_assign_pointer(dev->mp_port, port);
+
+ return 0;
+}
+EXPORT_SYMBOL(netdev_mp_port_attach);
+
+void netdev_mp_port_detach(struct net_device *dev)
+{
+ /* locked by mp_mutex */
+ if (!rcu_dereference(dev->mp_port))
+ return;
+
+ rcu_assign_pointer(dev->mp_port, NULL);
+ synchronize_rcu();
+}
+EXPORT_SYMBOL(netdev_mp_port_detach);
+
/**
* netif_receive_skb - process receive buffer from network
* @skb: buffer to process
--
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Re: [Qemu-devel] [PATCH v6 5/6] Inter-VM shared memory PCI device
On Fri, Jun 4, 2010 at 9:45 PM, Cam Macdonell wrote:
> Support an inter-vm shared memory device that maps a shared-memory object as a
> PCI device in the guest. This patch also supports interrupts between guest by
> communicating over a unix domain socket. This patch applies to the qemu-kvm
> repository.
>
> -device ivshmem,size=[,shm=]
>
> Interrupts are supported between multiple VMs by using a shared memory server
> by using a chardev socket.
>
> -device ivshmem,size=[,shm=]
> [,chardev=][,msi=on][,irqfd=on][,vectors=n][,role=peer|master]
> -chardev socket,path=,id=
>
> (shared memory server is qemu.git/contrib/ivshmem-server)
>
> Sample programs and init scripts are in a git repo here:
>
> www.gitorious.org/nahanni
> ---
> Makefile.target | 3 +
> hw/ivshmem.c | 852
> +++
> qemu-char.c | 6 +
> qemu-char.h | 3 +
> qemu-doc.texi | 43 +++
> 5 files changed, 907 insertions(+), 0 deletions(-)
> create mode 100644 hw/ivshmem.c
>
> diff --git a/Makefile.target b/Makefile.target
> index c4ba592..4888308 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -202,6 +202,9 @@ obj-$(CONFIG_USB_OHCI) += usb-ohci.o
> obj-y += rtl8139.o
> obj-y += e1000.o
>
> +# Inter-VM PCI shared memory
> +obj-y += ivshmem.o
> +
Can this be compiled once, simply by moving this to Makefile.objs
instead of Makefile.target? Also, because the code seems to be KVM
specific, it can't be compiled unconditionally but depending on at
least CONFIG_KVM and maybe CONFIG_EVENTFD.
Why is this KVM specific BTW, Posix SHM is available on many
platforms? What would happen if kvm_set_foobar functions were not
called when KVM is not being used? Is host eventfd support essential?
> # Hardware support
> obj-i386-y += vga.o
> obj-i386-y += mc146818rtc.o i8259.o pc.o
> diff --git a/hw/ivshmem.c b/hw/ivshmem.c
> new file mode 100644
> index 000..9057612
> --- /dev/null
> +++ b/hw/ivshmem.c
> @@ -0,0 +1,852 @@
> +/*
> + * Inter-VM Shared Memory PCI device.
> + *
> + * Author:
> + * Cam Macdonell
> + *
> + * Based On: cirrus_vga.c
> + * Copyright (c) 2004 Fabrice Bellard
> + * Copyright (c) 2004 Makoto Suzuki (suzu)
> + *
> + * and rtl8139.c
> + * Copyright (c) 2006 Igor Kovalenko
> + *
> + * This code is licensed under the GNU GPL v2.
> + */
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include "hw.h"
> +#include "console.h"
> +#include "pc.h"
> +#include "pci.h"
> +#include "sysemu.h"
> +
> +#include "msix.h"
> +#include "qemu-kvm.h"
> +#include "libkvm.h"
> +
> +#include
> +#include
> +#include
> +#include
> +
> +#define IVSHMEM_IRQFD 0
> +#define IVSHMEM_MSI 1
> +
> +//#define DEBUG_IVSHMEM
> +#ifdef DEBUG_IVSHMEM
> +#define IVSHMEM_DPRINTF(fmt, args...) \
> + do {printf("IVSHMEM: " fmt, ##args); } while (0)
Please use __VA_ARGS__.
> +#else
> +#define IVSHMEM_DPRINTF(fmt, args...)
> +#endif
> +
> +typedef struct Peer {
> + int nb_eventfds;
> + int *eventfds;
> +} Peer;
> +
> +typedef struct EventfdEntry {
> + PCIDevice *pdev;
> + int vector;
> +} EventfdEntry;
> +
> +typedef struct IVShmemState {
> + PCIDevice dev;
> + uint32_t intrmask;
> + uint32_t intrstatus;
> + uint32_t doorbell;
> +
> + CharDriverState ** eventfd_chr;
I'd remove the space between '**' and 'eventfd_chr', it's used inconsistently.
> + CharDriverState * server_chr;
> + int ivshmem_mmio_io_addr;
> +
> + pcibus_t mmio_addr;
> + pcibus_t shm_pci_addr;
> + uint64_t ivshmem_offset;
> + uint64_t ivshmem_size; /* size of shared memory region */
> + int shm_fd; /* shared memory file descriptor */
> +
> + Peer *peers;
> + int nb_peers; /* how many guests we have space for */
> + int max_peer; /* maximum numbered peer */
> +
> + int vm_id;
> + uint32_t vectors;
> + uint32_t features;
> + EventfdEntry *eventfd_table;
> +
> + char * shmobj;
> + char * sizearg;
> + char * role;
> +} IVShmemState;
> +
> +/* registers for the Inter-VM shared memory device */
> +enum ivshmem_registers {
> + IntrMask = 0,
> + IntrStatus = 4,
> + IVPosition = 8,
> + Doorbell = 12,
> +};
IIRC these should be uppercase.
> +
> +static inline uint32_t ivshmem_has_feature(IVShmemState *ivs, int feature) {
> + return (ivs->features & (1 << feature));
> +}
Since this is the first version, do we need any features at this
point, can't we expect that all features are available now? Why does
the user need to specify the features?
To avoid a negative shift, I'd make 'feature' unsigned.
> +
> +static inline bool is_power_of_two(uint64_t x) {
> + return (x & (x - 1)) == 0;
> +}
> +
> +static void ivshmem_map(PCIDevice *pci_dev, int region_num,
> + pcibus_t addr, pcibus_t size, int type)
> +{
> + IVShmemState *s = DO_UPCAST(IVShmemState, dev, pci_dev);
> +
> + s->shm_pci_addr = addr;
> +
> + if (s-
