[PATCH RFC 1/2] virtio-net: bql support

[Michael S. Tsirkin]

When use_napi is set, let's enable BQLs.  Note: some of the issues are
similar to wifi.  It's worth considering whether something similar to
commit 36148c2bbfbe ("mac80211: Adjust TSQ pacing shift") might be
benefitial.

Signed-off-by: Michael S. Tsirkin 
---
 drivers/net/virtio_net.c | 27 +++
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index cecfd77c9f3c..b657bde6b94b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1325,7 +1325,8 @@ static int virtnet_receive(struct receive_queue *rq, int 
budget,
return stats.packets;
 }
 
-static void free_old_xmit_skbs(struct send_queue *sq)
+static void free_old_xmit_skbs(struct send_queue *sq, struct netdev_queue *txq,
+  bool use_napi)
 {
struct sk_buff *skb;
unsigned int len;
@@ -1347,6 +1348,9 @@ static void free_old_xmit_skbs(struct send_queue *sq)
if (!packets)
return;
 
+   if (use_napi)
+   netdev_tx_completed_queue(txq, packets, bytes);
+
u64_stats_update_begin(>stats.syncp);
sq->stats.bytes += bytes;
sq->stats.packets += packets;
@@ -1364,7 +1368,7 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
return;
 
if (__netif_tx_trylock(txq)) {
-   free_old_xmit_skbs(sq);
+   free_old_xmit_skbs(sq, txq, true);
__netif_tx_unlock(txq);
}
 
@@ -1440,7 +1444,7 @@ static int virtnet_poll_tx(struct napi_struct *napi, int 
budget)
struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, vq2txq(sq->vq));
 
__netif_tx_lock(txq, raw_smp_processor_id());
-   free_old_xmit_skbs(sq);
+   free_old_xmit_skbs(sq, txq, true);
__netif_tx_unlock(txq);
 
virtqueue_napi_complete(napi, sq->vq, 0);
@@ -1505,13 +1509,15 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, 
struct net_device *dev)
struct send_queue *sq = >sq[qnum];
int err;
struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
-   bool kick = !skb->xmit_more;
+   bool more = skb->xmit_more;
bool use_napi = sq->napi.weight;
+   unsigned int bytes = skb->len;
+   bool kick;
 
/* Free up any pending old buffers before queueing new ones. */
-   free_old_xmit_skbs(sq);
+   free_old_xmit_skbs(sq, txq, use_napi);
 
-   if (use_napi && kick)
+   if (use_napi && !more)
virtqueue_enable_cb_delayed(sq->vq);
 
/* timestamp packet in software */
@@ -1552,7 +1558,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct 
net_device *dev)
if (!use_napi &&
unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
/* More just got used, free them then recheck. */
-   free_old_xmit_skbs(sq);
+   free_old_xmit_skbs(sq, txq, false);
if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
netif_start_subqueue(dev, qnum);
virtqueue_disable_cb(sq->vq);
@@ -1560,7 +1566,12 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, 
struct net_device *dev)
}
}
 
-   if (kick || netif_xmit_stopped(txq)) {
+   if (use_napi)
+   kick = __netdev_tx_sent_queue(txq, bytes, more);
+   else
+   kick = !more || netif_xmit_stopped(txq);
+
+   if (kick) {
if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) 
{
u64_stats_update_begin(>stats.syncp);
sq->stats.kicks++;
-- 
MST

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[PATCH RFC 2/2] virtio_net: bulk free tx skbs

[Michael S. Tsirkin]

Use napi_consume_skb() to get bulk free.  Note that napi_consume_skb is
safe to call in a non-napi context as long as the napi_budget flag is
correct.

Signed-off-by: Michael S. Tsirkin 
---
 drivers/net/virtio_net.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index b657bde6b94b..18c06322be40 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1339,7 +1339,7 @@ static void free_old_xmit_skbs(struct send_queue *sq, 
struct netdev_queue *txq,
bytes += skb->len;
packets++;
 
-   dev_consume_skb_any(skb);
+   napi_consume_skb(skb, use_napi);
}
 
/* Avoid overhead when no packets have been processed
-- 
MST

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[PATCH RFC 0/2] virtio-net: interrupt related improvements

[Michael S. Tsirkin]

Now that we have brought the virtio overhead way down with a fast packed
ring implementation, we seem to be actually observing TCP drops
indicative of bufferbloat. So let's try to enable TSQ.  Note: it isn't
clear that the default pacing is great for the virt usecase. It's worth
trying to play with sk_pacing_shift_update to see what happens.

For this reason, and for a more important one that I didn't
have time to test it yet, sending as an RFC.

Michael S. Tsirkin (2):
  virtio-net: bql support
  virtio_net: bulk free tx skbs

 drivers/net/virtio_net.c | 29 -
 1 file changed, 20 insertions(+), 9 deletions(-)

-- 
MST

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Call for Papers - MICRADS 2019, Rio de Janeiro, Brazil | Deadline: December 28

[Maria]

* Proceedings by Springer



--

MICRADS´19 - The 2019 Multidisciplinary International Conference of Research 
Applied to Defense and Security

Rio de Janeiro, Brazil, 8 - 10 May 2019

http://www.micrads.org/ 

--



Scope

MICRADS´19 - The 2019 Multidisciplinary International Conference of Research 
Applied to Defense and Security, to be held at Rio de Janeiro, Brazil, 8 - 10 
May 2019, is an international forum for researchers and practitioners to 
present and discuss the most recent innovations, trends, results, experiences 
and concerns in the several perspectives of Defense and Security.

We are pleased to invite you to submit your papers to MICRADS´19. They can be 
written in English, Spanish or Portuguese. All submissions will be reviewed on 
the basis of relevance, originality, importance and clarity.



Topics

Submitted papers should be related with one or more of the main themes proposed 
for the Conference:



Area A: Systems, Communication and Defense

A1) Information and Communication Technology in Education
A2) Simulation and computer vision in military applications
A3) Analysis and Signal Processing
A4) Cybersecurity and Cyberdefense
A5) Computer Networks, Mobility and Pervasive Systems



Area B: Strategy and political-administrative vision in Defense

B1) Safety and Maritime Protection
B2) Strategy, Geopolitics and Oceanopolitics
B3) Planning, economy and logistics applied to Defense
B4) Leadership and e-leadership
B5) Military Marketing
B6) Health informatics in military applications



Area C: Engineering and technologies applied to Defense

C1) Wearable Technology and Assistance Devices
C2) Military Naval Engineering
C3) Weapons and Combat Systems
C4) Chemical, Biological and Nuclear Defense
C5) Defense Engineering (General)



Submission and Decision

Submitted papers written in English (until 10-page limit) must comply with the 
format of Smart Innovation, Systems and Technologies series (see Instructions 
for Authors at Springer Website 
),
 must not have been published before, not be under review for any other 
conference or publication and not include any information leading to the 
authors’ identification. Therefore, the authors’ names, affiliations and 
e-mails should not be included in the version for evaluation by the Scientific 
Committee. This information should only be included in the camera-ready 
version, saved in Word or Latex format and also in PDF format. These files must 
be accompanied by the Consent to Publish form 
 filled out, in a ZIP file, and uploaded at 
the conference management system.

Submitted papers written in Spanish or Portuguese (until 15-page limit) must 
comply with the format of RISTI  - Revista Ibérica de 
Sistemas e Tecnologias de Informação (download instructions/template for 
authors in Spanish  or Portuguese 
), must not have been published before, 
not be under review for any other conference or publication and not include any 
information leading to the authors’ identification. Therefore, the authors’ 
names, affiliations and e-mails should not be included in the version for 
evaluation by the Scientific Committee. This information should only be 
included in the camera-ready version, saved in Word. These file must be 
uploaded at the conference management system in a ZIP file.

All papers will be subjected to a “blind review” by at least two members of the 
Scientific Committee.

Based on Scientific Committee evaluation, a paper can be rejected or accepted 
by the Conference Chairs. In the later case, it can be accepted as paper or 
poster.

The authors of papers accepted as posters must build and print a poster to be 
exhibited during the Conference. This poster must follow an A1 or A2 vertical 
format. The Conference can includes Work Sessions where these posters are 
presented and orally discussed, with a 7 minute limit per poster.

The authors of accepted papers will have 15 minutes to present their work in a 
Conference Work Session; approximately 5 minutes of discussion will follow each 
presentation.



Publication and Indexing

To ensure that an accepted paper is published, at least one of the authors must 
be fully registered by the 11 of February 2019, and the paper must comply with 
the suggested layout and page-limit (until 10 pages). Additionally, all 
recommended changes must be addressed by the authors before they submit the 
camera-ready version.

No more than one paper per registration will be published. An extra fee must be 
paid for publication of additional papers, with a maximum of one additional 
paper 

Re: [PATCH v9] virtio_blk: add discard and write zeroes support

[Michael S. Tsirkin]

On Wed, Dec 05, 2018 at 09:46:16AM +, Liu, Changpeng wrote:
> What's the status of this patch ? anybody pulled it for the branch ?

I will merge it for next.

> 
> > -Original Message-
> > From: Stefan Hajnoczi [mailto:stefa...@redhat.com]
> > Sent: Friday, November 2, 2018 12:18 PM
> > To: Daniel Verkamp 
> > Cc: virtualization@lists.linux-foundation.org; linux-bl...@vger.kernel.org;
> > Michael S. Tsirkin ; Jason Wang ;
> > Jens Axboe ; Paolo Bonzini ;
> > Christoph Hellwig ; Liu, Changpeng
> > 
> > Subject: Re: [PATCH v9] virtio_blk: add discard and write zeroes support
> > 
> > On Thu, Nov 01, 2018 at 03:40:35PM -0700, Daniel Verkamp wrote:
> > > From: Changpeng Liu 
> > >
> > > In commit 88c85538, "virtio-blk: add discard and write zeroes features
> > > to specification" (https://github.com/oasis-tcs/virtio-spec), the virtio
> > > block specification has been extended to add VIRTIO_BLK_T_DISCARD and
> > > VIRTIO_BLK_T_WRITE_ZEROES commands.  This patch enables support for
> > > discard and write zeroes in the virtio-blk driver when the device
> > > advertises the corresponding features, VIRTIO_BLK_F_DISCARD and
> > > VIRTIO_BLK_F_WRITE_ZEROES.
> > >
> > > Signed-off-by: Changpeng Liu 
> > > Signed-off-by: Daniel Verkamp 
> > > ---
> > > dverkamp: I've picked up this patch and made a few minor changes (as
> > > listed below); most notably, I changed the kmalloc back to GFP_ATOMIC,
> > > since it can be called from a context where sleeping is not allowed.
> > > To prevent large allocations, I've also clamped the maximum number of
> > > discard segments to 256; this results in a 4K allocation and should be
> > > plenty of descriptors for most use cases.
> > >
> > > I also removed most of the description from the commit message, since it
> > > was duplicating the comments from virtio_blk.h and quoting parts of the
> > > spec without adding any extra information.  I have tested this iteration
> > > of the patch using crosvm with modifications to enable the new features:
> > > https://chromium.googlesource.com/chromiumos/platform/crosvm/
> > >
> > > v9 fixes a number of review issues; I didn't attempt to optimize the
> > > single-element write zeroes case, so it still does an allocation per
> > > request (I did not see any easy place to put the payload that would
> > > avoid the allocation).
> > >
> > > CHANGELOG:
> > > v9: [dverkamp] fix LE types in discard struct; cleanups from Ming Lei
> > > v8: [dverkamp] replace shifts by 9 with SECTOR_SHIFT constant
> > > v7: [dverkamp] use GFP_ATOMIC for allocation that may not sleep; clarify
> > > descriptor flags field; comment wording cleanups.
> > > v6: don't set T_OUT bit to discard and write zeroes commands.
> > > v5: use new block layer API: blk_queue_flag_set.
> > > v4: several optimizations based on MST's comments, remove bit field
> > > usage for command descriptor.
> > > v3: define the virtio-blk protocol to add discard and write zeroes
> > > support, first version implementation based on proposed specification.
> > > v2: add write zeroes command support.
> > > v1: initial proposal implementation for discard command.
> > > ---
> > >  drivers/block/virtio_blk.c  | 83 -
> > >  include/uapi/linux/virtio_blk.h | 54 +
> > >  2 files changed, 135 insertions(+), 2 deletions(-)
> > 
> > Reviewed-by: Stefan Hajnoczi 
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[PATCH 3/3] drm/virtio: drop virtio_gpu_fence_cleanup()

[Gerd Hoffmann]

Just call drm_fence_put directly instead.
Also set vgfb->fence to NULL after dropping the reference.

Signed-off-by: Gerd Hoffmann 
---
 drivers/gpu/drm/virtio/virtgpu_drv.h   | 1 -
 drivers/gpu/drm/virtio/virtgpu_fence.c | 8 
 drivers/gpu/drm/virtio/virtgpu_ioctl.c | 2 +-
 drivers/gpu/drm/virtio/virtgpu_plane.c | 6 --
 4 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h 
b/drivers/gpu/drm/virtio/virtgpu_drv.h
index 1deb41d42e..551860497f 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -351,7 +351,6 @@ int virtio_gpu_mmap(struct file *filp, struct 
vm_area_struct *vma);
 /* virtio_gpu_fence.c */
 struct virtio_gpu_fence *virtio_gpu_fence_alloc(
struct virtio_gpu_device *vgdev);
-void virtio_gpu_fence_cleanup(struct virtio_gpu_fence *fence);
 int virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev,
  struct virtio_gpu_ctrl_hdr *cmd_hdr,
  struct virtio_gpu_fence *fence);
diff --git a/drivers/gpu/drm/virtio/virtgpu_fence.c 
b/drivers/gpu/drm/virtio/virtgpu_fence.c
index 4d6826b278..21bd4c4a32 100644
--- a/drivers/gpu/drm/virtio/virtgpu_fence.c
+++ b/drivers/gpu/drm/virtio/virtgpu_fence.c
@@ -81,14 +81,6 @@ struct virtio_gpu_fence *virtio_gpu_fence_alloc(struct 
virtio_gpu_device *vgdev)
return fence;
 }
 
-void virtio_gpu_fence_cleanup(struct virtio_gpu_fence *fence)
-{
-   if (!fence)
-   return;
-
-   dma_fence_put(>f);
-}
-
 int virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev,
  struct virtio_gpu_ctrl_hdr *cmd_hdr,
  struct virtio_gpu_fence *fence)
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c 
b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 161b80fee4..14ce8188c0 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -351,7 +351,7 @@ static int virtio_gpu_resource_create_ioctl(struct 
drm_device *dev, void *data,
virtio_gpu_cmd_resource_create_3d(vgdev, qobj, _3d);
ret = virtio_gpu_object_attach(vgdev, qobj, fence);
if (ret) {
-   virtio_gpu_fence_cleanup(fence);
+   dma_fence_put(>f);
goto fail_backoff;
}
ttm_eu_fence_buffer_objects(, _list, >f);
diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c 
b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 548265b8e8..024c2aa0c9 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -169,8 +169,10 @@ static void virtio_gpu_cursor_cleanup_fb(struct drm_plane 
*plane,
return;
 
vgfb = to_virtio_gpu_framebuffer(plane->state->fb);
-   if (vgfb->fence)
-   virtio_gpu_fence_cleanup(vgfb->fence);
+   if (vgfb->fence) {
+   dma_fence_put(>fence->f);
+   vgfb->fence = NULL;
+   }
 }
 
 static void virtio_gpu_cursor_plane_update(struct drm_plane *plane,
-- 
2.9.3

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[PATCH 1/3] drm/virtio: log error responses

[Gerd Hoffmann]

If we got an error response code from the host, print it to the log.

Signed-off-by: Gerd Hoffmann 
---
 drivers/gpu/drm/virtio/virtgpu_vq.c | 12 ++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c 
b/drivers/gpu/drm/virtio/virtgpu_vq.c
index e27c4aedb8..6bc2008b0d 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -192,8 +192,16 @@ void virtio_gpu_dequeue_ctrl_func(struct work_struct *work)
 
list_for_each_entry_safe(entry, tmp, _list, list) {
resp = (struct virtio_gpu_ctrl_hdr *)entry->resp_buf;
-   if (resp->type != cpu_to_le32(VIRTIO_GPU_RESP_OK_NODATA))
-   DRM_DEBUG("response 0x%x\n", le32_to_cpu(resp->type));
+   if (resp->type != cpu_to_le32(VIRTIO_GPU_RESP_OK_NODATA)) {
+   if (resp->type >= 
cpu_to_le32(VIRTIO_GPU_RESP_ERR_UNSPEC)) {
+   struct virtio_gpu_ctrl_hdr *cmd;
+   cmd = (struct virtio_gpu_ctrl_hdr *)entry->buf;
+   DRM_ERROR("response 0x%x (command 0x%x)\n",
+ le32_to_cpu(resp->type),
+ le32_to_cpu(cmd->type));
+   } else
+   DRM_DEBUG("response 0x%x\n", 
le32_to_cpu(resp->type));
+   }
if (resp->flags & cpu_to_le32(VIRTIO_GPU_FLAG_FENCE)) {
u64 f = le64_to_cpu(resp->fence_id);
 
-- 
2.9.3

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[PATCH 2/3] drm/virtio: fix pageflip flush

[Gerd Hoffmann]

Sending the flush command only makes sense if we actually have
a framebuffer attached to the scanout (handle != 0).

Signed-off-by: Gerd Hoffmann 
---
 drivers/gpu/drm/virtio/virtgpu_plane.c | 11 ++-
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c 
b/drivers/gpu/drm/virtio/virtgpu_plane.c
index ead5c53d4e..548265b8e8 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -130,11 +130,12 @@ static void virtio_gpu_primary_plane_update(struct 
drm_plane *plane,
   plane->state->src_h >> 16,
   plane->state->src_x >> 16,
   plane->state->src_y >> 16);
-   virtio_gpu_cmd_resource_flush(vgdev, handle,
- plane->state->src_x >> 16,
- plane->state->src_y >> 16,
- plane->state->src_w >> 16,
- plane->state->src_h >> 16);
+   if (handle)
+   virtio_gpu_cmd_resource_flush(vgdev, handle,
+ plane->state->src_x >> 16,
+ plane->state->src_y >> 16,
+ plane->state->src_w >> 16,
+ plane->state->src_h >> 16);
 }
 
 static int virtio_gpu_cursor_prepare_fb(struct drm_plane *plane,
-- 
2.9.3

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RE: [PATCH v9] virtio_blk: add discard and write zeroes support

[Liu, Changpeng]

What's the status of this patch ? anybody pulled it for the branch ?

> -Original Message-
> From: Stefan Hajnoczi [mailto:stefa...@redhat.com]
> Sent: Friday, November 2, 2018 12:18 PM
> To: Daniel Verkamp 
> Cc: virtualization@lists.linux-foundation.org; linux-bl...@vger.kernel.org;
> Michael S. Tsirkin ; Jason Wang ;
> Jens Axboe ; Paolo Bonzini ;
> Christoph Hellwig ; Liu, Changpeng
> 
> Subject: Re: [PATCH v9] virtio_blk: add discard and write zeroes support
> 
> On Thu, Nov 01, 2018 at 03:40:35PM -0700, Daniel Verkamp wrote:
> > From: Changpeng Liu 
> >
> > In commit 88c85538, "virtio-blk: add discard and write zeroes features
> > to specification" (https://github.com/oasis-tcs/virtio-spec), the virtio
> > block specification has been extended to add VIRTIO_BLK_T_DISCARD and
> > VIRTIO_BLK_T_WRITE_ZEROES commands.  This patch enables support for
> > discard and write zeroes in the virtio-blk driver when the device
> > advertises the corresponding features, VIRTIO_BLK_F_DISCARD and
> > VIRTIO_BLK_F_WRITE_ZEROES.
> >
> > Signed-off-by: Changpeng Liu 
> > Signed-off-by: Daniel Verkamp 
> > ---
> > dverkamp: I've picked up this patch and made a few minor changes (as
> > listed below); most notably, I changed the kmalloc back to GFP_ATOMIC,
> > since it can be called from a context where sleeping is not allowed.
> > To prevent large allocations, I've also clamped the maximum number of
> > discard segments to 256; this results in a 4K allocation and should be
> > plenty of descriptors for most use cases.
> >
> > I also removed most of the description from the commit message, since it
> > was duplicating the comments from virtio_blk.h and quoting parts of the
> > spec without adding any extra information.  I have tested this iteration
> > of the patch using crosvm with modifications to enable the new features:
> > https://chromium.googlesource.com/chromiumos/platform/crosvm/
> >
> > v9 fixes a number of review issues; I didn't attempt to optimize the
> > single-element write zeroes case, so it still does an allocation per
> > request (I did not see any easy place to put the payload that would
> > avoid the allocation).
> >
> > CHANGELOG:
> > v9: [dverkamp] fix LE types in discard struct; cleanups from Ming Lei
> > v8: [dverkamp] replace shifts by 9 with SECTOR_SHIFT constant
> > v7: [dverkamp] use GFP_ATOMIC for allocation that may not sleep; clarify
> > descriptor flags field; comment wording cleanups.
> > v6: don't set T_OUT bit to discard and write zeroes commands.
> > v5: use new block layer API: blk_queue_flag_set.
> > v4: several optimizations based on MST's comments, remove bit field
> > usage for command descriptor.
> > v3: define the virtio-blk protocol to add discard and write zeroes
> > support, first version implementation based on proposed specification.
> > v2: add write zeroes command support.
> > v1: initial proposal implementation for discard command.
> > ---
> >  drivers/block/virtio_blk.c  | 83 -
> >  include/uapi/linux/virtio_blk.h | 54 +
> >  2 files changed, 135 insertions(+), 2 deletions(-)
> 
> Reviewed-by: Stefan Hajnoczi 
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