subject:"\[PATCH RFC\] vhost\: basic device IOTLB support"

Re: [PATCH RFC] vhost: basic device IOTLB support

2016-01-05 Thread Jason Wang



On 01/05/2016 11:18 AM, Yang Zhang wrote:
> On 2016/1/4 14:22, Jason Wang wrote:
>>
>>
>> On 01/04/2016 09:39 AM, Yang Zhang wrote:
>>> On 2015/12/31 15:13, Jason Wang wrote:
 This patch tries to implement an device IOTLB for vhost. This could be
 used with for co-operation with userspace(qemu) implementation of
 iommu for a secure DMA environment in guest.

 The idea is simple. When vhost meets an IOTLB miss, it will request
 the assistance of userspace to do the translation, this is done
 through:

 - Fill the translation request in a preset userspace address (This
 address is set through ioctl VHOST_SET_IOTLB_REQUEST_ENTRY).
 - Notify userspace through eventfd (This eventfd was set through ioctl
 VHOST_SET_IOTLB_FD).

 When userspace finishes the translation, it will update the vhost
 IOTLB through VHOST_UPDATE_IOTLB ioctl. Userspace is also in charge of
 snooping the IOTLB invalidation of IOMMU IOTLB and use
 VHOST_UPDATE_IOTLB to invalidate the possible entry in vhost.
>>>
>>> Is there any performance data shows the difference with IOTLB
>>> supporting?
>>
>> Basic testing show it was slower than without IOTLB.
>>
>>> I doubt we may see performance decrease since the flush code path is
>>> longer than before.
>>>
>>
>> Yes, it also depend on the TLB hit rate.
>>
>> If lots of dynamic mappings and unmappings are used in guest (e.g normal
>> Linux driver). This method should be much more slower since:
>>
>> - lots of invalidation and its path is slow.
>> - the hit rate is low and the high price of userspace assisted address
>> translation.
>> - limitation of userspace IOMMU/IOTLB implementation (qemu's vtd
>> emulation simply empty all entries when it's full).
>>
>> Another method is to implement kernel IOMMU (e.g vtd). But I'm not sure
>> vhost is the best place to do this, since vhost should be architecture
>> independent. Maybe we'd better to do it in kvm or have a pv IOMMU
>> implementation in vhost.
>
> Actually, i have the kernel IOMMU(virtual vtd) patch which can pass
> though the physical device to L2 guest on hand.

A little bit confused, I believe the first step is to exporting an IOMMU
to L1 guest for it to use for a assigned device?

> But it is just a draft patch which was written several years ago. If
> there is real requirement for it, I can rebase it and send out it for
> review.

Interesting but I think the goal is different. This patch tries to make
vhost/virtio works with emulated IOMMU.

>
>>
>> Another side, if fixed mappings were used in guest, (e.g dpdk in guest).
>> We have the possibility to have 100% hit rate with almost no
>> invalidation, the performance penalty should be ignorable, this should
>> be the main use case for this patch.
>>
>> The patch is just a prototype for discussion. Any other ideas are
>> welcomed.
>>
>> Thanks
>>
>
>

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH RFC] vhost: basic device IOTLB support

2016-01-04 Thread Yang Zhang


On 2016/1/4 14:22, Jason Wang wrote:



On 01/04/2016 09:39 AM, Yang Zhang wrote:

On 2015/12/31 15:13, Jason Wang wrote:

This patch tries to implement an device IOTLB for vhost. This could be
used with for co-operation with userspace(qemu) implementation of
iommu for a secure DMA environment in guest.

The idea is simple. When vhost meets an IOTLB miss, it will request
the assistance of userspace to do the translation, this is done
through:

- Fill the translation request in a preset userspace address (This
address is set through ioctl VHOST_SET_IOTLB_REQUEST_ENTRY).
- Notify userspace through eventfd (This eventfd was set through ioctl
VHOST_SET_IOTLB_FD).

When userspace finishes the translation, it will update the vhost
IOTLB through VHOST_UPDATE_IOTLB ioctl. Userspace is also in charge of
snooping the IOTLB invalidation of IOMMU IOTLB and use
VHOST_UPDATE_IOTLB to invalidate the possible entry in vhost.


Is there any performance data shows the difference with IOTLB supporting?


Basic testing show it was slower than without IOTLB.


I doubt we may see performance decrease since the flush code path is
longer than before.



Yes, it also depend on the TLB hit rate.

If lots of dynamic mappings and unmappings are used in guest (e.g normal
Linux driver). This method should be much more slower since:

- lots of invalidation and its path is slow.
- the hit rate is low and the high price of userspace assisted address
translation.
- limitation of userspace IOMMU/IOTLB implementation (qemu's vtd
emulation simply empty all entries when it's full).

Another method is to implement kernel IOMMU (e.g vtd). But I'm not sure
vhost is the best place to do this, since vhost should be architecture
independent. Maybe we'd better to do it in kvm or have a pv IOMMU
implementation in vhost.


Actually, i have the kernel IOMMU(virtual vtd) patch which can pass 
though the physical device to L2 guest on hand. But it is just a draft 
patch which was written several years ago. If there is real requirement 
for it, I can rebase it and send out it for review.




Another side, if fixed mappings were used in guest, (e.g dpdk in guest).
We have the possibility to have 100% hit rate with almost no
invalidation, the performance penalty should be ignorable, this should
be the main use case for this patch.

The patch is just a prototype for discussion. Any other ideas are welcomed.

Thanks




--
best regards
yang
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH RFC] vhost: basic device IOTLB support

2016-01-03 Thread Yang Zhang


On 2015/12/31 15:13, Jason Wang wrote:

This patch tries to implement an device IOTLB for vhost. This could be
used with for co-operation with userspace(qemu) implementation of
iommu for a secure DMA environment in guest.

The idea is simple. When vhost meets an IOTLB miss, it will request
the assistance of userspace to do the translation, this is done
through:

- Fill the translation request in a preset userspace address (This
   address is set through ioctl VHOST_SET_IOTLB_REQUEST_ENTRY).
- Notify userspace through eventfd (This eventfd was set through ioctl
   VHOST_SET_IOTLB_FD).

When userspace finishes the translation, it will update the vhost
IOTLB through VHOST_UPDATE_IOTLB ioctl. Userspace is also in charge of
snooping the IOTLB invalidation of IOMMU IOTLB and use
VHOST_UPDATE_IOTLB to invalidate the possible entry in vhost.


Is there any performance data shows the difference with IOTLB 
supporting? I doubt we may see performance decrease since the flush code 
path is longer than before.


--
best regards
yang
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH RFC] vhost: basic device IOTLB support

2016-01-03 Thread Jason Wang

On 01/04/2016 09:39 AM, Yang Zhang wrote:
> On 2015/12/31 15:13, Jason Wang wrote:
>> This patch tries to implement an device IOTLB for vhost. This could be
>> used with for co-operation with userspace(qemu) implementation of
>> iommu for a secure DMA environment in guest.
>>
>> The idea is simple. When vhost meets an IOTLB miss, it will request
>> the assistance of userspace to do the translation, this is done
>> through:
>>
>> - Fill the translation request in a preset userspace address (This
>>address is set through ioctl VHOST_SET_IOTLB_REQUEST_ENTRY).
>> - Notify userspace through eventfd (This eventfd was set through ioctl
>>VHOST_SET_IOTLB_FD).
>>
>> When userspace finishes the translation, it will update the vhost
>> IOTLB through VHOST_UPDATE_IOTLB ioctl. Userspace is also in charge of
>> snooping the IOTLB invalidation of IOMMU IOTLB and use
>> VHOST_UPDATE_IOTLB to invalidate the possible entry in vhost.
>
> Is there any performance data shows the difference with IOTLB supporting?

Basic testing show it was slower than without IOTLB.

> I doubt we may see performance decrease since the flush code path is
> longer than before.
>

Yes, it also depend on the TLB hit rate.

If lots of dynamic mappings and unmappings are used in guest (e.g normal
Linux driver). This method should be much more slower since:

- lots of invalidation and its path is slow.
- the hit rate is low and the high price of userspace assisted address
translation.
- limitation of userspace IOMMU/IOTLB implementation (qemu's vtd
emulation simply empty all entries when it's full).

Another method is to implement kernel IOMMU (e.g vtd). But I'm not sure
vhost is the best place to do this, since vhost should be architecture
independent. Maybe we'd better to do it in kvm or have a pv IOMMU
implementation in vhost.

Another side, if fixed mappings were used in guest, (e.g dpdk in guest).
We have the possibility to have 100% hit rate with almost no
invalidation, the performance penalty should be ignorable, this should
be the main use case for this patch.

The patch is just a prototype for discussion. Any other ideas are welcomed.

Thanks

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH RFC] vhost: basic device IOTLB support

2016-01-03 Thread Jason Wang



On 12/31/2015 07:17 PM, Michael S. Tsirkin wrote:
> On Thu, Dec 31, 2015 at 03:13:45PM +0800, Jason Wang wrote:
>> This patch tries to implement an device IOTLB for vhost. This could be
>> used with for co-operation with userspace(qemu) implementation of
>> iommu for a secure DMA environment in guest.
>>
>> The idea is simple. When vhost meets an IOTLB miss, it will request
>> the assistance of userspace to do the translation, this is done
>> through:
>>
>> - Fill the translation request in a preset userspace address (This
>>   address is set through ioctl VHOST_SET_IOTLB_REQUEST_ENTRY).
>> - Notify userspace through eventfd (This eventfd was set through ioctl
>>   VHOST_SET_IOTLB_FD).
>>
>> When userspace finishes the translation, it will update the vhost
>> IOTLB through VHOST_UPDATE_IOTLB ioctl. Userspace is also in charge of
>> snooping the IOTLB invalidation of IOMMU IOTLB and use
>> VHOST_UPDATE_IOTLB to invalidate the possible entry in vhost.
>>
>> For simplicity, IOTLB was implemented with a simple hash array. The
>> index were calculated from IOVA page frame number which can only works
>> at PAGE_SIZE level.
>>
>> An qemu implementation (for reference) is available at:
>> g...@github.com:jasowang/qemu.git iommu
>>
>> TODO & Known issues:
>>
>> - read/write permission validation was not implemented.
>> - no feature negotiation.
>> - VHOST_SET_MEM_TABLE is not reused (maybe there's a chance).
>> - working at PAGE_SIZE level, don't support large mappings.
>> - better data structure for IOTLB instead of simple hash array.
>> - better API, e.g using mmap() instead of preset userspace address.
>>
>> Signed-off-by: Jason Wang 
> Interesting. I'm working on a slightly different approach
> which is direct vt-d support in vhost.

I've considered this approach. May have advantages but the issues here
is vt-d emulation is even in-complete in qemu and I believe we don't
want to duplicate the code in both vhost-kernel and vhost-user?

> This one has the advantage of being more portable.

Right, the patch tries to be architecture independent.

>
>> ---
>>  drivers/vhost/net.c|   2 +-
>>  drivers/vhost/vhost.c  | 190 
>> -
>>  drivers/vhost/vhost.h  |  13 
>>  include/uapi/linux/vhost.h |  26 +++
>>  4 files changed, 229 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
>> index 9eda69e..a172be9 100644
>> --- a/drivers/vhost/net.c
>> +++ b/drivers/vhost/net.c
>> @@ -1083,7 +1083,7 @@ static long vhost_net_ioctl(struct file *f, unsigned 
>> int ioctl,
>>  r = vhost_dev_ioctl(>dev, ioctl, argp);
>>  if (r == -ENOIOCTLCMD)
>>  r = vhost_vring_ioctl(>dev, ioctl, argp);
>> -else
>> +else if (ioctl != VHOST_UPDATE_IOTLB)
>>  vhost_net_flush(n);
>>  mutex_unlock(>dev.mutex);
>>  return r;
>> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
>> index eec2f11..729fe05 100644
>> --- a/drivers/vhost/vhost.c
>> +++ b/drivers/vhost/vhost.c
>> @@ -113,6 +113,11 @@ static void vhost_init_is_le(struct vhost_virtqueue *vq)
>>  }
>>  #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */
>>  
>> +static inline int vhost_iotlb_hash(u64 iova)
>> +{
>> +return (iova >> PAGE_SHIFT) & (VHOST_IOTLB_SIZE - 1);
>> +}
>> +
>>  static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,
>>  poll_table *pt)
>>  {
>> @@ -384,8 +389,14 @@ void vhost_dev_init(struct vhost_dev *dev,
>>  dev->memory = NULL;
>>  dev->mm = NULL;
>>  spin_lock_init(>work_lock);
>> +spin_lock_init(>iotlb_lock);
>> +mutex_init(>iotlb_req_mutex);
>>  INIT_LIST_HEAD(>work_list);
>>  dev->worker = NULL;
>> +dev->iotlb_request = NULL;
>> +dev->iotlb_ctx = NULL;
>> +dev->iotlb_file = NULL;
>> +dev->pending_request.flags.type = VHOST_IOTLB_INVALIDATE;
>>  
>>  for (i = 0; i < dev->nvqs; ++i) {
>>  vq = dev->vqs[i];
>> @@ -393,12 +404,17 @@ void vhost_dev_init(struct vhost_dev *dev,
>>  vq->indirect = NULL;
>>  vq->heads = NULL;
>>  vq->dev = dev;
>> +vq->iotlb_request = NULL;
>>  mutex_init(>mutex);
>>  vhost_vq_reset(dev, vq);
>>  if (vq->handle_kick)
>>  vhost_poll_init(>poll, vq->handle_kick,
>>  POLLIN, dev);
>>  }
>> +
>> +init_completion(>iotlb_completion);
>> +for (i = 0; i < VHOST_IOTLB_SIZE; i++)
>> +dev->iotlb[i].flags.valid = VHOST_IOTLB_INVALID;
>>  }
>>  EXPORT_SYMBOL_GPL(vhost_dev_init);
>>  
>> @@ -940,9 +956,10 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int 
>> ioctl, void __user *argp)
>>  {
>>  struct file *eventfp, *filep = NULL;
>>  struct eventfd_ctx *ctx = NULL;
>> +struct vhost_iotlb_entry entry;
>>  u64 p;
>>  long r;
>>

Re: [PATCH RFC] vhost: basic device IOTLB support

2015-12-31 Thread Michael S. Tsirkin

On Thu, Dec 31, 2015 at 03:13:45PM +0800, Jason Wang wrote:
> This patch tries to implement an device IOTLB for vhost. This could be
> used with for co-operation with userspace(qemu) implementation of
> iommu for a secure DMA environment in guest.
> 
> The idea is simple. When vhost meets an IOTLB miss, it will request
> the assistance of userspace to do the translation, this is done
> through:
> 
> - Fill the translation request in a preset userspace address (This
>   address is set through ioctl VHOST_SET_IOTLB_REQUEST_ENTRY).
> - Notify userspace through eventfd (This eventfd was set through ioctl
>   VHOST_SET_IOTLB_FD).
> 
> When userspace finishes the translation, it will update the vhost
> IOTLB through VHOST_UPDATE_IOTLB ioctl. Userspace is also in charge of
> snooping the IOTLB invalidation of IOMMU IOTLB and use
> VHOST_UPDATE_IOTLB to invalidate the possible entry in vhost.
> 
> For simplicity, IOTLB was implemented with a simple hash array. The
> index were calculated from IOVA page frame number which can only works
> at PAGE_SIZE level.
> 
> An qemu implementation (for reference) is available at:
> g...@github.com:jasowang/qemu.git iommu
> 
> TODO & Known issues:
> 
> - read/write permission validation was not implemented.
> - no feature negotiation.
> - VHOST_SET_MEM_TABLE is not reused (maybe there's a chance).
> - working at PAGE_SIZE level, don't support large mappings.
> - better data structure for IOTLB instead of simple hash array.
> - better API, e.g using mmap() instead of preset userspace address.
> 
> Signed-off-by: Jason Wang 

Interesting. I'm working on a slightly different approach
which is direct vt-d support in vhost.
This one has the advantage of being more portable.

> ---
>  drivers/vhost/net.c|   2 +-
>  drivers/vhost/vhost.c  | 190 
> -
>  drivers/vhost/vhost.h  |  13 
>  include/uapi/linux/vhost.h |  26 +++
>  4 files changed, 229 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index 9eda69e..a172be9 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -1083,7 +1083,7 @@ static long vhost_net_ioctl(struct file *f, unsigned 
> int ioctl,
>   r = vhost_dev_ioctl(>dev, ioctl, argp);
>   if (r == -ENOIOCTLCMD)
>   r = vhost_vring_ioctl(>dev, ioctl, argp);
> - else
> + else if (ioctl != VHOST_UPDATE_IOTLB)
>   vhost_net_flush(n);
>   mutex_unlock(>dev.mutex);
>   return r;
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index eec2f11..729fe05 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -113,6 +113,11 @@ static void vhost_init_is_le(struct vhost_virtqueue *vq)
>  }
>  #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */
>  
> +static inline int vhost_iotlb_hash(u64 iova)
> +{
> + return (iova >> PAGE_SHIFT) & (VHOST_IOTLB_SIZE - 1);
> +}
> +
>  static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,
>   poll_table *pt)
>  {
> @@ -384,8 +389,14 @@ void vhost_dev_init(struct vhost_dev *dev,
>   dev->memory = NULL;
>   dev->mm = NULL;
>   spin_lock_init(>work_lock);
> + spin_lock_init(>iotlb_lock);
> + mutex_init(>iotlb_req_mutex);
>   INIT_LIST_HEAD(>work_list);
>   dev->worker = NULL;
> + dev->iotlb_request = NULL;
> + dev->iotlb_ctx = NULL;
> + dev->iotlb_file = NULL;
> + dev->pending_request.flags.type = VHOST_IOTLB_INVALIDATE;
>  
>   for (i = 0; i < dev->nvqs; ++i) {
>   vq = dev->vqs[i];
> @@ -393,12 +404,17 @@ void vhost_dev_init(struct vhost_dev *dev,
>   vq->indirect = NULL;
>   vq->heads = NULL;
>   vq->dev = dev;
> + vq->iotlb_request = NULL;
>   mutex_init(>mutex);
>   vhost_vq_reset(dev, vq);
>   if (vq->handle_kick)
>   vhost_poll_init(>poll, vq->handle_kick,
>   POLLIN, dev);
>   }
> +
> + init_completion(>iotlb_completion);
> + for (i = 0; i < VHOST_IOTLB_SIZE; i++)
> + dev->iotlb[i].flags.valid = VHOST_IOTLB_INVALID;
>  }
>  EXPORT_SYMBOL_GPL(vhost_dev_init);
>  
> @@ -940,9 +956,10 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int 
> ioctl, void __user *argp)
>  {
>   struct file *eventfp, *filep = NULL;
>   struct eventfd_ctx *ctx = NULL;
> + struct vhost_iotlb_entry entry;
>   u64 p;
>   long r;
> - int i, fd;
> + int index, i, fd;
>  
>   /* If you are not the owner, you can become one */
>   if (ioctl == VHOST_SET_OWNER) {
> @@ -1008,6 +1025,80 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int 
> ioctl, void __user *argp)
>   if (filep)
>   fput(filep);
>   break;
> + case VHOST_SET_IOTLB_FD:
> +

[PATCH RFC] vhost: basic device IOTLB support

2015-12-30 Thread Jason Wang

This patch tries to implement an device IOTLB for vhost. This could be
used with for co-operation with userspace(qemu) implementation of
iommu for a secure DMA environment in guest.

The idea is simple. When vhost meets an IOTLB miss, it will request
the assistance of userspace to do the translation, this is done
through:

- Fill the translation request in a preset userspace address (This
  address is set through ioctl VHOST_SET_IOTLB_REQUEST_ENTRY).
- Notify userspace through eventfd (This eventfd was set through ioctl
  VHOST_SET_IOTLB_FD).

When userspace finishes the translation, it will update the vhost
IOTLB through VHOST_UPDATE_IOTLB ioctl. Userspace is also in charge of
snooping the IOTLB invalidation of IOMMU IOTLB and use
VHOST_UPDATE_IOTLB to invalidate the possible entry in vhost.

For simplicity, IOTLB was implemented with a simple hash array. The
index were calculated from IOVA page frame number which can only works
at PAGE_SIZE level.

An qemu implementation (for reference) is available at:
g...@github.com:jasowang/qemu.git iommu

TODO & Known issues:

- read/write permission validation was not implemented.
- no feature negotiation.
- VHOST_SET_MEM_TABLE is not reused (maybe there's a chance).
- working at PAGE_SIZE level, don't support large mappings.
- better data structure for IOTLB instead of simple hash array.
- better API, e.g using mmap() instead of preset userspace address.

Signed-off-by: Jason Wang 
---
 drivers/vhost/net.c|   2 +-
 drivers/vhost/vhost.c  | 190 -
 drivers/vhost/vhost.h  |  13 
 include/uapi/linux/vhost.h |  26 +++
 4 files changed, 229 insertions(+), 2 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 9eda69e..a172be9 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1083,7 +1083,7 @@ static long vhost_net_ioctl(struct file *f, unsigned int 
ioctl,
r = vhost_dev_ioctl(>dev, ioctl, argp);
if (r == -ENOIOCTLCMD)
r = vhost_vring_ioctl(>dev, ioctl, argp);
-   else
+   else if (ioctl != VHOST_UPDATE_IOTLB)
vhost_net_flush(n);
mutex_unlock(>dev.mutex);
return r;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index eec2f11..729fe05 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -113,6 +113,11 @@ static void vhost_init_is_le(struct vhost_virtqueue *vq)
 }
 #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */
 
+static inline int vhost_iotlb_hash(u64 iova)
+{
+   return (iova >> PAGE_SHIFT) & (VHOST_IOTLB_SIZE - 1);
+}
+
 static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,
poll_table *pt)
 {
@@ -384,8 +389,14 @@ void vhost_dev_init(struct vhost_dev *dev,
dev->memory = NULL;
dev->mm = NULL;
spin_lock_init(>work_lock);
+   spin_lock_init(>iotlb_lock);
+   mutex_init(>iotlb_req_mutex);
INIT_LIST_HEAD(>work_list);
dev->worker = NULL;
+   dev->iotlb_request = NULL;
+   dev->iotlb_ctx = NULL;
+   dev->iotlb_file = NULL;
+   dev->pending_request.flags.type = VHOST_IOTLB_INVALIDATE;
 
for (i = 0; i < dev->nvqs; ++i) {
vq = dev->vqs[i];
@@ -393,12 +404,17 @@ void vhost_dev_init(struct vhost_dev *dev,
vq->indirect = NULL;
vq->heads = NULL;
vq->dev = dev;
+   vq->iotlb_request = NULL;
mutex_init(>mutex);
vhost_vq_reset(dev, vq);
if (vq->handle_kick)
vhost_poll_init(>poll, vq->handle_kick,
POLLIN, dev);
}
+
+   init_completion(>iotlb_completion);
+   for (i = 0; i < VHOST_IOTLB_SIZE; i++)
+   dev->iotlb[i].flags.valid = VHOST_IOTLB_INVALID;
 }
 EXPORT_SYMBOL_GPL(vhost_dev_init);
 
@@ -940,9 +956,10 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int 
ioctl, void __user *argp)
 {
struct file *eventfp, *filep = NULL;
struct eventfd_ctx *ctx = NULL;
+   struct vhost_iotlb_entry entry;
u64 p;
long r;
-   int i, fd;
+   int index, i, fd;
 
/* If you are not the owner, you can become one */
if (ioctl == VHOST_SET_OWNER) {
@@ -1008,6 +1025,80 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int 
ioctl, void __user *argp)
if (filep)
fput(filep);
break;
+   case VHOST_SET_IOTLB_FD:
+   r = get_user(fd, (int __user *)argp);
+   if (r < 0)
+   break;
+   eventfp = fd == -1 ? NULL : eventfd_fget(fd);
+   if (IS_ERR(eventfp)) {
+   r = PTR_ERR(eventfp);
+   break;
+   }
+   if (eventfp != d->iotlb_file) {
+

Re: [PATCH RFC] vhost: basic device IOTLB support

Re: [PATCH RFC] vhost: basic device IOTLB support

Re: [PATCH RFC] vhost: basic device IOTLB support

Re: [PATCH RFC] vhost: basic device IOTLB support

Re: [PATCH RFC] vhost: basic device IOTLB support

Re: [PATCH RFC] vhost: basic device IOTLB support

[PATCH RFC] vhost: basic device IOTLB support

7 matches

Site Navigation

Mail list logo

Footer information