Displaying 7 results from an estimated 7 matches for "set_backend_features".
2020 Sep 09
0
[PATCH] vhost: new vhost_vdpa SET/GET_BACKEND_FEATURES handlers
----- Original Message -----
> This commit introduced vhost_vdpa_set/get_backend_features() to
> resolve these issues:
> (1)In vhost_vdpa ioctl SET_BACKEND_FEATURES path, currect code
> would try to acquire vhost dev mutex twice
> (first shown in vhost_vdpa_unlocked_ioctl), which can lead
> to a dead lock issue.
> (2)SET_BACKEND_FEATURES was blindly added to vring ioctl instead
> of vdpa device ioctl
>
> To resolve these issues, this comm...
2019 Aug 05
1
[PATCH V2 7/9] vhost: do not use RCU to synchronize MMU notifier with worker
...>
> > That's one direction to take. Another one is to give up on that and
> > write our own version of uaccess macros. Add a "high security" flag to
> > the vhost module and if not active use these for userspace memory
> > access.
>
>
> Or using SET_BACKEND_FEATURES?
No, I don't think it's considered best practice to allow unpriveledged
userspace control over whether kernel enables security features.
> But do you mean permanent GUP as I did in
> original RFC https://lkml.org/lkml/2018/12/13/218?
>
> Thanks
Permanent GUP breaks THP and N...
2019 Aug 02
2
[PATCH V2 7/9] vhost: do not use RCU to synchronize MMU notifier with worker
On Fri, Aug 02, 2019 at 05:40:07PM +0800, Jason Wang wrote:
> Btw, I come up another idea, that is to disable preemption when vhost thread
> need to access the memory. Then register preempt notifier and if vhost
> thread is preempted, we're sure no one will access the memory and can do the
> cleanup.
Great, more notifiers :(
Maybe can live with
1- disable preemption while using
2019 Aug 02
2
[PATCH V2 7/9] vhost: do not use RCU to synchronize MMU notifier with worker
On Fri, Aug 02, 2019 at 05:40:07PM +0800, Jason Wang wrote:
> Btw, I come up another idea, that is to disable preemption when vhost thread
> need to access the memory. Then register preempt notifier and if vhost
> thread is preempted, we're sure no one will access the memory and can do the
> cleanup.
Great, more notifiers :(
Maybe can live with
1- disable preemption while using
2019 Aug 05
0
[PATCH V2 7/9] vhost: do not use RCU to synchronize MMU notifier with worker
...work along the lines of 1-2 above.
>
> That's one direction to take. Another one is to give up on that and
> write our own version of uaccess macros. Add a "high security" flag to
> the vhost module and if not active use these for userspace memory
> access.
Or using SET_BACKEND_FEATURES? But do you mean permanent GUP as I did in
original RFC https://lkml.org/lkml/2018/12/13/218?
Thanks
>
>
2020 Sep 08
0
[PATCH 1/2] vhost: remove mutex ops in vhost_set_backend_features
On Mon, Sep 07, 2020 at 06:52:19PM +0800, Zhu Lingshan wrote:
> In vhost_vdpa ioctl SET_BACKEND_FEATURES path, currect code
> would try to acquire vhost dev mutex twice
> (first shown in vhost_vdpa_unlocked_ioctl), which can lead
> to a dead lock issue.
> This commit removed mutex operations in vhost_set_backend_features.
> As a compensation for vhost_net, a followinig commit will add
&...
2020 Sep 21
0
[PATCH 1/2] vhost: remove mutex ops in vhost_set_backend_features
On Tue, Sep 08, 2020 at 09:00:19PM +0800, Zhu, Lingshan wrote:
>
> On 9/8/2020 8:05 PM, Michael S. Tsirkin wrote:
>
> On Mon, Sep 07, 2020 at 06:52:19PM +0800, Zhu Lingshan wrote:
>
> In vhost_vdpa ioctl SET_BACKEND_FEATURES path, currect code
> would try to acquire vhost dev mutex twice
> (first shown in vhost_vdpa_unlocked_ioctl), which can lead
> to a dead lock issue.
> This commit removed mutex operations in vhost_set_backend_features.
> As a compensation for v...