vhost_copy_to_user is used to copy vring used elements to userspace.
We should use VHOST_ADDR_USED instead of VHOST_ADDR_DESC.
Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache")
Signed-off-by: Eric Auger <eric.auger at redhat.com>
---
This fixes a stall observed when running an aarch64 guest with
virtual smmu
---
drivers/vhost/vhost.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index bec722e..f44aead 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -744,7 +744,7 @@ static int vhost_copy_to_user(struct vhost_virtqueue *vq,
void __user *to,
struct iov_iter t;
void __user *uaddr = vhost_vq_meta_fetch(vq,
(u64)(uintptr_t)to, size,
- VHOST_ADDR_DESC);
+ VHOST_ADDR_USED);
if (uaddr)
return __copy_to_user(uaddr, from, size);
--
2.5.5
On 2018?04?11? 21:30, Eric Auger wrote:> vhost_copy_to_user is used to copy vring used elements to userspace. > We should use VHOST_ADDR_USED instead of VHOST_ADDR_DESC. > > Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache") > Signed-off-by: Eric Auger <eric.auger at redhat.com> > > --- > > This fixes a stall observed when running an aarch64 guest with > virtual smmu > --- > drivers/vhost/vhost.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index bec722e..f44aead 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -744,7 +744,7 @@ static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, > struct iov_iter t; > void __user *uaddr = vhost_vq_meta_fetch(vq, > (u64)(uintptr_t)to, size, > - VHOST_ADDR_DESC); > + VHOST_ADDR_USED); > > if (uaddr) > return __copy_to_user(uaddr, from, size);Acked-by: Jason Wang <jasowang at redhat.com> Thanks! Stable material I think.
Hi Jason, On 11/04/18 15:44, Jason Wang wrote:> > > On 2018?04?11? 21:30, Eric Auger wrote: >> vhost_copy_to_user is used to copy vring used elements to userspace. >> We should use VHOST_ADDR_USED instead of VHOST_ADDR_DESC. >> >> Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache") >> Signed-off-by: Eric Auger <eric.auger at redhat.com> >> >> --- >> >> This fixes a stall observed when running an aarch64 guest with >> virtual smmu >> --- >> drivers/vhost/vhost.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c >> index bec722e..f44aead 100644 >> --- a/drivers/vhost/vhost.c >> +++ b/drivers/vhost/vhost.c >> @@ -744,7 +744,7 @@ static int vhost_copy_to_user(struct >> vhost_virtqueue *vq, void __user *to, >> struct iov_iter t; >> void __user *uaddr = vhost_vq_meta_fetch(vq, >> (u64)(uintptr_t)to, size, >> - VHOST_ADDR_DESC); >> + VHOST_ADDR_USED); >> if (uaddr) >> return __copy_to_user(uaddr, from, size); > > Acked-by: Jason Wang <jasowang at redhat.com> > > Thanks! > > Stable material I think.yes I think so. Thanks Eric
On Wed, Apr 11, 2018 at 03:30:38PM +0200, Eric Auger wrote:> vhost_copy_to_user is used to copy vring used elements to userspace. > We should use VHOST_ADDR_USED instead of VHOST_ADDR_DESC. > > Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache") > Signed-off-by: Eric Auger <eric.auger at redhat.com>Acked-by: Michael S. Tsirkin <mst at redhat.com>> --- > > This fixes a stall observed when running an aarch64 guest with > virtual smmu > --- > drivers/vhost/vhost.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index bec722e..f44aead 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -744,7 +744,7 @@ static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, > struct iov_iter t; > void __user *uaddr = vhost_vq_meta_fetch(vq, > (u64)(uintptr_t)to, size, > - VHOST_ADDR_DESC); > + VHOST_ADDR_USED); > > if (uaddr) > return __copy_to_user(uaddr, from, size); > -- > 2.5.5