| Message ID | 20190726115021.7319-1-mst@redhat.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
| Series | vhost: disable metadata prefetch optimization | expand |
On 2019/7/26 下午7:51, Michael S. Tsirkin wrote: > This seems to cause guest and host memory corruption. > Disable for now until we get a better handle on that. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > > I put this in linux-next, we'll re-enable if we can fix > the outstanding issues in a short order. Btw, is this more suitable to e.g revert the 842aa64eddacd23adc6ecdbc69cb2030bec47122 and let syzbot fuzz more on the current code? I think we won't accept that patch eventually, so I suspect what syzbot reports today is a false positives. Thanks > > drivers/vhost/vhost.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > index 819296332913..42a8c2a13ab1 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -96,7 +96,7 @@ struct vhost_uaddr { > }; > > #if defined(CONFIG_MMU_NOTIFIER) && ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 0 > -#define VHOST_ARCH_CAN_ACCEL_UACCESS 1 > +#define VHOST_ARCH_CAN_ACCEL_UACCESS 0 > #else > #define VHOST_ARCH_CAN_ACCEL_UACCESS 0 > #endif
On Fri, Jul 26, 2019 at 07:57:25PM +0800, Jason Wang wrote: > > On 2019/7/26 下午7:51, Michael S. Tsirkin wrote: > > This seems to cause guest and host memory corruption. > > Disable for now until we get a better handle on that. > > > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > > --- > > > > I put this in linux-next, we'll re-enable if we can fix > > the outstanding issues in a short order. > > > Btw, is this more suitable to e.g revert the > 842aa64eddacd23adc6ecdbc69cb2030bec47122 Yes I did that too. > and let syzbot fuzz more on the > current code? Current metadata direct access code is known to corrupt guest and host memory - I don't feel we need more fuzzing. > > I think we won't accept that patch eventually, so I suspect what syzbot > reports today is a false positives. Today's reports are real, it's a bug in my patch. But I reverted it - the below is an easier way to make sure at least linux-next is stable for everyone. > > Thanks > > > > > > drivers/vhost/vhost.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > > index 819296332913..42a8c2a13ab1 100644 > > --- a/drivers/vhost/vhost.h > > +++ b/drivers/vhost/vhost.h > > @@ -96,7 +96,7 @@ struct vhost_uaddr { > > }; > > #if defined(CONFIG_MMU_NOTIFIER) && ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 0 > > -#define VHOST_ARCH_CAN_ACCEL_UACCESS 1 > > +#define VHOST_ARCH_CAN_ACCEL_UACCESS 0 > > #else > > #define VHOST_ARCH_CAN_ACCEL_UACCESS 0 > > #endif
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 819296332913..42a8c2a13ab1 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -96,7 +96,7 @@ struct vhost_uaddr { }; #if defined(CONFIG_MMU_NOTIFIER) && ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 0 -#define VHOST_ARCH_CAN_ACCEL_UACCESS 1 +#define VHOST_ARCH_CAN_ACCEL_UACCESS 0 #else #define VHOST_ARCH_CAN_ACCEL_UACCESS 0 #endif
This seems to cause guest and host memory corruption. Disable for now until we get a better handle on that. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- I put this in linux-next, we'll re-enable if we can fix the outstanding issues in a short order. drivers/vhost/vhost.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)