[PATCH] virtio: VIRTIO_HARDEN_NOTIFICATION is broken

[PATCH] virtio: VIRTIO_HARDEN_NOTIFICATION is broken

[Michael S. Tsirkin]

This option doesn't really work and breaks too many drivers.
Not yet sure what's the right thing to do, for now
let's make sure randconfig isn't broken by this.

Fixes: c346dae4f3fb ("virtio: disable notification hardening by default")
Cc: "Jason Wang" <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/virtio/Kconfig | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index e1556d2a355a..afb9051e0125 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -31,11 +31,12 @@ if VIRTIO_MENU
 
 config VIRTIO_HARDEN_NOTIFICATION
         bool "Harden virtio notification"
+        depends on BROKEN
         help
           Enable this to harden the device notifications and suppress
           those that happen at a time where notifications are illegal.
 
-          Experimental: Note that several drivers still have bugs that
+          Experimental: Note that several drivers still have issues that
           may cause crashes or hangs when correct handling of
           notifications is enforced; depending on the subset of
           drivers and devices you use, this may or may not work.
-- 
MST

Re: [PATCH] virtio: VIRTIO_HARDEN_NOTIFICATION is broken

[Jason Wang]

On Fri, Jul 1, 2022 at 3:16 AM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> This option doesn't really work and breaks too many drivers.
> Not yet sure what's the right thing to do, for now
> let's make sure randconfig isn't broken by this.
>
> Fixes: c346dae4f3fb ("virtio: disable notification hardening by default")
> Cc: "Jason Wang" <jasowang@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Acked-by: Jason Wang <jasowang@redhat.com>

> ---
>  drivers/virtio/Kconfig | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index e1556d2a355a..afb9051e0125 100644
> --- a/drivers/virtio/Kconfig
> +++ b/drivers/virtio/Kconfig
> @@ -31,11 +31,12 @@ if VIRTIO_MENU
>
>  config VIRTIO_HARDEN_NOTIFICATION
>          bool "Harden virtio notification"
> +        depends on BROKEN
>          help
>            Enable this to harden the device notifications and suppress
>            those that happen at a time where notifications are illegal.
>
> -          Experimental: Note that several drivers still have bugs that
> +          Experimental: Note that several drivers still have issues that
>            may cause crashes or hangs when correct handling of
>            notifications is enforced; depending on the subset of
>            drivers and devices you use, this may or may not work.
> --
> MST
>

Re: [PATCH] virtio: VIRTIO_HARDEN_NOTIFICATION is broken

[Cornelia Huck]

On Thu, Jun 30 2022, "Michael S. Tsirkin" <mst@redhat.com> wrote:

> This option doesn't really work and breaks too many drivers.
> Not yet sure what's the right thing to do, for now
> let's make sure randconfig isn't broken by this.
>
> Fixes: c346dae4f3fb ("virtio: disable notification hardening by default")
> Cc: "Jason Wang" <jasowang@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  drivers/virtio/Kconfig | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Cornelia Huck <cohuck@redhat.com>

Re: [PATCH] virtio: VIRTIO_HARDEN_NOTIFICATION is broken

[Thorsten Leemhuis]

Hi, this is your Linux kernel regression tracker.

On 30.06.22 21:16, Michael S. Tsirkin wrote:
> This option doesn't really work and breaks too many drivers.
> Not yet sure what's the right thing to do, for now
> let's make sure randconfig isn't broken by this.
> 
> Fixes: c346dae4f3fb ("virtio: disable notification hardening by default")
> Cc: "Jason Wang" <jasowang@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  drivers/virtio/Kconfig | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index e1556d2a355a..afb9051e0125 100644
> --- a/drivers/virtio/Kconfig
> +++ b/drivers/virtio/Kconfig
> @@ -31,11 +31,12 @@ if VIRTIO_MENU
>  
>  config VIRTIO_HARDEN_NOTIFICATION
>          bool "Harden virtio notification"
> +        depends on BROKEN
> [...]

Michael, just wondering: together with c346dae4f3fb this patch afaics
fixes a 5.19 regression I've been tracking. It's now for 10 days in
next, but not yet mainlined. Is that intentional or do you still plan to
submit it in this cycle?

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I deal with a lot of
reports and sometimes miss something important when writing mails like
this. If that's the case here, don't hesitate to tell me in a public
reply, it's in everyone's interest to set the public record straight.