2024-06-11 21:48:31

by Halil Pasic

[permalink] [raw]
Subject: [PATCH 1/1] s390/virtio_ccw: fix config change notifications

Commit e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
broke configuration change notifications for virtio-ccw by putting the
DMA address of *indicatorp directly into ccw->cda disregarding the fact
that if !!(vcdev->is_thinint) then the function
virtio_ccw_register_adapter_ind() will overwrite that ccw->cda value
with the address of the virtio_thinint_area so it can actually set up
the adapter interrupts via CCW_CMD_SET_IND_ADAPTER. Thus we end up
pointing to the wrong object for both CCW_CMD_SET_IND if setting up the
adapter interrupts fails, and for CCW_CMD_SET_CONF_IND regardless
whether it succeeds or fails.

To fix this, let us save away the dma address of *indicatorp in a local
variable, and copy it to ccw->cda after the "vcdev->is_thinint" branch.

Reported-by: Boqiao Fu <[email protected]>
Reported-by: Sebastian Mitterle <[email protected]>
Fixes: e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
Signed-off-by: Halil Pasic <[email protected]>
---
I know that checkpatch.pl complains about a missing 'Closes' tag.
Unfortunately I don't have an appropriate URL at hand. @Sebastian,
@Boqiao: do you have any suggetions?
---
drivers/s390/virtio/virtio_ccw.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index d7569f395559..d6491fc84e8c 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -698,6 +698,7 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
dma64_t *indicatorp = NULL;
int ret, i, queue_idx = 0;
struct ccw1 *ccw;
+ dma32_t indicatorp_dma = 0;

ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
if (!ccw)
@@ -725,7 +726,7 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
*/
indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
sizeof(*indicatorp),
- &ccw->cda);
+ &indicatorp_dma);
if (!indicatorp)
goto out;
*indicatorp = indicators_dma(vcdev);
@@ -735,6 +736,7 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
/* no error, just fall back to legacy interrupts */
vcdev->is_thinint = false;
}
+ ccw->cda = indicatorp_dma;
if (!vcdev->is_thinint) {
/* Register queue indicators with host. */
*indicators(vcdev) = 0;

base-commit: 83a7eefedc9b56fe7bfeff13b6c7356688ffa670
--
2.40.1



2024-06-12 14:04:36

by Thomas Huth

[permalink] [raw]
Subject: Re: [PATCH 1/1] s390/virtio_ccw: fix config change notifications

On 11/06/2024 23.47, Halil Pasic wrote:
> Commit e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
> broke configuration change notifications for virtio-ccw by putting the
> DMA address of *indicatorp directly into ccw->cda disregarding the fact
> that if !!(vcdev->is_thinint) then the function
> virtio_ccw_register_adapter_ind() will overwrite that ccw->cda value
> with the address of the virtio_thinint_area so it can actually set up
> the adapter interrupts via CCW_CMD_SET_IND_ADAPTER. Thus we end up
> pointing to the wrong object for both CCW_CMD_SET_IND if setting up the
> adapter interrupts fails, and for CCW_CMD_SET_CONF_IND regardless
> whether it succeeds or fails.
>
> To fix this, let us save away the dma address of *indicatorp in a local
> variable, and copy it to ccw->cda after the "vcdev->is_thinint" branch.
>
> Reported-by: Boqiao Fu <[email protected]>
> Reported-by: Sebastian Mitterle <[email protected]>
> Fixes: e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
> Signed-off-by: Halil Pasic <[email protected]>
> ---
> I know that checkpatch.pl complains about a missing 'Closes' tag.
> Unfortunately I don't have an appropriate URL at hand. @Sebastian,
> @Boqiao: do you have any suggetions?

Closes: https://issues.redhat.com/browse/RHEL-39983
?

Anyway, I've tested the patch and it indeed fixes the problem with
virtio-balloon and the link state for me:

Tested-by: Thomas Huth <[email protected]>


2024-06-13 13:25:11

by Halil Pasic

[permalink] [raw]
Subject: Re: [PATCH 1/1] s390/virtio_ccw: fix config change notifications

On Wed, 12 Jun 2024 16:04:15 +0200
Thomas Huth <[email protected]> wrote:

> On 11/06/2024 23.47, Halil Pasic wrote:
> > Commit e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
> > broke configuration change notifications for virtio-ccw by putting the
> > DMA address of *indicatorp directly into ccw->cda disregarding the fact
> > that if !!(vcdev->is_thinint) then the function
> > virtio_ccw_register_adapter_ind() will overwrite that ccw->cda value
> > with the address of the virtio_thinint_area so it can actually set up
> > the adapter interrupts via CCW_CMD_SET_IND_ADAPTER. Thus we end up
> > pointing to the wrong object for both CCW_CMD_SET_IND if setting up the
> > adapter interrupts fails, and for CCW_CMD_SET_CONF_IND regardless
> > whether it succeeds or fails.
> >
> > To fix this, let us save away the dma address of *indicatorp in a local
> > variable, and copy it to ccw->cda after the "vcdev->is_thinint" branch.
> >
> > Reported-by: Boqiao Fu <[email protected]>
> > Reported-by: Sebastian Mitterle <[email protected]>
> > Fixes: e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
> > Signed-off-by: Halil Pasic <[email protected]>
> > ---
> > I know that checkpatch.pl complains about a missing 'Closes' tag.
> > Unfortunately I don't have an appropriate URL at hand. @Sebastian,
> > @Boqiao: do you have any suggetions?
>
> Closes: https://issues.redhat.com/browse/RHEL-39983
> ?

Yep! That is a public bug tracker bug. Qualifies!
@Vasily: Can you guys pick hat one up when picking the patch?

>
> Anyway, I've tested the patch and it indeed fixes the problem with
> virtio-balloon and the link state for me:
>
> Tested-by: Thomas Huth <[email protected]>
>

Thanks!

2024-06-13 14:43:28

by Eric Farman

[permalink] [raw]
Subject: Re: [PATCH 1/1] s390/virtio_ccw: fix config change notifications

On Tue, 2024-06-11 at 23:47 +0200, Halil Pasic wrote:
> Commit e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
> broke configuration change notifications for virtio-ccw by putting
> the
> DMA address of *indicatorp directly into ccw->cda disregarding the
> fact
> that if !!(vcdev->is_thinint) then the function
> virtio_ccw_register_adapter_ind() will overwrite that ccw->cda value
> with the address of the virtio_thinint_area so it can actually set up
> the adapter interrupts via CCW_CMD_SET_IND_ADAPTER.  Thus we end up
> pointing to the wrong object for both CCW_CMD_SET_IND if setting up
> the
> adapter interrupts fails, and for CCW_CMD_SET_CONF_IND regardless
> whether it succeeds or fails.
>
> To fix this, let us save away the dma address of *indicatorp in a
> local
> variable, and copy it to ccw->cda after the "vcdev->is_thinint"
> branch.
>
> Reported-by: Boqiao Fu <[email protected]>
> Reported-by: Sebastian Mitterle <[email protected]>
> Fixes: e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
> Signed-off-by: Halil Pasic <[email protected]>
> ---
> I know that checkpatch.pl complains about a missing 'Closes' tag.
> Unfortunately I don't have an appropriate URL at hand. @Sebastian,
> @Boqiao: do you have any suggetions?
> ---
>  drivers/s390/virtio/virtio_ccw.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)

Reviewed-by: Eric Farman <[email protected]>

2024-06-13 21:51:00

by Vasily Gorbik

[permalink] [raw]
Subject: Re: [PATCH 1/1] s390/virtio_ccw: fix config change notifications

On Thu, Jun 13, 2024 at 03:21:15PM +0200, Halil Pasic wrote:
> On Wed, 12 Jun 2024 16:04:15 +0200
> Thomas Huth <[email protected]> wrote:
>
> > On 11/06/2024 23.47, Halil Pasic wrote:
> > > Commit e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
> > > broke configuration change notifications for virtio-ccw by putting the
> > > DMA address of *indicatorp directly into ccw->cda disregarding the fact
> > > that if !!(vcdev->is_thinint) then the function
> > > virtio_ccw_register_adapter_ind() will overwrite that ccw->cda value
> > > with the address of the virtio_thinint_area so it can actually set up
> > > the adapter interrupts via CCW_CMD_SET_IND_ADAPTER. Thus we end up
> > > pointing to the wrong object for both CCW_CMD_SET_IND if setting up the
> > > adapter interrupts fails, and for CCW_CMD_SET_CONF_IND regardless
> > > whether it succeeds or fails.
> > >
> > > To fix this, let us save away the dma address of *indicatorp in a local
> > > variable, and copy it to ccw->cda after the "vcdev->is_thinint" branch.
> > >
> > > Reported-by: Boqiao Fu <[email protected]>
> > > Reported-by: Sebastian Mitterle <[email protected]>
> > > Fixes: e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
> > > Signed-off-by: Halil Pasic <[email protected]>
> > > ---
> > > I know that checkpatch.pl complains about a missing 'Closes' tag.
> > > Unfortunately I don't have an appropriate URL at hand. @Sebastian,
> > > @Boqiao: do you have any suggetions?
> >
> > Closes: https://issues.redhat.com/browse/RHEL-39983
> > ?
>
> Yep! That is a public bug tracker bug. Qualifies!
> @Vasily: Can you guys pick hat one up when picking the patch?

Sure, applied. Thanks!