2021-07-20 05:26:49

by Eli Cohen

Subject: [PATCH v1] vdpa/vdpa_sim: Use the negotiated features when calling vringh_init_iotlb

When calling vringh_init_iotlb(), use the negotiated features which
might be different than the supported features.

Fixes: 2c53d0f64c06f ("vdpasim: vDPA device simulator")
Signed-off-by: Eli Cohen <[email protected]>
---
v0 --> v1:
Update "Fixes" line

drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 14e024de5cbf..89a474c7a096 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -66,7 +66,7 @@ static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
{
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];

- vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
+ vringh_init_iotlb(&vq->vring, vdpasim->features,
VDPASIM_QUEUE_MAX, false,
(struct vring_desc *)(uintptr_t)vq->desc_addr,
(struct vring_avail *)
@@ -86,7 +86,7 @@ static void vdpasim_vq_reset(struct vdpasim *vdpasim,
vq->device_addr = 0;
vq->cb = NULL;
vq->private = NULL;
- vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
+ vringh_init_iotlb(&vq->vring, vdpasim->features,
VDPASIM_QUEUE_MAX, false, NULL, NULL, NULL);

vq->vring.notify = NULL;
--
2.30.1

2021-07-20 07:00:28

by Stefano Garzarella

Subject: Re: [PATCH v1] vdpa/vdpa_sim: Use the negotiated features when calling vringh_init_iotlb

On Tue, Jul 20, 2021 at 08:25:33AM +0300, Eli Cohen wrote:
>When calling vringh_init_iotlb(), use the negotiated features which
>might be different than the supported features.
>
>Fixes: 2c53d0f64c06f ("vdpasim: vDPA device simulator")
>Signed-off-by: Eli Cohen <[email protected]>
>---
>v0 --> v1:
>Update "Fixes" line
>
> drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>index 14e024de5cbf..89a474c7a096 100644
>--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
>+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>@@ -66,7 +66,7 @@ static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
> {
> struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
>
>- vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
>+ vringh_init_iotlb(&vq->vring, vdpasim->features,
> VDPASIM_QUEUE_MAX, false,
> (struct vring_desc *)(uintptr_t)vq->desc_addr,
> (struct vring_avail *)
>@@ -86,7 +86,7 @@ static void vdpasim_vq_reset(struct vdpasim *vdpasim,
> vq->device_addr = 0;
> vq->cb = NULL;
> vq->private = NULL;
>- vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
>+ vringh_init_iotlb(&vq->vring, vdpasim->features,

vdpasim_vq_reset() is called while resetting the device in
vdpasim_reset() where we also set `vdpasim->features = 0` after
resetting the vqs, so maybe it's better to use the supported features
here, since the negotiated ones are related to the previous instance.

Thanks,
Stefano

2021-07-20 07:16:05

by Eli Cohen

Subject: Re: [PATCH v1] vdpa/vdpa_sim: Use the negotiated features when calling vringh_init_iotlb

On Tue, Jul 20, 2021 at 08:57:40AM +0200, Stefano Garzarella wrote:
> On Tue, Jul 20, 2021 at 08:25:33AM +0300, Eli Cohen wrote:
> > When calling vringh_init_iotlb(), use the negotiated features which
> > might be different than the supported features.
> >
> > Fixes: 2c53d0f64c06f ("vdpasim: vDPA device simulator")
> > Signed-off-by: Eli Cohen <[email protected]>
> > ---
> > v0 --> v1:
> > Update "Fixes" line
> >
> > drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > index 14e024de5cbf..89a474c7a096 100644
> > --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > @@ -66,7 +66,7 @@ static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
> > {
> > struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> >
> > - vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
> > + vringh_init_iotlb(&vq->vring, vdpasim->features,
> > VDPASIM_QUEUE_MAX, false,
> > (struct vring_desc *)(uintptr_t)vq->desc_addr,
> > (struct vring_avail *)
> > @@ -86,7 +86,7 @@ static void vdpasim_vq_reset(struct vdpasim *vdpasim,
> > vq->device_addr = 0;
> > vq->cb = NULL;
> > vq->private = NULL;
> > - vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
> > + vringh_init_iotlb(&vq->vring, vdpasim->features,
>
> vdpasim_vq_reset() is called while resetting the device in vdpasim_reset()
> where we also set `vdpasim->features = 0` after resetting the vqs, so maybe
> it's better to use the supported features here, since the negotiated ones
> are related to the previous instance.
>

I don't think using supported features is valid. Better to make sure
vringh_init_iotlb() is called after the features have been negotiated.

> Thanks,
> Stefano
>

2021-07-20 08:17:55

by Stefano Garzarella

Subject: Re: [PATCH v1] vdpa/vdpa_sim: Use the negotiated features when calling vringh_init_iotlb

On Tue, Jul 20, 2021 at 10:14:35AM +0300, Eli Cohen wrote:
>On Tue, Jul 20, 2021 at 08:57:40AM +0200, Stefano Garzarella wrote:
>> On Tue, Jul 20, 2021 at 08:25:33AM +0300, Eli Cohen wrote:
>> > When calling vringh_init_iotlb(), use the negotiated features which
>> > might be different than the supported features.
>> >
>> > Fixes: 2c53d0f64c06f ("vdpasim: vDPA device simulator")
>> > Signed-off-by: Eli Cohen <[email protected]>
>> > ---
>> > v0 --> v1:
>> > Update "Fixes" line
>> >
>> > drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 ++--
>> > 1 file changed, 2 insertions(+), 2 deletions(-)
>> >
>> > diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>> > index 14e024de5cbf..89a474c7a096 100644
>> > --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
>> > +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>> > @@ -66,7 +66,7 @@ static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
>> > {
>> > struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
>> >
>> > - vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
>> > + vringh_init_iotlb(&vq->vring, vdpasim->features,
>> > VDPASIM_QUEUE_MAX, false,
>> > (struct vring_desc *)(uintptr_t)vq->desc_addr,
>> > (struct vring_avail *)
>> > @@ -86,7 +86,7 @@ static void vdpasim_vq_reset(struct vdpasim *vdpasim,
>> > vq->device_addr = 0;
>> > vq->cb = NULL;
>> > vq->private = NULL;
>> > - vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
>> > + vringh_init_iotlb(&vq->vring, vdpasim->features,
>>
>> vdpasim_vq_reset() is called while resetting the device in vdpasim_reset()
>> where we also set `vdpasim->features = 0` after resetting the vqs, so maybe
>> it's better to use the supported features here, since the negotiated ones
>> are related to the previous instance.
>>
>
>I don't think using supported features is valid. Better to make sure
>vringh_init_iotlb() is called after the features have been negotiated.
>

I think the vringh_init_iotlb() call in vdpasim_vq_reset() is just used
to clean up the `struct vringh`, then it will be initialized in
vdpasim_queue_ready() when features have already been negotiated.

Maybe here we can pass 0 (to the features parameter) if we don't want to
use the features supported by the device.

Thanks,
Stefano

2021-08-10 16:44:18

by Michael S. Tsirkin

Subject: Re: [PATCH v1] vdpa/vdpa_sim: Use the negotiated features when calling vringh_init_iotlb

On Tue, Jul 20, 2021 at 10:13:27AM +0200, Stefano Garzarella wrote:
> On Tue, Jul 20, 2021 at 10:14:35AM +0300, Eli Cohen wrote:
> > On Tue, Jul 20, 2021 at 08:57:40AM +0200, Stefano Garzarella wrote:
> > > On Tue, Jul 20, 2021 at 08:25:33AM +0300, Eli Cohen wrote:
> > > > When calling vringh_init_iotlb(), use the negotiated features which
> > > > might be different than the supported features.
> > > >
> > > > Fixes: 2c53d0f64c06f ("vdpasim: vDPA device simulator")
> > > > Signed-off-by: Eli Cohen <[email protected]>
> > > > ---
> > > > v0 --> v1:
> > > > Update "Fixes" line
> > > >
> > > > drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 ++--
> > > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > > > index 14e024de5cbf..89a474c7a096 100644
> > > > --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > > > +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> > > > @@ -66,7 +66,7 @@ static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
> > > > {
> > > > struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> > > >
> > > > - vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
> > > > + vringh_init_iotlb(&vq->vring, vdpasim->features,
> > > > VDPASIM_QUEUE_MAX, false,
> > > > (struct vring_desc *)(uintptr_t)vq->desc_addr,
> > > > (struct vring_avail *)
> > > > @@ -86,7 +86,7 @@ static void vdpasim_vq_reset(struct vdpasim *vdpasim,
> > > > vq->device_addr = 0;
> > > > vq->cb = NULL;
> > > > vq->private = NULL;
> > > > - vringh_init_iotlb(&vq->vring, vdpasim->dev_attr.supported_features,
> > > > + vringh_init_iotlb(&vq->vring, vdpasim->features,
> > >
> > > vdpasim_vq_reset() is called while resetting the device in vdpasim_reset()
> > > where we also set `vdpasim->features = 0` after resetting the vqs, so maybe
> > > it's better to use the supported features here, since the negotiated ones
> > > are related to the previous instance.
> > >
> >
> > I don't think using supported features is valid. Better to make sure
> > vringh_init_iotlb() is called after the features have been negotiated.
> >
>
> I think the vringh_init_iotlb() call in vdpasim_vq_reset() is just used to
> clean up the `struct vringh`, then it will be initialized in
> vdpasim_queue_ready() when features have already been negotiated.
>
> Maybe here we can pass 0 (to the features parameter) if we don't want to use
> the features supported by the device.
>
> Thanks,
> Stefano

Eli? Maybe you can describe what is the observed bug the patch
is trying to fix.

Thanks!

--
MST