Since commit 65c7cdedeb30 ("genirq: Provide new interfaces for affinity
hints") irq_set_affinity_hint is being phased out.
Switch to new interfaces for setting and applying irq affinity hints.
Signed-off-by: Jakub Sitnicki <[email protected]>
---
v2:
- Leave cpumask_copy as is. We can't pass pointer to stack memory as hint.
Proposed a change to IRQ affinity interface to address this limitation:
https://lore.kernel.org/r/[email protected]
v1: https://lore.kernel.org/r/[email protected]
---
drivers/virtio/virtio_pci_common.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index c2524a7207cf..7a5593997e0e 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -242,7 +242,7 @@ void vp_del_vqs(struct virtio_device *vdev)
if (v != VIRTIO_MSI_NO_VECTOR) {
int irq = pci_irq_vector(vp_dev->pci_dev, v);
- irq_set_affinity_hint(irq, NULL);
+ irq_update_affinity_hint(irq, NULL);
free_irq(irq, vq);
}
}
@@ -443,10 +443,10 @@ int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask)
mask = vp_dev->msix_affinity_masks[info->msix_vector];
irq = pci_irq_vector(vp_dev->pci_dev, info->msix_vector);
if (!cpu_mask)
- irq_set_affinity_hint(irq, NULL);
+ irq_update_affinity_hint(irq, NULL);
else {
cpumask_copy(mask, cpu_mask);
- irq_set_affinity_hint(irq, mask);
+ irq_set_affinity_and_hint(irq, mask);
}
}
return 0;
--
2.41.0
On Wed, 25 Oct 2023 16:53:19 +0200, Jakub Sitnicki <[email protected]> wrote:
> Since commit 65c7cdedeb30 ("genirq: Provide new interfaces for affinity
> hints") irq_set_affinity_hint is being phased out.
>
> Switch to new interfaces for setting and applying irq affinity hints.
>
> Signed-off-by: Jakub Sitnicki <[email protected]>
Reviewed-by: Xuan Zhuo <[email protected]>
Thanks.
> ---
> v2:
> - Leave cpumask_copy as is. We can't pass pointer to stack memory as hint.
> Proposed a change to IRQ affinity interface to address this limitation:
> https://lore.kernel.org/r/[email protected]
>
> v1: https://lore.kernel.org/r/[email protected]
> ---
> drivers/virtio/virtio_pci_common.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
> index c2524a7207cf..7a5593997e0e 100644
> --- a/drivers/virtio/virtio_pci_common.c
> +++ b/drivers/virtio/virtio_pci_common.c
> @@ -242,7 +242,7 @@ void vp_del_vqs(struct virtio_device *vdev)
> if (v != VIRTIO_MSI_NO_VECTOR) {
> int irq = pci_irq_vector(vp_dev->pci_dev, v);
>
> - irq_set_affinity_hint(irq, NULL);
> + irq_update_affinity_hint(irq, NULL);
> free_irq(irq, vq);
> }
> }
> @@ -443,10 +443,10 @@ int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask)
> mask = vp_dev->msix_affinity_masks[info->msix_vector];
> irq = pci_irq_vector(vp_dev->pci_dev, info->msix_vector);
> if (!cpu_mask)
> - irq_set_affinity_hint(irq, NULL);
> + irq_update_affinity_hint(irq, NULL);
> else {
> cpumask_copy(mask, cpu_mask);
> - irq_set_affinity_hint(irq, mask);
> + irq_set_affinity_and_hint(irq, mask);
> }
> }
> return 0;
> --
> 2.41.0
>
On Wed, Oct 25, 2023 at 04:53 PM +02, Jakub Sitnicki wrote:
> Since commit 65c7cdedeb30 ("genirq: Provide new interfaces for affinity
> hints") irq_set_affinity_hint is being phased out.
>
> Switch to new interfaces for setting and applying irq affinity hints.
>
> Signed-off-by: Jakub Sitnicki <[email protected]>
> ---
> v2:
> - Leave cpumask_copy as is. We can't pass pointer to stack memory as hint.
> Proposed a change to IRQ affinity interface to address this limitation:
> https://lore.kernel.org/r/[email protected]
Just a note to the ^ - if we wanted to get rid of msix_affinity_masks,
we could call irq_set_affinity directly, instead of calling it through
irq_set_affinity[_and]_hint.
The hint wouldn't be available any more in /proc/irq/N/affinity_hint,
but the same information can be gathered from /proc/irq/N/smp_affinity.
[...]
On Thu, Oct 26, 2023 at 06:25:08PM +0200, Jakub Sitnicki wrote:
> On Wed, Oct 25, 2023 at 04:53 PM +02, Jakub Sitnicki wrote:
> > Since commit 65c7cdedeb30 ("genirq: Provide new interfaces for affinity
> > hints") irq_set_affinity_hint is being phased out.
> >
> > Switch to new interfaces for setting and applying irq affinity hints.
> >
> > Signed-off-by: Jakub Sitnicki <[email protected]>
> > ---
> > v2:
> > - Leave cpumask_copy as is. We can't pass pointer to stack memory as hint.
> > Proposed a change to IRQ affinity interface to address this limitation:
> > https://lore.kernel.org/r/[email protected]
>
> Just a note to the ^ - if we wanted to get rid of msix_affinity_masks,
> we could call irq_set_affinity directly, instead of calling it through
> irq_set_affinity[_and]_hint.
>
> The hint wouldn't be available any more in /proc/irq/N/affinity_hint,
> but the same information can be gathered from /proc/irq/N/smp_affinity.
>
> [...]
So we are potentially breaking some userspace - what's the value we
gain? Is there some way we can make disable_irq/enable_irq work?
That would have a lot of value.
There is an actual need for that in virtio for coco but we can't use
these APIs with affinity managed IRQs.
--
MST
On Thu, Oct 26, 2023 at 01:20 PM -04, Michael S. Tsirkin wrote:
> On Thu, Oct 26, 2023 at 06:25:08PM +0200, Jakub Sitnicki wrote:
>> On Wed, Oct 25, 2023 at 04:53 PM +02, Jakub Sitnicki wrote:
>> > Since commit 65c7cdedeb30 ("genirq: Provide new interfaces for affinity
>> > hints") irq_set_affinity_hint is being phased out.
>> >
>> > Switch to new interfaces for setting and applying irq affinity hints.
>> >
>> > Signed-off-by: Jakub Sitnicki <[email protected]>
>> > ---
>> > v2:
>> > - Leave cpumask_copy as is. We can't pass pointer to stack memory as hint.
>> > Proposed a change to IRQ affinity interface to address this limitation:
>> > https://lore.kernel.org/r/[email protected]
>>
>> Just a note to the ^ - if we wanted to get rid of msix_affinity_masks,
>> we could call irq_set_affinity directly, instead of calling it through
>> irq_set_affinity[_and]_hint.
>>
>> The hint wouldn't be available any more in /proc/irq/N/affinity_hint,
>> but the same information can be gathered from /proc/irq/N/smp_affinity.
>>
>> [...]
>
>
> So we are potentially breaking some userspace - what's the value we
> gain? Is there some way we can make disable_irq/enable_irq work?
> That would have a lot of value.
> There is an actual need for that in virtio for coco but we can't use
> these APIs with affinity managed IRQs.
Sorry, that is beyond my ken today.
I saw the comment in vp_modern_disable_vq_and_reset:
/* For the case where vq has an exclusive irq, call synchronize_irq() to
* wait for completion.
*
* note: We can't use disable_irq() since it conflicts with the affinity
* managed IRQ that is used by some drivers.
*/
... but I fail to follow how the two conflict.
Perhaps Xuah could shed some light here.
On Fri, 27 Oct 2023 12:03:17 +0200, Jakub Sitnicki <[email protected]> wrote:
> On Thu, Oct 26, 2023 at 01:20 PM -04, Michael S. Tsirkin wrote:
> > On Thu, Oct 26, 2023 at 06:25:08PM +0200, Jakub Sitnicki wrote:
> >> On Wed, Oct 25, 2023 at 04:53 PM +02, Jakub Sitnicki wrote:
> >> > Since commit 65c7cdedeb30 ("genirq: Provide new interfaces for affinity
> >> > hints") irq_set_affinity_hint is being phased out.
> >> >
> >> > Switch to new interfaces for setting and applying irq affinity hints.
> >> >
> >> > Signed-off-by: Jakub Sitnicki <[email protected]>
> >> > ---
> >> > v2:
> >> > - Leave cpumask_copy as is. We can't pass pointer to stack memory as hint.
> >> > Proposed a change to IRQ affinity interface to address this limitation:
> >> > https://lore.kernel.org/r/[email protected]
> >>
> >> Just a note to the ^ - if we wanted to get rid of msix_affinity_masks,
> >> we could call irq_set_affinity directly, instead of calling it through
> >> irq_set_affinity[_and]_hint.
> >>
> >> The hint wouldn't be available any more in /proc/irq/N/affinity_hint,
> >> but the same information can be gathered from /proc/irq/N/smp_affinity.
> >>
> >> [...]
> >
> >
> > So we are potentially breaking some userspace - what's the value we
> > gain? Is there some way we can make disable_irq/enable_irq work?
> > That would have a lot of value.
> > There is an actual need for that in virtio for coco but we can't use
> > these APIs with affinity managed IRQs.
>
> Sorry, that is beyond my ken today.
>
> I saw the comment in vp_modern_disable_vq_and_reset:
>
> /* For the case where vq has an exclusive irq, call synchronize_irq() to
> * wait for completion.
> *
> * note: We can't use disable_irq() since it conflicts with the affinity
> * managed IRQ that is used by some drivers.
> */
>
> ... but I fail to follow how the two conflict.
>
> Perhaps Xuah could shed some light here.
I forgot which device that manages the irq by it self. If we disable the irq,
then the device will lost the irq, so we must not call disable_irq().
Thanks.