| Message ID | 20201125111657.1141295-3-lvivier@redhat.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | powerpc/pseries: fix MSI/X IRQ affinity on pseries | expand |
On Wed, 25 Nov 2020 12:16:57 +0100 Laurent Vivier <lvivier@redhat.com> wrote: > With virtio multiqueue, normally each queue IRQ is mapped to a CPU. > > But since commit 0d9f0a52c8b9f ("virtio_scsi: use virtio IRQ affinity") > this is broken on pseries. > > The affinity is correctly computed in msi_desc but this is not applied > to the system IRQs. > > It appears the affinity is correctly passed to rtas_setup_msi_irqs() but > lost at this point and never passed to irq_domain_alloc_descs() > (see commit 06ee6d571f0e ("genirq: Add affinity hint to irq allocation")) > because irq_create_mapping() doesn't take an affinity parameter. > > As the previous patch has added the affinity parameter to > irq_create_mapping() we can forward the affinity from rtas_setup_msi_irqs() > to irq_domain_alloc_descs(). > > With this change, the virtqueues are correctly dispatched between the CPUs > on pseries. > Since it is public, maybe add: BugId: https://bugzilla.redhat.com/show_bug.cgi?id=1702939 ? > Signed-off-by: Laurent Vivier <lvivier@redhat.com> > --- Anyway, Reviewed-by: Greg Kurz <groug@kaod.org> > arch/powerpc/platforms/pseries/msi.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c > index 133f6adcb39c..b3ac2455faad 100644 > --- a/arch/powerpc/platforms/pseries/msi.c > +++ b/arch/powerpc/platforms/pseries/msi.c > @@ -458,7 +458,8 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type) > return hwirq; > } > > - virq = irq_create_mapping(NULL, hwirq); > + virq = irq_create_mapping_affinity(NULL, hwirq, > + entry->affinity); > > if (!virq) { > pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);
diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c index 133f6adcb39c..b3ac2455faad 100644 --- a/arch/powerpc/platforms/pseries/msi.c +++ b/arch/powerpc/platforms/pseries/msi.c @@ -458,7 +458,8 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type) return hwirq; } - virq = irq_create_mapping(NULL, hwirq); + virq = irq_create_mapping_affinity(NULL, hwirq, + entry->affinity); if (!virq) { pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);
With virtio multiqueue, normally each queue IRQ is mapped to a CPU. But since commit 0d9f0a52c8b9f ("virtio_scsi: use virtio IRQ affinity") this is broken on pseries. The affinity is correctly computed in msi_desc but this is not applied to the system IRQs. It appears the affinity is correctly passed to rtas_setup_msi_irqs() but lost at this point and never passed to irq_domain_alloc_descs() (see commit 06ee6d571f0e ("genirq: Add affinity hint to irq allocation")) because irq_create_mapping() doesn't take an affinity parameter. As the previous patch has added the affinity parameter to irq_create_mapping() we can forward the affinity from rtas_setup_msi_irqs() to irq_domain_alloc_descs(). With this change, the virtqueues are correctly dispatched between the CPUs on pseries. Signed-off-by: Laurent Vivier <lvivier@redhat.com> --- arch/powerpc/platforms/pseries/msi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)