From: Laurent Vivier lvivier@redhat.com
commit 9ea69a55b3b9a71cded9726af591949c1138f235 upstream.
With virtio multiqueue, normally each queue IRQ is mapped to a CPU.
Commit 0d9f0a52c8b9f ("virtio_scsi: use virtio IRQ affinity") exposed an existing shortcoming of the arch code by moving virtio_scsi to the automatic IRQ affinity assignment.
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.
Use the new irq_create_mapping_affinity() function, which allows to forward the affinity setting from rtas_setup_msi_irqs() to irq_domain_alloc_descs().
With this change, the virtqueues are correctly dispatched between the CPUs on pseries.
Fixes: e75eafb9b039 ("genirq/msi: Switch to new irq spreading infrastructure") Signed-off-by: Laurent Vivier lvivier@redhat.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Greg Kurz groug@kaod.org Acked-by: Michael Ellerman mpe@ellerman.id.au Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201126082852.1178497-3-lvivier@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/platforms/pseries/msi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/powerpc/platforms/pseries/msi.c +++ b/arch/powerpc/platforms/pseries/msi.c @@ -458,7 +458,8 @@ again: 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);