From: Laurent Vivier <lvivier@redhat.com> To: linux-kernel@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de>, Paul Mackerras <paulus@samba.org>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Michael Ellerman <mpe@ellerman.id.au>, linux-block@vger.kernel.org, "Michael S . Tsirkin" <mst@redhat.com>, Marc Zyngier <maz@kernel.org>, linuxppc-dev@lists.ozlabs.org, linux-pci@vger.kernel.org, Christoph Hellwig <hch@lst.de>, Laurent Vivier <lvivier@redhat.com> Subject: [PATCH 2/2] powerpc/pseries: pass MSI affinity to irq_create_mapping() Date: Tue, 24 Nov 2020 21:03:08 +0100 [thread overview] Message-ID: <20201124200308.1110744-3-lvivier@redhat.com> (raw) In-Reply-To: <20201124200308.1110744-1-lvivier@redhat.com> 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. This problem cannot be shown on x86_64 for two reasons: - the call path traverses arch_setup_msi_irqs() that is arch specific: virtscsi_probe() virtscsi_init() vp_modern_find_vqs() vp_find_vqs() vp_find_vqs_msix() pci_alloc_irq_vectors_affinity() __pci_enable_msix_range() pci_msi_setup_msi_irqs() arch_setup_msi_irqs() rtas_setup_msi_irqs() irq_create_mapping() irq_domain_alloc_descs() __irq_alloc_descs() - and x86_64 has CONFIG_PCI_MSI_IRQ_DOMAIN that uses another path: virtscsi_probe() virtscsi_init() vp_modern_find_vqs() vp_find_vqs() vp_find_vqs_msix() pci_alloc_irq_vectors_affinity() __pci_enable_msix_range() __msi_domain_alloc_irqs() __irq_domain_alloc_irqs() __irq_alloc_descs() Signed-off-by: Laurent Vivier <lvivier@redhat.com> --- arch/powerpc/platforms/pseries/msi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c index 42ba08eaea91..58197f92c6a2 100644 --- a/arch/powerpc/platforms/pseries/msi.c +++ b/arch/powerpc/platforms/pseries/msi.c @@ -458,7 +458,7 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type) return hwirq; } - virq = irq_create_mapping(NULL, hwirq, NULL); + virq = irq_create_mapping(NULL, hwirq, entry->affinity); if (!virq) { pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq); -- 2.28.0
WARNING: multiple messages have this Message-ID (diff)
From: Laurent Vivier <lvivier@redhat.com> To: linux-kernel@vger.kernel.org Cc: Laurent Vivier <lvivier@redhat.com>, Marc Zyngier <maz@kernel.org>, "Michael S . Tsirkin" <mst@redhat.com>, linux-pci@vger.kernel.org, linux-block@vger.kernel.org, Paul Mackerras <paulus@samba.org>, Thomas Gleixner <tglx@linutronix.de>, linuxppc-dev@lists.ozlabs.org, Christoph Hellwig <hch@lst.de> Subject: [PATCH 2/2] powerpc/pseries: pass MSI affinity to irq_create_mapping() Date: Tue, 24 Nov 2020 21:03:08 +0100 [thread overview] Message-ID: <20201124200308.1110744-3-lvivier@redhat.com> (raw) In-Reply-To: <20201124200308.1110744-1-lvivier@redhat.com> 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. This problem cannot be shown on x86_64 for two reasons: - the call path traverses arch_setup_msi_irqs() that is arch specific: virtscsi_probe() virtscsi_init() vp_modern_find_vqs() vp_find_vqs() vp_find_vqs_msix() pci_alloc_irq_vectors_affinity() __pci_enable_msix_range() pci_msi_setup_msi_irqs() arch_setup_msi_irqs() rtas_setup_msi_irqs() irq_create_mapping() irq_domain_alloc_descs() __irq_alloc_descs() - and x86_64 has CONFIG_PCI_MSI_IRQ_DOMAIN that uses another path: virtscsi_probe() virtscsi_init() vp_modern_find_vqs() vp_find_vqs() vp_find_vqs_msix() pci_alloc_irq_vectors_affinity() __pci_enable_msix_range() __msi_domain_alloc_irqs() __irq_domain_alloc_irqs() __irq_alloc_descs() Signed-off-by: Laurent Vivier <lvivier@redhat.com> --- arch/powerpc/platforms/pseries/msi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c index 42ba08eaea91..58197f92c6a2 100644 --- a/arch/powerpc/platforms/pseries/msi.c +++ b/arch/powerpc/platforms/pseries/msi.c @@ -458,7 +458,7 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type) return hwirq; } - virq = irq_create_mapping(NULL, hwirq, NULL); + virq = irq_create_mapping(NULL, hwirq, entry->affinity); if (!virq) { pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq); -- 2.28.0
next prev parent reply other threads:[~2020-11-24 20:03 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-11-24 20:03 [PATCH 0/2] powerpc/pseries: fix MSI/X IRQ affinity on pseries Laurent Vivier 2020-11-24 20:03 ` Laurent Vivier 2020-11-24 20:03 ` [PATCH 1/2] genirq: add an affinity parameter to irq_create_mapping() Laurent Vivier 2020-11-24 20:03 ` Laurent Vivier 2020-11-24 22:19 ` Thomas Gleixner 2020-11-24 22:19 ` Thomas Gleixner 2020-11-25 7:30 ` Laurent Vivier 2020-11-25 7:30 ` Laurent Vivier 2020-11-24 22:50 ` kernel test robot 2020-11-24 22:50 ` kernel test robot 2020-11-24 22:50 ` kernel test robot 2020-11-25 1:03 ` kernel test robot 2020-11-25 1:03 ` kernel test robot 2020-11-25 1:03 ` kernel test robot 2020-11-24 20:03 ` Laurent Vivier [this message] 2020-11-24 20:03 ` [PATCH 2/2] powerpc/pseries: pass MSI affinity " Laurent Vivier 2020-11-24 22:35 ` Thomas Gleixner 2020-11-24 22:35 ` Thomas Gleixner 2020-11-24 21:08 ` [PATCH 0/2] powerpc/pseries: fix MSI/X IRQ affinity on pseries Michael S. Tsirkin 2020-11-24 21:08 ` Michael S. Tsirkin
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