The effective_affinity_mask is always set when an interrupt is assigned in __assign_irq_vector() -> apic->cpu_mask_to_apicid(), e.g. for struct apic apic_physflat: -> default_cpu_mask_to_apicid() -> irq_data_update_effective_affinity(), but it looks d->common->affinity remains all-1's before the user space or the kernel changes it later.
In the early allocation/initialization phase of an irq, we should use the effective_affinity_mask, otherwise Hyper-V may not deliver the interrupt to the expected cpu. Without the patch, if we assign 7 Mellanox ConnectX-3 VFs to a 32-vCPU VM, one of the VFs may fail to receive interrupts. Signed-off-by: Dexuan Cui <de...@microsoft.com> Cc: Jake Oshins <ja...@microsoft.com> Cc: Jork Loeser <jloe...@microsoft.com> Cc: Stephen Hemminger <sthem...@microsoft.com> Cc: K. Y. Srinivasan <k...@microsoft.com> --- Please consider this for v4.14, if it's not too late. drivers/pci/host/pci-hyperv.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c index 5ccb47d..8b5f66d 100644 --- a/drivers/pci/host/pci-hyperv.c +++ b/drivers/pci/host/pci-hyperv.c @@ -879,7 +879,7 @@ static void hv_irq_unmask(struct irq_data *data) int cpu; u64 res; - dest = irq_data_get_affinity_mask(data); + dest = irq_data_get_effective_affinity_mask(data); pdev = msi_desc_to_pci_dev(msi_desc); pbus = pdev->bus; hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata); @@ -1042,6 +1042,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) struct hv_pci_dev *hpdev; struct pci_bus *pbus; struct pci_dev *pdev; + struct cpumask *dest; struct compose_comp_ctxt comp; struct tran_int_desc *int_desc; struct { @@ -1056,6 +1057,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) int ret; pdev = msi_desc_to_pci_dev(irq_data_get_msi_desc(data)); + dest = irq_data_get_effective_affinity_mask(data); pbus = pdev->bus; hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata); hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn)); @@ -1081,14 +1083,14 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) switch (pci_protocol_version) { case PCI_PROTOCOL_VERSION_1_1: size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1, - irq_data_get_affinity_mask(data), + dest, hpdev->desc.win_slot.slot, cfg->vector); break; case PCI_PROTOCOL_VERSION_1_2: size = hv_compose_msi_req_v2(&ctxt.int_pkts.v2, - irq_data_get_affinity_mask(data), + dest, hpdev->desc.win_slot.slot, cfg->vector); break; -- 2.7.4