PCI: hv: Use effective affinity mask

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.

Tested-by: Adrian Suhov <v-adsuho@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jake Oshins <jakeo@microsoft.com>
Cc: stable@vger.kernel.org
Cc: Jork Loeser <jloeser@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 0fe3ea164ee5..04dac6a42c9f 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;