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authorBjorn Helgaas <bhelgaas@google.com>2020-10-21 09:58:39 -0500
committerBjorn Helgaas <bhelgaas@google.com>2020-10-21 09:58:39 -0500
commit9d69d649bbf8bef7983b9343d4514b214860a50b (patch)
tree723daec2649e27b13016d1ef0f648f524a758112 /drivers/pci/controller
parent924bb1f9b014bec2d38ebe98d5ee37f448dac691 (diff)
parent915cff7f38c5e4d47f187f8049245afc2cb3e503 (diff)
downloadlinux-9d69d649bbf8bef7983b9343d4514b214860a50b.tar.bz2
Merge branch 'remotes/lorenzo/pci/hv'
- Fix hibernation in case interrupts are not re-created (Dexuan Cui) * remotes/lorenzo/pci/hv: PCI: hv: Fix hibernation in case interrupts are not re-created
Diffstat (limited to 'drivers/pci/controller')
-rw-r--r--drivers/pci/controller/pci-hyperv.c50
1 files changed, 47 insertions, 3 deletions
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index fc4c3a15e570..a9df492fbffa 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -1276,11 +1276,25 @@ static void hv_irq_unmask(struct irq_data *data)
exit_unlock:
spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags);
- if (res) {
+ /*
+ * During hibernation, when a CPU is offlined, the kernel tries
+ * to move the interrupt to the remaining CPUs that haven't
+ * been offlined yet. In this case, the below hv_do_hypercall()
+ * always fails since the vmbus channel has been closed:
+ * refer to cpu_disable_common() -> fixup_irqs() ->
+ * irq_migrate_all_off_this_cpu() -> migrate_one_irq().
+ *
+ * Suppress the error message for hibernation because the failure
+ * during hibernation does not matter (at this time all the devices
+ * have been frozen). Note: the correct affinity info is still updated
+ * into the irqdata data structure in migrate_one_irq() ->
+ * irq_do_set_affinity() -> hv_set_affinity(), so later when the VM
+ * resumes, hv_pci_restore_msi_state() is able to correctly restore
+ * the interrupt with the correct affinity.
+ */
+ if (res && hbus->state != hv_pcibus_removing)
dev_err(&hbus->hdev->device,
"%s() failed: %#llx", __func__, res);
- return;
- }
pci_msi_unmask_irq(data);
}
@@ -3372,6 +3386,34 @@ static int hv_pci_suspend(struct hv_device *hdev)
return 0;
}
+static int hv_pci_restore_msi_msg(struct pci_dev *pdev, void *arg)
+{
+ struct msi_desc *entry;
+ struct irq_data *irq_data;
+
+ for_each_pci_msi_entry(entry, pdev) {
+ irq_data = irq_get_irq_data(entry->irq);
+ if (WARN_ON_ONCE(!irq_data))
+ return -EINVAL;
+
+ hv_compose_msi_msg(irq_data, &entry->msg);
+ }
+
+ return 0;
+}
+
+/*
+ * Upon resume, pci_restore_msi_state() -> ... -> __pci_write_msi_msg()
+ * directly writes the MSI/MSI-X registers via MMIO, but since Hyper-V
+ * doesn't trap and emulate the MMIO accesses, here hv_compose_msi_msg()
+ * must be used to ask Hyper-V to re-create the IOMMU Interrupt Remapping
+ * Table entries.
+ */
+static void hv_pci_restore_msi_state(struct hv_pcibus_device *hbus)
+{
+ pci_walk_bus(hbus->pci_bus, hv_pci_restore_msi_msg, NULL);
+}
+
static int hv_pci_resume(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
@@ -3405,6 +3447,8 @@ static int hv_pci_resume(struct hv_device *hdev)
prepopulate_bars(hbus);
+ hv_pci_restore_msi_state(hbus);
+
hbus->state = hv_pcibus_installed;
return 0;
out: