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Merge branch 'remotes/lorenzo/pci/hv'

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- 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
This commit is contained in:
Bjorn Helgaas 2020-10-21 09:58:39 -05:00
commit 9d69d649bb
1 changed files with 47 additions and 3 deletions
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50
drivers/pci/controller/pci-hyperv.c
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@ -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: