diff mbox series

[v10,1/2] virtio-pci: only reset pm state during resetting

Message ID 20240515073526.17297-2-Jiqian.Chen@amd.com (mailing list archive)
State New
Headers show
Series S3 support | expand

Commit Message

Jiqian Chen May 15, 2024, 7:35 a.m. UTC 
Fix bug imported by 27ce0f3afc9dd ("fix Power Management Control Register for PCI Express virtio devices"
After this change, observe that QEMU may erroneously clear the power status of the device,
or may erroneously clear non writable registers, such as NO_SOFT_RESET, etc.

Only state of PM_CTRL is writable.
Only when flag VIRTIO_PCI_FLAG_INIT_PM is set, need to reset state.

Fixes: 27ce0f3afc9dd ("fix Power Management Control Register for PCI Express virtio devices"

Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
---
 hw/virtio/virtio-pci.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index b1d02f4b3de0..1b63bcb3f15c 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -2300,10 +2300,16 @@  static void virtio_pci_bus_reset_hold(Object *obj, ResetType type)
     virtio_pci_reset(qdev);
 
     if (pci_is_express(dev)) {
+        VirtIOPCIProxy *proxy = VIRTIO_PCI(dev);
+
         pcie_cap_deverr_reset(dev);
         pcie_cap_lnkctl_reset(dev);
 
-        pci_set_word(dev->config + dev->exp.pm_cap + PCI_PM_CTRL, 0);
+        if (proxy->flags & VIRTIO_PCI_FLAG_INIT_PM) {
+            pci_word_test_and_clear_mask(
+                dev->config + dev->exp.pm_cap + PCI_PM_CTRL,
+                PCI_PM_CTRL_STATE_MASK);
+        }
     }
 }