In current code, when guest does S3, virtio-gpu are reset due to the
bit No_Soft_Reset is not set. After resetting, the display resources
of virtio-gpu are destroyed, then the display can't come back and only
show blank after resuming.
Implement No_Soft_Reset bit of PCI_PM_CTRL register, then guest can check
this bit, if this bit is set, the devices resetting will not be done, and
then the display can work after resuming.
No_Soft_Reset bit is implemented for all virtio devices, and was tested
only on virtio-gpu device. Set it false by default for safety.
Signed-off-by: Jiqian Chen <jiqian.c...@amd.com>
---
hw/virtio/virtio-pci.c | 37 ++++++++++++++++++++++++++++++++++
include/hw/virtio/virtio-pci.h | 5 +++++
2 files changed, 42 insertions(+)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 1b63bcb3f15c..3052528c0730 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -2230,6 +2230,11 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error
**errp)
pcie_cap_lnkctl_init(pci_dev);
}
+ if (proxy->flags & VIRTIO_PCI_FLAG_PM_NO_SOFT_RESET) {
+ pci_set_word(pci_dev->config + pos + PCI_PM_CTRL,
+ PCI_PM_CTRL_NO_SOFT_RESET);
+ }
+
if (proxy->flags & VIRTIO_PCI_FLAG_INIT_PM) {
/* Init Power Management Control Register */
pci_set_word(pci_dev->wmask + pos + PCI_PM_CTRL,
@@ -2292,11 +2297,37 @@ static void virtio_pci_reset(DeviceState *qdev)
}
}
+static bool virtio_pci_no_soft_reset(PCIDevice *dev)
+{
+ uint16_t pmcsr;
+
+ if (!pci_is_express(dev) || !dev->exp.pm_cap) {
+ return false;
+ }
+
+ pmcsr = pci_get_word(dev->config + dev->exp.pm_cap + PCI_PM_CTRL);
+
+ /*
+ * When No_Soft_Reset bit is set and the device
+ * is in D3hot state, don't reset device
+ */
+ return (pmcsr & PCI_PM_CTRL_NO_SOFT_RESET) &&
+ (pmcsr & PCI_PM_CTRL_STATE_MASK) == 3;
+}
+
static void virtio_pci_bus_reset_hold(Object *obj, ResetType type)
{
PCIDevice *dev = PCI_DEVICE(obj);
DeviceState *qdev = DEVICE(obj);
+ /*
+ * Note that: a proposal to add SUSPEND bit is being discussed,
+ * may need to consider the state of SUSPEND bit in future
+ */
+ if (virtio_pci_no_soft_reset(dev)) {
+ return;
+ }
+
virtio_pci_reset(qdev);
if (pci_is_express(dev)) {
@@ -2336,6 +2367,12 @@ static Property virtio_pci_properties[] = {
VIRTIO_PCI_FLAG_INIT_LNKCTL_BIT, true),
DEFINE_PROP_BIT("x-pcie-pm-init", VirtIOPCIProxy, flags,
VIRTIO_PCI_FLAG_INIT_PM_BIT, true),
+ /*
+ * For safety, set this false by default, if change it to true,
+ * need to consider compatible for old machine
+ */
+ DEFINE_PROP_BIT("pcie-pm-no-soft-reset", VirtIOPCIProxy, flags,
+ VIRTIO_PCI_FLAG_PM_NO_SOFT_RESET_BIT, false),
DEFINE_PROP_BIT("x-pcie-flr-init", VirtIOPCIProxy, flags,
VIRTIO_PCI_FLAG_INIT_FLR_BIT, true),
DEFINE_PROP_BIT("aer", VirtIOPCIProxy, flags,
diff --git a/include/hw/virtio/virtio-pci.h b/include/hw/virtio/virtio-pci.h
index 59d88018c16a..9e67ba38c748 100644
--- a/include/hw/virtio/virtio-pci.h
+++ b/include/hw/virtio/virtio-pci.h
@@ -43,6 +43,7 @@ enum {
VIRTIO_PCI_FLAG_INIT_FLR_BIT,
VIRTIO_PCI_FLAG_AER_BIT,
VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT,
+ VIRTIO_PCI_FLAG_PM_NO_SOFT_RESET_BIT,
};
/* Need to activate work-arounds for buggy guests at vmstate load. */
@@ -79,6 +80,10 @@ enum {
/* Init Power Management */
#define VIRTIO_PCI_FLAG_INIT_PM (1 << VIRTIO_PCI_FLAG_INIT_PM_BIT)
+/* Init The No_Soft_Reset bit of Power Management */
+#define VIRTIO_PCI_FLAG_PM_NO_SOFT_RESET \
+ (1 << VIRTIO_PCI_FLAG_PM_NO_SOFT_RESET_BIT)
+
/* Init Function Level Reset capability */
#define VIRTIO_PCI_FLAG_INIT_FLR (1 << VIRTIO_PCI_FLAG_INIT_FLR_BIT)
--
2.34.1
