From: Jiqian Chen <Jiqian.Chen@amd.com>
To: "Michael S . Tsirkin" <mst@redhat.com>, <qemu-devel@nongnu.org>
Cc: Huang Rui <Ray.Huang@amd.com>, Jiqian Chen <Jiqian.Chen@amd.com>
Subject: [RFC QEMU PATCH v8 2/2] virtio-pci: implement No_Soft_Reset bit
Date: Thu, 28 Mar 2024 18:39:03 +0800 [thread overview]
Message-ID: <20240328103903.408290-3-Jiqian.Chen@amd.com> (raw)
In-Reply-To: <20240328103903.408290-1-Jiqian.Chen@amd.com>
In current code, when guest does S3, virtio devices 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.
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
---
hw/virtio/virtio-pci.c | 29 +++++++++++++++++++++++++++++
include/hw/virtio/virtio-pci.h | 5 +++++
2 files changed, 34 insertions(+)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 05dd03758d9f..8d9fab855c7d 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -2378,6 +2378,11 @@ 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,
@@ -2440,11 +2445,33 @@ 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)
{
PCIDevice *dev = PCI_DEVICE(obj);
DeviceState *qdev = DEVICE(obj);
+ if (virtio_pci_no_soft_reset(dev)) {
+ return;
+ }
+
virtio_pci_reset(qdev);
if (pci_is_express(dev)) {
@@ -2484,6 +2511,8 @@ 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),
+ DEFINE_PROP_BIT("x-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 4d57a9c75130..c758eb738234 100644
--- a/include/hw/virtio/virtio-pci.h
+++ b/include/hw/virtio/virtio-pci.h
@@ -44,6 +44,7 @@ enum {
VIRTIO_PCI_FLAG_AER_BIT,
VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT,
VIRTIO_PCI_FLAG_VDPA_BIT,
+ VIRTIO_PCI_FLAG_PM_NO_SOFT_RESET_BIT,
};
/* Need to activate work-arounds for buggy guests at vmstate load. */
@@ -80,6 +81,10 @@ 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
next prev parent reply other threads:[~2024-03-28 10:40 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-28 10:39 [RFC QEMU PATCH v8 0/1] S3 support Jiqian Chen
2024-03-28 10:39 ` [RFC QEMU PATCH v8 1/2] virtio-pci: only reset pm state during resetting Jiqian Chen
2024-03-28 10:39 ` Jiqian Chen [this message]
2024-03-28 10:57 ` [RFC QEMU PATCH v8 2/2] virtio-pci: implement No_Soft_Reset bit Michael S. Tsirkin
2024-03-28 11:08 ` Chen, Jiqian
2024-03-28 12:36 ` Michael S. Tsirkin
2024-03-29 7:00 ` Chen, Jiqian
2024-03-29 7:20 ` Jason Wang
2024-03-29 8:00 ` Chen, Jiqian
2024-03-29 10:38 ` Jason Wang
2024-04-02 2:56 ` Chen, Jiqian
2024-03-29 10:44 ` Michael S. Tsirkin
2024-04-02 3:03 ` Chen, Jiqian
2024-04-07 3:20 ` Jason Wang
2024-04-07 11:49 ` Michael S. Tsirkin
2024-04-08 4:56 ` Jason Wang
2024-04-12 6:10 ` Chen, Jiqian
2024-04-12 6:04 ` Chen, Jiqian
2024-04-12 6:41 ` Jason Wang
2024-04-12 6:49 ` Chen, Jiqian
2024-04-12 5:59 ` Chen, Jiqian
2024-04-12 6:42 ` Jason Wang
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