On 2024/6/21 17:20, Chen, Jiqian wrote:
> Hi MST,
>
> On 2024/6/6 18:22, Jiqian Chen wrote:
>> 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/core/machine.c | 1 +
>> hw/virtio/virtio-pci.c | 29 +++++++++++++++++++++++++++++
>> include/hw/virtio/virtio-pci.h | 5 +++++
>> 3 files changed, 35 insertions(+)
>>
>> diff --git a/hw/core/machine.c b/hw/core/machine.c
>> index 77a356f232f5..b6af94edcd0a 100644
>> --- a/hw/core/machine.c
>> +++ b/hw/core/machine.c
>> @@ -36,6 +36,7 @@
>> GlobalProperty hw_compat_9_0[] = {
>> {"arm-cpu", "backcompat-cntfrq", "true" },
>> {"vfio-pci", "skip-vsc-check", "false" },
>> + { "virtio-pci", "x-pcie-pm-no-soft-reset", "off" },
>> };
>> const size_t hw_compat_9_0_len = G_N_ELEMENTS(hw_compat_9_0);
>>
>> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
>> index 1b63bcb3f15c..c881f853253c 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 +2297,33 @@ 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, ResetType type)
>> {
>> 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)) {
>> @@ -2336,6 +2363,8 @@ 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 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)
>>
> I have added compatibility for old machine.
> Do you have any other concerns about this patch?
>
If you don't have other concerns. May I get your Review-by?
--
Best regards,
Jiqian Chen.
