[PATCH] drm/amdgpu: Toggle msix after FLR for sriov

[Deng, Emily]

[AMD Official Use Only - Internal Distribution Only]

Ping ......

>-----Original Message-----
>From: Emily Deng <Emily.Deng at amd.com>
>Sent: Tuesday, March 30, 2021 5:43 PM
>To: amd-gfx at lists.freedesktop.org
>Cc: Deng, Emily <Emily.Deng at amd.com>
>Subject: [PATCH] drm/amdgpu: Toggle msix after FLR for sriov
>
>From: "Emily.Deng" <Emily.Deng at amd.com>
>
>For vf assigned to guest VM, after FLR, the msix table will be reset.
>As the flr is done on host driver. The qemu and vfio driver don't know this,
>and the msix is still enable from qemu and vfio driver side.
>So if want to  re-setup the msix table, first need to disable and re-enable the
>msix from guest VM side or the qemu will do nothing as it thought the msix is
>already enabled.
>
>v2:
>Change name with amdgpu_irq prefix, remove #ifdef.
>
>Signed-off-by: Emily.Deng <Emily.Deng at amd.com>
>---
> drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
>diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
>b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
>index 03412543427a..3045f52e613d 100644
>--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
>+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
>@@ -277,6 +277,17 @@ static bool amdgpu_msi_ok(struct amdgpu_device
>*adev)
> return true;
> }
>
>+static void amdgpu_irq_restore_msix(struct amdgpu_device *adev) {
>+u16 ctrl;
>+
>+pci_read_config_word(adev->pdev, adev->pdev->msix_cap +
>PCI_MSIX_FLAGS, &ctrl);
>+ctrl &= ~PCI_MSIX_FLAGS_ENABLE;
>+pci_write_config_word(adev->pdev, adev->pdev->msix_cap +
>PCI_MSIX_FLAGS, ctrl);
>+ctrl |= PCI_MSIX_FLAGS_ENABLE;
>+pci_write_config_word(adev->pdev, adev->pdev->msix_cap +
>+PCI_MSIX_FLAGS, ctrl); }
>+
> /**
>  * amdgpu_irq_init - initialize interrupt handling
>  *
>@@ -558,6 +569,9 @@ void amdgpu_irq_gpu_reset_resume_helper(struct
>amdgpu_device *adev)  {
> int i, j, k;
>
>+if (amdgpu_sriov_vf(adev))
>+amdgpu_irq_restore_msix(adev);
>+
> for (i = 0; i < AMDGPU_IRQ_CLIENTID_MAX; ++i) {
> if (!adev->irq.client[i].sources)
> continue;
>--
>2.25.1