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

[Deng, Emily]

[AMD Official Use Only - Internal Distribution Only]

Hi Monk,
     Could you help to review this patch?

Best wishes
Emily Deng

>-----Original Message-----
>From: Deng, Emily <Emily.Deng at amd.com>
>Sent: Wednesday, March 31, 2021 5:02 PM
>To: Deng, Emily <Emily.Deng at amd.com>; amd-gfx at lists.freedesktop.org
>Subject: RE: [PATCH] drm/amdgpu: Toggle msix after FLR for sriov
>
>[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
>