Am 19.09.2017 um 06:14 schrieb Liu, Monk:
Christian,

That sounds at least a bit better. But my question is why doesn't this work 
like it does on Tonga, e.g. correctly clean things up?
Tonga also suffer with this issue, just that we fixed it in the branch for CSP 
customer and staging code usually behind our private branch ...

Yeah, gut keeping the GART mapping alive is complete nonsense. When the driver 
unloads all memory should be returned to the OS.
So we either keep a GART mapping to pages which are about to be reused and 
overwritten, or we leak memory on driver shutdown.
Neither options sounds very good,
Unbinding the GART mapping makes CPC hang if it run MQD commands, and CPC must 
run MQD commands because RLCV always
Requires CPC do that when RLCV doing SAVE_VF commands,

Do you have way to fix above circle ?

Well the question is why does the CPC still needs the MQD commands and how can we prevent that?

The point is when we need to keep the GART alive to avoid a crash after driver unload we also need to keep the pages alive where the GART points to.

This means that the pages are either overwritten or we get massive complains from the MM that we are leaking pages here.

If it's not possible to turn of the CPC on driver unload the only alternative I can see is to reprogram it so that the MQD commands come from VRAM instead of GART.

Regards,
Christian.



BR Monk


-----Original Message-----
From: Christian König [mailto:ckoenig.leichtzumer...@gmail.com]
Sent: 2017年9月18日 19:54
To: Liu, Monk <monk....@amd.com>; Koenig, Christian <christian.koe...@amd.com>; 
amd-gfx@lists.freedesktop.org
Cc: Chen, Horace <horace.c...@amd.com>
Subject: Re: [PATCH 13/18] drm/amdgpu:fix driver unloading bug

Am 18.09.2017 um 12:12 schrieb Liu, Monk:
Christian,

Let's discuss this patch and the one follows which skip the KIQ MQD free to 
avoid SAVE_FAIL issue.


For skipping KIQ MQD deallocation patch, I think I will drop it and use a new 
way:
We allocate KIQ MQD in VRAM domain and this BO can be safely freed after driver 
unloaded, because after driver unloaded no one will change the data in this BO 
*usually*.
e.g. some root  app can map visible vram and alter the value in it
That sounds at least a bit better. But my question is why doesn't this work 
like it does on Tonga, e.g. correctly clean things up?

for this patch "to skipping unbind the GART mapping to keep KIQ MQD always 
valid":
Since hypervisor side always have couple hw component working, and they rely on 
GMC kept alive, so this is very different with BARE-METAL. That's to say we can 
only do like this way.
Yeah, gut keeping the GART mapping alive is complete nonsense. When the driver 
unloads all memory should be returned to the OS.

So we either keep a GART mapping to pages which are about to be reused and 
overwritten, or we leak memory on driver shutdown.

Neither options sounds very good,
Christian.

Besides, we'll have more patches in future for L1 secure mode, which
forbidden VF access GMC registers, so under L1 secure mode driver will
always skip GMC programing under SRIOV both in init and fini, but that
will come later

BR Monk



-----Original Message-----
From: Christian König [mailto:ckoenig.leichtzumer...@gmail.com]
Sent: 2017年9月18日 17:28
To: Liu, Monk <monk....@amd.com>; amd-gfx@lists.freedesktop.org
Cc: Chen, Horace <horace.c...@amd.com>
Subject: Re: [PATCH 13/18] drm/amdgpu:fix driver unloading bug

Am 18.09.2017 um 08:11 schrieb Monk Liu:
[SWDEV-126631] - fix hypervisor save_vf fail that occured after
driver
removed:
1. Because the KIQ and KCQ were not ummapped, save_vf will fail if driver freed 
mqd of KIQ and KCQ.
2. KIQ can't be unmapped since RLCV always need it, the bo_free on
KIQ should be skipped 3. KCQ can be unmapped, and should be unmapped
during hw_fini, 4. RLCV still need to access other mc address from some hw even 
after driver unloaded,
      So we should not unbind gart for VF.

Change-Id: I320487a9a848f41484c5f8cc11be34aca807b424
Signed-off-by: Horace Chen <horace.c...@amd.com>
Signed-off-by: Monk Liu <monk....@amd.com>
I absolutely can't judge if this is correct or not, but keeping the GART and 
KIQ alive after the driver is unloaded sounds really fishy to me.

Isn't there any other clean way of handling this?

Christian.

---
    drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c |  3 +-
    drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c  |  5 +++
    drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c    | 60 
+++++++++++++++++++++++++++++++-
    3 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
index f437008..2fee071 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
@@ -394,7 +394,8 @@ int amdgpu_gart_init(struct amdgpu_device *adev)
     */
    void amdgpu_gart_fini(struct amdgpu_device *adev)
    {
-       if (adev->gart.ready) {
+       /* gart is still used by other hw under SRIOV, don't unbind it */
+       if (adev->gart.ready && !amdgpu_sriov_vf(adev)) {
                /* unbind pages */
                amdgpu_gart_unbind(adev, 0, adev->gart.num_cpu_pages);
        }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
index 4f6c68f..bf6656f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
@@ -309,6 +309,11 @@ void amdgpu_gfx_compute_mqd_sw_fini(struct amdgpu_device 
*adev)
                                      &ring->mqd_ptr);
        }
+ /* don't deallocate KIQ mqd because the bo is still used by RLCV even
+       the guest VM is shutdown */
+       if (amdgpu_sriov_vf(adev))
+               return;
+
        ring = &adev->gfx.kiq.ring;
        kfree(adev->gfx.mec.mqd_backup[AMDGPU_MAX_COMPUTE_RINGS]);
        amdgpu_bo_free_kernel(&ring->mqd_obj,
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index 44960b3..a577bbc 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -2892,14 +2892,72 @@ static int gfx_v9_0_hw_init(void *handle)
        return r;
    }
+static int gfx_v9_0_kcq_disable(struct amdgpu_ring *kiq_ring,struct
+amdgpu_ring *ring) {
+       struct amdgpu_device *adev = kiq_ring->adev;
+       uint32_t scratch, tmp = 0;
+       int r, i;
+
+       r = amdgpu_gfx_scratch_get(adev, &scratch);
+       if (r) {
+               DRM_ERROR("Failed to get scratch reg (%d).\n", r);
+               return r;
+       }
+       WREG32(scratch, 0xCAFEDEAD);
+
+       r = amdgpu_ring_alloc(kiq_ring, 10);
+       if (r) {
+               DRM_ERROR("Failed to lock KIQ (%d).\n", r);
+               amdgpu_gfx_scratch_free(adev, scratch);
+               return r;
+       }
+
+       /* unmap queues */
+       amdgpu_ring_write(kiq_ring, PACKET3(PACKET3_UNMAP_QUEUES, 4));
+       amdgpu_ring_write(kiq_ring, /* Q_sel: 0, vmid: 0, engine: 0, num_Q: 1 */
+                                               PACKET3_UNMAP_QUEUES_ACTION(1) 
| /* RESET_QUEUES */
+                                               
PACKET3_UNMAP_QUEUES_QUEUE_SEL(0) |
+                                               
PACKET3_UNMAP_QUEUES_ENGINE_SEL(0) |
+                                               
PACKET3_UNMAP_QUEUES_NUM_QUEUES(1));
+       amdgpu_ring_write(kiq_ring, 
PACKET3_UNMAP_QUEUES_DOORBELL_OFFSET0(ring->doorbell_index));
+       amdgpu_ring_write(kiq_ring, 0);
+       amdgpu_ring_write(kiq_ring, 0);
+       amdgpu_ring_write(kiq_ring, 0);
+       /* write to scratch for completion */
+       amdgpu_ring_write(kiq_ring, PACKET3(PACKET3_SET_UCONFIG_REG, 1));
+       amdgpu_ring_write(kiq_ring, (scratch - PACKET3_SET_UCONFIG_REG_START));
+       amdgpu_ring_write(kiq_ring, 0xDEADBEEF);
+       amdgpu_ring_commit(kiq_ring);
+
+       for (i = 0; i < adev->usec_timeout; i++) {
+               tmp = RREG32(scratch);
+               if (tmp == 0xDEADBEEF)
+                       break;
+               DRM_UDELAY(1);
+       }
+       if (i >= adev->usec_timeout) {
+               DRM_ERROR("KCQ disabled failed (scratch(0x%04X)=0x%08X)\n", 
scratch, tmp);
+               r = -EINVAL;
+       }
+       amdgpu_gfx_scratch_free(adev, scratch);
+       return r;
+}
+
+
    static int gfx_v9_0_hw_fini(void *handle)
    {
        struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+       int i, r;
amdgpu_irq_put(adev, &adev->gfx.priv_reg_irq, 0);
        amdgpu_irq_put(adev, &adev->gfx.priv_inst_irq, 0);
        if (amdgpu_sriov_vf(adev)) {
-               pr_debug("For SRIOV client, shouldn't do anything.\n");
+               /* disable KCQ to avoid CPC touch memory not valid anymore */
+               for (i = 0; i < adev->gfx.num_compute_rings; i++) {
+                       r = gfx_v9_0_kcq_disable(&adev->gfx.kiq.ring, 
&adev->gfx.compute_ring[i]);
+                       if (r)
+                               return r;
+               }
                return 0;
        }
        gfx_v9_0_cp_enable(adev, false);
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx


_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

Reply via email to