linux-kernel - [PATCH AUTOSEL 5.4 139/175] drm/amdgpu: Sync with VM root BO when switching VM to CPU update mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200608231848.3366970-139-sashal@kernel.org>
Date:   Mon,  8 Jun 2020 19:18:12 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Felix Kuehling <Felix.Kuehling@....com>,
        Jay Cornwall <Jay.Cornwall@....com>,
        Christian König <christian.koenig@....com>,
        Alex Deucher <alexander.deucher@....com>,
        Sasha Levin <sashal@...nel.org>, amd-gfx@...ts.freedesktop.org,
        dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 5.4 139/175] drm/amdgpu: Sync with VM root BO when switching VM to CPU update mode

From: Felix Kuehling <Felix.Kuehling@....com>

[ Upstream commit 90ca78deb004abe75b5024968a199acb96bb70f9 ]

This fixes an intermittent bug where a root PD clear operation still in
progress could overwrite a PDE update done by the CPU, resulting in a
VM fault.

Fixes: 108b4d928c03 ("drm/amd/amdgpu: Update VM function pointer")
Reported-by: Jay Cornwall <Jay.Cornwall@....com>
Tested-by: Jay Cornwall <Jay.Cornwall@....com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@....com>
Reviewed-by: Christian König <christian.koenig@....com>
Signed-off-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index c7514f743409..6335bd4ae374 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2867,10 +2867,17 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm, uns
 	WARN_ONCE((vm->use_cpu_for_update && !amdgpu_gmc_vram_full_visible(&adev->gmc)),
 		  "CPU update of VM recommended only for large BAR system\n");
 
-	if (vm->use_cpu_for_update)
+	if (vm->use_cpu_for_update) {
+		/* Sync with last SDMA update/clear before switching to CPU */
+		r = amdgpu_bo_sync_wait(vm->root.base.bo,
+					AMDGPU_FENCE_OWNER_UNDEFINED, true);
+		if (r)
+			goto free_idr;
+
 		vm->update_funcs = &amdgpu_vm_cpu_funcs;
-	else
+	} else {
 		vm->update_funcs = &amdgpu_vm_sdma_funcs;
+	}
 	dma_fence_put(vm->last_update);
 	vm->last_update = NULL;
 
-- 
2.25.1