From 96c211f1f9ef82183493f4ceed4e347b52849149 Mon Sep 17 00:00:00 2001 From: Jay Cornwall Date: Wed, 12 Jul 2023 15:53:44 -0500 Subject: [PATCH] drm/amdkfd: Relocate TBA/TMA to opposite side of VM hole The TBA and TMA, along with an unused IB allocation, reside at low addresses in the VM address space. A stray VM fault which hits these pages must be serviced by making their page table entries invalid. The scheduler depends upon these pages being resident and fails, preventing a debugger from inspecting the failure state. By relocating these pages above 47 bits in the VM address space they can only be reached when bits [63:48] are set to 1. This makes it much less likely for a misbehaving program to generate accesses to them. The current placement at VA (PAGE_SIZE*2) is readily hit by a NULL access with a small offset. Signed-off-by: Jay Cornwall Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c | 30 ++++++++++---------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c b/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c index da2ca00d79e5e..dd6984c785adf 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_flat_memory.c @@ -330,6 +330,12 @@ static void kfd_init_apertures_vi(struct kfd_process_device *pdd, uint8_t id) pdd->gpuvm_base = SVM_USER_BASE; pdd->gpuvm_limit = pdd->dev->kfd->shared_resources.gpuvm_size - 1; + + /* dGPUs: the reserved space for kernel + * before SVM + */ + pdd->qpd.cwsr_base = SVM_CWSR_BASE; + pdd->qpd.ib_base = SVM_IB_BASE; } else { /* set them to non CANONICAL addresses, and no SVM is * allocated. @@ -348,18 +354,20 @@ static void kfd_init_apertures_v9(struct kfd_process_device *pdd, uint8_t id) pdd->lds_base = MAKE_LDS_APP_BASE_V9(); pdd->lds_limit = MAKE_LDS_APP_LIMIT(pdd->lds_base); - /* Raven needs SVM to support graphic handle, etc. Leave the small - * reserved space before SVM on Raven as well, even though we don't - * have to. - * Set gpuvm_base and gpuvm_limit to CANONICAL addresses so that they - * are used in Thunk to reserve SVM. - */ - pdd->gpuvm_base = SVM_USER_BASE; + pdd->gpuvm_base = PAGE_SIZE; pdd->gpuvm_limit = pdd->dev->kfd->shared_resources.gpuvm_size - 1; pdd->scratch_base = MAKE_SCRATCH_APP_BASE_V9(); pdd->scratch_limit = MAKE_SCRATCH_APP_LIMIT(pdd->scratch_base); + + if (!pdd->dev->kfd->use_iommu_v2) { + /* + * Place TBA/TMA on opposite side of VM hole to prevent + * stray faults from triggering SVM on these pages. + */ + pdd->qpd.cwsr_base = pdd->dev->kfd->shared_resources.gpuvm_size; + } } int kfd_init_apertures(struct kfd_process *process) @@ -416,14 +424,6 @@ int kfd_init_apertures(struct kfd_process *process) return -EINVAL; } } - - if (!dev->kfd->use_iommu_v2) { - /* dGPUs: the reserved space for kernel - * before SVM - */ - pdd->qpd.cwsr_base = SVM_CWSR_BASE; - pdd->qpd.ib_base = SVM_IB_BASE; - } } dev_dbg(kfd_device, "node id %u\n", id); -- 2.30.2