gpu: nvgpu: add guest_managed field in vm_gk20a

Add a field in vm_gk20a to identify guest managed VM, with the
corresponding checks to ensure that there's no kernel section for
guest managed VMs.
Also make the __nvgpu_vm_init function available globally, so that
the vm can be allocated elsewhere, requisite fields set, and passed
to the function to initialize the vm.

Change-Id: Iad841d1b8ff9c894fe9d350dc43d74247e9c5512
Signed-off-by: Sourab Gupta <sourabg@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1617171
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/common/mm/vm.c b/drivers/gpu/nvgpu/common/mm/vm.c
index ee9d2e0b..e90437a3 100644
--- a/drivers/gpu/nvgpu/common/mm/vm.c
+++ b/drivers/gpu/nvgpu/common/mm/vm.c
@@ -109,6 +109,11 @@ u64 __nvgpu_vm_alloc_va(struct vm_gk20a *vm, u64 size,
 
         vma = vm->vma[pgsz_idx];
 
+        if (vm->guest_managed) {
+                nvgpu_err(g, "Illegal GPU allocation on behalf of guest OS");
+                return 0;
+        }
+
         if (pgsz_idx >= gmmu_nr_page_sizes) {
                 nvgpu_err(g, "(%s) invalid page size requested", vma->name);
                 return 0;
@@ -237,7 +242,10 @@ static int nvgpu_init_sema_pool(struct vm_gk20a *vm)
         return 0;
 }
 
-static int __nvgpu_vm_init(struct mm_gk20a *mm,
+/*
+ * Initialize a preallocated vm
+ */
+int __nvgpu_vm_init(struct mm_gk20a *mm,
                            struct vm_gk20a *vm,
                            u32 big_page_size,
                            u64 low_hole,
@@ -258,6 +266,9 @@ static int __nvgpu_vm_init(struct mm_gk20a *mm,
         if (WARN_ON(kernel_reserved + low_hole > aperture_size))
                 return -ENOMEM;
 
+        if (WARN_ON(vm->guest_managed && kernel_reserved != 0))
+                return -EINVAL;
+
         nvgpu_log_info(g, "Init space for %s: valimit=0x%llx, "
                        "LP size=0x%x lowhole=0x%llx",
                        name, aperture_size,
@@ -337,7 +348,7 @@ static int __nvgpu_vm_init(struct mm_gk20a *mm,
 
         if (WARN_ON(user_vma_start > user_vma_limit) ||
             WARN_ON(user_lp_vma_start > user_lp_vma_limit) ||
-            WARN_ON(kernel_vma_start >= kernel_vma_limit)) {
+                WARN_ON(!vm->guest_managed && kernel_vma_start >= kernel_vma_limit)) {
                 err = -EINVAL;
                 goto clean_up_page_tables;
         }