gpu: nvgpu: vgpu: debugger interface fixes

To run CUDA apps, the following minimal changes have been
made:
- power-gating is disabled for vgpu
- regop rd/wr returns -ENOSYS

Tools (debugger/profiler) support is known to not work and
not needed at this time.

Bug 200043227

Change-Id: I923caad78450e72d310fb9290cf2849ed5460ad5
Signed-off-by: Aingara Paramakuru <aparamakuru@nvidia.com>
Reviewed-on: http://git-master/r/592878
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/regops_gk20a.c b/drivers/gpu/nvgpu/gk20a/regops_gk20a.c
index fe444c78..cbdd1a55 100644
--- a/drivers/gpu/nvgpu/gk20a/regops_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/regops_gk20a.c
@@ -392,6 +392,17 @@ int exec_regops_gk20a(struct dbg_session_gk20a *dbg_s,
 
         ch = dbg_s->ch;
 
+        /* For vgpu, the regops routines need to be handled in the
+         * context of the server and support for that does not exist.
+         *
+         * The two users of the regops interface are the compute driver
+         * and tools. The compute driver will work without a functional
+         * regops implementation, so we return -ENOSYS. This will allow
+         * compute apps to run with vgpu. Tools will not work in this
+         * configuration and are not required to work at this time. */
+        if (gk20a_gpu_is_virtual(dbg_s->pdev))
+                return -ENOSYS;
+
         ok = g->allow_all || validate_reg_ops(dbg_s,
                               &ctx_rd_count, &ctx_wr_count,
                               ops, num_ops);