drm/i915: Add support for mandatory cmdparsing
commit 311a50e76a33d1e029563c24b2ff6db0c02b5afe upstream.
The existing cmdparser for gen7 can be bypassed by specifying
batch_len=0 in the execbuf call. This is safe because bypassing
simply reduces the cmd-set available.
In a later patch we will introduce cmdparsing for gen9, as a
security measure, which must be strictly enforced since without
it we are vulnerable to DoS attacks.
Introduce the concept of 'required' cmd parsing that cannot be
bypassed by submitting zero-length bb's.
v2: rebase (Mika)
v2: rebase (Mika)
v3: fix conflict on engine flags (Mika)
Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 462d0f7..da91d36 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -916,7 +916,7 @@
return;
}
- engine->flags |= I915_ENGINE_NEEDS_CMD_PARSER;
+ engine->flags |= I915_ENGINE_USING_CMD_PARSER;
}
/**
@@ -928,7 +928,7 @@
*/
void intel_engine_cleanup_cmd_parser(struct intel_engine_cs *engine)
{
- if (!intel_engine_needs_cmd_parser(engine))
+ if (!intel_engine_using_cmd_parser(engine))
return;
fini_hash_table(engine);
@@ -1316,7 +1316,7 @@
/* If the command parser is not enabled, report 0 - unsupported */
for_each_engine(engine, dev_priv) {
- if (intel_engine_needs_cmd_parser(engine)) {
+ if (intel_engine_using_cmd_parser(engine)) {
active = true;
break;
}
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 1f5e641..069f26a 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1716,7 +1716,8 @@
}
params->args_batch_start_offset = args->batch_start_offset;
- if (intel_engine_needs_cmd_parser(engine) && args->batch_len) {
+ if (intel_engine_requires_cmd_parser(engine) ||
+ (intel_engine_using_cmd_parser(engine) && args->batch_len)) {
struct i915_vma *vma;
vma = i915_gem_execbuffer_parse(engine, &shadow_exec_entry,
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index e24d132..ce14cd8 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -341,7 +341,8 @@
struct intel_engine_hangcheck hangcheck;
-#define I915_ENGINE_NEEDS_CMD_PARSER BIT(0)
+#define I915_ENGINE_USING_CMD_PARSER BIT(0)
+#define I915_ENGINE_REQUIRES_CMD_PARSER BIT(3)
unsigned int flags;
/*
@@ -375,9 +376,16 @@
return engine->i915 != NULL;
}
-static inline bool intel_engine_needs_cmd_parser(struct intel_engine_cs *engine)
+static inline bool
+intel_engine_using_cmd_parser(const struct intel_engine_cs *engine)
{
- return engine->flags & I915_ENGINE_NEEDS_CMD_PARSER;
+ return engine->flags & I915_ENGINE_USING_CMD_PARSER;
+}
+
+static inline bool
+intel_engine_requires_cmd_parser(const struct intel_engine_cs *engine)
+{
+ return engine->flags & I915_ENGINE_REQUIRES_CMD_PARSER;
}
static inline unsigned int