drm/i915: Add support for mandatory cmdparsing

commit 311a50e76a 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: Joonas Lahtinen <joonas.lahtinen@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jon Bloomfield 2018-08-01 09:33:59 -07:00 committed by Greg Kroah-Hartman
parent 0b19d8fdfc
commit 397944fc40
3 changed files with 16 additions and 7 deletions

View file

@ -916,7 +916,7 @@ void intel_engine_init_cmd_parser(struct intel_engine_cs *engine)
return;
}
engine->flags |= I915_ENGINE_NEEDS_CMD_PARSER;
engine->flags |= I915_ENGINE_USING_CMD_PARSER;
}
/**
@ -928,7 +928,7 @@ void intel_engine_init_cmd_parser(struct intel_engine_cs *engine)
*/
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);
@ -1317,7 +1317,7 @@ int i915_cmd_parser_get_version(struct drm_i915_private *dev_priv)
/* If the command parser is not enabled, report 0 - unsupported */
for_each_engine(engine, dev_priv, id) {
if (intel_engine_needs_cmd_parser(engine)) {
if (intel_engine_using_cmd_parser(engine)) {
active = true;
break;
}

View file

@ -270,7 +270,8 @@ static inline u64 gen8_noncanonical_addr(u64 address)
static inline bool eb_use_cmdparser(const struct i915_execbuffer *eb)
{
return intel_engine_needs_cmd_parser(eb->engine) && eb->batch_len;
return intel_engine_requires_cmd_parser(eb->engine) ||
(intel_engine_using_cmd_parser(eb->engine) && eb->batch_len);
}
static int eb_create(struct i915_execbuffer *eb)

View file

@ -417,7 +417,8 @@ struct intel_engine_cs {
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;
/*
@ -445,9 +446,16 @@ struct intel_engine_cs {
u32 (*get_cmd_length_mask)(u32 cmd_header);
};
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