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authorAkeem G Abodunrin <akeem.g.abodunrin@intel.com>2020-01-08 09:34:16 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-01-14 20:08:40 +0100
commit53b9bd37af59d1def99b20707536105857eb9bd0 (patch)
tree289713d19f679baa78da23704feef6b2bba5e022
parentf58642c1bc7946c315d8617d61916f754d90583f (diff)
drm/i915/gen9: Clear residual context state on context switch
commit bc8a76a152c5f9ef3b48104154a65a68a8b76946 upstream. Intel ID: PSIRT-TA-201910-001 CVEID: CVE-2019-14615 Intel GPU Hardware prior to Gen11 does not clear EU state during a context switch. This can result in information leakage between contexts. For Gen8 and Gen9, hardware provides a mechanism for fast cleardown of the EU state, by issuing a PIPE_CONTROL with bit 27 set. We can use this in a context batch buffer to explicitly cleardown the state on every context switch. As this workaround is already in place for gen8, we can borrow the code verbatim for Gen9. Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com> Cc: Kumar Valsan Prathap <prathap.kumar.valsan@intel.com> Cc: Chris Wilson <chris.p.wilson@intel.com> Cc: Balestrieri Francesco <francesco.balestrieri@intel.com> Cc: Bloomfield Jon <jon.bloomfield@intel.com> Cc: Dutt Sudeep <sudeep.dutt@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/gpu/drm/i915/gt/intel_lrc.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 1ba31969c7d2..4949b5ad860f 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -2132,6 +2132,14 @@ static u32 *gen9_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch)
/* WaFlushCoherentL3CacheLinesAtContextSwitch:skl,bxt,glk */
batch = gen8_emit_flush_coherentl3_wa(engine, batch);
+ /* WaClearSlmSpaceAtContextSwitch:skl,bxt,kbl,glk,cfl */
+ batch = gen8_emit_pipe_control(batch,
+ PIPE_CONTROL_FLUSH_L3 |
+ PIPE_CONTROL_GLOBAL_GTT_IVB |
+ PIPE_CONTROL_CS_STALL |
+ PIPE_CONTROL_QW_WRITE,
+ slm_offset(engine));
+
batch = emit_lri(batch, lri, ARRAY_SIZE(lri));
/* WaMediaPoolStateCmdInWABB:bxt,glk */