From: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx> commit 699aa57b35672c3b2f230e2b7e5d0ab8c2bde80a upstream. We've seen recent regression with host and windows VM running simultaneously that cause gpu hang or even crash. Finally bisect to commit 58586680ffad ("drm/i915: Disable atomics in L3 for gen9"), which seems cached atomics behavior difference caused regression issue. This tries to add new scratch register handler and add those in mmio save/restore list for context switch. No gpu hang produced with this one. Cc: stable@xxxxxxxxxxxxxxx # 5.12+ Cc: "Xu, Terrence" <terrence.xu@xxxxxxxxx> Cc: "Bloomfield, Jon" <jon.bloomfield@xxxxxxxxx> Cc: "Ekstrand, Jason" <jason.ekstrand@xxxxxxxxx> Reviewed-by: Colin Xu <colin.xu@xxxxxxxxx> Fixes: 58586680ffad ("drm/i915: Disable atomics in L3 for gen9") Signed-off-by: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx> Link: http://patchwork.freedesktop.org/patch/msgid/20210806044056.648016-1-zhenyuw@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/gvt/handlers.c | 1 + drivers/gpu/drm/i915/gvt/mmio_context.c | 2 ++ 2 files changed, 3 insertions(+) --- a/drivers/gpu/drm/i915/gvt/handlers.c +++ b/drivers/gpu/drm/i915/gvt/handlers.c @@ -3149,6 +3149,7 @@ static int init_bdw_mmio_info(struct int MMIO_DFH(_MMIO(0xb100), D_BDW, F_CMD_ACCESS, NULL, NULL); MMIO_DFH(_MMIO(0xb10c), D_BDW, F_CMD_ACCESS, NULL, NULL); MMIO_D(_MMIO(0xb110), D_BDW); + MMIO_D(GEN9_SCRATCH_LNCF1, D_BDW_PLUS); MMIO_F(_MMIO(0x24d0), 48, F_CMD_ACCESS | F_CMD_WRITE_PATCH, 0, 0, D_BDW_PLUS, NULL, force_nonpriv_write); --- a/drivers/gpu/drm/i915/gvt/mmio_context.c +++ b/drivers/gpu/drm/i915/gvt/mmio_context.c @@ -105,6 +105,8 @@ static struct engine_mmio gen9_engine_mm {RCS0, COMMON_SLICE_CHICKEN2, 0xffff, true}, /* 0x7014 */ {RCS0, GEN9_CS_DEBUG_MODE1, 0xffff, false}, /* 0x20ec */ {RCS0, GEN8_L3SQCREG4, 0, false}, /* 0xb118 */ + {RCS0, GEN9_SCRATCH1, 0, false}, /* 0xb11c */ + {RCS0, GEN9_SCRATCH_LNCF1, 0, false}, /* 0xb008 */ {RCS0, GEN7_HALF_SLICE_CHICKEN1, 0xffff, true}, /* 0xe100 */ {RCS0, HALF_SLICE_CHICKEN2, 0xffff, true}, /* 0xe180 */ {RCS0, HALF_SLICE_CHICKEN3, 0xffff, true}, /* 0xe184 */