From f402f2d6c3c5a5192869ffbdc079b782ef32dd01 Mon Sep 17 00:00:00 2001 From: Weinan Li Date: Wed, 13 Dec 2017 10:47:01 +0800 Subject: [PATCH] drm/i915/gvt: refine mocs save restore policy Save and restore the mocs regs of one VM in GVT-g burning too much CPU utilization. Add LRI command scan to monitor the change of mocs registers, save the state in vreg, and use delta update policy to restore them. It can obviously reduce the MMIO r/w count, and improve the performance of context switch. Signed-off-by: Weinan Li Signed-off-by: Zhenyu Wang --- drivers/gpu/drm/i915/gvt/cmd_parser.c | 19 +++++++++++++++++++ drivers/gpu/drm/i915/gvt/mmio_context.c | 33 ++++++++++++++++++--------------- 2 files changed, 37 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/i915/gvt/cmd_parser.c b/drivers/gpu/drm/i915/gvt/cmd_parser.c index 18c4573..be5c519b 100644 --- a/drivers/gpu/drm/i915/gvt/cmd_parser.c +++ b/drivers/gpu/drm/i915/gvt/cmd_parser.c @@ -825,6 +825,21 @@ static int force_nonpriv_reg_handler(struct parser_exec_state *s, return 0; } +static inline bool is_mocs_mmio(unsigned int offset) +{ + return ((offset >= 0xc800) && (offset <= 0xcff8)) || + ((offset >= 0xb020) && (offset <= 0xb0a0)); +} + +static int mocs_cmd_reg_handler(struct parser_exec_state *s, + unsigned int offset, unsigned int index) +{ + if (!is_mocs_mmio(offset)) + return -EINVAL; + vgpu_vreg(s->vgpu, offset) = cmd_val(s, index + 1); + return 0; +} + static int cmd_reg_handler(struct parser_exec_state *s, unsigned int offset, unsigned int index, char *cmd) { @@ -848,6 +863,10 @@ static int cmd_reg_handler(struct parser_exec_state *s, return 0; } + if (is_mocs_mmio(offset) && + mocs_cmd_reg_handler(s, offset, index)) + return -EINVAL; + if (is_force_nonpriv_mmio(offset) && force_nonpriv_reg_handler(s, offset, index)) return -EPERM; diff --git a/drivers/gpu/drm/i915/gvt/mmio_context.c b/drivers/gpu/drm/i915/gvt/mmio_context.c index 5ad72fc..06ea3d2 100644 --- a/drivers/gpu/drm/i915/gvt/mmio_context.c +++ b/drivers/gpu/drm/i915/gvt/mmio_context.c @@ -203,6 +203,8 @@ static void switch_mocs(struct intel_vgpu *pre, struct intel_vgpu *next, { struct drm_i915_private *dev_priv; i915_reg_t offset, l3_offset; + u32 old_v, new_v; + u32 regs[] = { [RCS] = 0xc800, [VCS] = 0xc900, @@ -220,16 +222,17 @@ static void switch_mocs(struct intel_vgpu *pre, struct intel_vgpu *next, for (i = 0; i < 64; i++) { if (pre) - vgpu_vreg(pre, offset) = - I915_READ_FW(offset); + old_v = vgpu_vreg(pre, offset); else - gen9_render_mocs[ring_id][i] = - I915_READ_FW(offset); - + old_v = gen9_render_mocs[ring_id][i] + = I915_READ_FW(offset); if (next) - I915_WRITE_FW(offset, vgpu_vreg(next, offset)); + new_v = vgpu_vreg(next, offset); else - I915_WRITE_FW(offset, gen9_render_mocs[ring_id][i]); + new_v = gen9_render_mocs[ring_id][i]; + + if (old_v != new_v) + I915_WRITE_FW(offset, new_v); offset.reg += 4; } @@ -238,17 +241,17 @@ static void switch_mocs(struct intel_vgpu *pre, struct intel_vgpu *next, l3_offset.reg = 0xb020; for (i = 0; i < 32; i++) { if (pre) - vgpu_vreg(pre, l3_offset) = - I915_READ_FW(l3_offset); + old_v = vgpu_vreg(pre, l3_offset); else - gen9_render_mocs_L3[i] = - I915_READ_FW(l3_offset); + old_v = gen9_render_mocs_L3[i] + = I915_READ_FW(offset); if (next) - I915_WRITE_FW(l3_offset, - vgpu_vreg(next, l3_offset)); + new_v = vgpu_vreg(next, l3_offset); else - I915_WRITE_FW(l3_offset, - gen9_render_mocs_L3[i]); + new_v = gen9_render_mocs_L3[i]; + + if (old_v != new_v) + I915_WRITE_FW(l3_offset, new_v); l3_offset.reg += 4; } -- 2.7.4