From fd64be636708d808852c4c8c1efce0a0a51c24c5 Mon Sep 17 00:00:00 2001 From: Min He Date: Fri, 17 Feb 2017 15:02:36 +0800 Subject: [PATCH] drm/i915/gvt: introduced failsafe mode into vgpu New failsafe mode is introduced, when we detect guest not supporting GVT-g. In failsafe mode, we will ignore all the MMIO and cfg space read/write from guest. This patch can fix the issue that when guest kernel or graphics driver version is too low, there will be a lot of kernel traces in host. V5: rebased onto latest gvt-staging V4: changed coding style by Zhenyu and Ping's advice V3: modified coding style and error messages according to Zhenyu's comment V2: 1) implemented MMIO/GTT/WP pages read/write logic; 2) used a unified function to enter failsafe mode Signed-off-by: Min He Signed-off-by: Pei Zhang Signed-off-by: Zhenyu Wang --- drivers/gpu/drm/i915/gvt/cfg_space.c | 3 ++ drivers/gpu/drm/i915/gvt/gvt.h | 6 ++++ drivers/gpu/drm/i915/gvt/handlers.c | 36 +++++++++++++++++++++ drivers/gpu/drm/i915/gvt/mmio.c | 62 ++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/i915/gvt/vgpu.c | 6 +++- 5 files changed, 112 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gvt/cfg_space.c b/drivers/gpu/drm/i915/gvt/cfg_space.c index 4a6a2ed..a77e050 100644 --- a/drivers/gpu/drm/i915/gvt/cfg_space.c +++ b/drivers/gpu/drm/i915/gvt/cfg_space.c @@ -237,6 +237,9 @@ int intel_vgpu_emulate_cfg_write(struct intel_vgpu *vgpu, unsigned int offset, { int ret; + if (vgpu->failsafe) + return 0; + if (WARN_ON(bytes > 4)) return -EINVAL; diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h index 5ee6600..48ef077 100644 --- a/drivers/gpu/drm/i915/gvt/gvt.h +++ b/drivers/gpu/drm/i915/gvt/gvt.h @@ -143,6 +143,8 @@ struct intel_vgpu { int id; unsigned long handle; /* vGPU handle used by hypervisor MPT modules */ bool active; + bool pv_notified; + bool failsafe; bool resetting; void *sched_data; @@ -449,6 +451,10 @@ struct intel_gvt_ops { }; +enum { + GVT_FAILSAFE_UNSUPPORTED_GUEST, +}; + #include "mpt.h" #endif diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c index 1d45062..6f098bb 100644 --- a/drivers/gpu/drm/i915/gvt/handlers.c +++ b/drivers/gpu/drm/i915/gvt/handlers.c @@ -150,10 +150,34 @@ static int render_mmio_to_ring_id(struct intel_gvt *gvt, unsigned int reg) #define fence_num_to_offset(num) \ (num * 8 + i915_mmio_reg_offset(FENCE_REG_GEN6_LO(0))) + +static void enter_failsafe_mode(struct intel_vgpu *vgpu, int reason) +{ + switch (reason) { + case GVT_FAILSAFE_UNSUPPORTED_GUEST: + pr_err("Detected your guest driver doesn't support GVT-g.\n"); + break; + default: + break; + } + pr_err("Now vgpu %d will enter failsafe mode.\n", vgpu->id); + vgpu->failsafe = true; +} + static int sanitize_fence_mmio_access(struct intel_vgpu *vgpu, unsigned int fence_num, void *p_data, unsigned int bytes) { if (fence_num >= vgpu_fence_sz(vgpu)) { + + /* When guest access oob fence regs without access + * pv_info first, we treat guest not supporting GVT, + * and we will let vgpu enter failsafe mode. + */ + if (!vgpu->pv_notified) { + enter_failsafe_mode(vgpu, + GVT_FAILSAFE_UNSUPPORTED_GUEST); + return -EINVAL; + } gvt_err("vgpu%d: found oob fence register access\n", vgpu->id); gvt_err("vgpu%d: total fence num %d access fence num %d\n", @@ -1001,6 +1025,7 @@ static int pvinfo_mmio_read(struct intel_vgpu *vgpu, unsigned int offset, if (invalid_read) gvt_err("invalid pvinfo read: [%x:%x] = %x\n", offset, bytes, *(u32 *)p_data); + vgpu->pv_notified = true; return 0; } @@ -1318,6 +1343,17 @@ static int ring_mode_mmio_write(struct intel_vgpu *vgpu, unsigned int offset, bool enable_execlist; write_vreg(vgpu, offset, p_data, bytes); + + /* when PPGTT mode enabled, we will check if guest has called + * pvinfo, if not, we will treat this guest as non-gvtg-aware + * guest, and stop emulating its cfg space, mmio, gtt, etc. + */ + if (((data & _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE)) || + (data & _MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE))) + && !vgpu->pv_notified) { + enter_failsafe_mode(vgpu, GVT_FAILSAFE_UNSUPPORTED_GUEST); + return 0; + } if ((data & _MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE)) || (data & _MASKED_BIT_DISABLE(GFX_RUN_LIST_ENABLE))) { enable_execlist = !!(data & GFX_RUN_LIST_ENABLE); diff --git a/drivers/gpu/drm/i915/gvt/mmio.c b/drivers/gpu/drm/i915/gvt/mmio.c index 4df078b..b2d72da 100644 --- a/drivers/gpu/drm/i915/gvt/mmio.c +++ b/drivers/gpu/drm/i915/gvt/mmio.c @@ -57,6 +57,58 @@ int intel_vgpu_gpa_to_mmio_offset(struct intel_vgpu *vgpu, u64 gpa) (reg >= gvt->device_info.gtt_start_offset \ && reg < gvt->device_info.gtt_start_offset + gvt_ggtt_sz(gvt)) +static void failsafe_emulate_mmio_rw(struct intel_vgpu *vgpu, uint64_t pa, + void *p_data, unsigned int bytes, bool read) +{ + struct intel_gvt *gvt = NULL; + void *pt = NULL; + unsigned int offset = 0; + + if (!vgpu || !p_data) + return; + + gvt = vgpu->gvt; + mutex_lock(&gvt->lock); + offset = intel_vgpu_gpa_to_mmio_offset(vgpu, pa); + if (reg_is_mmio(gvt, offset)) { + if (read) + intel_vgpu_default_mmio_read(vgpu, offset, p_data, + bytes); + else + intel_vgpu_default_mmio_write(vgpu, offset, p_data, + bytes); + } else if (reg_is_gtt(gvt, offset) && + vgpu->gtt.ggtt_mm->virtual_page_table) { + offset -= gvt->device_info.gtt_start_offset; + pt = vgpu->gtt.ggtt_mm->virtual_page_table + offset; + if (read) + memcpy(p_data, pt, bytes); + else + memcpy(pt, p_data, bytes); + + } else if (atomic_read(&vgpu->gtt.n_write_protected_guest_page)) { + struct intel_vgpu_guest_page *gp; + + /* Since we enter the failsafe mode early during guest boot, + * guest may not have chance to set up its ppgtt table, so + * there should not be any wp pages for guest. Keep the wp + * related code here in case we need to handle it in furture. + */ + gp = intel_vgpu_find_guest_page(vgpu, pa >> PAGE_SHIFT); + if (gp) { + /* remove write protection to prevent furture traps */ + intel_vgpu_clean_guest_page(vgpu, gp); + if (read) + intel_gvt_hypervisor_read_gpa(vgpu, pa, + p_data, bytes); + else + intel_gvt_hypervisor_write_gpa(vgpu, pa, + p_data, bytes); + } + } + mutex_unlock(&gvt->lock); +} + /** * intel_vgpu_emulate_mmio_read - emulate MMIO read * @vgpu: a vGPU @@ -75,6 +127,11 @@ int intel_vgpu_emulate_mmio_read(struct intel_vgpu *vgpu, uint64_t pa, unsigned int offset = 0; int ret = -EINVAL; + + if (vgpu->failsafe) { + failsafe_emulate_mmio_rw(vgpu, pa, p_data, bytes, true); + return 0; + } mutex_lock(&gvt->lock); if (atomic_read(&vgpu->gtt.n_write_protected_guest_page)) { @@ -188,6 +245,11 @@ int intel_vgpu_emulate_mmio_write(struct intel_vgpu *vgpu, uint64_t pa, u32 old_vreg = 0, old_sreg = 0; int ret = -EINVAL; + if (vgpu->failsafe) { + failsafe_emulate_mmio_rw(vgpu, pa, p_data, bytes, false); + return 0; + } + mutex_lock(&gvt->lock); if (atomic_read(&vgpu->gtt.n_write_protected_guest_page)) { diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c index 95a97aa..dcfcce1 100644 --- a/drivers/gpu/drm/i915/gvt/vgpu.c +++ b/drivers/gpu/drm/i915/gvt/vgpu.c @@ -387,8 +387,12 @@ void intel_gvt_reset_vgpu_locked(struct intel_vgpu *vgpu, bool dmlr, populate_pvinfo_page(vgpu); intel_vgpu_reset_display(vgpu); - if (dmlr) + if (dmlr) { intel_vgpu_reset_cfg_space(vgpu); + /* only reset the failsafe mode when dmlr reset */ + vgpu->failsafe = false; + vgpu->pv_notified = false; + } } vgpu->resetting = false; -- 2.7.4