diff options
author | Min He <min.he@intel.com> | 2017-02-17 15:02:36 +0800 |
---|---|---|
committer | Zhenyu Wang <zhenyuw@linux.intel.com> | 2017-02-17 16:03:38 +0800 |
commit | fd64be636708d808852c4c8c1efce0a0a51c24c5 (patch) | |
tree | 1a5fa8ae968cf2edc33134812a30f1693a4adcba /drivers/gpu/drm/i915/gvt/mmio.c | |
parent | f655e67ac8d797425abb0404d0878758f3f71c1a (diff) | |
download | linux-fd64be636708d808852c4c8c1efce0a0a51c24c5.tar.bz2 |
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 <min.he@intel.com>
Signed-off-by: Pei Zhang <pei.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915/gvt/mmio.c')
-rw-r--r-- | drivers/gpu/drm/i915/gvt/mmio.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gvt/mmio.c b/drivers/gpu/drm/i915/gvt/mmio.c index 4df078bc5d04..b2d72dad1537 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)) { |