Quoting Du, Changbin (2017-12-21 09:52:16) > Hi Chris, > Our QA reported a problem caused by movntdqa instructions. Currently, the KVM > hypervisor doesn't support VEX-prefix instructions emulation. If users passthrough > a GPU to guest with vfio option 'x-no-mmap=on', then all access to the BARs will > be trapped and emulated. The KVM hypervisor would raise an inertal error to qemu > which cause the guest killed. (Since 'movntdqa' ins is not supported.) > > One possible solution is that disable this optimization at i915_memcpy_init_early. > This require us to identify the CPUID to check if it is running in guest mode. Is this mode not detected by intel_vgpu_active() ? If we need to disable movntdqa, we need to disable it. But not by directly checking CPUID, it should be already decoded into a cpu feature flag -- assuming we need more than intel_vgpu_active and possibly rearranging the init order. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
