Messages in this thread | | | From | Paolo Bonzini <> | Date | Tue, 21 Mar 2023 10:43:24 +0100 | Subject | Re: [PATCH 0/3] KVM: support the cpu feature FLUSH_L1D |
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On Mon, Mar 20, 2023 at 5:52 PM Jim Mattson <jmattson@google.com> wrote: > > Patch 1 and 2 are just taken and refactored from Jim Mattison's serie that it > > seems was lost a while ago: > > https://patchwork.kernel.org/project/kvm/patch/20180814173049.21756-1-jmattson@google.com/ > > > > I thought it was worth re-posting them. > > What has changed since the patches were originally posted, and Konrad > dissed them?
What has changed is that the reporting of mmio_stale_data now piggybacks on flush_l1d as well.
if ((ia32_cap & ARCH_CAP_FB_CLEAR) || (boot_cpu_has(X86_FEATURE_MD_CLEAR) && boot_cpu_has(X86_FEATURE_FLUSH_L1D) && !(ia32_cap & ARCH_CAP_MDS_NO))) mmio_mitigation = MMIO_MITIGATION_VERW; else mmio_mitigation = MMIO_MITIGATION_UCODE_NEEDED;
Maybe Intel only defines CPUID bits after a firstborn has been sacriificed to the microcode gods?
Paolo
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