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    SubjectRe: [PATCH v4 11/19] x86/cpu: Print VMX flags in /proc/cpuinfo using VMX_FEATURES_*
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    > On 12 Dec 2019, at 19:47, Paolo Bonzini <pbonzini@redhat.com> wrote:
    >
    > On 12/12/19 18:43, Sean Christopherson wrote:
    >> Key word being "usually". My intent in printing out partially redundant
    >> flags was to help users debug/understand why the combined feature isn't
    >> supported. E.g. userspace can already easily (relatively speaking) query
    >> flexpriority support via /sys/module/kvm_intel/parameters/flexpriority.
    >> But if that comes back "N", the user has no way to determine exactly why
    >> flexpriority is disabled.
    >
    > There are tools such as vmxcap. It is part of QEMU, but I wouldn't mind
    > moving it into the kernel tree.
    >
    > Paolo
    >

    True. But it relies on /dev/msr0 (exposed from msr kernel module) to be able to read any host arbitrary MSR.
    It’s much more elegant to just report CPU VMX features in a /proc/cpuinfo pseudo-file and don’t require strong privileges.
    Why should CPU VMX features be treated differently than standard CPUID deduced features?
    CPU SVM features are also present in /proc/cpuinfo today (Because they are deduced from CPUID leafs). So it should be similar.

    -Liran
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