• Sean Christopherson's avatar
    KVM: VMX: Ignore userspace MSR filters for x2APIC · 9389b9d5
    Sean Christopherson authored
    Rework the resetting of the MSR bitmap for x2APIC MSRs to ignore userspace
    filtering.  Allowing userspace to intercept reads to x2APIC MSRs when
    APICV is fully enabled for the guest simply can't work; the LAPIC and thus
    virtual APIC is in-kernel and cannot be directly accessed by userspace.
    To keep things simple we will in fact forbid intercepting x2APIC MSRs
    altogether, independent of the default_allow setting.
    
    Cc: Alexander Graf <graf@amazon.com>
    Cc: Aaron Lewis <aaronlewis@google.com>
    Cc: Peter Xu <peterx@redhat.com>
    Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
    Message-Id: <20201005195532.8674-3-sean.j.christopherson@intel.com>
    [Modified to operate even if APICv is disabled, adjust documentation. - Paolo]
    Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
    9389b9d5
vmx.c 221 KB