Messages in this thread | | | Subject | Re: [PATCH v2 02/10] KVM: x86: Clear KVM's cached guest CR3 at RESET/INIT | From | Paolo Bonzini <> | Date | Tue, 21 Sep 2021 19:35:56 +0200 |
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On 21/09/21 02:02, Sean Christopherson wrote: > Explicitly zero the guest's CR3 and mark it available+dirty at RESET/INIT. > Per Intel's SDM and AMD's APM, CR3 is zeroed at both RESET and INIT. For > RESET, this is a nop as vcpu is zero-allocated. For INIT, the bug has > likely escaped notice because no firmware/kernel puts its page tables root > at PA=0, let alone relies on INIT to get the desired CR3 for such page > tables. > > Cc: stable@vger.kernel.org > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/x86/kvm/x86.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index e77a5bf2d940..2cb38c67ed43 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -10899,6 +10899,9 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) > kvm_set_rflags(vcpu, X86_EFLAGS_FIXED); > kvm_rip_write(vcpu, 0xfff0); > > + vcpu->arch.cr3 = 0; > + kvm_register_mark_dirty(vcpu, VCPU_EXREG_CR3); > + > /* > * CR0.CD/NW are set on RESET, preserved on INIT. Note, some versions > * of Intel's SDM list CD/NW as being set on INIT, but they contradict >
Queued patches 1-2 for 5.15-rc3, thanks.
Paolo
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