Messages in this thread | | | Date | Thu, 9 Dec 2021 18:55:05 +0100 | Subject | Re: [PATCH] KVM: X86: Raise #GP when clearing CR0_PG in 64 bit mode | From | Paolo Bonzini <> |
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On 12/7/21 10:52, Lai Jiangshan wrote: > From: Lai Jiangshan <laijs@linux.alibaba.com> > > In the SDM: > If the logical processor is in 64-bit mode or if CR4.PCIDE = 1, an > attempt to clear CR0.PG causes a general-protection exception (#GP). > Software should transition to compatibility mode and clear CR4.PCIDE > before attempting to disable paging. > > Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> > --- > arch/x86/kvm/x86.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 00f5b2b82909..78c40ac3b197 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -906,7 +906,8 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) > !load_pdptrs(vcpu, kvm_read_cr3(vcpu))) > return 1; > > - if (!(cr0 & X86_CR0_PG) && kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE)) > + if (!(cr0 & X86_CR0_PG) && > + (is_64_bit_mode(vcpu) || kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE))) > return 1; > > static_call(kvm_x86_set_cr0)(vcpu, cr0); >
Queued, thanks.
Paolo
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