Commit 777ab82d authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Paolo Bonzini
Browse files

KVM: X86: Raise #GP when clearing CR0_PG in 64 bit mode 



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: default avatarLai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211207095230.53437-1-jiangshanlai@gmail.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c8cc43c1

arch/x86/kvm/x86.c

+2 −1
Original line number Diff line number Diff line
@@ -890,7 +890,8 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) 
	    !load_pdptrs(vcpu, vcpu->arch.walk_mmu, 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);