From 777ab82d7ce0451fd47bb57e331548deba57394e Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Tue, 7 Dec 2021 17:52:30 +0800 Subject: [PATCH] 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: Lai Jiangshan Message-Id: <20211207095230.53437-1-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini --- 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 e0aa4dd..c473498c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -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); -- 2.7.4