From c19986fea873f3c745122bf79013a872a190f212 Mon Sep 17 00:00:00 2001 From: Junaid Shahid Date: Fri, 4 May 2018 11:37:13 -0700 Subject: [PATCH] kvm: x86: Suppress CR3_PCID_INVD bit only when PCIDs are enabled If the PCIDE bit is not set in CR4, then the MSb of CR3 is a reserved bit. If the guest tries to set it, that should cause a #GP fault. So mask out the bit only when the PCIDE bit is set. Signed-off-by: Junaid Shahid Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 44bd4a23b59c..37dd9a9d050a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -843,7 +843,10 @@ EXPORT_SYMBOL_GPL(kvm_set_cr4); int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) { #ifdef CONFIG_X86_64 - cr3 &= ~CR3_PCID_INVD; + bool pcid_enabled = kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE); + + if (pcid_enabled) + cr3 &= ~CR3_PCID_INVD; #endif if (cr3 == kvm_read_cr3(vcpu) && !pdptrs_changed(vcpu)) { -- 2.45.2