From b4d185175bc13d238d96998b1dba5ddeb7c69d71 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Mon, 5 Mar 2018 12:04:40 -0800 Subject: [PATCH] KVM: VMX: give unrestricted guest full control of CR3 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Now CR3 is not forced to a host-controlled value when paging is disabled in an unrestricted guest, CR3 load/store exiting can be left disabled (for an unrestricted guest). And because CR0.WP and CR4.PAE/PSE are also not force to host-controlled values, all of ept_update_paging_mode_cr0() is no longer needed, i.e. skip ept_update_paging_mode_cr0() for an unrestricted guest. Because MOV CR3 no longer exits when paging is disabled for an unrestricted guest, vmx_decache_cr3() must always read GUEST_CR3 from the VMCS for an unrestricted guest. Signed-off-by: Sean Christopherson Signed-off-by: Radim Krčmář --- arch/x86/kvm/vmx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index d35e5c643091..c517e966b829 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4314,7 +4314,7 @@ static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu) static void vmx_decache_cr3(struct kvm_vcpu *vcpu) { - if (enable_ept && is_paging(vcpu)) + if (enable_unrestricted_guest || (enable_ept && is_paging(vcpu))) vcpu->arch.cr3 = vmcs_readl(GUEST_CR3); __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail); } @@ -4451,7 +4451,7 @@ static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) } #endif - if (enable_ept) + if (enable_ept && !enable_unrestricted_guest) ept_update_paging_mode_cr0(&hw_cr0, cr0, vcpu); vmcs_writel(CR0_READ_SHADOW, cr0); -- 2.11.0