From 92fbc7b195b824e201d9f06f2b93105f72384d65 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Thu, 8 Aug 2013 16:26:33 +0200 Subject: [PATCH] KVM: nVMX: Enable unrestricted guest mode support Now that we provide EPT support, there is no reason to torture our guests by hiding the relieving unrestricted guest mode feature. We just need to relax CR0 checks for always-on bits as PE and PG can now be switched off. Signed-off-by: Jan Kiszka Reviewed-by: Gleb Natapov Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 58d07a1..e6e8fbc 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2252,6 +2252,7 @@ static __init void nested_vmx_setup_ctls_msrs(void) nested_vmx_secondary_ctls_low = 0; nested_vmx_secondary_ctls_high &= SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES | + SECONDARY_EXEC_UNRESTRICTED_GUEST | SECONDARY_EXEC_WBINVD_EXITING; if (enable_ept) { @@ -4877,6 +4878,17 @@ vmx_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall) hypercall[2] = 0xc1; } +static bool nested_cr0_valid(struct vmcs12 *vmcs12, unsigned long val) +{ + unsigned long always_on = VMXON_CR0_ALWAYSON; + + if (nested_vmx_secondary_ctls_high & + SECONDARY_EXEC_UNRESTRICTED_GUEST && + nested_cpu_has2(vmcs12, SECONDARY_EXEC_UNRESTRICTED_GUEST)) + always_on &= ~(X86_CR0_PE | X86_CR0_PG); + return (val & always_on) == always_on; +} + /* called to set cr0 as appropriate for a mov-to-cr0 exit. */ static int handle_set_cr0(struct kvm_vcpu *vcpu, unsigned long val) { @@ -4895,9 +4907,7 @@ static int handle_set_cr0(struct kvm_vcpu *vcpu, unsigned long val) val = (val & ~vmcs12->cr0_guest_host_mask) | (vmcs12->guest_cr0 & vmcs12->cr0_guest_host_mask); - /* TODO: will have to take unrestricted guest mode into - * account */ - if ((val & VMXON_CR0_ALWAYSON) != VMXON_CR0_ALWAYSON) + if (!nested_cr0_valid(vmcs12, val)) return 1; if (kvm_set_cr0(vcpu, val)) @@ -7876,7 +7886,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) return 1; } - if (((vmcs12->guest_cr0 & VMXON_CR0_ALWAYSON) != VMXON_CR0_ALWAYSON) || + if (!nested_cr0_valid(vmcs12, vmcs12->guest_cr0) || ((vmcs12->guest_cr4 & VMXON_CR4_ALWAYSON) != VMXON_CR4_ALWAYSON)) { nested_vmx_entry_failure(vcpu, vmcs12, EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT); -- 2.7.4