diff options
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 9 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/nested.h | 7 |
2 files changed, 7 insertions, 9 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 61c83424285c..b6f4411b613e 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2588,12 +2588,9 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, nested_ept_init_mmu_context(vcpu); /* - * This sets GUEST_CR0 to vmcs12->guest_cr0, possibly modifying those - * bits which we consider mandatory enabled. - * The CR0_READ_SHADOW is what L2 should have expected to read given - * the specifications by L1; It's not enough to take - * vmcs12->cr0_read_shadow because on our cr0_guest_host_mask we - * have more bits than L1 expected. + * Override the CR0/CR4 read shadows after setting the effective guest + * CR0/CR4. The common helpers also set the shadows, but they don't + * account for vmcs12's cr0/4_guest_host_mask. */ vmx_set_cr0(vcpu, vmcs12->guest_cr0); vmcs_writel(CR0_READ_SHADOW, nested_read_cr0(vmcs12)); diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h index 6312c9541c3c..96952263b029 100644 --- a/arch/x86/kvm/vmx/nested.h +++ b/arch/x86/kvm/vmx/nested.h @@ -79,9 +79,10 @@ static inline bool nested_ept_ad_enabled(struct kvm_vcpu *vcpu) } /* - * Return the cr0 value that a nested guest would read. This is a combination - * of the real cr0 used to run the guest (guest_cr0), and the bits shadowed by - * its hypervisor (cr0_read_shadow). + * Return the cr0/4 value that a nested guest would read. This is a combination + * of L1's "real" cr0 used to run the guest (guest_cr0), and the bits shadowed + * by the L1 hypervisor (cr0_read_shadow). KVM must emulate CPU behavior as + * the value+mask loaded into vmcs02 may not match the vmcs12 fields. */ static inline unsigned long nested_read_cr0(struct vmcs12 *fields) { |