[PATCH v3 5/5] KVM: nVMX: load GUEST_EFER after GUEST_CR0 during emulated VM-entry

[David Matlack]

vmx_set_cr0() modifies GUEST_EFER and "IA-32e mode guest" in the current
VMCS. Call vmx_set_efer() after vmx_set_cr0() so that emulated VM-entry
is more faithful to VMCS12.

This patch correctly causes VM-entry to fail when "IA-32e mode guest" is
1 and GUEST_CR0.PG is 0. Previously this configuration would succeed and
"IA-32e mode guest" would silently be disabled by KVM.

Signed-off-by: David Matlack 
---
 arch/x86/kvm/vmx.c | 18 +-
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 49270c4..776dc67 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10386,15 +10386,6 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, 
struct vmcs12 *vmcs12)
nested_ept_init_mmu_context(vcpu);
}
 
-   if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)
-   vcpu->arch.efer = vmcs12->guest_ia32_efer;
-   else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)
-   vcpu->arch.efer |= (EFER_LMA | EFER_LME);
-   else
-   vcpu->arch.efer &= ~(EFER_LMA | EFER_LME);
-   /* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */
-   vmx_set_efer(vcpu, vcpu->arch.efer);
-
/*
 * This sets GUEST_CR0 to vmcs12->guest_cr0, with possibly a modified
 * TS bit (for lazy fpu) and bits which we consider mandatory enabled.
@@ -10409,6 +10400,15 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, 
struct vmcs12 *vmcs12)
vmx_set_cr4(vcpu, vmcs12->guest_cr4);
vmcs_writel(CR4_READ_SHADOW, nested_read_cr4(vmcs12));
 
+   if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)
+   vcpu->arch.efer = vmcs12->guest_ia32_efer;
+   else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)
+   vcpu->arch.efer |= (EFER_LMA | EFER_LME);
+   else
+   vcpu->arch.efer &= ~(EFER_LMA | EFER_LME);
+   /* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */
+   vmx_set_efer(vcpu, vcpu->arch.efer);
+
/* shadow page tables on either EPT or shadow page tables */
kvm_set_cr3(vcpu, vmcs12->guest_cr3);
kvm_mmu_reset_context(vcpu);
-- 
2.8.0.rc3.226.g39d4020

[PATCH v3 5/5] KVM: nVMX: load GUEST_EFER after GUEST_CR0 during emulated VM-entry

[David Matlack]

vmx_set_cr0() modifies GUEST_EFER and "IA-32e mode guest" in the current
VMCS. Call vmx_set_efer() after vmx_set_cr0() so that emulated VM-entry
is more faithful to VMCS12.

This patch correctly causes VM-entry to fail when "IA-32e mode guest" is
1 and GUEST_CR0.PG is 0. Previously this configuration would succeed and
"IA-32e mode guest" would silently be disabled by KVM.

Signed-off-by: David Matlack 
---
 arch/x86/kvm/vmx.c | 18 +-
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 49270c4..776dc67 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10386,15 +10386,6 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, 
struct vmcs12 *vmcs12)
nested_ept_init_mmu_context(vcpu);
}
 
-   if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)
-   vcpu->arch.efer = vmcs12->guest_ia32_efer;
-   else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)
-   vcpu->arch.efer |= (EFER_LMA | EFER_LME);
-   else
-   vcpu->arch.efer &= ~(EFER_LMA | EFER_LME);
-   /* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */
-   vmx_set_efer(vcpu, vcpu->arch.efer);
-
/*
 * This sets GUEST_CR0 to vmcs12->guest_cr0, with possibly a modified
 * TS bit (for lazy fpu) and bits which we consider mandatory enabled.
@@ -10409,6 +10400,15 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, 
struct vmcs12 *vmcs12)
vmx_set_cr4(vcpu, vmcs12->guest_cr4);
vmcs_writel(CR4_READ_SHADOW, nested_read_cr4(vmcs12));
 
+   if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)
+   vcpu->arch.efer = vmcs12->guest_ia32_efer;
+   else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)
+   vcpu->arch.efer |= (EFER_LMA | EFER_LME);
+   else
+   vcpu->arch.efer &= ~(EFER_LMA | EFER_LME);
+   /* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */
+   vmx_set_efer(vcpu, vcpu->arch.efer);
+
/* shadow page tables on either EPT or shadow page tables */
kvm_set_cr3(vcpu, vmcs12->guest_cr3);
kvm_mmu_reset_context(vcpu);
-- 
2.8.0.rc3.226.g39d4020