From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Emulation of GUEST_PML_INDEX for a nested VMM is a bit weird. Because
L0 flushes the PML on every VM-Exit, the value in vmcs02 at the time of
VM-Enter is a constant -1, regardless of what L1 thinks/wants.
Fixes: 09abe32002665 ("KVM: nVMX: split pieces of prepare_vmcs02() to prepare_vmcs02_early()")
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index fee297a5edda..01275cbd7478 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1940,8 +1940,17 @@ static void prepare_vmcs02_constant_state(struct vcpu_vmx *vmx)
if (cpu_has_vmx_msr_bitmap())
vmcs_write64(MSR_BITMAP, __pa(vmx->nested.vmcs02.msr_bitmap));
- if (enable_pml)
+ /*
+ * The PML address never changes, so it is constant in vmcs02.
+ * Conceptually we want to copy the PML index from vmcs01 here,
+ * and then back to vmcs01 on nested vmexit. But since we flush
+ * the log and reset GUEST_PML_INDEX on each vmexit, the PML
+ * index is also effectively constant in vmcs02.
+ */
+ if (enable_pml) {
vmcs_write64(PML_ADDRESS, page_to_phys(vmx->pml_pg));
+ vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1);
+ }
if (cpu_has_vmx_encls_vmexit())
vmcs_write64(ENCLS_EXITING_BITMAP, -1ull);
@@ -2102,16 +2111,6 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
vm_exit_controls_init(vmx, exec_control);
/*
- * Conceptually we want to copy the PML address and index from
- * vmcs01 here, and then back to vmcs01 on nested vmexit. But,
- * since we always flush the log on each vmexit and never change
- * the PML address (once set), this happens to be equivalent to
- * simply resetting the index in vmcs02.
- */
- if (enable_pml)
- vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1);
-
- /*
* Interrupt/Exception Fields
*/
if (vmx->nested.nested_run_pending) {
--
1.8.3.1
