From 4d6c989284ca61176f60148ba3f3c70650ee1aff Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 7 May 2019 09:06:30 -0700 Subject: [PATCH] KVM: nVMX: Don't rewrite GUEST_PML_INDEX during nested VM-Entry 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 Signed-off-by: Paolo Bonzini --- 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 7b6628edd617..a090bfb10796 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); @@ -2101,16 +2110,6 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) exec_control |= VM_EXIT_LOAD_IA32_EFER; 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 */ -- GitLab