This is a note to let you know that I've just added the patch titled
kvm: vmx: Flush TLB when the APIC-access address changes
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: kvm-vmx-flush-tlb-when-the-apic-access-address-changes.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Thu Dec 21 09:02:40 CET 2017
From: Jim Mattson jmattson@google.com Date: Thu, 16 Mar 2017 13:53:59 -0700 Subject: kvm: vmx: Flush TLB when the APIC-access address changes
From: Jim Mattson jmattson@google.com
[ Upstream commit fb6c8198431311027c3434d4e94ab8bc040f7aea ]
Quoting from the Intel SDM, volume 3, section 28.3.3.4: Guidelines for Use of the INVEPT Instruction:
If EPT was in use on a logical processor at one time with EPTP X, it is recommended that software use the INVEPT instruction with the "single-context" INVEPT type and with EPTP X in the INVEPT descriptor before a VM entry on the same logical processor that enables EPT with EPTP X and either (a) the "virtualize APIC accesses" VM-execution control was changed from 0 to 1; or (b) the value of the APIC-access address was changed.
In the nested case, the burden falls on L1, unless L0 enables EPT in vmcs02 when L1 doesn't enable EPT in vmcs12.
Signed-off-by: Jim Mattson jmattson@google.com Signed-off-by: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/vmx.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
--- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3818,6 +3818,12 @@ static void vmx_flush_tlb(struct kvm_vcp __vmx_flush_tlb(vcpu, to_vmx(vcpu)->vpid); }
+static void vmx_flush_tlb_ept_only(struct kvm_vcpu *vcpu) +{ + if (enable_ept) + vmx_flush_tlb(vcpu); +} + static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu) { ulong cr0_guest_owned_bits = vcpu->arch.cr0_guest_owned_bits; @@ -8505,6 +8511,7 @@ static void vmx_set_virtual_x2apic_mode( } else { sec_exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE; sec_exec_control |= SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES; + vmx_flush_tlb_ept_only(vcpu); } vmcs_write32(SECONDARY_VM_EXEC_CONTROL, sec_exec_control);
@@ -8530,8 +8537,10 @@ static void vmx_set_apic_access_page_add */ if (!is_guest_mode(vcpu) || !nested_cpu_has2(get_vmcs12(&vmx->vcpu), - SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) + SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) { vmcs_write64(APIC_ACCESS_ADDR, hpa); + vmx_flush_tlb_ept_only(vcpu); + } }
static void vmx_hwapic_isr_update(struct kvm_vcpu *vcpu, int max_isr) @@ -10110,6 +10119,9 @@ static void prepare_vmcs02(struct kvm_vc if (nested_cpu_has_ept(vmcs12)) { kvm_mmu_unload(vcpu); nested_ept_init_mmu_context(vcpu); + } else if (nested_cpu_has2(vmcs12, + SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) { + vmx_flush_tlb_ept_only(vcpu); }
if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER) @@ -10850,6 +10862,10 @@ static void nested_vmx_vmexit(struct kvm vmx->nested.change_vmcs01_virtual_x2apic_mode = false; vmx_set_virtual_x2apic_mode(vcpu, vcpu->arch.apic_base & X2APIC_ENABLE); + } else if (!nested_cpu_has_ept(vmcs12) && + nested_cpu_has2(vmcs12, + SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) { + vmx_flush_tlb_ept_only(vcpu); }
/* This is needed for same reason as it was needed in prepare_vmcs02 */
Patches currently in stable-queue which might be from jmattson@google.com are
queue-4.9/x86-kvm-vmx-simplify-segment_base.patch queue-4.9/kvm-vmx-flush-tlb-when-the-apic-access-address-changes.patch queue-4.9/kvm-vmx-fix-enable-vpid-conditions.patch