[PATCH 4.14 118/119] kvm: vmx: Basic APIC virtualization controls have three settings

From: Greg Kroah-Hartman
Date: Sun Oct 27 2019 - 17:12:20 EST


From: Jim Mattson <jmattson@xxxxxxxxxx>

commit 8d860bbeedef97fe981d28fa7b71d77f3b29563f upstream.

Previously, we toggled between SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE
and SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES, depending on whether or
not the EXTD bit was set in MSR_IA32_APICBASE. However, if the local
APIC is disabled, we should not set either of these APIC
virtualization control bits.

Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: "Jitindar SIngh, Suraj" <surajjs@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/include/asm/kvm_host.h | 2 -
arch/x86/kvm/lapic.c | 12 ++++------
arch/x86/kvm/svm.c | 4 +--
arch/x86/kvm/vmx.c | 48 +++++++++++++++++++++++++---------------
4 files changed, 38 insertions(+), 28 deletions(-)

--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -998,7 +998,7 @@ struct kvm_x86_ops {
void (*hwapic_irr_update)(struct kvm_vcpu *vcpu, int max_irr);
void (*hwapic_isr_update)(struct kvm_vcpu *vcpu, int isr);
void (*load_eoi_exitmap)(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap);
- void (*set_virtual_x2apic_mode)(struct kvm_vcpu *vcpu, bool set);
+ void (*set_virtual_apic_mode)(struct kvm_vcpu *vcpu);
void (*set_apic_access_page_addr)(struct kvm_vcpu *vcpu, hpa_t hpa);
void (*deliver_posted_interrupt)(struct kvm_vcpu *vcpu, int vector);
int (*sync_pir_to_irr)(struct kvm_vcpu *vcpu);
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1967,13 +1967,11 @@ void kvm_lapic_set_base(struct kvm_vcpu
}
}

- if ((old_value ^ value) & X2APIC_ENABLE) {
- if (value & X2APIC_ENABLE) {
- kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id);
- kvm_x86_ops->set_virtual_x2apic_mode(vcpu, true);
- } else
- kvm_x86_ops->set_virtual_x2apic_mode(vcpu, false);
- }
+ if (((old_value ^ value) & X2APIC_ENABLE) && (value & X2APIC_ENABLE))
+ kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id);
+
+ if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE))
+ kvm_x86_ops->set_virtual_apic_mode(vcpu);

apic->base_address = apic->vcpu->arch.apic_base &
MSR_IA32_APICBASE_BASE;
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4589,7 +4589,7 @@ static void update_cr8_intercept(struct
set_cr_intercept(svm, INTERCEPT_CR8_WRITE);
}

-static void svm_set_virtual_x2apic_mode(struct kvm_vcpu *vcpu, bool set)
+static void svm_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
{
return;
}
@@ -5713,7 +5713,7 @@ static struct kvm_x86_ops svm_x86_ops __
.enable_nmi_window = enable_nmi_window,
.enable_irq_window = enable_irq_window,
.update_cr8_intercept = update_cr8_intercept,
- .set_virtual_x2apic_mode = svm_set_virtual_x2apic_mode,
+ .set_virtual_apic_mode = svm_set_virtual_apic_mode,
.get_enable_apicv = svm_get_enable_apicv,
.refresh_apicv_exec_ctrl = svm_refresh_apicv_exec_ctrl,
.load_eoi_exitmap = svm_load_eoi_exitmap,
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -591,7 +591,8 @@ struct nested_vmx {
*/
bool sync_shadow_vmcs;

- bool change_vmcs01_virtual_x2apic_mode;
+ bool change_vmcs01_virtual_apic_mode;
+
/* L2 must run next, and mustn't decide to exit to L1. */
bool nested_run_pending;

@@ -9290,31 +9291,43 @@ static void update_cr8_intercept(struct
vmcs_write32(TPR_THRESHOLD, irr);
}

-static void vmx_set_virtual_x2apic_mode(struct kvm_vcpu *vcpu, bool set)
+static void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
{
u32 sec_exec_control;

+ if (!lapic_in_kernel(vcpu))
+ return;
+
/* Postpone execution until vmcs01 is the current VMCS. */
if (is_guest_mode(vcpu)) {
- to_vmx(vcpu)->nested.change_vmcs01_virtual_x2apic_mode = true;
+ to_vmx(vcpu)->nested.change_vmcs01_virtual_apic_mode = true;
return;
}

- if (!cpu_has_vmx_virtualize_x2apic_mode())
- return;
-
if (!cpu_need_tpr_shadow(vcpu))
return;

sec_exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
+ sec_exec_control &= ~(SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
+ SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE);

- if (set) {
- sec_exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
- sec_exec_control |= SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE;
- } else {
- sec_exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE;
- sec_exec_control |= SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
- vmx_flush_tlb(vcpu, true);
+ switch (kvm_get_apic_mode(vcpu)) {
+ case LAPIC_MODE_INVALID:
+ WARN_ONCE(true, "Invalid local APIC state");
+ case LAPIC_MODE_DISABLED:
+ break;
+ case LAPIC_MODE_XAPIC:
+ if (flexpriority_enabled) {
+ sec_exec_control |=
+ SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
+ vmx_flush_tlb(vcpu, true);
+ }
+ break;
+ case LAPIC_MODE_X2APIC:
+ if (cpu_has_vmx_virtualize_x2apic_mode())
+ sec_exec_control |=
+ SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE;
+ break;
}
vmcs_write32(SECONDARY_VM_EXEC_CONTROL, sec_exec_control);

@@ -12185,10 +12198,9 @@ static void nested_vmx_vmexit(struct kvm
if (kvm_has_tsc_control)
decache_tsc_multiplier(vmx);

- if (vmx->nested.change_vmcs01_virtual_x2apic_mode) {
- vmx->nested.change_vmcs01_virtual_x2apic_mode = false;
- vmx_set_virtual_x2apic_mode(vcpu,
- vcpu->arch.apic_base & X2APIC_ENABLE);
+ if (vmx->nested.change_vmcs01_virtual_apic_mode) {
+ vmx->nested.change_vmcs01_virtual_apic_mode = false;
+ vmx_set_virtual_apic_mode(vcpu);
} else if (!nested_cpu_has_ept(vmcs12) &&
nested_cpu_has2(vmcs12,
SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) {
@@ -12749,7 +12761,7 @@ static struct kvm_x86_ops vmx_x86_ops __
.enable_nmi_window = enable_nmi_window,
.enable_irq_window = enable_irq_window,
.update_cr8_intercept = update_cr8_intercept,
- .set_virtual_x2apic_mode = vmx_set_virtual_x2apic_mode,
+ .set_virtual_apic_mode = vmx_set_virtual_apic_mode,
.set_apic_access_page_addr = vmx_set_apic_access_page_addr,
.get_enable_apicv = vmx_get_enable_apicv,
.refresh_apicv_exec_ctrl = vmx_refresh_apicv_exec_ctrl,