The decision on whether to use hardware APIC virtualization used to be
taken globally, based on the availability of the feature in the CPU
and the value of a module parameter.
However, under certain circumstances we want to control it on per-vcpu
basis. In particular, when the userspace activates HyperV synthetic
interrupt controller (SynIC), APICv has to be disabled as it's
incompatible with SynIC auto-EOI behavior.
To achieve that, introduce 'apicv_active' flag on struct
kvm_vcpu_arch, and kvm_vcpu_deactivate_apicv() function to turn APICv
off. The flag is initialized based on the module parameter and CPU
capability, and consulted whenever an APICv-specific action is
performed.
Signed-off-by: Andrey Smetanin <asmetanin@xxxxxxxxxxxxx>
Reviewed-by: Roman Kagan <rkagan@xxxxxxxxxxxxx>
Signed-off-by: Denis V. Lunev <den@xxxxxxxxxx>
CC: Gleb Natapov <gleb@xxxxxxxxxx>
CC: Paolo Bonzini <pbonzini@xxxxxxxxxx>
CC: Roman Kagan <rkagan@xxxxxxxxxxxxx>
CC: Denis V. Lunev <den@xxxxxxxxxx>
CC: qemu-devel@xxxxxxxxxx
---
arch/x86/include/asm/kvm_host.h | 6 +++++-
arch/x86/kvm/irq.c | 2 +-
arch/x86/kvm/lapic.c | 23 +++++++++++----------
arch/x86/kvm/lapic.h | 4 ++--
arch/x86/kvm/svm.c | 11 +++++++---
arch/x86/kvm/vmx.c | 45 +++++++++++++++++------------------------
arch/x86/kvm/x86.c | 19 ++++++++++++++---
7 files changed, 63 insertions(+), 47 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index d51a7e1d..a60a461 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -400,6 +400,7 @@ struct kvm_vcpu_arch {
u64 efer;
u64 apic_base;
struct kvm_lapic *apic; /* kernel irqchip context */
+ bool apicv_active;
DECLARE_BITMAP(ioapic_handled_vectors, 256);
unsigned long apic_attention;
int32_t apic_arb_prio;
@@ -830,7 +831,8 @@ struct kvm_x86_ops {
void (*enable_nmi_window)(struct kvm_vcpu *vcpu);
void (*enable_irq_window)(struct kvm_vcpu *vcpu);
void (*update_cr8_intercept)(struct kvm_vcpu *vcpu, int tpr, int irr);
- int (*cpu_uses_apicv)(struct kvm_vcpu *vcpu);
+ bool (*get_enable_apicv)(void);
+ void (*refresh_apicv_exec_ctrl)(struct kvm_vcpu *vcpu);
void (*hwapic_irr_update)(struct kvm_vcpu *vcpu, int max_irr);
void (*hwapic_isr_update)(struct kvm *kvm, int isr);
void (*load_eoi_exitmap)(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap);
@@ -1096,6 +1098,8 @@ gpa_t kvm_mmu_gva_to_gpa_write(struct kvm_vcpu *vcpu, gva_t gva,
gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva,
struct x86_exception *exception);
+void kvm_vcpu_deactivate_apicv(struct kvm_vcpu *vcpu);
+
int kvm_emulate_hypercall(struct kvm_vcpu *vcpu);
int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t gva, u32 error_code,
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 097060e..3982b47 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -76,7 +76,7 @@ int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
if (kvm_cpu_has_extint(v))
return 1;
- if (kvm_vcpu_apic_vid_enabled(v))
+ if (kvm_vcpu_apicv_active(v))
return 0;
return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index b14436d..14d6fcc 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -379,7 +379,8 @@ static inline int apic_find_highest_irr(struct kvm_lapic *apic)
if (!apic->irr_pending)
return -1;
- kvm_x86_ops->sync_pir_to_irr(apic->vcpu);
+ if (apic->vcpu->arch.apicv_active)
+ kvm_x86_ops->sync_pir_to_irr(apic->vcpu);
result = apic_search_irr(apic);
ASSERT(result == -1 || result >= 16);
@@ -392,7 +393,7 @@ static inline void apic_clear_irr(int vec, struct kvm_lapic *apic)
vcpu = apic->vcpu;
- if (unlikely(kvm_vcpu_apic_vid_enabled(vcpu))) {
+ if (unlikely(vcpu->arch.apicv_active)) {
/* try to update RVI */
apic_clear_vector(vec, apic->regs + APIC_IRR);
kvm_make_request(KVM_REQ_EVENT, vcpu);
@@ -418,7 +419,7 @@ static inline void apic_set_isr(int vec, struct kvm_lapic *apic)
* because the processor can modify ISR under the hood. Instead
* just set SVI.
*/
- if (unlikely(kvm_x86_ops->hwapic_isr_update))
+ if (unlikely(vcpu->arch.apicv_active))
kvm_x86_ops->hwapic_isr_update(vcpu->kvm, vec);
else {
++apic->isr_count;
@@ -466,7 +467,7 @@ static inline void apic_clear_isr(int vec, struct kvm_lapic *apic)
* on the other hand isr_count and highest_isr_cache are unused
* and must be left alone.
*/
- if (unlikely(kvm_x86_ops->hwapic_isr_update))
+ if (unlikely(vcpu->arch.apicv_active))
kvm_x86_ops->hwapic_isr_update(vcpu->kvm,
apic_find_highest_isr(apic));
else {
@@ -852,7 +853,7 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
apic_clear_vector(vector, apic->regs + APIC_TMR);
}
- if (kvm_x86_ops->deliver_posted_interrupt)
+ if (vcpu->arch.apicv_active)
kvm_x86_ops->deliver_posted_interrupt(vcpu, vector);
else {
apic_set_irr(vector, apic);
@@ -1225,7 +1226,7 @@ static bool lapic_timer_int_injected(struct kvm_vcpu *vcpu)
int vec = reg & APIC_VECTOR_MASK;
void *bitmap = apic->regs + APIC_ISR;
- if (kvm_x86_ops->deliver_posted_interrupt)
+ if (vcpu->arch.apicv_active)
bitmap = apic->regs + APIC_IRR;
if (apic_test_vector(vec, bitmap))
@@ -1693,8 +1694,8 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
apic_set_reg(apic, APIC_ISR + 0x10 * i, 0);
apic_set_reg(apic, APIC_TMR + 0x10 * i, 0);
}
- apic->irr_pending = kvm_vcpu_apic_vid_enabled(vcpu);
- apic->isr_count = kvm_x86_ops->hwapic_isr_update ? 1 : 0;
+ apic->irr_pending = vcpu->arch.apicv_active;
+ apic->isr_count = vcpu->arch.apicv_active ? 1 : 0;
apic->highest_isr_cache = -1;
update_divide_count(apic);
atomic_set(&apic->lapic_timer.pending, 0);
@@ -1906,15 +1907,15 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu,
update_divide_count(apic);
start_apic_timer(apic);
apic->irr_pending = true;
- apic->isr_count = kvm_x86_ops->hwapic_isr_update ?
+ apic->isr_count = vcpu->arch.apicv_active ?
1 : count_vectors(apic->regs + APIC_ISR);
apic->highest_isr_cache = -1;
- if (kvm_x86_ops->hwapic_irr_update)
+ if (vcpu->arch.apicv_active) {
kvm_x86_ops->hwapic_irr_update(vcpu,
apic_find_highest_irr(apic));
- if (unlikely(kvm_x86_ops->hwapic_isr_update))
kvm_x86_ops->hwapic_isr_update(vcpu->kvm,
apic_find_highest_isr(apic));
+ }
kvm_make_request(KVM_REQ_EVENT, vcpu);
if (ioapic_in_kernel(vcpu->kvm))
kvm_rtc_eoi_tracking_restore_one(vcpu);
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index fde8e35d..5fc60e4 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -143,9 +143,9 @@ static inline int apic_x2apic_mode(struct kvm_lapic *apic)
return apic->vcpu->arch.apic_base & X2APIC_ENABLE;
}
-static inline bool kvm_vcpu_apic_vid_enabled(struct kvm_vcpu *vcpu)
+static inline bool kvm_vcpu_apicv_active(struct kvm_vcpu *vcpu)
{
- return kvm_x86_ops->cpu_uses_apicv(vcpu);
+ return vcpu->arch.apic && vcpu->arch.apicv_active;
}
static inline bool kvm_apic_has_events(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 38d3adf..07b19cf 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3650,9 +3650,13 @@ static void svm_set_virtual_x2apic_mode(struct kvm_vcpu *vcpu, bool set)
return;
}
-static int svm_cpu_uses_apicv(struct kvm_vcpu *vcpu)
+static bool svm_get_enable_apicv(void)
+{
+ return false;
+}
+
+static void svm_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu)
{
- return 0;
}
static void svm_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
@@ -4420,7 +4424,8 @@ static struct kvm_x86_ops svm_x86_ops = {
.enable_irq_window = enable_irq_window,
.update_cr8_intercept = update_cr8_intercept,
.set_virtual_x2apic_mode = svm_set_virtual_x2apic_mode,
- .cpu_uses_apicv = svm_cpu_uses_apicv,
+ .get_enable_apicv = svm_get_enable_apicv,
+ .refresh_apicv_exec_ctrl = svm_refresh_apicv_exec_ctrl,
.load_eoi_exitmap = svm_load_eoi_exitmap,
.sync_pir_to_irr = svm_sync_pir_to_irr,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 9562542..bf7488e 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -19,6 +19,7 @@
#include "irq.h"
#include "mmu.h"
#include "cpuid.h"
+#include "lapic.h"
#include <linux/kvm_host.h>
#include <linux/module.h>
@@ -860,7 +861,6 @@ static void kvm_cpu_vmxon(u64 addr);
static void kvm_cpu_vmxoff(void);
static bool vmx_mpx_supported(void);
static bool vmx_xsaves_supported(void);
-static int vmx_cpu_uses_apicv(struct kvm_vcpu *vcpu);
static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr);
static void vmx_set_segment(struct kvm_vcpu *vcpu,
struct kvm_segment *var, int seg);
@@ -868,7 +868,6 @@ static void vmx_get_segment(struct kvm_vcpu *vcpu,
struct kvm_segment *var, int seg);
static bool guest_state_valid(struct kvm_vcpu *vcpu);
static u32 vmx_segment_access_rights(struct kvm_segment *var);
-static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu *vcpu);
static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx);
static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx);
static int alloc_identity_pagetable(struct kvm *kvm);
@@ -2504,7 +2503,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx)
vmx->nested.nested_vmx_pinbased_ctls_high |=
PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR |
PIN_BASED_VMX_PREEMPTION_TIMER;
- if (vmx_cpu_uses_apicv(&vmx->vcpu))
+ if (kvm_vcpu_apicv_active(&vmx->vcpu))
vmx->nested.nested_vmx_pinbased_ctls_high |=
PIN_BASED_POSTED_INTR;
@@ -4467,9 +4466,9 @@ static void vmx_disable_intercept_msr_write_x2apic(u32 msr)
msr, MSR_TYPE_W);
}
-static int vmx_cpu_uses_apicv(struct kvm_vcpu *vcpu)
+static bool vmx_get_enable_apicv(void)
{
- return enable_apicv && lapic_in_kernel(vcpu);
+ return enable_apicv;
}
static int vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu)
@@ -4591,11 +4590,6 @@ static void vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu)
kvm_apic_update_irr(vcpu, vmx->pi_desc.pir);
}
-static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu *vcpu)
-{
- return;
-}
-
/*
* Set up the vmcs's constant host-state fields, i.e., host-state fields that
* will not change in the lifetime of the guest.
@@ -4665,11 +4659,18 @@ static u32 vmx_pin_based_exec_ctrl(struct vcpu_vmx *vmx)
{
u32 pin_based_exec_ctrl = vmcs_config.pin_based_exec_ctrl;
- if (!vmx_cpu_uses_apicv(&vmx->vcpu))
+ if (!kvm_vcpu_apicv_active(&vmx->vcpu))
pin_based_exec_ctrl &= ~PIN_BASED_POSTED_INTR;
return pin_based_exec_ctrl;
}
+static void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+ vmcs_write32(PIN_BASED_VM_EXEC_CONTROL, vmx_pin_based_exec_ctrl(vmx));
+}
+
static u32 vmx_exec_control(struct vcpu_vmx *vmx)
{
u32 exec_control = vmcs_config.cpu_based_exec_ctrl;
@@ -4708,7 +4709,7 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx)
exec_control &= ~SECONDARY_EXEC_UNRESTRICTED_GUEST;
if (!ple_gap)
exec_control &= ~SECONDARY_EXEC_PAUSE_LOOP_EXITING;
- if (!vmx_cpu_uses_apicv(&vmx->vcpu))
+ if (!kvm_vcpu_apicv_active(&vmx->vcpu))
exec_control &= ~(SECONDARY_EXEC_APIC_REGISTER_VIRT |
SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);
exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE;
@@ -4772,7 +4773,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
vmx_secondary_exec_control(vmx));
- if (vmx_cpu_uses_apicv(&vmx->vcpu)) {
+ if (kvm_vcpu_apicv_active(&vmx->vcpu)) {
vmcs_write64(EOI_EXIT_BITMAP0, 0);
vmcs_write64(EOI_EXIT_BITMAP1, 0);
vmcs_write64(EOI_EXIT_BITMAP2, 0);
@@ -4924,7 +4925,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu);
- if (vmx_cpu_uses_apicv(vcpu))
+ if (kvm_vcpu_apicv_active(vcpu))
memset(&vmx->pi_desc, 0, sizeof(struct pi_desc));
if (vmx->vpid != 0)
@@ -6199,15 +6200,6 @@ static __init int hardware_setup(void)
if (!cpu_has_vmx_apicv())
enable_apicv = 0;
- if (enable_apicv)
- kvm_x86_ops->update_cr8_intercept = NULL;
- else {
- kvm_x86_ops->hwapic_irr_update = NULL;
- kvm_x86_ops->hwapic_isr_update = NULL;
- kvm_x86_ops->deliver_posted_interrupt = NULL;
- kvm_x86_ops->sync_pir_to_irr = vmx_sync_pir_to_irr_dummy;
- }
-
vmx_disable_intercept_for_msr(MSR_FS_BASE, false);
vmx_disable_intercept_for_msr(MSR_GS_BASE, false);
vmx_disable_intercept_for_msr(MSR_KERNEL_GS_BASE, true);
@@ -8150,7 +8142,7 @@ static void vmx_set_virtual_x2apic_mode(struct kvm_vcpu *vcpu, bool set)
* apicv
*/
if (!cpu_has_vmx_virtualize_x2apic_mode() ||
- !vmx_cpu_uses_apicv(vcpu))
+ !kvm_vcpu_apicv_active(vcpu))
return;
if (!cpu_need_tpr_shadow(vcpu))
@@ -8257,7 +8249,7 @@ static void vmx_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr)
static void vmx_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
{
- if (!vmx_cpu_uses_apicv(vcpu))
+ if (!kvm_vcpu_apicv_active(vcpu))
return;
vmcs_write64(EOI_EXIT_BITMAP0, eoi_exit_bitmap[0]);
@@ -10801,7 +10793,8 @@ static struct kvm_x86_ops vmx_x86_ops = {
.update_cr8_intercept = update_cr8_intercept,
.set_virtual_x2apic_mode = vmx_set_virtual_x2apic_mode,
.set_apic_access_page_addr = vmx_set_apic_access_page_addr,
- .cpu_uses_apicv = vmx_cpu_uses_apicv,
+ .get_enable_apicv = vmx_get_enable_apicv,
+ .refresh_apicv_exec_ctrl = vmx_refresh_apicv_exec_ctrl,
.load_eoi_exitmap = vmx_load_eoi_exitmap,
.hwapic_irr_update = vmx_hwapic_irr_update,
.hwapic_isr_update = vmx_hwapic_isr_update,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4cf2cb9..afb0a60 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2645,7 +2645,9 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
struct kvm_lapic_state *s)
{
- kvm_x86_ops->sync_pir_to_irr(vcpu);
+ if (vcpu->arch.apicv_active)
+ kvm_x86_ops->sync_pir_to_irr(vcpu);
+
memcpy(s->regs, vcpu->arch.apic->regs, sizeof *s);
return 0;
@@ -5743,6 +5745,12 @@ static void kvm_pv_kick_cpu_op(struct kvm *kvm, unsigned long flags, int apicid)
kvm_irq_delivery_to_apic(kvm, NULL, &lapic_irq, NULL);
}
+void kvm_vcpu_deactivate_apicv(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.apicv_active = false;
+ kvm_x86_ops->refresh_apicv_exec_ctrl(vcpu);
+}
+
int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
{
unsigned long nr, a0, a1, a2, a3, ret;
@@ -5857,6 +5865,9 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu)
if (!vcpu->arch.apic)
return;
+ if (vcpu->arch.apicv_active)
+ return;
+
if (!vcpu->arch.apic->vapic_addr)
max_irr = kvm_lapic_find_highest_irr(vcpu);
else
@@ -6203,7 +6214,8 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
if (irqchip_split(vcpu->kvm))
kvm_scan_ioapic_routes(vcpu, vcpu->arch.ioapic_handled_vectors);
else {
- kvm_x86_ops->sync_pir_to_irr(vcpu);
+ if (vcpu->arch.apicv_active)
+ kvm_x86_ops->sync_pir_to_irr(vcpu);
kvm_ioapic_scan_entry(vcpu, vcpu->arch.ioapic_handled_vectors);
}
kvm_x86_ops->load_eoi_exitmap(vcpu,
@@ -6348,7 +6360,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
* Update architecture specific hints for APIC
* virtual interrupt delivery.
*/
- if (kvm_x86_ops->hwapic_irr_update)
+ if (vcpu->arch.apicv_active)
kvm_x86_ops->hwapic_irr_update(vcpu,
kvm_lapic_find_highest_irr(vcpu));
}
@@ -7405,6 +7417,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
BUG_ON(vcpu->kvm == NULL);
kvm = vcpu->kvm;
+ vcpu->arch.apicv_active = kvm_x86_ops->get_enable_apicv();
vcpu->arch.pv.pv_unhalted = false;
vcpu->arch.emulate_ctxt.ops = &emulate_ops;
if (!irqchip_in_kernel(kvm) || kvm_vcpu_is_reset_bsp(vcpu))
--
2.4.3
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