aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorJim Mattson <jmattson@google.com>2020-05-08 13:36:43 -0700
committerPaolo Bonzini <pbonzini@redhat.com>2020-05-15 12:26:26 -0400
commit93dff2fed2fb4a513196b7df05742c6fcdfd5178 (patch)
tree752131d4fa0b06cc34efef6e037f3122e2684059
parentada0098df6569b7f9e9495beb0f1e35718895aa0 (diff)
KVM: nVMX: Migrate the VMX-preemption timer
The hrtimer used to emulate the VMX-preemption timer must be pinned to the same logical processor as the vCPU thread to be interrupted if we want to have any hope of adhering to the architectural specification of the VMX-preemption timer. Even with this change, the emulated VMX-preemption timer VM-exit occasionally arrives too late. Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Oliver Upton <oupton@google.com> Message-Id: <20200508203643.85477-4-jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/include/asm/kvm_host.h2
-rw-r--r--arch/x86/kvm/irq.c2
-rw-r--r--arch/x86/kvm/vmx/vmx.c11
3 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c3906fb2b93f..a3ce391c9e7a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1247,6 +1247,8 @@ struct kvm_x86_ops {
bool (*apic_init_signal_blocked)(struct kvm_vcpu *vcpu);
int (*enable_direct_tlbflush)(struct kvm_vcpu *vcpu);
+
+ void (*migrate_timers)(struct kvm_vcpu *vcpu);
};
struct kvm_x86_nested_ops {
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index e330e7d125f7..54f7ea68083b 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -159,6 +159,8 @@ void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
{
__kvm_migrate_apic_timer(vcpu);
__kvm_migrate_pit_timer(vcpu);
+ if (kvm_x86_ops.migrate_timers)
+ kvm_x86_ops.migrate_timers(vcpu);
}
bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 68f4efb2b9c2..6a03c27ff314 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7814,6 +7814,16 @@ static bool vmx_apic_init_signal_blocked(struct kvm_vcpu *vcpu)
return to_vmx(vcpu)->nested.vmxon;
}
+static void vmx_migrate_timers(struct kvm_vcpu *vcpu)
+{
+ if (is_guest_mode(vcpu)) {
+ struct hrtimer *timer = &to_vmx(vcpu)->nested.preemption_timer;
+
+ if (hrtimer_try_to_cancel(timer) == 1)
+ hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED);
+ }
+}
+
static void hardware_unsetup(void)
{
if (nested)
@@ -7957,6 +7967,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
.need_emulation_on_page_fault = vmx_need_emulation_on_page_fault,
.apic_init_signal_blocked = vmx_apic_init_signal_blocked,
+ .migrate_timers = vmx_migrate_timers,
};
static __init int hardware_setup(void)

Privacy Policy