diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 5 | ||||
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/xen.c | 55 |
4 files changed, 58 insertions, 6 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index db02305eb9e3..ae48fd8cb278 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -687,6 +687,7 @@ struct kvm_hypervisor_cpuid { u32 limit; }; +#ifdef CONFIG_KVM_XEN /* Xen HVM per vcpu emulation context */ struct kvm_vcpu_xen { u64 hypercall_rip; @@ -709,6 +710,7 @@ struct kvm_vcpu_xen { struct timer_list poll_timer; struct kvm_hypervisor_cpuid cpuid; }; +#endif struct kvm_queued_exception { bool pending; @@ -937,8 +939,9 @@ struct kvm_vcpu_arch { bool hyperv_enabled; struct kvm_vcpu_hv *hyperv; +#ifdef CONFIG_KVM_XEN struct kvm_vcpu_xen xen; - +#endif cpumask_var_t wbinvd_dirty_mask; unsigned long last_retry_eip; diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 6fb3249ae683..dda6fc4cfae8 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -448,7 +448,9 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2, vcpu->arch.cpuid_nent = nent; vcpu->arch.kvm_cpuid = kvm_get_hypervisor_cpuid(vcpu, KVM_SIGNATURE); +#ifdef CONFIG_KVM_XEN vcpu->arch.xen.cpuid = kvm_get_hypervisor_cpuid(vcpu, XEN_SIGNATURE); +#endif kvm_vcpu_after_set_cpuid(vcpu); return 0; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3584363b8fa6..34a6c7b267c5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3240,11 +3240,13 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) if (vcpu->pv_time.active) kvm_setup_guest_pvclock(v, &vcpu->pv_time, 0); +#ifdef CONFIG_KVM_XEN if (vcpu->xen.vcpu_info_cache.active) kvm_setup_guest_pvclock(v, &vcpu->xen.vcpu_info_cache, offsetof(struct compat_vcpu_info, time)); if (vcpu->xen.vcpu_time_info_cache.active) kvm_setup_guest_pvclock(v, &vcpu->xen.vcpu_time_info_cache, 0); +#endif kvm_hv_setup_tsc_page(v->kvm, &vcpu->hv_clock); return 0; } diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index b946d9f28030..e53fad915a62 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -134,9 +134,23 @@ static enum hrtimer_restart xen_timer_callback(struct hrtimer *timer) { struct kvm_vcpu *vcpu = container_of(timer, struct kvm_vcpu, arch.xen.timer); + struct kvm_xen_evtchn e; + int rc; + if (atomic_read(&vcpu->arch.xen.timer_pending)) return HRTIMER_NORESTART; + e.vcpu_id = vcpu->vcpu_id; + e.vcpu_idx = vcpu->vcpu_idx; + e.port = vcpu->arch.xen.timer_virq; + e.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL; + + rc = kvm_xen_set_evtchn_fast(&e, vcpu->kvm); + if (rc != -EWOULDBLOCK) { + vcpu->arch.xen.timer_expires = 0; + return HRTIMER_NORESTART; + } + atomic_inc(&vcpu->arch.xen.timer_pending); kvm_make_request(KVM_REQ_UNBLOCK, vcpu); kvm_vcpu_kick(vcpu); @@ -146,6 +160,14 @@ static enum hrtimer_restart xen_timer_callback(struct hrtimer *timer) static void kvm_xen_start_timer(struct kvm_vcpu *vcpu, u64 guest_abs, s64 delta_ns) { + /* + * Avoid races with the old timer firing. Checking timer_expires + * to avoid calling hrtimer_cancel() will only have false positives + * so is fine. + */ + if (vcpu->arch.xen.timer_expires) + hrtimer_cancel(&vcpu->arch.xen.timer); + atomic_set(&vcpu->arch.xen.timer_pending, 0); vcpu->arch.xen.timer_expires = guest_abs; @@ -1019,9 +1041,36 @@ int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) break; case KVM_XEN_VCPU_ATTR_TYPE_TIMER: + /* + * Ensure a consistent snapshot of state is captured, with a + * timer either being pending, or the event channel delivered + * to the corresponding bit in the shared_info. Not still + * lurking in the timer_pending flag for deferred delivery. + * Purely as an optimisation, if the timer_expires field is + * zero, that means the timer isn't active (or even in the + * timer_pending flag) and there is no need to cancel it. + */ + if (vcpu->arch.xen.timer_expires) { + hrtimer_cancel(&vcpu->arch.xen.timer); + kvm_xen_inject_timer_irqs(vcpu); + } + data->u.timer.port = vcpu->arch.xen.timer_virq; data->u.timer.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL; data->u.timer.expires_ns = vcpu->arch.xen.timer_expires; + + /* + * The hrtimer may trigger and raise the IRQ immediately, + * while the returned state causes it to be set up and + * raised again on the destination system after migration. + * That's fine, as the guest won't even have had a chance + * to run and handle the interrupt. Asserting an already + * pending event channel is idempotent. + */ + if (vcpu->arch.xen.timer_expires) + hrtimer_start_expires(&vcpu->arch.xen.timer, + HRTIMER_MODE_ABS_HARD); + r = 0; break; @@ -1374,12 +1423,8 @@ static bool kvm_xen_hcall_vcpu_op(struct kvm_vcpu *vcpu, bool longmode, int cmd, return true; } + /* A delta <= 0 results in an immediate callback, which is what we want */ delta = oneshot.timeout_abs_ns - get_kvmclock_ns(vcpu->kvm); - if ((oneshot.flags & VCPU_SSHOTTMR_future) && delta < 0) { - *r = -ETIME; - return true; - } - kvm_xen_start_timer(vcpu, oneshot.timeout_abs_ns, delta); *r = 0; return true; |