diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2022-03-03 15:41:24 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-04-02 05:41:17 -0400 |
| commit | fde0451be8fb3208d4d146b8602d99ee8139e515 (patch) | |
| tree | a6b8d95db243f33f19be2971fff7dc4dc45d9e83 /arch/x86/kvm/xen.c | |
| parent | 28d1629f751c4a5f9437fbaa0ee4ed81d1a8e587 (diff) | |
| download | linux-fde0451be8fb3208d4d146b8602d99ee8139e515.tar.bz2 | |
KVM: x86/xen: Support per-vCPU event channel upcall via local APIC
Windows uses a per-vCPU vector, and it's delivered via the local APIC
basically like an MSI (with associated EOI) unlike the traditional
guest-wide vector which is just magically asserted by Xen (and in the
KVM case by kvm_xen_has_interrupt() / kvm_cpu_get_extint()).
Now that the kernel is able to raise event channel events for itself,
being able to do so for Windows guests is also going to be useful.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220303154127.202856-15-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/xen.c')
| -rw-r--r-- | arch/x86/kvm/xen.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index 98438f27f6b3..5afaf7b59944 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -314,6 +314,22 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state) mark_page_dirty_in_slot(v->kvm, gpc->memslot, gpc->gpa >> PAGE_SHIFT); } +static void kvm_xen_inject_vcpu_vector(struct kvm_vcpu *v) +{ + struct kvm_lapic_irq irq = { }; + int r; + + irq.dest_id = v->vcpu_id; + irq.vector = v->arch.xen.upcall_vector; + irq.dest_mode = APIC_DEST_PHYSICAL; + irq.shorthand = APIC_DEST_NOSHORT; + irq.delivery_mode = APIC_DM_FIXED; + irq.level = 1; + + /* The fast version will always work for physical unicast */ + WARN_ON_ONCE(!kvm_irq_delivery_to_apic_fast(v->kvm, NULL, &irq, &r, NULL)); +} + /* * On event channel delivery, the vcpu_info may not have been accessible. * In that case, there are bits in vcpu->arch.xen.evtchn_pending_sel which @@ -374,6 +390,10 @@ void kvm_xen_inject_pending_events(struct kvm_vcpu *v) } read_unlock_irqrestore(&gpc->lock, flags); + /* For the per-vCPU lapic vector, deliver it as MSI. */ + if (v->arch.xen.upcall_vector) + kvm_xen_inject_vcpu_vector(v); + mark_page_dirty_in_slot(v->kvm, gpc->memslot, gpc->gpa >> PAGE_SHIFT); } @@ -708,6 +728,15 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) r = 0; break; + case KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR: + if (data->u.vector && data->u.vector < 0x10) + r = -EINVAL; + else { + vcpu->arch.xen.upcall_vector = data->u.vector; + r = 0; + } + break; + default: break; } @@ -795,6 +824,11 @@ int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) r = 0; break; + case KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR: + data->u.vector = vcpu->arch.xen.upcall_vector; + r = 0; + break; + default: break; } @@ -1228,6 +1262,12 @@ int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe, struct kvm *kvm) kick_vcpu = true; } } + + /* For the per-vCPU lapic vector, deliver it as MSI. */ + if (kick_vcpu && vcpu->arch.xen.upcall_vector) { + kvm_xen_inject_vcpu_vector(vcpu); + kick_vcpu = false; + } } out_rcu: |