KVM: x86: add KVM_CAP_X2APIC_API
KVM_CAP_X2APIC_API is a capability for features related to x2APIC
enablement. KVM_X2APIC_API_32BIT_FORMAT feature can be enabled to
extend APIC ID in get/set ioctl and MSI addresses to 32 bits.
Both are needed to support x2APIC.
The feature has to be enableable and disabled by default, because
get/set ioctl shifted and truncated APIC ID to 8 bits by using a
non-standard protocol inspired by xAPIC and the change is not
backward-compatible.
Changes to MSI addresses follow the format used by interrupt remapping
unit. The upper address word, that used to be 0, contains upper 24 bits
of the LAPIC address in its upper 24 bits. Lower 8 bits are reserved as
0. Using the upper address word is not backward-compatible either as we
didn't check that userspace zeroed the word. Reserved bits are still
not explicitly checked, but non-zero data will affect LAPIC addresses,
which will cause a bug.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c
index 889563d..25810b1 100644
--- a/arch/x86/kvm/irq_comm.c
+++ b/arch/x86/kvm/irq_comm.c
@@ -110,13 +110,17 @@
return r;
}
-void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
+void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
struct kvm_lapic_irq *irq)
{
- trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
+ trace_kvm_msi_set_irq(e->msi.address_lo | (kvm->arch.x2apic_format ?
+ (u64)e->msi.address_hi << 32 : 0),
+ e->msi.data);
irq->dest_id = (e->msi.address_lo &
MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
+ if (kvm->arch.x2apic_format)
+ irq->dest_id |= MSI_ADDR_EXT_DEST_ID(e->msi.address_hi);
irq->vector = (e->msi.data &
MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
@@ -129,15 +133,24 @@
}
EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
+static inline bool kvm_msi_route_invalid(struct kvm *kvm,
+ struct kvm_kernel_irq_routing_entry *e)
+{
+ return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
+}
+
int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id, int level, bool line_status)
{
struct kvm_lapic_irq irq;
+ if (kvm_msi_route_invalid(kvm, e))
+ return -EINVAL;
+
if (!level)
return -1;
- kvm_set_msi_irq(e, &irq);
+ kvm_set_msi_irq(kvm, e, &irq);
return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
}
@@ -153,7 +166,10 @@
if (unlikely(e->type != KVM_IRQ_ROUTING_MSI))
return -EWOULDBLOCK;
- kvm_set_msi_irq(e, &irq);
+ if (kvm_msi_route_invalid(kvm, e))
+ return -EINVAL;
+
+ kvm_set_msi_irq(kvm, e, &irq);
if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
return r;
@@ -286,6 +302,9 @@
e->msi.address_lo = ue->u.msi.address_lo;
e->msi.address_hi = ue->u.msi.address_hi;
e->msi.data = ue->u.msi.data;
+
+ if (kvm_msi_route_invalid(kvm, e))
+ goto out;
break;
case KVM_IRQ_ROUTING_HV_SINT:
e->set = kvm_hv_set_sint;
@@ -394,7 +413,7 @@
if (entry->type != KVM_IRQ_ROUTING_MSI)
continue;
- kvm_set_msi_irq(entry, &irq);
+ kvm_set_msi_irq(vcpu->kvm, entry, &irq);
if (irq.level && kvm_apic_match_dest(vcpu, NULL, 0,
irq.dest_id, irq.dest_mode))
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 3c2a8c1..d27a782 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1991,10 +1991,15 @@
if (apic_x2apic_mode(vcpu->arch.apic)) {
u32 *id = (u32 *)(s->regs + APIC_ID);
- if (set)
- *id >>= 24;
- else
- *id <<= 24;
+ if (vcpu->kvm->arch.x2apic_format) {
+ if (*id != vcpu->vcpu_id)
+ return -EINVAL;
+ } else {
+ if (set)
+ *id >>= 24;
+ else
+ *id <<= 24;
+ }
}
return 0;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 7bdd6b1..b61cdad 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11104,7 +11104,7 @@
* We will support full lowest-priority interrupt later.
*/
- kvm_set_msi_irq(e, &irq);
+ kvm_set_msi_irq(kvm, e, &irq);
if (!kvm_intr_is_single_vcpu(kvm, &irq, &vcpu)) {
/*
* Make sure the IRTE is in remapped mode if
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b6e402d..d86f563 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -90,6 +90,8 @@
#define VM_STAT(x) offsetof(struct kvm, stat.x), KVM_STAT_VM
#define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
+#define KVM_X2APIC_API_VALID_FLAGS (KVM_X2APIC_API_USE_32BIT_IDS)
+
static void update_cr8_intercept(struct kvm_vcpu *vcpu);
static void process_nmi(struct kvm_vcpu *vcpu);
static void enter_smm(struct kvm_vcpu *vcpu);
@@ -2625,6 +2627,9 @@
case KVM_CAP_TSC_CONTROL:
r = kvm_has_tsc_control;
break;
+ case KVM_CAP_X2APIC_API:
+ r = KVM_X2APIC_API_VALID_FLAGS;
+ break;
default:
r = 0;
break;
@@ -3799,6 +3804,16 @@
mutex_unlock(&kvm->lock);
break;
}
+ case KVM_CAP_X2APIC_API:
+ r = -EINVAL;
+ if (cap->args[0] & ~KVM_X2APIC_API_VALID_FLAGS)
+ break;
+
+ if (cap->args[0] & KVM_X2APIC_API_USE_32BIT_IDS)
+ kvm->arch.x2apic_format = true;
+
+ r = 0;
+ break;
default:
r = -EINVAL;
break;
