kvm/x86: Hyper-V synthetic interrupt controller
SynIC (synthetic interrupt controller) is a lapic extension,
which is controlled via MSRs and maintains for each vCPU
- 16 synthetic interrupt "lines" (SINT's); each can be configured to
trigger a specific interrupt vector optionally with auto-EOI
semantics
- a message page in the guest memory with 16 256-byte per-SINT message
slots
- an event flag page in the guest memory with 16 2048-bit per-SINT
event flag areas
The host triggers a SINT whenever it delivers a new message to the
corresponding slot or flips an event flag bit in the corresponding area.
The guest informs the host that it can try delivering a message by
explicitly asserting EOI in lapic or writing to End-Of-Message (EOM)
MSR.
The userspace (qemu) triggers interrupts and receives EOM notifications
via irqfd with resampler; for that, a GSI is allocated for each
configured SINT, and irq_routing api is extended to support GSI-SINT
mapping.
Changes v4:
* added activation of SynIC by vcpu KVM_ENABLE_CAP
* added per SynIC active flag
* added deactivation of APICv upon SynIC activation
Changes v3:
* added KVM_CAP_HYPERV_SYNIC and KVM_IRQ_ROUTING_HV_SINT notes into
docs
Changes v2:
* do not use posted interrupts for Hyper-V SynIC AutoEOI vectors
* add Hyper-V SynIC vectors into EOI exit bitmap
* Hyper-V SyniIC SINT msr write logic simplified
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 618a20d..36591fa 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -41,6 +41,7 @@
#include "trace.h"
#include "x86.h"
#include "cpuid.h"
+#include "hyperv.h"
#ifndef CONFIG_X86_64
#define mod_64(x, y) ((x) - (y) * div64_u64(x, y))
@@ -128,11 +129,6 @@
(LVT_MASK | APIC_MODE_MASK | APIC_INPUT_POLARITY | \
APIC_LVT_REMOTE_IRR | APIC_LVT_LEVEL_TRIGGER)
-static inline int kvm_apic_id(struct kvm_lapic *apic)
-{
- return (kvm_apic_get_reg(apic, APIC_ID) >> 24) & 0xff;
-}
-
/* The logical map is definitely wrong if we have multiple
* modes at the same time. (Physical map is always right.)
*/
@@ -975,6 +971,9 @@
apic_clear_isr(vector, apic);
apic_update_ppr(apic);
+ if (test_bit(vector, vcpu_to_synic(apic->vcpu)->vec_bitmap))
+ kvm_hv_synic_send_eoi(apic->vcpu, vector);
+
kvm_ioapic_send_eoi(apic, vector);
kvm_make_request(KVM_REQ_EVENT, apic->vcpu);
return vector;
@@ -1884,6 +1883,12 @@
apic_set_isr(vector, apic);
apic_update_ppr(apic);
apic_clear_irr(vector, apic);
+
+ if (test_bit(vector, vcpu_to_synic(vcpu)->auto_eoi_bitmap)) {
+ apic_clear_isr(vector, apic);
+ apic_update_ppr(apic);
+ }
+
return vector;
}