From 5c919412fe61c35947816fdbd5f7bd09fe0dd073 Mon Sep 17 00:00:00 2001 From: Andrey Smetanin Date: Tue, 10 Nov 2015 15:36:34 +0300 Subject: 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 Reviewed-by: Roman Kagan Signed-off-by: Denis V. Lunev CC: Gleb Natapov CC: Paolo Bonzini CC: Roman Kagan CC: Denis V. Lunev CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini --- Documentation/virtual/kvm/api.txt | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'Documentation/virtual') diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 092ee9fbaf2b..88af84675af0 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1451,6 +1451,7 @@ struct kvm_irq_routing_entry { struct kvm_irq_routing_irqchip irqchip; struct kvm_irq_routing_msi msi; struct kvm_irq_routing_s390_adapter adapter; + struct kvm_irq_routing_hv_sint hv_sint; __u32 pad[8]; } u; }; @@ -1459,6 +1460,7 @@ struct kvm_irq_routing_entry { #define KVM_IRQ_ROUTING_IRQCHIP 1 #define KVM_IRQ_ROUTING_MSI 2 #define KVM_IRQ_ROUTING_S390_ADAPTER 3 +#define KVM_IRQ_ROUTING_HV_SINT 4 No flags are specified so far, the corresponding field must be set to zero. @@ -1482,6 +1484,10 @@ struct kvm_irq_routing_s390_adapter { __u32 adapter_id; }; +struct kvm_irq_routing_hv_sint { + __u32 vcpu; + __u32 sint; +}; 4.53 KVM_ASSIGN_SET_MSIX_NR (deprecated) @@ -3685,3 +3691,16 @@ available, means that that the kernel has an implementation of the H_RANDOM hypercall backed by a hardware random-number generator. If present, the kernel H_RANDOM handler can be enabled for guest use with the KVM_CAP_PPC_ENABLE_HCALL capability. + +8.2 KVM_CAP_HYPERV_SYNIC + +Architectures: x86 +This capability, if KVM_CHECK_EXTENSION indicates that it is +available, means that that the kernel has an implementation of the +Hyper-V Synthetic interrupt controller(SynIC). Hyper-V SynIC is +used to support Windows Hyper-V based guest paravirt drivers(VMBus). + +In order to use SynIC, it has to be activated by setting this +capability via KVM_ENABLE_CAP ioctl on the vcpu fd. Note that this +will disable the use of APIC hardware virtualization even if supported +by the CPU, as it's incompatible with SynIC auto-EOI behavior. -- cgit v1.2.1