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author | Andrey Smetanin <asmetanin@virtuozzo.com> | 2015-11-10 15:36:34 +0300 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-11-25 17:24:22 +0100 |
commit | 5c919412fe61c35947816fdbd5f7bd09fe0dd073 (patch) | |
tree | e2435a515aac386a05869a20edc61dc5f9d2047d /Documentation/virtual | |
parent | d62caabb41f33d96333f9ef15e09cd26e1c12760 (diff) | |
download | linux-next-5c919412fe61c35947816fdbd5f7bd09fe0dd073.tar.gz |
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>
Diffstat (limited to 'Documentation/virtual')
-rw-r--r-- | Documentation/virtual/kvm/api.txt | 19 |
1 files changed, 19 insertions, 0 deletions
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. |