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authorDavid Woodhouse <dwmw@amazon.co.uk>2021-12-10 16:36:23 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2022-01-07 10:44:45 -0500
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KVM: x86/xen: Add KVM_IRQ_ROUTING_XEN_EVTCHN and event channel delivery
This adds basic support for delivering 2 level event channels to a guest. Initially, it only supports delivery via the IRQ routing table, triggered by an eventfd. In order to do so, it has a kvm_xen_set_evtchn_fast() function which will use the pre-mapped shared_info page if it already exists and is still valid, while the slow path through the irqfd_inject workqueue will remap the shared_info page if necessary. It sets the bits in the shared_info page but not the vcpu_info; that is deferred to __kvm_xen_has_interrupt() which raises the vector to the appropriate vCPU. Add a 'verbose' mode to xen_shinfo_test while adding test cases for this. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211210163625.2886-5-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virt/kvm/api.rst')
-rw-r--r--Documentation/virt/kvm/api.rst21
1 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index c168be764707..6b683dfea8f2 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -1799,6 +1799,7 @@ No flags are specified so far, the corresponding field must be set to zero.
struct kvm_irq_routing_msi msi;
struct kvm_irq_routing_s390_adapter adapter;
struct kvm_irq_routing_hv_sint hv_sint;
+ struct kvm_irq_routing_xen_evtchn xen_evtchn;
__u32 pad[8];
} u;
};
@@ -1808,6 +1809,7 @@ No flags are specified so far, the corresponding field must be set to zero.
#define KVM_IRQ_ROUTING_MSI 2
#define KVM_IRQ_ROUTING_S390_ADAPTER 3
#define KVM_IRQ_ROUTING_HV_SINT 4
+ #define KVM_IRQ_ROUTING_XEN_EVTCHN 5
flags:
@@ -1859,6 +1861,20 @@ address_hi must be zero.
__u32 sint;
};
+ struct kvm_irq_routing_xen_evtchn {
+ __u32 port;
+ __u32 vcpu;
+ __u32 priority;
+ };
+
+
+When KVM_CAP_XEN_HVM includes the KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL bit
+in its indication of supported features, routing to Xen event channels
+is supported. Although the priority field is present, only the value
+KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL is supported, which means delivery by
+2 level event channels. FIFO event channel support may be added in
+the future.
+
4.55 KVM_SET_TSC_KHZ
--------------------
@@ -7413,6 +7429,7 @@ PVHVM guests. Valid flags are::
#define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL (1 << 1)
#define KVM_XEN_HVM_CONFIG_SHARED_INFO (1 << 2)
#define KVM_XEN_HVM_CONFIG_RUNSTATE (1 << 2)
+ #define KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL (1 << 3)
The KVM_XEN_HVM_CONFIG_HYPERCALL_MSR flag indicates that the KVM_XEN_HVM_CONFIG
ioctl is available, for the guest to set its hypercall page.
@@ -7432,6 +7449,10 @@ The KVM_XEN_HVM_CONFIG_RUNSTATE flag indicates that the runstate-related
features KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR/_CURRENT/_DATA/_ADJUST are
supported by the KVM_XEN_VCPU_SET_ATTR/KVM_XEN_VCPU_GET_ATTR ioctls.
+The KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL flag indicates that IRQ routing entries
+of the type KVM_IRQ_ROUTING_XEN_EVTCHN are supported, with the priority
+field set to indicate 2 level event channel delivery.
+
8.31 KVM_CAP_PPC_MULTITCE
-------------------------