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authorAvi Kivity <avi@redhat.com>2011-12-07 12:42:47 +0200
committerAvi Kivity <avi@redhat.com>2011-12-27 11:22:18 +0200
commit3f745f1e224e05e845a15760a55f3fd323f7a753 (patch)
treed71d44d4d506cdb55604c0eaa0b77d041f39c06b /Documentation/virtual
parent234b639206a7d9d5ca362cff64ceddd4f27e4a46 (diff)
downloadlinux-3f745f1e224e05e845a15760a55f3fd323f7a753.tar.bz2
KVM: Document KVM_NMI
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'Documentation/virtual')
-rw-r--r--Documentation/virtual/kvm/api.txt25
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index e2a4b5287361..e1d94bf4056e 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1466,6 +1466,31 @@ is supported; 2 if the processor requires all virtual machines to have
an RMA, or 1 if the processor can use an RMA but doesn't require it,
because it supports the Virtual RMA (VRMA) facility.
+4.64 KVM_NMI
+
+Capability: KVM_CAP_USER_NMI
+Architectures: x86
+Type: vcpu ioctl
+Parameters: none
+Returns: 0 on success, -1 on error
+
+Queues an NMI on the thread's vcpu. Note this is well defined only
+when KVM_CREATE_IRQCHIP has not been called, since this is an interface
+between the virtual cpu core and virtual local APIC. After KVM_CREATE_IRQCHIP
+has been called, this interface is completely emulated within the kernel.
+
+To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the
+following algorithm:
+
+ - pause the vpcu
+ - read the local APIC's state (KVM_GET_LAPIC)
+ - check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1)
+ - if so, issue KVM_NMI
+ - resume the vcpu
+
+Some guests configure the LINT1 NMI input to cause a panic, aiding in
+debugging.
+
5. The kvm_run structure
Application code obtains a pointer to the kvm_run structure by