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| author | Jan Kiszka <jan.kiszka@web.de> | 2009-12-06 18:24:15 +0100 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2009-12-27 13:36:33 -0200 |
| commit | dab4b911a5327859bb8f969249c6978c26cd4853 (patch) | |
| tree | a21d0ef04e3bf831b2f9e674b6266535267cc9ce /Documentation/kvm | |
| parent | 6e24a6eff4571002cd48b99a2b92dc829ce39cb9 (diff) | |
| download | lwn-dab4b911a5327859bb8f969249c6978c26cd4853.tar.gz lwn-dab4b911a5327859bb8f969249c6978c26cd4853.zip | |
KVM: x86: Extend KVM_SET_VCPU_EVENTS with selective updates
User space may not want to overwrite asynchronously changing VCPU event
states on write-back. So allow to skip nmi.pending and sipi_vector by
setting corresponding bits in the flags field of kvm_vcpu_events.
[avi: advertise the bits in KVM_GET_VCPU_EVENTS]
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'Documentation/kvm')
| -rw-r--r-- | Documentation/kvm/api.txt | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt index e1a114161027..2811e452f756 100644 --- a/Documentation/kvm/api.txt +++ b/Documentation/kvm/api.txt @@ -685,7 +685,7 @@ struct kvm_vcpu_events { __u8 pad; } nmi; __u32 sipi_vector; - __u32 flags; /* must be zero */ + __u32 flags; }; 4.30 KVM_SET_VCPU_EVENTS @@ -701,6 +701,14 @@ vcpu. See KVM_GET_VCPU_EVENTS for the data structure. +Fields that may be modified asynchronously by running VCPUs can be excluded +from the update. These fields are nmi.pending and sipi_vector. Keep the +corresponding bits in the flags field cleared to suppress overwriting the +current in-kernel state. The bits are: + +KVM_VCPUEVENT_VALID_NMI_PENDING - transfer nmi.pending to the kernel +KVM_VCPUEVENT_VALID_SIPI_VECTOR - transfer sipi_vector + 5. The kvm_run structure |