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>
This commit is contained in:
Jan Kiszka
2009-12-06 18:24:15 +01:00
committed by Marcelo Tosatti
parent 6e24a6eff4
commit dab4b911a5
3 changed files with 21 additions and 5 deletions

View File

@@ -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