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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 | |
| parent | 6e24a6eff4571002cd48b99a2b92dc829ce39cb9 (diff) | |
| download | linux-dab4b911a5327859bb8f969249c6978c26cd4853.tar.bz2 | |
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>
| -rw-r--r-- | Documentation/kvm/api.txt | 10 | ||||
| -rw-r--r-- | arch/x86/include/asm/kvm.h | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 12 |
3 files changed, 21 insertions, 5 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 diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h index 950df434763f..f46b79f6c16c 100644 --- a/arch/x86/include/asm/kvm.h +++ b/arch/x86/include/asm/kvm.h @@ -254,6 +254,10 @@ struct kvm_reinject_control { __u8 reserved[31]; }; +/* When set in flags, include corresponding fields on KVM_SET_VCPU_EVENTS */ +#define KVM_VCPUEVENT_VALID_NMI_PENDING 0x00000001 +#define KVM_VCPUEVENT_VALID_SIPI_VECTOR 0x00000002 + /* for KVM_GET/SET_VCPU_EVENTS */ struct kvm_vcpu_events { struct { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 9d068966fb2a..6651dbf58675 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1913,7 +1913,8 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu, events->sipi_vector = vcpu->arch.sipi_vector; - events->flags = 0; + events->flags = (KVM_VCPUEVENT_VALID_NMI_PENDING + | KVM_VCPUEVENT_VALID_SIPI_VECTOR); vcpu_put(vcpu); } @@ -1921,7 +1922,8 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu, static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu, struct kvm_vcpu_events *events) { - if (events->flags) + if (events->flags & ~(KVM_VCPUEVENT_VALID_NMI_PENDING + | KVM_VCPUEVENT_VALID_SIPI_VECTOR)) return -EINVAL; vcpu_load(vcpu); @@ -1938,10 +1940,12 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu, kvm_pic_clear_isr_ack(vcpu->kvm); vcpu->arch.nmi_injected = events->nmi.injected; - vcpu->arch.nmi_pending = events->nmi.pending; + if (events->flags & KVM_VCPUEVENT_VALID_NMI_PENDING) + vcpu->arch.nmi_pending = events->nmi.pending; kvm_x86_ops->set_nmi_mask(vcpu, events->nmi.masked); - vcpu->arch.sipi_vector = events->sipi_vector; + if (events->flags & KVM_VCPUEVENT_VALID_SIPI_VECTOR) + vcpu->arch.sipi_vector = events->sipi_vector; vcpu_put(vcpu); |