KVM: Add guest mode signal mask

Allow a special signal mask to be used while executing in guest mode.  This
allows signals to be used to interrupt a vcpu without requiring signal
delivery to a userspace handler, which is quite expensive.  Userspace still
receives -EINTR and can get the signal via sigwait().

Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index b3af92e7bf5d..c0d10cd8088e 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -234,6 +234,12 @@ struct kvm_cpuid {
         struct kvm_cpuid_entry entries[0];
 };
 
+/* for KVM_SET_SIGNAL_MASK */
+struct kvm_signal_mask {
+        __u32 len;
+        __u8  sigset[0];
+};
+
 #define KVMIO 0xAE
 
 /*
@@ -273,5 +279,6 @@ struct kvm_cpuid {
 #define KVM_GET_MSRS              _IOWR(KVMIO, 0x88, struct kvm_msrs)
 #define KVM_SET_MSRS              _IOW(KVMIO,  0x89, struct kvm_msrs)
 #define KVM_SET_CPUID             _IOW(KVMIO,  0x8a, struct kvm_cpuid)
+#define KVM_SET_SIGNAL_MASK       _IOW(KVMIO,  0x8b, struct kvm_signal_mask)
 
 #endif