Add an ioctl to suspend a virtual machine (VM_SUSPEND). The ioctl can be called

from any context i.e., it is not required to be called from a vcpu thread. The
ioctl simply sets a state variable 'vm->suspend' to '1' and returns.

The vcpus inspect 'vm->suspend' in the run loop and if it is set to '1' the
vcpu breaks out of the loop with a reason of 'VM_EXITCODE_SUSPENDED'. The
suspend handler waits until all 'vm->active_cpus' have transitioned to
'vm->suspended_cpus' before returning to userspace.

Discussed with:	grehan

2 files changed, 8 insertions, 0 deletions

diff --git a/lib/libvmmapi/vmmapi.c b/lib/libvmmapi/vmmapi.c
index 22b536a..60d3105 100644
--- a/lib/libvmmapi/vmmapi.c
+++ b/lib/libvmmapi/vmmapi.c
@@ -342,6 +342,13 @@ vm_run(struct vmctx *ctx, int vcpu, uint64_t rip, struct vm_exit *vmexit)
 	return (error);
 }
 
+int
+vm_suspend(struct vmctx *ctx)
+{
+
+	return (ioctl(ctx->fd, VM_SUSPEND, 0));
+}
+
 static int
 vm_inject_exception_real(struct vmctx *ctx, int vcpu, int vector,
     int error_code, int error_code_valid)
diff --git a/lib/libvmmapi/vmmapi.h b/lib/libvmmapi/vmmapi.h
index 085af94..ce150d8 100644
--- a/lib/libvmmapi/vmmapi.h
+++ b/lib/libvmmapi/vmmapi.h
@@ -61,6 +61,7 @@ int	vm_set_register(struct vmctx *ctx, int vcpu, int reg, uint64_t val);
 int	vm_get_register(struct vmctx *ctx, int vcpu, int reg, uint64_t *retval);
 int	vm_run(struct vmctx *ctx, int vcpu, uint64_t rip,
 	       struct vm_exit *ret_vmexit);
+int	vm_suspend(struct vmctx *ctx);
 int	vm_apicid2vcpu(struct vmctx *ctx, int apicid);
 int	vm_inject_exception(struct vmctx *ctx, int vcpu, int vec);
 int	vm_inject_exception2(struct vmctx *ctx, int vcpu, int vec, int errcode);