MFC 263780,264516,265062,265101,265203,265364:

Add an ioctl to suspend a virtual machine (VM_SUSPEND).

Add logic in the HLT exit handler to detect if the guest has put all vcpus
to sleep permanently by executing a HLT with interrupts disabled.

When this condition is detected the guest with be suspended with a reason of
VM_SUSPEND_HALT and the bhyve(8) process will exit.

This logic can be disabled via the tunable 'hw.vmm.halt_detection'.

2 files changed, 11 insertions, 0 deletions

diff --git a/lib/libvmmapi/vmmapi.c b/lib/libvmmapi/vmmapi.c
index 22b536a..4a7f852 100644
--- a/lib/libvmmapi/vmmapi.c
+++ b/lib/libvmmapi/vmmapi.c
@@ -342,6 +342,16 @@ vm_run(struct vmctx *ctx, int vcpu, uint64_t rip, struct vm_exit *vmexit)
 	return (error);
 }
 
+int
+vm_suspend(struct vmctx *ctx, enum vm_suspend_how how)
+{
+	struct vm_suspend vmsuspend;
+
+	bzero(&vmsuspend, sizeof(vmsuspend));
+	vmsuspend.how = how;
+	return (ioctl(ctx->fd, VM_SUSPEND, &vmsuspend));
+}
+
 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 f8921d3..2a2ca6b 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, enum vm_suspend_how how);
 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);