MFC r256425:

Centralize the detection logic for the Hyper-V hypervisor.

Submitted by:	Roger Pau Monné
Sponsored by:	Citrix Systems R&D
Reviewed by:	gibbs, grehan
Approved by:	re (gjb)

sys/sys/systm.h:
 * Add a new VM_GUEST type, VM_GUEST_HV (HyperV guest).

sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c:
sys/dev/hyperv/vmbus/hv_hv.c:
sys/dev/hyperv/stordisengage/hv_ata_pci_disengage.c:
 * Set vm_guest to VM_GUEST_HV and use that on other HyperV related
   devices instead of cloning the cpuid hypervisor check.
 * Cleanup the vmbus_identify function.
------------------------------------------------------------------------

2 files changed, 14 insertions, 10 deletions

diff --git a/sys/dev/hyperv/vmbus/hv_hv.c b/sys/dev/hyperv/vmbus/hv_hv.c
index 77d3b0b..80a1f42 100644
--- a/sys/dev/hyperv/vmbus/hv_hv.c
+++ b/sys/dev/hyperv/vmbus/hv_hv.c
@@ -218,7 +218,7 @@ hv_vmbus_init(void)
 	    0,
 	    sizeof(hv_vmbus_handle) * MAXCPU);
 
-	if (!hv_vmbus_query_hypervisor_presence())
+	if (vm_guest != VM_GUEST_HV)
 	    goto cleanup;
 
 	max_leaf = hv_vmbus_get_hypervisor_version();
diff --git a/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c b/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c
index fb9e147..7f1647b 100644
--- a/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c
+++ b/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c
@@ -295,11 +295,15 @@ hv_vmbus_child_device_unregister(struct hv_device *child_dev)
 	return(ret);
 }
 
-static void vmbus_identify(driver_t *driver, device_t parent) {
+static void
+vmbus_identify(driver_t *driver, device_t parent)
+{
+	if (!hv_vmbus_query_hypervisor_presence())
+		return;
+
+	vm_guest = VM_GUEST_HV;
+
 	BUS_ADD_CHILD(parent, 0, "vmbus", 0);
-	if (device_find_child(parent, "vmbus", 0) == NULL) {
-		BUS_ADD_CHILD(parent, 0, "vmbus", 0);
-	}
 }
 
 static int
@@ -307,9 +311,6 @@ vmbus_probe(device_t dev) {
 	if(bootverbose)
 		device_printf(dev, "VMBUS: probe\n");
 
-	if (!hv_vmbus_query_hypervisor_presence())
-		return (ENXIO);
-
 	device_set_desc(dev, "Vmbus Devices");
 
 	return (0);
@@ -491,10 +492,13 @@ vmbus_attach(device_t dev)
 static void
 vmbus_init(void)
 {
+	if (vm_guest != VM_GUEST_HV)
+		return;
+
 	/* 
 	 * If the system has already booted and thread
-	 * scheduling is possible indicated by the global
-	 * cold set to zero, we just call the driver
+	 * scheduling is possible, as indicated by the
+	 * global cold set to zero, we just call the driver
 	 * initialization directly.
 	 */
 	if (!cold)