bhyve: do not exit if LPC finds no host selector

The host selector is only required when the user likes to use the same
LPC device IDs as the physical LPC device. This is an uncommon use case.
For that reason, it makes no sense to exit when we don't find the host
selector.

Reviewed by:		markj
MFC after:		1 week
Sponsored by:		Beckhoff Automation GmbH & Co. KG
Differential Revision:	https://reviews.freebsd.org/D39311

usr.sbin/bhyve/pci_lpc.c

@@ -480,6 +480,8 @@ pci_lpc_get_sel(struct pcisel *const sel)
 		}
 	}
 
+	warnx("%s: Unable to find host selector of LPC bridge.", __func__);
+
 	return (-1);
 }
 
@@ -487,6 +489,7 @@ static int
 pci_lpc_init(struct pci_devinst *pi, nvlist_t *nvl)
 {
 	struct pcisel sel = { 0 };
+	struct pcisel *selp = NULL;
 	uint16_t device, subdevice, subvendor, vendor;
 	uint8_t revid;
 
@@ -511,15 +514,15 @@ pci_lpc_init(struct pci_devinst *pi, nvlist_t *nvl)
 	if (lpc_init(pi->pi_vmctx) != 0)
 		return (-1);
 
-	if (pci_lpc_get_sel(&sel) != 0)
-		return (-1);
+	if (pci_lpc_get_sel(&sel) == 0)
+		selp = &sel;
 
-	vendor = pci_config_read_reg(&sel, nvl, PCIR_VENDOR, 2, LPC_VENDOR);
-	device = pci_config_read_reg(&sel, nvl, PCIR_DEVICE, 2, LPC_DEV);
-	revid = pci_config_read_reg(&sel, nvl, PCIR_REVID, 1, LPC_REVID);
-	subvendor = pci_config_read_reg(&sel, nvl, PCIR_SUBVEND_0, 2,
+	vendor = pci_config_read_reg(selp, nvl, PCIR_VENDOR, 2, LPC_VENDOR);
+	device = pci_config_read_reg(selp, nvl, PCIR_DEVICE, 2, LPC_DEV);
+	revid = pci_config_read_reg(selp, nvl, PCIR_REVID, 1, LPC_REVID);
+	subvendor = pci_config_read_reg(selp, nvl, PCIR_SUBVEND_0, 2,
 	    LPC_SUBVEND_0);
-	subdevice = pci_config_read_reg(&sel, nvl, PCIR_SUBDEV_0, 2,
+	subdevice = pci_config_read_reg(selp, nvl, PCIR_SUBDEV_0, 2,
 	    LPC_SUBDEV_0);
 
 	/* initialize config space */