DM: Disable audio NHLT table by default

NHLT table is used by some audio driver for topology data, but current
default audio driver doens't depend on it. Disable it by default due
to possible boot failure with different SOS firmware.

Signed-off-by: Edwin Zhai <edwin.zhai@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>

Author: gzhai7

devicemodel/hw/pci/passthrough.c

@@ -81,6 +81,12 @@
 #define PCI_BDF(bus, dev, func)  (((bus & 0xFF)<<8) | ((dev & 0x1F)<<3)     \
 		| ((func & 0x7)))
 
+/* Some audio driver get topology data from ACPI NHLT table, thus need copy host
+ * NHLT to guest. Default audio driver doesn't require this, so make it off by
+ * default to avoid unexpected failure.
+ */
+#define AUDIO_NHLT_HACK 0
+
 static int iofd = -1;
 static int memfd = -1;
 
@@ -968,12 +974,14 @@ passthru_init(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
 	pci_set_cfgdata16(dev, PCIR_MINGNT,
 			  read_config(ptdev->phys_dev, PCIR_MINGNT, 2));
 
+#if AUDIO_NHLT_HACK
 	/* device specific handling:
 	 * audio: enable NHLT ACPI table
 	 */
 	if (read_config(ptdev->phys_dev, PCIR_VENDOR, 2) == 0x8086 &&
 		read_config(ptdev->phys_dev, PCIR_DEVICE, 2) == 0x5a98)
 		acpi_table_enable(NHLT_ENTRY_NO);
+#endif
 
 	/* initialize config space */
 	error = cfginit(ctx, ptdev, bus, slot, func);