use the sysfs interface to enable the PCI ROM

Writing the base address directly to the ROM BAR may cause problem
since the kernel is not aware of the operation.

Signed-off-by: Yu Zhao <yu.zhao@intel.com>

diff --git a/hw/pass-through.c b/hw/pass-through.c
index 207bdf0476b4c619c3855dfbe9ae2bdb82643a5c..e76a3c31be6fc9d4ef5bdcab1437e8216bb2ab7c 100644 (file)
--- a/hw/pass-through.c
+++ b/hw/pass-through.c
@@ -1447,6 +1447,27 @@ exit:
     return val;
 }
 
+static int pt_pci_enable_rom(struct pci_dev *dev)
+{
+    FILE *fp;
+    char path[PATH_MAX];
+
+    sprintf(path, "/sys/bus/pci/devices/%04x:%02x:%02x.%x/rom",
+            dev->domain, dev->bus, dev->dev, dev->func);
+
+    fp = fopen(path, "w");
+    if ( !fp )
+    {
+        PT_LOG("Can't open %s: %s\n", path, strerror(errno));
+        return -1;
+    }
+
+    fprintf(fp, "1");
+    fclose(fp);
+
+    return 0;
+}
+
 static void pt_libpci_fixup(struct pci_dev *dev)
 {
 #if PCI_LIB_VERSION < 0x030100
@@ -1526,8 +1547,8 @@ static int pt_register_regions(struct pt_dev *assigned_device)
 
         /* Re-set BAR reported by OS, otherwise ROM can't be read. */
         if ( (pci_dev->rom_base_addr & PCI_ROM_ADDRESS_MASK) == 0 )
-            pci_write_long(pci_dev, PCI_ROM_ADDRESS,
-                           (pci_dev->rom_base_addr | PCI_ROM_ADDRESS_MASK));
+            if ( pt_pci_enable_rom(pci_dev) )
+                return -1;
 
         assigned_device->bases[PCI_ROM_SLOT].e_physbase =
             pci_dev->rom_base_addr;