pv-on-hvm: Only unplug emulated devices if requested via module parameter.

dev_unplug=[all,][ide-disks,][aux-ide-disks,][nics]

ide-disks: Unplug all emulated IDE disks (but not CD-ROMs)
aux-ide-disks: As above, but doesn't touch primary IDE master
nics: Unplug all emulated NICs
all: ide-disks and nics

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

diff --git a/unmodified_drivers/linux-2.6/platform-pci/platform-pci.c b/unmodified_drivers/linux-2.6/platform-pci/platform-pci.c
index 87dac049c05cb0fd05c51543dc4a04849275da0b..b2ea7b5bbe7367735821ace170b51990c0692021 100644 (file)
--- a/unmodified_drivers/linux-2.6/platform-pci/platform-pci.c
+++ b/unmodified_drivers/linux-2.6/platform-pci/platform-pci.c
@@ -62,6 +62,13 @@ MODULE_AUTHOR("ssmith@xensource.com");
 MODULE_DESCRIPTION("Xen platform PCI device");
 MODULE_LICENSE("GPL");
 
+/* NB. [aux-]ide-disks options do not unplug IDE CD-ROM drives. */
+/* NB. aux-ide-disks is equiv to ide-disks except ignores primary master. */
+static char *dev_unplug;
+module_param(dev_unplug, charp, 0644);
+MODULE_PARM_DESC(dev_unplug, "Emulated devices to unplug: "
+                "[all,][ide-disks,][aux-ide-disks,][nics]\n");
+
 struct pci_dev *xen_platform_pdev;
 
 static unsigned long shared_info_frame;
@@ -272,19 +279,43 @@ int gnttab_init(void);
 #define XEN_IOPORT_LINUX_PRODNUM 0xffff /* NB: register a proper one */
 #define XEN_IOPORT_LINUX_DRVVER  ((LINUX_VERSION_CODE << 8) + 0x0)
 
+#define UNPLUG_ALL_IDE_DISKS 1
+#define UNPLUG_ALL_NICS 2
+#define UNPLUG_AUX_IDE_DISKS 4
+#define UNPLUG_ALL 7
+
 static int check_platform_magic(struct device *dev, long ioaddr, long iolen)
 {
-       short magic;
-       char protocol;
+       short magic, unplug = 0;
+       char protocol, *p, *q, *err;
+
+       for (p = dev_unplug; p; p = q) {
+               q = strchr(dev_unplug, ',');
+               if (q)
+                       *q++ = '\0';
+               if (!strcmp(p, "all"))
+                       unplug |= UNPLUG_ALL;
+               else if (!strcmp(p, "ide-disks"))
+                       unplug |= UNPLUG_ALL_IDE_DISKS;
+               else if (!strcmp(p, "aux-ide-disks"))
+                       unplug |= UNPLUG_AUX_IDE_DISKS;
+               else if (!strcmp(p, "nics"))
+                       unplug |= UNPLUG_ALL_NICS;
+               else
+                       dev_warn(dev, "unrecognised option '%s' "
+                                "in module parameter 'dev_unplug'\n", p);
+       }
 
-       if (iolen < 0x16)
-               return -ENODEV;
+       if (iolen < 0x16) {
+               err = "backend too old";
+               goto no_dev;
+       }
 
        magic = inw(XEN_IOPORT_MAGIC);
 
        if (magic != XEN_IOPORT_MAGIC_VAL) {
-               dev_err(dev, "invalid magic %#x", magic);
-               return -ENODEV;
+               err = "unrecognised magic value";
+               goto no_dev;
        }
 
        protocol = inb(XEN_IOPORT_PROTOVER);
@@ -293,8 +324,8 @@ static int check_platform_magic(struct device *dev, long ioaddr, long iolen)
 
        switch (protocol) {
        case 1:
-               outw(XEN_IOPORT_PRODNUM, 0xbeef);
-               outl(XEN_IOPORT_DRVVER, 0xdead);
+               outw(XEN_IOPORT_PRODNUM, XEN_IOPORT_LINUX_PRODNUM);
+               outl(XEN_IOPORT_DRVVER, XEN_IOPORT_LINUX_DRVVER);
                if (inw(XEN_IOPORT_MAGIC) != XEN_IOPORT_MAGIC_VAL) {
                        dev_err(dev, "blacklisted by host\n");
                        return -ENODEV;
@@ -304,11 +335,18 @@ static int check_platform_magic(struct device *dev, long ioaddr, long iolen)
                outw(XEN_IOPORT_UNPLUG, 0xf);
                break;
        default:
-               dev_err(dev, "unknown qemu version\n");
-               return -ENODEV;
+               err = "unknown I/O protocol version";
+               goto no_dev;
        }
 
        return 0;
+
+ no_dev:
+       dev_warn(dev, "failed backend handshake: %s\n", err);
+       if (!unplug)
+               return 0;
+       dev_err(dev, "failed to execute specified dev_unplug options!\n");
+       return -ENODEV;
 }
 
 static int __devinit platform_pci_init(struct pci_dev *pdev,