[PATCH 4 of 4 v2] xl: Add pci_assignable_add and remove commands

[George Dunlap <george.dunlap@eu.citrix.com>]

pci-assignable-add will always store the driver rebind path, but
pci-assignable-remove will only actually rebind if asked to do so.

v2:
 - Use libxl_device_pci_init() instead of memset()
 - Call xlu_cfg_destroy() properly

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>

diff -r 5e21532dab5b -r ba3d30d721ee docs/man/xl.pod.1
--- a/docs/man/xl.pod.1	Fri May 11 13:55:04 2012 +0100
+++ b/docs/man/xl.pod.1	Fri May 11 14:19:50 2012 +0100
@@ -1026,6 +1026,26 @@ These are devices in the system which ar
 available for passthrough and are bound to a suitable PCI
 backend driver in domain 0 rather than a real driver.
 
+=item B<pci-assignable-add> I<BDF>
+
+Make the device at PCI Bus/Device/Function BDF assignable to guests.  This
+will bind the device to the pciback driver.  If it is already bound to a
+driver, it will first be unbound, and the original driver stored so that it
+can be re-bound to the same driver later if desired.  
+
+CAUTION: This will make the device unusable by Domain 0 until it is
+returned with pci-assignable-remove.  Care should therefore be taken
+not to do this on a device critical to domain 0's operation, such as
+storage controllers, network interfaces, or GPUs that are currently
+being used.
+
+=item B<pci-assignable-remove> [I<-r>] I<BDF>
+
+Make the device at PCI Bus/Device/Function BDF assignable to guests.  This
+will at least unbind the device from pciback.  If the -r option is specified,
+it will also attempt to re-bind the device to its original driver, making it
+usable by Domain 0 again.
+
 =item B<pci-attach> I<domain-id> I<BDF>
 
 Hot-plug a new pass-through pci device to the specified domain.
diff -r 5e21532dab5b -r ba3d30d721ee tools/libxl/xl.h
--- a/tools/libxl/xl.h	Fri May 11 13:55:04 2012 +0100
+++ b/tools/libxl/xl.h	Fri May 11 14:19:50 2012 +0100
@@ -36,6 +36,8 @@ int main_vncviewer(int argc, char **argv
 int main_pcilist(int argc, char **argv);
 int main_pcidetach(int argc, char **argv);
 int main_pciattach(int argc, char **argv);
+int main_pciassignable_add(int argc, char **argv);
+int main_pciassignable_remove(int argc, char **argv);
 int main_pciassignable_list(int argc, char **argv);
 int main_restore(int argc, char **argv);
 int main_migrate_receive(int argc, char **argv);
diff -r 5e21532dab5b -r ba3d30d721ee tools/libxl/xl_cmdimpl.c
--- a/tools/libxl/xl_cmdimpl.c	Fri May 11 13:55:04 2012 +0100
+++ b/tools/libxl/xl_cmdimpl.c	Fri May 11 14:19:50 2012 +0100
@@ -2368,6 +2368,86 @@ int main_pciassignable_list(int argc, ch
     return 0;
 }
 
+static void pciassignable_add(const char *bdf, int rebind)
+{
+    libxl_device_pci pcidev;
+    XLU_Config *config;
+
+    libxl_device_pci_init(&pcidev);
+    
+    config = xlu_cfg_init(stderr, "command line");
+    if (!config) { perror("xlu_cfg_inig"); exit(-1); }
+
+    if (xlu_pci_parse_bdf(config, &pcidev, bdf)) {
+        fprintf(stderr, "pci-assignable-add: malformed BDF specification \"%s\"\n", bdf);
+        exit(2);
+    }
+    libxl_device_pci_assignable_add(ctx, &pcidev, rebind);
+
+    libxl_device_pci_dispose(&pcidev);
+    xlu_cfg_destroy(config);
+}
+
+int main_pciassignable_add(int argc, char **argv)
+{
+    int opt;
+    const char *bdf = NULL;
+
+    while ((opt = def_getopt(argc, argv, "", "pci-assignable-add", 1)) != -1) {
+        switch (opt) {
+        case 0: case 2:
+            return opt;
+        }
+    }
+
+    bdf = argv[optind];
+
+    pciassignable_add(bdf, 1);
+    return 0;
+}
+
+static void pciassignable_remove(const char *bdf, int rebind)
+{
+    libxl_device_pci pcidev;
+    XLU_Config *config;
+
+    libxl_device_pci_init(&pcidev);
+
+    config = xlu_cfg_init(stderr, "command line");
+    if (!config) { perror("xlu_cfg_inig"); exit(-1); }
+
+    if (xlu_pci_parse_bdf(config, &pcidev, bdf)) {
+        fprintf(stderr, "pci-assignable-remove: malformed BDF specification \"%s\"\n", bdf);
+        exit(2);
+    }
+    libxl_device_pci_assignable_remove(ctx, &pcidev, rebind);
+
+    libxl_device_pci_dispose(&pcidev);
+    xlu_cfg_destroy(config);
+}
+
+int main_pciassignable_remove(int argc, char **argv)
+{
+    int opt;
+    const char *bdf = NULL;
+    int rebind = 0;
+
+    while ((opt = def_getopt(argc, argv, "r", "pci-assignable-remove", 1)) != -1) {
+        switch (opt) {
+        case 0: case 2:
+            return opt;
+        case 'r':
+            rebind=1;
+            break;
+        }
+    }
+
+    bdf = argv[optind];
+
+    pciassignable_remove(bdf, rebind);
+    return 0;
+}
+
 static void pause_domain(const char *p)
 {
     find_domain(p);
diff -r 5e21532dab5b -r ba3d30d721ee tools/libxl/xl_cmdtable.c
--- a/tools/libxl/xl_cmdtable.c	Fri May 11 13:55:04 2012 +0100
+++ b/tools/libxl/xl_cmdtable.c	Fri May 11 14:19:50 2012 +0100
@@ -86,6 +86,20 @@ struct cmd_spec cmd_table[] = {
       "List pass-through pci devices for a domain",
       "<Domain>",
     },
+    { "pci-assignable-add",
+      &main_pciassignable_add, 0,
+      "Make a device assignable for pci-passthru",
+      "<BDF>",
+      "-h                      Print this help.\n"
+    },
+    { "pci-assignable-remove",
+      &main_pciassignable_remove, 0,
+      "Remove a device from being assignable",
+      "[options] <BDF>",
+      "-h                      Print this help.\n"
+      "-r                      Attempt to re-assign the device to the\n"
+      "                        original driver"
+    },
     { "pci-assignable-list",
       &main_pciassignable_list, 0,
       "List all the assignable pci devices",