[PATCH v7 RFC 2/2] xl: Add commands for usb hot-plug

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

Add xl commands for USB hot-plug.  Domain creation and config file
support not yet added.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
---
v7:
 - Don't check for invalid return values for find_domain()
 - Use {foo}_to_string in usb_list()
 - call dispose on list elements to avoid leaks
v6:
 - Rename to usb-attach and usb-detach to fit better w/ other device
   add/remove commands
 - Use positional arguments, to fit better w/ other device add/remove
   commands
 - Change specifier to "hostdev:xx.yy", looking forward to a day when
   we may be able to accept something like "tablet"
 - Style fix-ups
v5:
 - Remove extraneous is_hex
 - Replace is_dec with ctype.h isdigit()
 - Replace domid -1 with INVALID_DOMID
 - Fix up a couple of mistaken function names in strings
 - Copy CTYPE macro from libxl_internal.h
 - Fix to usb-list manpage (use -d domid)

CC: Ian Jackson <ian.jackson@citrix.com>
CC: Roger Pau Monne <roger.pau@citrix.com>
CC: sstanisi@cbnco.com
CC: Fabio Fantoni <fabio.fantoni@m2r.biz>
CC: Ian Campbell <ian.campbell@citrix.com>
CC: Anthony Perard <anthony.perard@citrix.com>
CC: Simon (Bo) Cao <caobosimon@gmail.com>
---
 docs/man/xl.pod.1         |   30 ++++++++
 tools/libxl/xl.h          |   21 ++++++
 tools/libxl/xl_cmdimpl.c  |  182 +++++++++++++++++++++++++++++++++++++++++++++
 tools/libxl/xl_cmdtable.c |   15 ++++
 4 files changed, 248 insertions(+)

diff --git a/docs/man/xl.pod.1 b/docs/man/xl.pod.1
index 30bd4bf..e04a4a8 100644
--- a/docs/man/xl.pod.1
+++ b/docs/man/xl.pod.1
@@ -1194,6 +1194,36 @@ List virtual network interfaces for a domain.
 
 =back
 
+=head2 USB DEVICES
+
+=over 4
+
+=item B<usb-attach> I<domain-id> I<hostdev:hostbus.hostaddr>
+
+Passes through the host USB device specified by I<hostbus.hostaddr>.  At
+the moment this will only work for HVM domains via qemu.
+
+The best way to find out the information for the device is typically using
+lsusb.
+
+This command is only available for domains using qemu-xen, not
+qemu-traditional.
+
+=item B<usb-detach> I<domain-id> I<hostdev:hosbus.hostaddr>
+
+Remove the host USB device from I<domain-id> which is specified
+by <hostbus.hostaddr>.  This command only works for devices added
+with usb-add; not for those specified in the config file.
+
+This command is only available for domains using qemu-xen, not
+qemu-traditional.
+
+=item B<usb-list> I<domain-id>
+
+Show host USB devices assigned to the guest.
+
+=back
+
 =head2 VTPM DEVICES
 
 =over 4
diff --git a/tools/libxl/xl.h b/tools/libxl/xl.h
index 10a2e66..2f1f612 100644
--- a/tools/libxl/xl.h
+++ b/tools/libxl/xl.h
@@ -35,6 +35,9 @@ int main_info(int argc, char **argv);
 int main_sharing(int argc, char **argv);
 int main_cd_eject(int argc, char **argv);
 int main_cd_insert(int argc, char **argv);
+int main_usb_attach(int argc, char **argv);
+int main_usb_detach(int argc, char **argv);
+int main_usb_list(int argc, char **argv);
 int main_console(int argc, char **argv);
 int main_vncviewer(int argc, char **argv);
 int main_pcilist(int argc, char **argv);
@@ -183,6 +186,24 @@ extern void printf_info_sexp(int domid, libxl_domain_config *d_config);
 #define XL_GLOBAL_CONFIG XEN_CONFIG_DIR "/xl.conf"
 #define XL_LOCK_FILE XEN_LOCK_DIR "/xl"
 
+/*
+ * int CTYPE(ISFOO, char c);
+ * int CTYPE(toupper, char c);
+ * int CTYPE(tolower, char c);
+ *
+ * This is necessary because passing a simple char to a ctype.h
+ * is forbidden.  ctype.h macros take ints derived from _unsigned_ chars.
+ *
+ * If you have a char which might be EOF then you should already have
+ * it in an int representing an unsigned char, and you can use the
+ * <ctype.h> macros directly.  This generally happens only with values
+ * from fgetc et al.
+ *
+ * For any value known to be a character (eg, anything that came from
+ * a char[]), use CTYPE.
+ */
+#define CTYPE(isfoo,c) (isfoo((unsigned char)(c)))
+
 #endif /* XL_H */
 
 /*
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 5195914..7973b4c 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -2771,6 +2771,188 @@ int main_cd_insert(int argc, char **argv)
     return 0;
 }
 
+static int parse_usb_specifier(libxl_device_usb *dev, char *s)
+{
+    char *devtype, * hostbus, *hostaddr, *p;
+
+    /*
+     * General format:
+     * <type>[:<type-specific options>]
+     */
+    p = s;
+    devtype = strsep(&p, ":");
+
+    if (strcmp(devtype, "hostdev")) {
+        fprintf(stderr, "Unknown device type: %s\n", devtype);
+        return -1;
+    }
+    
+    hostbus = strsep(&p, ".");
+
+    hostaddr = p;
+
+    if (!hostbus) {
+        fprintf(stderr, "Device type %s requires hostaddr\n",
+                devtype);
+        return -1;
+    }
+
+    if (!hostaddr) {
+        fprintf(stderr, "Device type %s requires hostaddr\n",
+                devtype);
+        return -1;
+    }
+
+    /* Make sure they look right */
+    for (p=hostbus; *p; p++) {
+        if (!CTYPE(isdigit,*p)) {
+            fprintf(stderr, "Bad hostbus: %s\n", hostbus);
+            return -1;
+        }
+    }
+    
+    for (p=hostaddr; *p; p++) {
+        if (!CTYPE(isdigit,*p)) {
+            fprintf(stderr, "Bad hostaddr: %s\n", hostaddr);
+            return -1;
+        }
+    }
+
+    dev->type = LIBXL_DEVICE_USB_TYPE_HOSTDEV;
+
+    dev->u.hostdev.hostbus  = atoi(hostbus);
+    dev->u.hostdev.hostaddr = atoi(hostaddr);
+
+    return 0;
+}
+
+static int usb_attach(uint32_t domid, char * device)
+{
+    libxl_device_usb usbdev;
+    int rc;
+
+    libxl_device_usb_init(&usbdev);
+
+    if (parse_usb_specifier(&usbdev, device)<0) {
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    rc = libxl_device_usb_add(ctx, domid, &usbdev, NULL);
+    if (rc<0)
+        fprintf(stderr, "libxl_device_usb_add failed.\n");
+
+    libxl_device_usb_dispose(&usbdev);
+
+out:
+    return rc;
+}
+
+int main_usb_attach(int argc, char **argv)
+{
+    uint32_t domid = INVALID_DOMID;
+    int opt = 0, rc;
+    char *device = NULL;
+
+    SWITCH_FOREACH_OPT(opt, "", NULL, "usb-attach", 2) {
+        /* No options */
+    }
+
+    domid = find_domain(argv[optind]);
+    device = argv[optind + 1];
+
+    rc = usb_attach(domid, device);
+    if (rc<0)
+        return 1;
+    else
+        return 0;
+}
+
+static int usb_detach(uint32_t domid, libxl_device_usb_type type,
+                      char * device)
+{
+    libxl_device_usb usbdev;
+    int rc;
+
+    libxl_device_usb_init(&usbdev);
+
+    if (parse_usb_specifier(&usbdev, device)<0) {
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    rc = libxl_device_usb_remove(ctx, domid, &usbdev, NULL);
+    if (rc<0)
+        fprintf(stderr, "libxl_device_usb_remove failed.\n");
+
+    libxl_device_usb_dispose(&usbdev);
+
+out:
+    return rc;
+}
+
+int main_usb_detach(int argc, char **argv)
+{
+    uint32_t domid = INVALID_DOMID;
+    int opt = 0, rc;
+    char *device = NULL;
+    int type = 0;
+
+    SWITCH_FOREACH_OPT(opt, "", NULL, "usb-detach", 2) {
+        /* No options */
+    }
+
+    domid = find_domain(argv[optind]);
+    device = argv[optind + 1];
+
+    rc = usb_detach(domid, type, device);
+    if (rc < 0)
+        return 1;
+    else
+        return 0;
+}
+
+static void usb_list(uint32_t domid)
+{
+    libxl_device_usb *dev;
+    int num, i;
+
+    dev = libxl_device_usb_list(ctx, domid, &num);
+    if (dev == NULL)
+        return;
+    printf("protocol    backend  type     device\n");
+    for (i = 0; i < num; i++) {
+        printf("%10s  ", 
+               libxl_usb_protocol_to_string(dev[i].protocol));
+        printf("%7d  ", dev[i].backend_domid);
+        printf("%7s  ", libxl_device_usb_type_to_string(dev[i].type));
+        if (dev[i].type == LIBXL_DEVICE_USB_TYPE_HOSTDEV)
+            printf("%03d.%03d",
+                   dev[i].u.hostdev.hostbus,
+                   dev[i].u.hostdev.hostaddr);
+        printf("\n");
+        libxl_device_usb_dispose(&dev[i]);
+    }
+    free(dev);
+}
+
+
+int main_usb_list(int argc, char **argv)
+{
+    uint32_t domid = INVALID_DOMID;
+    int opt;
+
+    SWITCH_FOREACH_OPT(opt, "", NULL, "usb-list", 1) {
+        /* No options */
+    }
+
+    domid = find_domain(argv[optind]);
+    usb_list(domid);
+    return 0;
+}
+
+
+
 int main_console(int argc, char **argv)
 {
     uint32_t domid;
diff --git a/tools/libxl/xl_cmdtable.c b/tools/libxl/xl_cmdtable.c
index 4279b9f..c97796b 100644
--- a/tools/libxl/xl_cmdtable.c
+++ b/tools/libxl/xl_cmdtable.c
@@ -194,6 +194,21 @@ struct cmd_spec cmd_table[] = {
       "Eject a cdrom from a guest's cd drive",
       "<Domain> <VirtualDevice>",
     },
+    { "usb-attach",
+      &main_usb_attach, 1, 1,
+      "Hot-plug a usb device to a domain.",
+      "<Domain> <hostdev:<hostbus.hostaddr>>",
+    },
+    { "usb-detach",
+      &main_usb_detach, 1, 1,
+      "Hot-unplug a usb device from a domain.",
+      "<Domain> <hostdev:hostbus.hostaddr>",
+    },
+    { "usb-list",
+      &main_usb_list, 0, 0,
+      "List usb devices for a domain",
+      "<Domain>",
+    },
     { "mem-max",
       &main_memmax, 0, 1,
       "Set the maximum amount reservation for a domain",
-- 
1.7.9.5