xl / libxl: support naming of assignable devices

This patch modifies libxl_device_pci_assignable_add() to take an optional
'name' argument, which (if supplied) is saved into xenstore and can hence be
used to refer to the now-assignable BDF in subsequent operations. To
facilitate this, a new libxl_device_pci_assignable_name2bdf() function is
added.

The xl code is modified to allow a name to be specified in the
'pci-assignable-add' operation and also allow an option to be specified to
'pci-assignable-list' requesting that names be displayed. The latter is
facilitated by a new libxl_device_pci_assignable_bdf2name() function. Finally
xl 'pci-assignable-remove' is modified to that either a name or BDF can be
supplied. The supplied 'identifier' is first assumed to be a name, but if
libxl_device_pci_assignable_name2bdf() fails to find a matching BDF the
identifier itself will be parsed as a BDF. Names my only include printable
characters and may not include whitespace.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
Cc: Ian Jackson <iwj@xenproject.org>
Cc: Wei Liu <wl@xen.org>
Cc: Christian Lindig <christian.lindig@citrix.com>
Cc: David Scott <dave@recoil.org>
Cc: Anthony PERARD <anthony.perard@citrix.com>

diff --git a/tools/include/libxl.h b/tools/include/libxl.h
index 5703fdf367c57daf19f3b4347d6a67aae60b912c..4025d3a3d437cceccbb958bce6476af1d08c215e 100644 (file)
--- a/tools/include/libxl.h
+++ b/tools/include/libxl.h
@@ -476,6 +476,14 @@
  */
 #define LIBXL_HAVE_PCI_ASSIGNABLE_BDF 1
 
+/*
+ * LIBXL_HAVE_PCI_ASSIGNABLE_NAME indicates that the
+ * libxl_device_pci_assignable_add() function takes a 'name' argument
+ * and that the libxl_device_pci_assignable_name2bdf() and
+ * libxl_device_pci_assignable_bdf2name() functions are defined.
+ */
+#define LIBXL_HAVE_PCI_ASSIGNABLE_NAME 1
+
 /*
  * libxl ABI compatibility
  *
@@ -2385,11 +2393,18 @@ int libxl_device_events_handler(libxl_ctx *ctx,
  * added or is not bound, the functions will emit a warning but return
  * SUCCESS.
  */
-int libxl_device_pci_assignable_add(libxl_ctx *ctx, libxl_pci_bdf *pcibdf, int rebind);
-int libxl_device_pci_assignable_remove(libxl_ctx *ctx, libxl_pci_bdf *pcibdf, int rebind);
+int libxl_device_pci_assignable_add(libxl_ctx *ctx, libxl_pci_bdf *pcibdf,
+                                    const char *name, int rebind);
+int libxl_device_pci_assignable_remove(libxl_ctx *ctx, libxl_pci_bdf *pcibdf,
+                                       int rebind);
 libxl_pci_bdf *libxl_device_pci_assignable_list(libxl_ctx *ctx, int *num);
 void libxl_device_pci_assignable_list_free(libxl_pci_bdf *list, int num);
 
+libxl_pci_bdf *libxl_device_pci_assignable_name2bdf(libxl_ctx *ctx,
+                                                    const char *name);
+char *libxl_device_pci_assignable_bdf2name(libxl_ctx *ctx,
+                                           libxl_pci_bdf *pcibdf);
+
 /* CPUID handling */
 int libxl_cpuid_parse_config(libxl_cpuid_policy_list *cpuid, const char* str);
 int libxl_cpuid_parse_config_xend(libxl_cpuid_policy_list *cpuid,

diff --git a/tools/libs/light/libxl_pci.c b/tools/libs/light/libxl_pci.c
index d436e0a42b0cbb61ebbcdd3bcb660bb47ee1aea1..a789ade036fa2c9a0172e138e59c204f941a6808 100644 (file)
--- a/tools/libs/light/libxl_pci.c
+++ b/tools/libs/light/libxl_pci.c
@@ -713,6 +713,7 @@ static int pciback_dev_unassign(libxl__gc *gc, libxl_pci_bdf *pcibdf)
 
 static int libxl__device_pci_assignable_add(libxl__gc *gc,
                                             libxl_pci_bdf *pcibdf,
+                                            const char *name,
                                             int rebind)
 {
     libxl_ctx *ctx = libxl__gc_owner(gc);
@@ -721,6 +722,23 @@ static int libxl__device_pci_assignable_add(libxl__gc *gc,
     int rc;
     struct stat st;
 
+    /* Sanitise any name that was passed */
+    if (name) {
+        unsigned int i, n = strlen(name);
+
+        if (n > 64) { /* Reasonable upper bound on name length */
+            LOG(ERROR, "Name too long");
+            return ERROR_FAIL;
+        }
+
+        for (i = 0; i < n; i++) {
+            if (!isgraph(name[i])) {
+                LOG(ERROR, "Names may only include printable characters");
+                return ERROR_FAIL;
+            }
+        }
+    }
+
     /* Local copy for convenience */
     dom = pcibdf->domain;
     bus = pcibdf->bus;
@@ -741,7 +759,7 @@ static int libxl__device_pci_assignable_add(libxl__gc *gc,
     }
     if ( rc ) {
         LOG(WARN, PCI_BDF" already assigned to pciback", dom, bus, dev, func);
-        goto quarantine;
+        goto name;
     }
 
     /* Check to see if there's already a driver that we need to unbind from */
@@ -772,7 +790,12 @@ static int libxl__device_pci_assignable_add(libxl__gc *gc,
         return ERROR_FAIL;
     }
 
-quarantine:
+name:
+    if (name)
+        pci_info_xs_write(gc, pcibdf, "name", name);
+    else
+        pci_info_xs_remove(gc, pcibdf, "name");
+
     /*
      * DOMID_IO is just a sentinel domain, without any actual mappings,
      * so always pass XEN_DOMCTL_DEV_RDM_RELAXED to avoid assignment being
@@ -836,16 +859,18 @@ static int libxl__device_pci_assignable_remove(libxl__gc *gc,
         }
     }
 
+    pci_info_xs_remove(gc, pcibdf, "name");
+
     return 0;
 }
 
 int libxl_device_pci_assignable_add(libxl_ctx *ctx, libxl_pci_bdf *pcibdf,
-                                    int rebind)
+                                    const char *name, int rebind)
 {
     GC_INIT(ctx);
     int rc;
 
-    rc = libxl__device_pci_assignable_add(gc, pcibdf, rebind);
+    rc = libxl__device_pci_assignable_add(gc, pcibdf, name, rebind);
 
     GC_FREE;
     return rc;
@@ -864,6 +889,57 @@ int libxl_device_pci_assignable_remove(libxl_ctx *ctx, libxl_pci_bdf *pcibdf,
     return rc;
 }
 
+libxl_pci_bdf *libxl_device_pci_assignable_name2bdf(libxl_ctx *ctx,
+                                                    const char *name)
+{
+    GC_INIT(ctx);
+    char **bdfs;
+    libxl_pci_bdf *pcibdf;
+    unsigned int i, n;
+
+    bdfs = libxl__xs_directory(gc, XBT_NULL, PCI_INFO_PATH, &n);
+    if (!n)
+        goto out;
+
+    pcibdf = calloc(1, sizeof(*pcibdf));
+    if (!pcibdf)
+        goto out;
+
+    for (i = 0; i < n; i++) {
+        unsigned dom, bus, dev, func;
+        const char *tmp;
+
+        if (sscanf(bdfs[i], PCI_BDF_XSPATH, &dom, &bus, &dev, &func) != 4)
+            continue;
+
+        pcibdf_struct_fill(pcibdf, dom, bus, dev, func);
+
+        tmp = pci_info_xs_read(gc, pcibdf, "name");
+        if (tmp && !strcmp(tmp, name))
+            goto out;
+    }
+
+    free(pcibdf);
+    pcibdf = NULL;
+
+out:
+    GC_FREE;
+    return pcibdf;
+}
+
+char *libxl_device_pci_assignable_bdf2name(libxl_ctx *ctx,
+                                           libxl_pci_bdf *pcibdf)
+{
+    GC_INIT(ctx);
+    char *name = NULL, *tmp = pci_info_xs_read(gc, pcibdf, "name");
+
+    if (tmp)
+        name = strdup(tmp);
+
+    GC_FREE;
+    return name;
+}
+
 /*
  * This function checks that all functions of a device are bound to pciback
  * driver. It also initialises a bit-mask of which function numbers are present
@@ -1528,7 +1604,7 @@ void libxl__device_pci_add(libxl__egc *egc, uint32_t domid,
     if (rc) goto out;
 
     if (pci->seize && !pciback_dev_is_assigned(gc, &pci->bdf)) {
-        rc = libxl__device_pci_assignable_add(gc, &pci->bdf, 1);
+        rc = libxl__device_pci_assignable_add(gc, &pci->bdf, NULL, 1);
         if ( rc )
             goto out;
     }

diff --git a/tools/ocaml/libs/xl/xenlight_stubs.c b/tools/ocaml/libs/xl/xenlight_stubs.c
index 2388f238697c6c4bda4fb0e6d6872cc2c94fe920..96bb4655e0b1751980485cfe593ee9ac7930f3eb 100644 (file)
--- a/tools/ocaml/libs/xl/xenlight_stubs.c
+++ b/tools/ocaml/libs/xl/xenlight_stubs.c
@@ -840,7 +840,8 @@ value stub_xl_device_pci_assignable_add(value ctx, value info, value rebind)
        device_pci_val(CTX, &c_info, info);
 
        caml_enter_blocking_section();
-       ret = libxl_device_pci_assignable_add(CTX, &c_info.bdf, c_rebind);
+       ret = libxl_device_pci_assignable_add(CTX, &c_info.bdf, NULL,
+                                             c_rebind);
        caml_leave_blocking_section();
 
        libxl_device_pci_dispose(&c_info);

diff --git a/tools/xl/xl_cmdtable.c b/tools/xl/xl_cmdtable.c
index 2ee0c4967334c6961e0d75c30dd45def62145e23..9e9aa448e2a60a42748b031e1fac6d4a55a64c45 100644 (file)
--- a/tools/xl/xl_cmdtable.c
+++ b/tools/xl/xl_cmdtable.c
@@ -105,21 +105,25 @@ struct cmd_spec cmd_table[] = {
     { "pci-assignable-add",
       &main_pciassignable_add, 0, 1,
       "Make a device assignable for pci-passthru",
-      "<BDF>",
+      "[options] <BDF>",
+      "-n NAME, --name=NAME    Name the assignable device.\n"
       "-h                      Print this help.\n"
     },
     { "pci-assignable-remove",
       &main_pciassignable_remove, 0, 1,
       "Remove a device from being assignable",
-      "[options] <BDF>",
+      "[options] <BDF>|NAME",
       "-h                      Print this help.\n"
       "-r                      Attempt to re-assign the device to the\n"
-      "                        original driver"
+      "                        original driver."
     },
     { "pci-assignable-list",
       &main_pciassignable_list, 0, 0,
       "List all the assignable pci devices",
-      "",
+      "[options]",
+      "-h                      Print this help.\n"
+      "-n, --show-names        Display assignable device names where\n"
+      "                        supplied.\n"
     },
     { "pause",
       &main_pause, 0, 1,

diff --git a/tools/xl/xl_pci.c b/tools/xl/xl_pci.c
index 37708b4eb14d25f08f7db65f2c34e183210e2275..f1b58b39762a80f8b66d37349dd57a5776014d63 100644 (file)
--- a/tools/xl/xl_pci.c
+++ b/tools/xl/xl_pci.c
@@ -152,7 +152,7 @@ int main_pciattach(int argc, char **argv)
     return EXIT_SUCCESS;
 }
 
-static void pciassignable_list(void)
+static void pciassignable_list(bool show_names)
 {
     libxl_pci_bdf *pcibdfs;
     int num, i;
@@ -162,9 +162,15 @@ static void pciassignable_list(void)
     if ( pcibdfs == NULL )
         return;
     for (i = 0; i < num; i++) {
-        printf("%04x:%02x:%02x.%01x\n",
-               pcibdfs[i].domain, pcibdfs[i].bus, pcibdfs[i].dev,
-               pcibdfs[i].func);
+        libxl_pci_bdf *pcibdf = &pcibdfs[i];
+        char *name = show_names ?
+            libxl_device_pci_assignable_bdf2name(ctx, pcibdf) : NULL;
+
+        printf("%04x:%02x:%02x.%01x %s\n",
+               pcibdf->domain, pcibdf->bus, pcibdf->dev, pcibdf->func,
+               name ?: "");
+
+        free(name);
     }
     libxl_device_pci_assignable_list_free(pcibdfs, num);
 }
@@ -172,16 +178,23 @@ static void pciassignable_list(void)
 int main_pciassignable_list(int argc, char **argv)
 {
     int opt;
-
-    SWITCH_FOREACH_OPT(opt, "", NULL, "pci-assignable-list", 0) {
-        /* No options */
+    static struct option opts[] = {
+        {"show-names", 0, 0, 'n'},
+        COMMON_LONG_OPTS
+    };
+    bool show_names = false;
+
+    SWITCH_FOREACH_OPT(opt, "n", opts, "pci-assignable-list", 0) {
+    case 'n':
+        show_names = true;
+        break;
     }
 
-    pciassignable_list();
+    pciassignable_list(show_names);
     return 0;
 }
 
-static int pciassignable_add(const char *bdf, int rebind)
+static int pciassignable_add(const char *bdf, const char *name, int rebind)
 {
     libxl_pci_bdf pcibdf;
     XLU_Config *config;
@@ -197,7 +210,7 @@ static int pciassignable_add(const char *bdf, int rebind)
         exit(2);
     }
 
-    if (libxl_device_pci_assignable_add(ctx, &pcibdf, rebind))
+    if (libxl_device_pci_assignable_add(ctx, &pcibdf, name, rebind))
         r = 1;
 
     libxl_pci_bdf_dispose(&pcibdf);
@@ -210,39 +223,58 @@ int main_pciassignable_add(int argc, char **argv)
 {
     int opt;
     const char *bdf = NULL;
-
-    SWITCH_FOREACH_OPT(opt, "", NULL, "pci-assignable-add", 1) {
-        /* No options */
+    static struct option opts[] = {
+        {"name", 1, 0, 'n'},
+        COMMON_LONG_OPTS
+    };
+    const char *name = NULL;
+
+    SWITCH_FOREACH_OPT(opt, "n:", opts, "pci-assignable-add", 0) {
+    case 'n':
+        name = optarg;
+        break;
     }
 
     bdf = argv[optind];
 
-    if (pciassignable_add(bdf, 1))
+    if (pciassignable_add(bdf, name, 1))
         return EXIT_FAILURE;
 
     return EXIT_SUCCESS;
 }
 
-static int pciassignable_remove(const char *bdf, int rebind)
+static int pciassignable_remove(const char *ident, int rebind)
 {
-    libxl_pci_bdf pcibdf;
+    libxl_pci_bdf *pcibdf;
     XLU_Config *config;
     int r = 0;
 
-    libxl_pci_bdf_init(&pcibdf);
-
     config = xlu_cfg_init(stderr, "command line");
     if (!config) { perror("xlu_cfg_init"); exit(-1); }
 
-    if (xlu_pci_parse_bdf(config, &pcibdf, bdf)) {
-        fprintf(stderr, "pci-assignable-remove: malformed BDF \"%s\"\n", bdf);
-        exit(2);
+    pcibdf = libxl_device_pci_assignable_name2bdf(ctx, ident);
+    if (!pcibdf) {
+        pcibdf = calloc(1, sizeof(*pcibdf));
+
+        if (!pcibdf) {
+            fprintf(stderr,
+                    "pci-assignable-remove: failed to allocate memory\n");
+            exit(2);
+        }
+
+        libxl_pci_bdf_init(pcibdf);
+        if (xlu_pci_parse_bdf(config, pcibdf, ident)) {
+            fprintf(stderr,
+                    "pci-assignable-remove: malformed BDF '%s'\n", ident);
+            exit(2);
+        }
     }
 
-    if (libxl_device_pci_assignable_remove(ctx, &pcibdf, rebind))
+    if (libxl_device_pci_assignable_remove(ctx, pcibdf, rebind))
         r = 1;
 
-    libxl_pci_bdf_dispose(&pcibdf);
+    libxl_pci_bdf_dispose(pcibdf);
+    free(pcibdf);
     xlu_cfg_destroy(config);
 
     return r;
@@ -251,7 +283,7 @@ static int pciassignable_remove(const char *bdf, int rebind)
 int main_pciassignable_remove(int argc, char **argv)
 {
     int opt;
-    const char *bdf = NULL;
+    const char *ident = NULL;
     int rebind = 0;
 
     SWITCH_FOREACH_OPT(opt, "r", NULL, "pci-assignable-remove", 1) {
@@ -260,9 +292,9 @@ int main_pciassignable_remove(int argc, char **argv)
         break;
     }
 
-    bdf = argv[optind];
+    ident = argv[optind];
 
-    if (pciassignable_remove(bdf, rebind))
+    if (pciassignable_remove(ident, rebind))
         return EXIT_FAILURE;
 
     return EXIT_SUCCESS;