diff mbox series

[RFC,v4,9/9] tools/libs/light: pcid: implement write_bdf command

Message ID 20230209155604.2753219-10-dmitry.semenets@gmail.com (mailing list archive)
State New, archived
Headers show
Series PCID server | expand

Commit Message

Dmytro Semenets Feb. 9, 2023, 3:56 p.m. UTC
From: Dmytro Semenets <dmytro_semenets@epam.com>

Signed-off-by: Dmytro Semenets <dmytro_semenets@epam.com>
---
 tools/include/xen-pcid.h      | 17 +++++++++
 tools/libs/light/libxl_pci.c  | 67 ++++++++++++++++++-----------------
 tools/libs/light/libxl_pcid.c | 38 ++++++++++++++++++++
 3 files changed, 90 insertions(+), 32 deletions(-)
diff mbox series

Patch

diff --git a/tools/include/xen-pcid.h b/tools/include/xen-pcid.h
index ad2dec80df..e731340653 100644
--- a/tools/include/xen-pcid.h
+++ b/tools/include/xen-pcid.h
@@ -182,6 +182,23 @@ 
 #define PCID_RESULT_KEY_IOMEM           "iomem"
 #define PCID_RESULT_KEY_IRQS            "irqs"
 
+/*
+ *******************************************************************************
+ * Write BDF values to the pciback sysfs path
+ *
+ * This command resets PCI device
+ *
+ * Request (see other mandatory fields above):
+ *  - "cmd" field of the request must be set to "write_bdf".
+ *  - "sbdf" SBDF of the device in format defined by PCID_SBDF_FMT.
+ *  - "name" name of sysfs file of pciback driver
+ *
+ * Response (see other mandatory fields above):
+ *  - "resp" field of the response must be set to "write_bdf".
+ */
+#define PCID_CMD_WRITE_BDF               "write_bdf"
+#define PCID_MSG_FIELD_NAME              "name"
+
 /*
  *******************************************************************************
  * Reset PCI device
diff --git a/tools/libs/light/libxl_pci.c b/tools/libs/light/libxl_pci.c
index 955635125f..d771f587c5 100644
--- a/tools/libs/light/libxl_pci.c
+++ b/tools/libs/light/libxl_pci.c
@@ -94,6 +94,8 @@  static int pci_handle_response(libxl__gc *gc,
     else if (strcmp(command_name, PCID_CMD_RESOURCE_LIST) == 0)
         *result = (libxl__json_object *)libxl__json_map_get(PCID_MSG_FIELD_RESOURCES,
                 response, JSON_MAP);
+    else if (strcmp(command_name, PCID_CMD_WRITE_BDF) == 0)
+        *result = libxl__json_object_alloc(gc, JSON_NULL);
     return ret;
 }
 
@@ -511,33 +513,6 @@  static bool is_pci_in_array(libxl_device_pci *pcis, int num,
     return i < num;
 }
 
-/* Write the standard BDF into the sysfs path given by sysfs_path. */
-static int sysfs_write_bdf(libxl__gc *gc, const char * sysfs_path,
-                           libxl_device_pci *pci)
-{
-    int rc, fd;
-    char *buf;
-
-    fd = open(sysfs_path, O_WRONLY);
-    if (fd < 0) {
-        LOGE(ERROR, "Couldn't open %s", sysfs_path);
-        return ERROR_FAIL;
-    }
-
-    buf = GCSPRINTF(PCI_BDF, pci->domain, pci->bus,
-                    pci->dev, pci->func);
-    rc = write(fd, buf, strlen(buf));
-    /* Annoying to have two if's, but we need the errno */
-    if (rc < 0)
-        LOGE(ERROR, "write to %s returned %d", sysfs_path, rc);
-    close(fd);
-
-    if (rc < 0)
-        return ERROR_FAIL;
-
-    return 0;
-}
-
 #define PCI_INFO_PATH "/libxl/pci"
 
 static char *pci_info_xs_path(libxl__gc *gc, libxl_device_pci *pci,
@@ -1384,6 +1359,36 @@  static bool pci_supp_legacy_irq(void)
 #endif
 }
 
+static int pciback_write_bdf(libxl__gc *gc, char *name, libxl_device_pci *pci)
+{
+    struct vchan_info *vchan;
+    int rc;
+    libxl__json_object *args, *result;
+
+    vchan = pci_vchan_get_client(gc);
+    if (!vchan) {
+        rc = ERROR_NOT_READY;
+        goto out;
+    }
+
+    args = libxl__vchan_start_args(gc);
+
+    libxl__vchan_arg_add_string(gc, args, PCID_MSG_FIELD_SBDF,
+            GCSPRINTF(PCID_SBDF_FMT, pci->domain,
+                pci->bus, pci->dev, pci->func));
+    libxl__vchan_arg_add_string(gc, args, PCID_MSG_FIELD_NAME, name);
+
+    result = vchan_send_command(gc, vchan, PCID_CMD_WRITE_BDF, args);
+    if (!result) {
+        rc = ERROR_FAIL;
+        goto vchan_free;
+    }
+vchan_free:
+    pci_vchan_free(gc, vchan);
+out:
+    return rc;
+}
+
 static void pci_add_dm_done(libxl__egc *egc,
                             pci_add_state *pas,
                             int rc)
@@ -1421,8 +1426,9 @@  static void pci_add_dm_done(libxl__egc *egc,
     libxl__vchan_arg_add_integer(gc, args, PCID_MSG_FIELD_DOMID, domid);
 
     result = vchan_send_command(gc, vchan, PCID_CMD_RESOURCE_LIST, args);
+    pci_vchan_free(gc, vchan);
     if (!result)
-        goto vchan_free;
+        goto out;
     value = libxl__json_map_get(PCID_RESULT_KEY_IOMEM, result, JSON_ARRAY);
 
     /* stubdomain is always running by now, even at create time */
@@ -1483,8 +1489,7 @@  static void pci_add_dm_done(libxl__egc *egc,
 
     /* Don't restrict writes to the PCI config space from this VM */
     if (pci->permissive) {
-        if ( sysfs_write_bdf(gc, SYSFS_PCIBACK_DRIVER"/permissive",
-                             pci) < 0 ) {
+        if (pciback_write_bdf(gc, "permissive", pci)) {
             LOGD(ERROR, domainid, "Setting permissive for device");
             rc = ERROR_FAIL;
             goto out;
@@ -1512,8 +1517,6 @@  out_no_irq:
         rc = libxl__device_pci_add_xenstore(gc, domid, pci, starting);
     else
         rc = 0;
-vchan_free:
-    pci_vchan_free(gc, vchan);
 out:
     libxl__ev_time_deregister(gc, &pas->timeout);
     libxl__ev_time_deregister(gc, &pas->timeout_retries);
diff --git a/tools/libs/light/libxl_pcid.c b/tools/libs/light/libxl_pcid.c
index 0befb1999d..9368ba6c73 100644
--- a/tools/libs/light/libxl_pcid.c
+++ b/tools/libs/light/libxl_pcid.c
@@ -257,6 +257,41 @@  static int pciback_dev_is_assigned(libxl__gc *gc, unsigned int domain,
     return 0;
 }
 
+static int process_pciback_write_bdf(libxl__gc *gc, yajl_gen gen,
+                                   char *command_name,
+                                   const struct libxl__json_object *request,
+                                   struct libxl__json_object **response)
+{
+    const struct libxl__json_object *json_o;
+    unsigned int dom, bus, dev, func;
+    int rc = 0;
+    const char *name;
+    char *spath;
+
+    json_o = libxl__json_map_get(PCID_MSG_FIELD_SBDF, request, JSON_STRING);
+    if (!json_o) {
+        make_error_reply(gc, gen, "No mandatory parameter 'sbdf'", command_name);
+        return ERROR_FAIL;
+    }
+
+    if (sscanf(libxl__json_object_get_string(json_o), PCID_SBDF_FMT,
+           &dom, &bus, &dev, &func) != 4) {
+        make_error_reply(gc, gen, "Can't parse SBDF", command_name);
+        return ERROR_FAIL;
+    }
+
+    json_o = libxl__json_map_get(PCID_MSG_FIELD_NAME, request, JSON_STRING);
+    if (!json_o) {
+        make_error_reply(gc, gen, "No mandatory parameter 'rebind'", command_name);
+        return ERROR_FAIL;
+    }
+
+    name = libxl__json_object_get_string(json_o);
+    spath = GCSPRINTF("%s/%s", SYSFS_PCIBACK_DRIVER, name);
+    LOG(WARN, "sysf_write_bdf(%s, %d, %d, %d, %d)", spath, dom, bus, dev,func);
+    return rc;
+}
+
 #define PCID_INFO_PATH		"pcid"
 #define PCID_BDF_XSPATH         "%04x-%02x-%02x-%01x"
 
@@ -746,6 +781,9 @@  static int pcid_handle_request(libxl__gc *gc, yajl_gen gen,
     else if (strcmp(command_name, PCID_CMD_RESOURCE_LIST) == 0)
        ret = process_list_resources(gc, gen, command_name,
                                      request, &command_response);
+    else if (strcmp(command_name, PCID_CMD_WRITE_BDF) == 0)
+       ret = process_pciback_write_bdf(gc, gen, command_name,
+                                     request, &command_response);
     else {
         /*
          * This is an unsupported command: make a reply and proceed over