util: Introduce new module virmdev

Beside creation, disposal, getter, and setter methods the module exports
methods to work with lists of mediated devices.

Signed-off-by: Erik Skultety <eskultet@redhat.com>

po/POTFILES.in

@@ -223,6 +223,7 @@ src/util/virlease.c
 src/util/virlockspace.c
 src/util/virlog.c
 src/util/virmacmap.c
+src/util/virmdev.c
 src/util/virnetdev.c
 src/util/virnetdevbandwidth.c
 src/util/virnetdevbridge.c

src/Makefile.am

@@ -190,6 +190,7 @@ UTIL_SOURCES =							\
 		util/virvhba.c util/virvhba.h			\
 		util/virxdrdefs.h                               \
 		util/virxml.c util/virxml.h			\
+		util/virmdev.c util/virmdev.h			\
 		$(NULL)
 
 EXTRA_DIST += $(srcdir)/util/keymaps.csv $(srcdir)/util/virkeycode-mapgen.py

src/libvirt_private.syms

@@ -2000,6 +2000,28 @@ virMacMapNew;
 virMacMapRemove;
 virMacMapWriteFile;
 
+# util/virmdev.h
+virMediatedDeviceFree;
+virMediatedDeviceGetIOMMUGroupDev;
+virMediatedDeviceGetIOMMUGroupNum;
+virMediatedDeviceGetSysfsPath;
+virMediatedDeviceGetUsedBy;
+virMediatedDeviceIsUsed;
+virMediatedDeviceListAdd;
+virMediatedDeviceListCount;
+virMediatedDeviceListDel;
+virMediatedDeviceListFind;
+virMediatedDeviceListGet;
+virMediatedDeviceListMarkDevices;
+virMediatedDeviceListNew;
+virMediatedDeviceListSteal;
+virMediatedDeviceListStealIndex;
+virMediatedDeviceModelTypeFromString;
+virMediatedDeviceModelTypeToString;
+virMediatedDeviceNew;
+virMediatedDeviceSetUsedBy;
+
+
 
 # util/virnetdev.h
 virNetDevAddMulti;

src/util/virmdev.c

@@ -0,0 +1,476 @@
+/*
+ * virmdev.c: helper APIs for managing host mediated devices
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+
+#include "dirname.h"
+#include "virmdev.h"
+#include "virlog.h"
+#include "viralloc.h"
+#include "virerror.h"
+#include "virfile.h"
+#include "virstring.h"
+
+#define VIR_FROM_THIS VIR_FROM_NONE
+
+VIR_LOG_INIT("util.mdev");
+
+struct _virMediatedDevice {
+    char *path;                             /* sysfs path */
+    virMediatedDeviceModelType model;
+
+    char *used_by_drvname;
+    char *used_by_domname;
+};
+
+struct _virMediatedDeviceList {
+    virObjectLockable parent;
+
+    size_t count;
+    virMediatedDevicePtr *devs;
+};
+
+VIR_ENUM_IMPL(virMediatedDeviceModel, VIR_MDEV_MODEL_TYPE_LAST,
+              "vfio-pci")
+
+static virClassPtr virMediatedDeviceListClass;
+
+static void
+virMediatedDeviceListDispose(void *obj);
+
+static int
+virMediatedOnceInit(void)
+{
+    if (!(virMediatedDeviceListClass = virClassNew(virClassForObjectLockable(),
+                                                   "virMediatedDeviceList",
+                                                   sizeof(virMediatedDeviceList),
+                                                   virMediatedDeviceListDispose)))
+        return -1;
+
+    return 0;
+}
+
+VIR_ONCE_GLOBAL_INIT(virMediated)
+
+#ifdef __linux__
+# define MDEV_SYSFS_DEVICES "/sys/bus/mdev/devices/"
+
+static int
+virMediatedDeviceGetSysfsDeviceAPI(virMediatedDevicePtr dev,
+                                   char **device_api)
+{
+    int ret = -1;
+    char *buf = NULL;
+    char *file = NULL;
+    char *tmp = NULL;
+
+    if (virAsprintf(&file, "%s/mdev_type/device_api", dev->path) < 0)
+        goto cleanup;
+
+    /* TODO - make this a generic method to access sysfs files for various
+     * kinds of devices
+     */
+    if (!virFileExists(file)) {
+        virReportSystemError(errno, _("failed to read '%s'"), file);
+        goto cleanup;
+    }
+
+    if (virFileReadAll(file, 1024, &buf) < 0)
+        goto cleanup;
+
+    if ((tmp = strchr(buf, '\n')))
+        *tmp = '\0';
+
+    *device_api = buf;
+    buf = NULL;
+
+    ret = 0;
+ cleanup:
+    VIR_FREE(file);
+    VIR_FREE(buf);
+    return ret;
+}
+
+
+static int
+virMediatedDeviceCheckModel(virMediatedDevicePtr dev,
+                            virMediatedDeviceModelType model)
+{
+    int ret = -1;
+    char *dev_api = NULL;
+    int actual_model;
+
+    if (virMediatedDeviceGetSysfsDeviceAPI(dev, &dev_api) < 0)
+        return -1;
+
+    /* safeguard in case we've got an older libvirt which doesn't know newer
+     * device_api models yet
+     */
+    if ((actual_model = virMediatedDeviceModelTypeFromString(dev_api)) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("device API '%s' not supported yet"),
+                       dev_api);
+        goto cleanup;
+    }
+
+    if (actual_model != model) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("invalid device API '%s' for device %s: "
+                         "device only supports '%s'"),
+                       virMediatedDeviceModelTypeToString(model),
+                       dev->path, dev_api);
+        goto cleanup;
+    }
+
+    ret = 0;
+ cleanup:
+    VIR_FREE(dev_api);
+    return ret;
+}
+
+
+virMediatedDevicePtr
+virMediatedDeviceNew(const char *uuidstr, virMediatedDeviceModelType model)
+{
+    virMediatedDevicePtr ret = NULL;
+    virMediatedDevicePtr dev = NULL;
+
+    if (VIR_ALLOC(dev) < 0)
+        return NULL;
+
+    if (!(dev->path = virMediatedDeviceGetSysfsPath(uuidstr)))
+        goto cleanup;
+
+    /* Check whether the user-provided model corresponds with the actually
+     * supported mediated device's API.
+     */
+    if (virMediatedDeviceCheckModel(dev, model))
+        goto cleanup;
+
+    dev->model = model;
+    VIR_STEAL_PTR(ret, dev);
+
+ cleanup:
+    virMediatedDeviceFree(dev);
+    return ret;
+}
+
+#else
+
+virMediatedDevicePtr
+virMediatedDeviceNew(virPCIDeviceAddressPtr pciaddr ATTRIBUTE_UNUSED,
+                     const char *uuidstr ATTRIBUTE_UNUSED)
+{
+    virRerportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                    _("mediated devices are not supported on non-linux "
+                      "platforms"));
+    return NULL;
+}
+
+#endif /* __linux__ */
+
+void
+virMediatedDeviceFree(virMediatedDevicePtr dev)
+{
+    if (!dev)
+        return;
+    VIR_FREE(dev->path);
+    VIR_FREE(dev->used_by_drvname);
+    VIR_FREE(dev->used_by_domname);
+    VIR_FREE(dev);
+}
+
+
+const char *
+virMediatedDeviceGetPath(virMediatedDevicePtr dev)
+{
+    return dev->path;
+}
+
+
+/* Returns an absolute canonicalized path to the device used to control the
+ * mediated device's IOMMU group (e.g. "/dev/vfio/15"). Caller is responsible
+ * for freeing the result.
+ */
+char *
+virMediatedDeviceGetIOMMUGroupDev(virMediatedDevicePtr dev)
+{
+    char *resultpath = NULL;
+    char *iommu_path = NULL;
+    char *vfio_path = NULL;
+
+    if (virAsprintf(&iommu_path, "%s/iommu_group", dev->path) < 0)
+        return NULL;
+
+    if (!virFileExists(iommu_path)) {
+        virReportSystemError(errno, _("failed to access '%s'"), iommu_path);
+        goto cleanup;
+    }
+
+    if (virFileResolveLink(iommu_path, &resultpath) < 0) {
+        virReportSystemError(errno, _("failed to resolve '%s'"), iommu_path);
+        goto cleanup;
+    }
+
+    if (virAsprintf(&vfio_path, "/dev/vfio/%s", last_component(resultpath)) < 0)
+        goto cleanup;
+
+ cleanup:
+    VIR_FREE(resultpath);
+    VIR_FREE(iommu_path);
+    return vfio_path;
+}
+
+
+int
+virMediatedDeviceGetIOMMUGroupNum(virMediatedDevicePtr dev)
+{
+    char *vfio_path = NULL;
+    char *group_num_str = NULL;
+    unsigned int group_num = -1;
+
+    if (!(vfio_path = virMediatedDeviceGetIOMMUGroupDev(dev)))
+        return -1;
+
+    group_num_str = last_component(vfio_path);
+    ignore_value(virStrToLong_ui(group_num_str, NULL, 10, &group_num));
+
+    VIR_FREE(vfio_path);
+    return group_num;
+}
+
+
+void
+virMediatedDeviceGetUsedBy(virMediatedDevicePtr dev,
+                           const char **drvname, const char **domname)
+{
+    *drvname = dev->used_by_drvname;
+    *domname = dev->used_by_domname;
+}
+
+
+int
+virMediatedDeviceSetUsedBy(virMediatedDevicePtr dev,
+                           const char *drvname,
+                           const char *domname)
+{
+    VIR_FREE(dev->used_by_drvname);
+    VIR_FREE(dev->used_by_domname);
+    if (VIR_STRDUP(dev->used_by_drvname, drvname) < 0)
+        return -1;
+    if (VIR_STRDUP(dev->used_by_domname, domname) < 0)
+        return -1;
+
+    return 0;
+}
+
+
+virMediatedDeviceListPtr
+virMediatedDeviceListNew(void)
+{
+    virMediatedDeviceListPtr list;
+
+    if (virMediatedInitialize() < 0)
+        return NULL;
+
+    if (!(list = virObjectLockableNew(virMediatedDeviceListClass)))
+        return NULL;
+
+    return list;
+}
+
+
+static void
+virMediatedDeviceListDispose(void *obj)
+{
+    virMediatedDeviceListPtr list = obj;
+    size_t i;
+
+    for (i = 0; i < list->count; i++) {
+        virMediatedDeviceFree(list->devs[i]);
+        list->devs[i] = NULL;
+    }
+
+    list->count = 0;
+    VIR_FREE(list->devs);
+}
+
+
+int
+virMediatedDeviceListAdd(virMediatedDeviceListPtr list,
+                         virMediatedDevicePtr dev)
+{
+    if (virMediatedDeviceListFind(list, dev)) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("device %s is already in use"), dev->path);
+        return -1;
+    }
+    return VIR_APPEND_ELEMENT(list->devs, list->count, dev);
+}
+
+
+virMediatedDevicePtr
+virMediatedDeviceListGet(virMediatedDeviceListPtr list,
+                         ssize_t idx)
+{
+    if (idx < 0 || idx >= list->count)
+        return NULL;
+
+    return list->devs[idx];
+}
+
+
+size_t
+virMediatedDeviceListCount(virMediatedDeviceListPtr list)
+{
+    return list->count;
+}
+
+
+virMediatedDevicePtr
+virMediatedDeviceListStealIndex(virMediatedDeviceListPtr list,
+                                ssize_t idx)
+{
+    virMediatedDevicePtr ret;
+
+    if (idx < 0 || idx >= list->count)
+        return NULL;
+
+    ret = list->devs[idx];
+    VIR_DELETE_ELEMENT(list->devs, idx, list->count);
+    return ret;
+}
+
+
+virMediatedDevicePtr
+virMediatedDeviceListSteal(virMediatedDeviceListPtr list,
+                           virMediatedDevicePtr dev)
+{
+    int idx = virMediatedDeviceListFindIndex(list, dev);
+
+    return virMediatedDeviceListStealIndex(list, idx);
+}
+
+
+void
+virMediatedDeviceListDel(virMediatedDeviceListPtr list,
+                         virMediatedDevicePtr dev)
+{
+    virMediatedDevicePtr ret = virMediatedDeviceListSteal(list, dev);
+    virMediatedDeviceFree(ret);
+}
+
+
+int
+virMediatedDeviceListFindIndex(virMediatedDeviceListPtr list,
+                               virMediatedDevicePtr dev)
+{
+    size_t i;
+
+    for (i = 0; i < list->count; i++) {
+        virMediatedDevicePtr other = list->devs[i];
+        if (STREQ(other->path, dev->path))
+            return i;
+    }
+    return -1;
+}
+
+
+virMediatedDevicePtr
+virMediatedDeviceListFind(virMediatedDeviceListPtr list,
+                          virMediatedDevicePtr dev)
+{
+    int idx;
+
+    if ((idx = virMediatedDeviceListFindIndex(list, dev)) >= 0)
+        return list->devs[idx];
+    else
+        return NULL;
+}
+
+
+bool
+virMediatedDeviceIsUsed(virMediatedDevicePtr dev,
+                        virMediatedDeviceListPtr list)
+{
+    const char *drvname, *domname;
+    virMediatedDevicePtr tmp = NULL;
+
+    if ((tmp = virMediatedDeviceListFind(list, dev))) {
+        virMediatedDeviceGetUsedBy(tmp, &drvname, &domname);
+        virReportError(VIR_ERR_OPERATION_INVALID,
+                       _("mediated device %s is in use by "
+                         "driver %s, domain %s"),
+                       tmp->path, drvname, domname);
+    }
+
+    return !!tmp;
+}
+
+
+char *
+virMediatedDeviceGetSysfsPath(const char *uuidstr)
+{
+    char *ret = NULL;
+
+    ignore_value(virAsprintf(&ret, MDEV_SYSFS_DEVICES "%s", uuidstr));
+    return ret;
+}
+
+
+int
+virMediatedDeviceListMarkDevices(virMediatedDeviceListPtr dst,
+                                 virMediatedDeviceListPtr src,
+                                 const char *drvname,
+                                 const char *domname)
+{
+    int ret = -1;
+    size_t count = virMediatedDeviceListCount(src);
+    size_t i, j;
+
+    virObjectLock(dst);
+    for (i = 0; i < count; i++) {
+        virMediatedDevicePtr mdev = virMediatedDeviceListGet(src, i);
+
+        if (virMediatedDeviceIsUsed(mdev, dst) ||
+            virMediatedDeviceSetUsedBy(mdev, drvname, domname) < 0)
+            goto cleanup;
+
+        /* Copy mdev references to the driver list:
+         * - caller is responsible for NOT freeing devices in @list on success
+         * - we're responsible for performing a rollback on failure
+         */
+        if (virMediatedDeviceListAdd(dst, mdev) < 0)
+            goto rollback;
+
+        VIR_DEBUG("'%s' added to list of active mediated devices used by '%s'",
+                  mdev->path, domname);
+    }
+
+    ret = 0;
+ cleanup:
+    virObjectUnlock(dst);
+    return ret;
+
+ rollback:
+    for (j = 0; j < i; j++) {
+        virMediatedDevicePtr tmp = virMediatedDeviceListGet(src, j);
+        virMediatedDeviceListSteal(dst, tmp);
+    }
+    goto cleanup;
+}

src/util/virmdev.h

@@ -0,0 +1,123 @@
+/*
+ * virmdev.h: helper APIs for managing host mediated devices
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __VIR_MDEV_H__
+# define __VIR_MDEV_H__
+
+# include "internal.h"
+# include "virobject.h"
+# include "virutil.h"
+# include "virpci.h"
+
+typedef enum {
+    VIR_MDEV_MODEL_TYPE_VFIO_PCI = 0,
+
+    VIR_MDEV_MODEL_TYPE_LAST
+} virMediatedDeviceModelType;
+
+VIR_ENUM_DECL(virMediatedDeviceModel)
+
+
+typedef struct _virMediatedDevice virMediatedDevice;
+typedef virMediatedDevice *virMediatedDevicePtr;
+typedef struct _virMediatedDeviceAddress virMediatedDeviceAddress;
+typedef virMediatedDeviceAddress *virMediatedDeviceAddressPtr;
+typedef struct _virMediatedDeviceList virMediatedDeviceList;
+typedef virMediatedDeviceList *virMediatedDeviceListPtr;
+
+typedef int (*virMediatedDeviceCallback)(virMediatedDevicePtr dev,
+                                         const char *path, void *opaque);
+
+virMediatedDevicePtr
+virMediatedDeviceNew(const char *uuidstr, virMediatedDeviceModelType model);
+
+virMediatedDevicePtr
+virMediatedDeviceCopy(virMediatedDevicePtr dev);
+
+void
+virMediatedDeviceFree(virMediatedDevicePtr dev);
+
+const char *
+virMediatedDeviceGetPath(virMediatedDevicePtr dev);
+
+void
+virMediatedDeviceGetUsedBy(virMediatedDevicePtr dev,
+                           const char **drvname, const char **domname);
+
+int
+virMediatedDeviceSetUsedBy(virMediatedDevicePtr dev,
+                           const char *drvname,
+                           const char *domname);
+
+char *
+virMediatedDeviceGetIOMMUGroupDev(virMediatedDevicePtr dev);
+
+int
+virMediatedDeviceGetIOMMUGroupNum(virMediatedDevicePtr dev);
+
+char *
+virMediatedDeviceGetSysfsPath(const char *uuidstr);
+
+bool
+virMediatedDeviceIsUsed(virMediatedDevicePtr dev,
+                        virMediatedDeviceListPtr list);
+
+bool
+virMediatedDeviceIsUsed(virMediatedDevicePtr dev,
+                        virMediatedDeviceListPtr list);
+
+virMediatedDeviceListPtr
+virMediatedDeviceListNew(void);
+
+int
+virMediatedDeviceListAdd(virMediatedDeviceListPtr list,
+                         virMediatedDevicePtr dev);
+
+virMediatedDevicePtr
+virMediatedDeviceListGet(virMediatedDeviceListPtr list,
+                         ssize_t idx);
+
+size_t
+virMediatedDeviceListCount(virMediatedDeviceListPtr list);
+
+virMediatedDevicePtr
+virMediatedDeviceListSteal(virMediatedDeviceListPtr list,
+                           virMediatedDevicePtr dev);
+
+virMediatedDevicePtr
+virMediatedDeviceListStealIndex(virMediatedDeviceListPtr list,
+                                ssize_t idx);
+
+void
+virMediatedDeviceListDel(virMediatedDeviceListPtr list,
+                         virMediatedDevicePtr dev);
+
+virMediatedDevicePtr
+virMediatedDeviceListFind(virMediatedDeviceListPtr list,
+                          virMediatedDevicePtr dev);
+
+int
+virMediatedDeviceListFindIndex(virMediatedDeviceListPtr list,
+                               virMediatedDevicePtr dev);
+
+int
+virMediatedDeviceListMarkDevices(virMediatedDeviceListPtr dst,
+                                 virMediatedDeviceListPtr src,
+                                 const char *drvname,
+                                 const char *domname);
+#endif /* __VIR_MDEV_H__ */