[libvirt PATCH v2 05/10] nodedev: add mdev support to virNodeDeviceCreateXML()
Michal Privoznik
mprivozn at redhat.com
Wed Jun 10 18:01:45 UTC 2020
On 6/9/20 11:43 PM, Jonathon Jongsma wrote:
> With recent additions to the node device xml schema, an xml schema can
> now describe a mdev device sufficiently for libvirt to create and start
> the device using the mdevctl utility.
>
> Note that some of the the configuration for a mediated device must be
> passed to mdevctl as a JSON-formatted file. In order to avoid creating
> and cleaning up temporary files, the JSON is instead fed to stdin and we
> pass the filename /dev/stdin to mdevctl. While this may not be portable,
> neither are mediated devices, so I don't believe it should cause any
> problems.
>
Agreed. mdevs are Linux specific and /dev/stdin is UNIX-wide understood
(which is a strict superset of the former), so we are safe on that front.
> Signed-off-by: Jonathon Jongsma <jjongsma at redhat.com>
> ---
> libvirt.spec.in | 2 +
> m4/virt-external-programs.m4 | 3 +
> src/conf/virnodedeviceobj.c | 34 +++++
> src/conf/virnodedeviceobj.h | 3 +
> src/libvirt_private.syms | 1 +
> src/node_device/node_device_driver.c | 203 +++++++++++++++++++++++++++
> src/node_device/node_device_driver.h | 6 +
> 7 files changed, 252 insertions(+)
>
> diff --git a/libvirt.spec.in b/libvirt.spec.in
> index 262e66f3cc..2b3a4d2e71 100644
> --- a/libvirt.spec.in
> +++ b/libvirt.spec.in
> @@ -522,6 +522,8 @@ Requires: libvirt-daemon = %{version}-%{release}
> Requires: libvirt-libs = %{version}-%{release}
> # needed for device enumeration
> Requires: systemd >= 185
> +# For managing persistent mediated devices
> +Requires: mdevctl
>
> %description daemon-driver-nodedev
> The nodedev driver plugin for the libvirtd daemon, providing
> diff --git a/m4/virt-external-programs.m4 b/m4/virt-external-programs.m4
> index 9046e3bf07..bd3cb1f757 100644
> --- a/m4/virt-external-programs.m4
> +++ b/m4/virt-external-programs.m4
> @@ -65,6 +65,7 @@ AC_DEFUN([LIBVIRT_CHECK_EXTERNAL_PROGRAMS], [
> AC_PATH_PROG([OVSVSCTL], [ovs-vsctl], [ovs-vsctl], [$LIBVIRT_SBIN_PATH])
> AC_PATH_PROG([SCRUB], [scrub], [scrub], [$LIBVIRT_SBIN_PATH])
> AC_PATH_PROG([ADDR2LINE], [addr2line], [addr2line], [$LIBVIRT_SBIN_PATH])
> + AC_PATH_PROG([MDEVCTL], [mdevctl], [mdevctl], [$LIBVIRT_SBIN_PATH])
This will need to look slightly different - see 07/10.
>
> AC_DEFINE_UNQUOTED([DMIDECODE], ["$DMIDECODE"],
> [Location or name of the dmidecode program])
> @@ -88,6 +89,8 @@ AC_DEFUN([LIBVIRT_CHECK_EXTERNAL_PROGRAMS], [
> [Location or name of the scrub program (for wiping algorithms)])
> AC_DEFINE_UNQUOTED([ADDR2LINE], ["$ADDR2LINE"],
> [Location of addr2line program])
> + AC_DEFINE_UNQUOTED([MDEVCTL], ["$MDEVCTL"],
> + [Location or name of the mdevctl program])
>
> AC_PATH_PROG([IP_PATH], [ip], [/sbin/ip], [$LIBVIRT_SBIN_PATH])
> AC_DEFINE_UNQUOTED([IP_PATH], ["$IP_PATH"], [path to ip binary])
> diff --git a/src/conf/virnodedeviceobj.c b/src/conf/virnodedeviceobj.c
> index 3a34a324ca..fd20d5f9e2 100644
> --- a/src/conf/virnodedeviceobj.c
> +++ b/src/conf/virnodedeviceobj.c
> @@ -399,6 +399,40 @@ virNodeDeviceObjListFindSCSIHostByWWNs(virNodeDeviceObjListPtr devs,
> &data);
> }
>
> +static int
> +virNodeDeviceObjListFindMediatedDeviceByUUIDCallback(const void *payload,
> + const void *name G_GNUC_UNUSED,
> + const void *opaque G_GNUC_UNUSED)
> +{
> + virNodeDeviceObjPtr obj = (virNodeDeviceObjPtr) payload;
> + const char *uuid = (const char *) opaque;
> + virNodeDevCapsDefPtr cap;
> + int want = 0;
> +
> + virObjectLock(obj);
> +
> + for (cap = obj->def->caps; cap != NULL; cap = cap->next) {
> + if (cap->data.type == VIR_NODE_DEV_CAP_MDEV) {
> + if (STREQ(cap->data.mdev.uuid, uuid)) {
> + want = 1;
> + break;
> + }
> + }
> + }
> +
> + virObjectUnlock(obj);
> + return want;
> +}
> +
> +
> +virNodeDeviceObjPtr
> +virNodeDeviceObjListFindMediatedDeviceByUUID(virNodeDeviceObjListPtr devs,
> + const char *uuid)
> +{
> + return virNodeDeviceObjListSearch(devs,
> + virNodeDeviceObjListFindMediatedDeviceByUUIDCallback,
> + uuid);
> +}
>
> static void
> virNodeDeviceObjListDispose(void *obj)
> diff --git a/src/conf/virnodedeviceobj.h b/src/conf/virnodedeviceobj.h
> index c9df8dedab..6efdb23d36 100644
> --- a/src/conf/virnodedeviceobj.h
> +++ b/src/conf/virnodedeviceobj.h
> @@ -118,3 +118,6 @@ virNodeDeviceObjListExport(virConnectPtr conn,
> void
> virNodeDeviceObjSetSkipUpdateCaps(virNodeDeviceObjPtr obj,
> bool skipUpdateCaps);
> +virNodeDeviceObjPtr
> +virNodeDeviceObjListFindMediatedDeviceByUUID(virNodeDeviceObjListPtr devs,
> + const char *uuid);
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index b8e6f058c3..532169d93d 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -1178,6 +1178,7 @@ virNodeDeviceObjListAssignDef;
> virNodeDeviceObjListExport;
> virNodeDeviceObjListFindByName;
> virNodeDeviceObjListFindBySysfsPath;
> +virNodeDeviceObjListFindMediatedDeviceByUUID;
> virNodeDeviceObjListFindSCSIHostByWWNs;
> virNodeDeviceObjListFree;
> virNodeDeviceObjListGetNames;
> diff --git a/src/node_device/node_device_driver.c b/src/node_device/node_device_driver.c
> index 629d4bcf91..dbc7eb4d1e 100644
> --- a/src/node_device/node_device_driver.c
> +++ b/src/node_device/node_device_driver.c
> @@ -30,6 +30,7 @@
> #include "datatypes.h"
> #include "viralloc.h"
> #include "virfile.h"
> +#include "virjson.h"
> #include "virstring.h"
> #include "node_device_conf.h"
> #include "node_device_event.h"
> @@ -40,6 +41,7 @@
> #include "viraccessapicheck.h"
> #include "virnetdev.h"
> #include "virutil.h"
> +#include "vircommand.h"
>
> #define VIR_FROM_THIS VIR_FROM_NODEDEV
>
> @@ -304,6 +306,30 @@ nodeDeviceLookupSCSIHostByWWN(virConnectPtr conn,
> return device;
> }
>
> +static virNodeDevicePtr
> +nodeDeviceLookupMediatedDeviceByUUID(virConnectPtr conn,
> + const char *uuid,
> + unsigned int flags)
> +{
> + virNodeDeviceObjPtr obj = NULL;
> + virNodeDeviceDefPtr def;
> + virNodeDevicePtr device = NULL;
> +
> + virCheckFlags(0, NULL);
> +
> + if (!(obj = virNodeDeviceObjListFindMediatedDeviceByUUID(driver->devs,
> + uuid)))
> + return NULL;
> +
> + def = virNodeDeviceObjGetDef(obj);
> +
> + if ((device = virGetNodeDevice(conn, def->name)))
> + device->parentName = g_strdup(def->parent);
> +
> + virNodeDeviceObjEndAPI(&obj);
> + return device;
> +}
> +
>
> char *
> nodeDeviceGetXMLDesc(virNodeDevicePtr device,
> @@ -492,6 +518,25 @@ nodeDeviceFindNewDevice(virConnectPtr conn,
> }
>
>
> +static virNodeDevicePtr
> +nodeDeviceFindNewMediatedDeviceFunc(virConnectPtr conn,
> + const void *opaque)
> +{
> + const char *uuid = opaque;
> + return nodeDeviceLookupMediatedDeviceByUUID(conn, uuid, 0);
> +}
> +
> +
> +static virNodeDevicePtr
> +nodeDeviceFindNewMediatedDevice(virConnectPtr conn,
> + const char *mdev_uuid)
> +{
> + return nodeDeviceFindNewDevice(conn,
> + nodeDeviceFindNewMediatedDeviceFunc,
> + mdev_uuid);
> +}
> +
> +
> typedef struct _NewSCSIHostFuncData NewSCSIHostFuncData;
> struct _NewSCSIHostFuncData
> {
> @@ -534,6 +579,162 @@ nodeDeviceHasCapability(virNodeDeviceDefPtr def, virNodeDevCapType type)
> }
>
>
> +/* format a json string that provides configuration information about this mdev
> + * to the mdevctl utility */
> +static int
> +nodeDeviceDefToMdevctlConfig(virNodeDeviceDefPtr def, char **buf)
> +{
> + size_t i;
> + virNodeDevCapMdevPtr mdev = &def->caps->data.mdev;
> + g_autoptr(virJSONValue) json = virJSONValueNewObject();
> +
> + if (virJSONValueObjectAppendString(json, "mdev_type", mdev->type) < 0)
> + return -1;
> + if (virJSONValueObjectAppendString(json, "start", "manual") < 0)
> + return -1;
> + if (mdev->attributes) {
> + g_autoptr(virJSONValue) attributes = virJSONValueNewArray();
> + for (i = 0; i < mdev->nattributes; i++) {
> + virMediatedDeviceAttrPtr attr = mdev->attributes[i];
> + g_autoptr(virJSONValue) jsonattr = virJSONValueNewObject();
> +
> + if (virJSONValueObjectAppendString(jsonattr, attr->name, attr->value) < 0)
> + return -1;
> + if (virJSONValueArrayAppend(attributes, g_steal_pointer(&jsonattr)) < 0)
> + return -1;
> + }
> + if (virJSONValueObjectAppend(json, "attrs", g_steal_pointer(&attributes)) < 0)
> + return -1;
> + }
> +
> + *buf = virJSONValueToString(json, false);
> + if (!*buf)
> + return -1;
> +
> + return 0;
> +}
> +
> +
> +static char *
> +nodeDeviceFindAddressByName(const char *name)
> +{
> + virNodeDeviceDefPtr def = NULL;
> + virNodeDevCapsDefPtr caps = NULL;
> + char *pci_addr = NULL;
> + virNodeDeviceObjPtr dev = virNodeDeviceObjListFindByName(driver->devs, name);
> +
> + if (!dev) {
> + virReportError(VIR_ERR_NO_NODE_DEVICE,
> + _("could not find device '%s'"), name);
> + return NULL;
> + }
> +
> + def = virNodeDeviceObjGetDef(dev);
> + for (caps = def->caps; caps != NULL; caps = caps->next) {
> + if (caps->data.type == VIR_NODE_DEV_CAP_PCI_DEV) {
> + virPCIDeviceAddress addr = {
> + .domain = caps->data.pci_dev.domain,
> + .bus = caps->data.pci_dev.bus,
> + .slot = caps->data.pci_dev.slot,
> + .function = caps->data.pci_dev.function
> + };
> +
> + pci_addr = virPCIDeviceAddressAsString(&addr);
> + break;
> + }
> + }
> +
> + virNodeDeviceObjEndAPI(&dev);
> +
> + return pci_addr;
> +}
> +
> +
> +virCommandPtr
> +nodeDeviceGetMdevctlStartCommand(virNodeDeviceDefPtr def,
> + bool persist,
> + char **uuid_out)
> +{
> + virCommandPtr cmd;
> + const char *subcommand;
> + g_autofree char *json = NULL;
> + g_autofree char *mdevctl = virFindFileInPath(MDEVCTL);
> + g_autofree char *parent_pci = nodeDeviceFindAddressByName(def->parent);
> +
> + if (!mdevctl)
> + return NULL;
This virFindFileInPath() and @mdevctl variable aren't necessary.
virCommandRun() will call virFindFileInPath() under the hood (see
v6.4.0-66-gf603b99ad9). And also, if the function fails, it does so
silently. And this doesn't report error neither.
> +
> + if (!parent_pci) {
> + virReportError(VIR_ERR_NO_NODE_DEVICE,
> + _("unable to find PCI address for parent device '%s'"), def->parent);
> + return NULL;
> + }
> +
> + if (nodeDeviceDefToMdevctlConfig(def, &json) < 0) {
> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> + _("couldn't convert node device def to mdevctl JSON"));
> + return NULL;
> + }
> +
> + if (persist)
> + subcommand = "define";
> + else
> + subcommand = "start";
> +
> + cmd = virCommandNewArgList(mdevctl, subcommand,
> + "-p", parent_pci,
> + "--jsonfile", "/dev/stdin",
> + NULL);
> +
> + virCommandSetInputBuffer(cmd, json);
> + virCommandSetOutputBuffer(cmd, uuid_out);
> +
> + return cmd;
> +}
> +
> +static int
> +virMdevctlStart(virNodeDeviceDefPtr def, char **uuid)
> +{
> + int status;
> + g_autoptr(virCommand) cmd = nodeDeviceGetMdevctlStartCommand(def, false,
> + uuid);
> + if (!cmd)
> + return -1;
> +
> + /* an auto-generated uuid is returned via stdout if no uuid is specified in
> + * the mdevctl args */
> + if (virCommandRun(cmd, &status) < 0 || status != 0)
> + return -1;
> +
> + /* remove newline */
> + *uuid = g_strstrip(*uuid);
> +
> + return 0;
> +}
> +
> +
> +static virNodeDevicePtr
> +nodeDeviceCreateXMLMdev(virConnectPtr conn,
> + virNodeDeviceDefPtr def)
> +{
> + g_autofree char *uuid = NULL;
> +
> + if (!def->parent) {
> + virReportError(VIR_ERR_XML_ERROR, "%s",
> + _("cannot create a mediated device without a parent"));
> + return NULL;
> + }
> +
> + if (virMdevctlStart(def, &uuid) < 0) {
> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> + _("Unable to start mediated device"));
> + return NULL;
> + }
> +
> + return nodeDeviceFindNewMediatedDevice(conn, uuid);
> +}
> +
> +
> virNodeDevicePtr
> nodeDeviceCreateXML(virConnectPtr conn,
> const char *xmlDesc,
> @@ -578,6 +779,8 @@ nodeDeviceCreateXML(virConnectPtr conn,
> _("no node device for '%s' with matching "
> "wwnn '%s' and wwpn '%s'"),
> def->name, wwnn, wwpn);
> + } else if (nodeDeviceHasCapability(def, VIR_NODE_DEV_CAP_MDEV)) {
> + device = nodeDeviceCreateXMLMdev(conn, def);
> } else {
> virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> _("Unsupported device type"));
> diff --git a/src/node_device/node_device_driver.h b/src/node_device/node_device_driver.h
> index eae5e2cb17..576f75375f 100644
> --- a/src/node_device/node_device_driver.h
> +++ b/src/node_device/node_device_driver.h
> @@ -24,6 +24,7 @@
> #include "internal.h"
> #include "driver.h"
> #include "virnodedeviceobj.h"
> +#include "vircommand.h"
>
> #define LINUX_NEW_DEVICE_WAIT_TIME 60
>
> @@ -116,3 +117,8 @@ nodeConnectNodeDeviceEventRegisterAny(virConnectPtr conn,
> int
> nodeConnectNodeDeviceEventDeregisterAny(virConnectPtr conn,
> int callbackID);
> +
> +virCommandPtr
> +nodeDeviceGetMdevctlStartCommand(virNodeDeviceDefPtr def,
> + bool persist,
> + char **uuid_out);
>
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