[libvirt PATCHv2 08/10] qemu: add code for handling virtiofsd
Ján Tomko
jtomko at redhat.com
Thu Jan 23 17:46:09 UTC 2020
Start virtiofsd for each <filesystem> device using it.
Pre-create the socket for communication with QEMU and pass it
to virtiofsd.
Note that virtiofsd needs to run as root.
https://bugzilla.redhat.com/show_bug.cgi?id=1694166
Introduced by QEMU commit TBD, pull request here:
https://lists.nongnu.org/archive/html/qemu-devel/2020-01/msg05389.html
Signed-off-by: Ján Tomko <jtomko at redhat.com>
---
po/POTFILES.in | 1 +
src/qemu/Makefile.inc.am | 2 +
src/qemu/qemu_domain.c | 3 +
src/qemu/qemu_domain.h | 2 +-
src/qemu/qemu_extdevice.c | 19 +++
src/qemu/qemu_virtiofs.c | 241 ++++++++++++++++++++++++++++++++++++++
src/qemu/qemu_virtiofs.h | 37 ++++++
tests/qemuxml2argvtest.c | 6 +
8 files changed, 310 insertions(+), 1 deletion(-)
create mode 100644 src/qemu/qemu_virtiofs.c
create mode 100644 src/qemu/qemu_virtiofs.h
diff --git a/po/POTFILES.in b/po/POTFILES.in
index e266871907..4ea646e127 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -169,6 +169,7 @@
@SRCDIR@/src/qemu/qemu_tpm.c
@SRCDIR@/src/qemu/qemu_vhost_user.c
@SRCDIR@/src/qemu/qemu_vhost_user_gpu.c
+ at SRCDIR@/src/qemu/qemu_virtiofs.c
@SRCDIR@/src/remote/remote_daemon.c
@SRCDIR@/src/remote/remote_daemon_config.c
@SRCDIR@/src/remote/remote_daemon_dispatch.c
diff --git a/src/qemu/Makefile.inc.am b/src/qemu/Makefile.inc.am
index 967f6e75a2..77786526ea 100644
--- a/src/qemu/Makefile.inc.am
+++ b/src/qemu/Makefile.inc.am
@@ -67,6 +67,8 @@ QEMU_DRIVER_SOURCES = \
qemu/qemu_vhost_user.h \
qemu/qemu_vhost_user_gpu.c \
qemu/qemu_vhost_user_gpu.h \
+ qemu/qemu_virtiofs.c \
+ qemu/qemu_virtiofs.h \
qemu/qemu_checkpoint.c \
qemu/qemu_checkpoint.h \
qemu/qemu_backup.c \
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 4db0075b89..19b3eb0fab 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -1442,6 +1442,9 @@ qemuDomainFSPrivateNew(void)
static void
qemuDomainFSPrivateDispose(void *obj G_GNUC_UNUSED)
{
+ qemuDomainFSPrivatePtr priv = obj;
+
+ g_free(priv->vhostuser_fs_sock);
}
static virClassPtr qemuDomainVideoPrivateClass;
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 21ece23177..ea50c687d4 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -568,7 +568,7 @@ typedef qemuDomainFSPrivate *qemuDomainFSPrivatePtr;
struct _qemuDomainFSPrivate {
virObject parent;
- int dummy;
+ char *vhostuser_fs_sock;
};
diff --git a/src/qemu/qemu_extdevice.c b/src/qemu/qemu_extdevice.c
index 463f76c21a..1f4b605eb3 100644
--- a/src/qemu/qemu_extdevice.c
+++ b/src/qemu/qemu_extdevice.c
@@ -20,11 +20,13 @@
#include <config.h>
+#include "qemu_command.h"
#include "qemu_extdevice.h"
#include "qemu_vhost_user_gpu.h"
#include "qemu_domain.h"
#include "qemu_tpm.h"
#include "qemu_slirp.h"
+#include "qemu_virtiofs.h"
#include "viralloc.h"
#include "virlog.h"
@@ -184,6 +186,16 @@ qemuExtDevicesStart(virQEMUDriverPtr driver,
return -1;
}
+ for (i = 0; i < def->nfss; i++) {
+ virDomainFSDefPtr fs = def->fss[i];
+
+ if (fs->fsdriver == VIR_DOMAIN_FS_DRIVER_TYPE_VIRTIOFS) {
+ if (qemuVirtioFSStart(driver, vm, fs) < 0)
+ return -1;
+ }
+ }
+
+
return ret;
}
@@ -215,6 +227,13 @@ qemuExtDevicesStop(virQEMUDriverPtr driver,
if (slirp)
qemuSlirpStop(slirp, vm, driver, net, false);
}
+
+ for (i = 0; i < def->nfss; i++) {
+ virDomainFSDefPtr fs = def->fss[i];
+
+ if (fs->fsdriver == VIR_DOMAIN_FS_DRIVER_TYPE_VIRTIOFS)
+ qemuVirtioFSStop(driver, vm, fs);
+ }
}
diff --git a/src/qemu/qemu_virtiofs.c b/src/qemu/qemu_virtiofs.c
new file mode 100644
index 0000000000..1a3bfd53f5
--- /dev/null
+++ b/src/qemu/qemu_virtiofs.c
@@ -0,0 +1,241 @@
+/*
+ * qemu_virtiofs.c: virtiofs support
+ *
+ * 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 "qemu_command.h"
+#include "qemu_conf.h"
+#include "qemu_extdevice.h"
+#include "qemu_security.h"
+#include "qemu_virtiofs.h"
+#include "virpidfile.h"
+
+#define VIR_FROM_THIS VIR_FROM_QEMU
+
+
+char *
+qemuVirtioFSCreatePidFilename(virQEMUDriverConfigPtr cfg,
+ const virDomainDef *def,
+ const char *alias)
+{
+ g_autofree char *shortName = NULL;
+ g_autofree char *name = NULL;
+
+ if (!(shortName = virDomainDefGetShortName(def)))
+ return NULL;
+
+ name = g_strdup_printf("%s-%s-virtiofsd", shortName, alias);
+
+ return virPidFileBuildPath(cfg->stateDir, name);
+}
+
+
+char *
+qemuVirtioFSCreateSocketFilename(virDomainObjPtr vm,
+ const char *alias)
+{
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+
+ return virFileBuildPath(priv->libDir, alias, "-virtiofsd.sock");
+}
+
+
+static int
+qemuVirtioFSOpenChardev(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ const char *socket_path)
+{
+ virDomainChrSourceDefPtr chrdev = virDomainChrSourceDefNew(NULL);
+ virDomainChrDef chr = { .source = chrdev };
+ VIR_AUTOCLOSE fd = -1;
+ int ret = -1;
+
+ chrdev->type = VIR_DOMAIN_CHR_TYPE_UNIX;
+ chrdev->data.nix.listen = true;
+ chrdev->data.nix.path = g_strdup(socket_path);
+
+ if (qemuSecuritySetDaemonSocketLabel(driver->securityManager, vm->def) < 0)
+ goto cleanup;
+ fd = qemuOpenChrChardevUNIXSocket(chrdev);
+ if (fd < 0) {
+ ignore_value(qemuSecurityClearSocketLabel(driver->securityManager, vm->def));
+ goto cleanup;
+ }
+ if (qemuSecurityClearSocketLabel(driver->securityManager, vm->def) < 0)
+ goto cleanup;
+
+ if (qemuSecuritySetChardevLabel(driver, vm, &chr) < 0)
+ goto cleanup;
+
+ ret = fd;
+ fd = -1;
+
+ cleanup:
+ virObjectUnref(chrdev);
+ return ret;
+}
+
+static virCommandPtr
+qemuVirtioFSBuildCommandLine(virQEMUDriverConfigPtr cfg,
+ virDomainFSDefPtr fs,
+ int *fd)
+{
+ g_autoptr(virCommand) cmd = NULL;
+ g_auto(virBuffer) opts = VIR_BUFFER_INITIALIZER;
+
+ if (!(cmd = virCommandNew(fs->binary)))
+ return NULL;
+
+ virCommandAddArg(cmd, "--syslog");
+ virCommandAddArgFormat(cmd, "--fd=%d", *fd);
+ virCommandPassFD(cmd, *fd, VIR_COMMAND_PASS_FD_CLOSE_PARENT);
+ *fd = -1;
+
+ virCommandAddArg(cmd, "-o");
+ virBufferAsprintf(&opts, "source=%s,", fs->src->path);
+ if (fs->cache)
+ virBufferAsprintf(&opts, "cache=%s,", virDomainFSCacheModeTypeToString(fs->cache));
+ if (fs->xattr)
+ virBufferAsprintf(&opts, "%sxattr,", fs->xattr == VIR_TRISTATE_SWITCH_OFF ? "no_" : "");
+ if (fs->flock)
+ virBufferAsprintf(&opts, "%sflock,", fs->flock == VIR_TRISTATE_SWITCH_OFF ? "no_" : "");
+ if (fs->posix_lock)
+ virBufferAsprintf(&opts, "%sposix_lock,", fs->posix_lock == VIR_TRISTATE_SWITCH_OFF ? "no_" : "");
+ virBufferTrim(&opts, ",", -1);
+
+ virCommandAddArgBuffer(cmd, &opts);
+ if (cfg->virtiofsDebug)
+ virCommandAddArg(cmd, "-d");
+
+ return g_steal_pointer(&cmd);
+}
+
+int
+qemuVirtioFSStart(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ virDomainFSDefPtr fs)
+{
+ g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
+ g_autoptr(virCommand) cmd = NULL;
+ g_autofree char *socket_path = NULL;
+ g_autofree char *pidfile = NULL;
+ char errbuf[1024] = { 0 };
+ pid_t pid = (pid_t) -1;
+ VIR_AUTOCLOSE errfd = -1;
+ VIR_AUTOCLOSE fd = -1;
+ int exitstatus = 0;
+ int cmdret = 0;
+ int ret = -1;
+ int rc;
+
+ if (!(pidfile = qemuVirtioFSCreatePidFilename(cfg, vm->def, fs->info.alias)))
+ goto cleanup;
+
+ if (!(socket_path = qemuVirtioFSCreateSocketFilename(vm, fs->info.alias)))
+ goto cleanup;
+
+ if ((fd = qemuVirtioFSOpenChardev(driver, vm, socket_path)) < 0)
+ goto cleanup;
+
+ if (!(cmd = qemuVirtioFSBuildCommandLine(cfg, fs, &fd)))
+ goto cleanup;
+
+ virCommandSetPidFile(cmd, pidfile);
+ virCommandSetErrorFD(cmd, &errfd);
+ virCommandDaemonize(cmd);
+
+ if (qemuExtDeviceLogCommand(driver, vm, cmd, "virtiofsd") < 0)
+ goto cleanup;
+
+ cmdret = virCommandRun(cmd, &exitstatus);
+
+ if (cmdret < 0 || exitstatus != 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Could not start 'virtiofsd'. exitstatus: %d"), exitstatus);
+ goto error;
+ }
+
+ rc = virPidFileReadPath(pidfile, &pid);
+ if (rc < 0) {
+ virReportSystemError(-rc,
+ _("Unable to read virtiofsd pidfile '%s'"),
+ pidfile);
+ goto error;
+ }
+
+ if (virProcessKill(pid, 0) != 0) {
+ if (saferead(errfd, errbuf, sizeof(errbuf) - 1) < 0) {
+ virReportSystemError(errno, "%s",
+ _("virtiofsd died unexpectedly"));
+ } else {
+ virReportError(VIR_ERR_OPERATION_FAILED,
+ _("virtiofsd died and reported: %s"), errbuf);
+ }
+ goto error;
+ }
+
+ QEMU_DOMAIN_FS_PRIVATE(fs)->vhostuser_fs_sock = g_steal_pointer(&socket_path);
+ ret = 0;
+
+ cleanup:
+ if (socket_path)
+ unlink(socket_path);
+ return ret;
+
+ error:
+ if (pid != -1)
+ virProcessKillPainfully(pid, true);
+ if (pidfile)
+ unlink(pidfile);
+ goto cleanup;
+}
+
+
+void
+qemuVirtioFSStop(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ virDomainFSDefPtr fs)
+{
+ g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
+ g_autofree char *pidfile = NULL;
+ virErrorPtr orig_err;
+ pid_t pid = -1;
+ int rc;
+
+ virErrorPreserveLast(&orig_err);
+
+ if (!(pidfile = qemuVirtioFSCreatePidFilename(cfg, vm->def, fs->info.alias)))
+ goto cleanup;
+
+ rc = virPidFileReadPathIfAlive(pidfile, &pid, NULL);
+ if (rc >= 0 && pid != (pid_t) -1)
+ virProcessKillPainfully(pid, true);
+
+ if (unlink(pidfile) < 0 &&
+ errno != ENOENT) {
+ virReportSystemError(errno,
+ _("Unable to remove stale pidfile %s"),
+ pidfile);
+ }
+
+ if (QEMU_DOMAIN_FS_PRIVATE(fs)->vhostuser_fs_sock)
+ unlink(QEMU_DOMAIN_FS_PRIVATE(fs)->vhostuser_fs_sock);
+
+ cleanup:
+ virErrorRestore(&orig_err);
+}
diff --git a/src/qemu/qemu_virtiofs.h b/src/qemu/qemu_virtiofs.h
new file mode 100644
index 0000000000..ffaeee0275
--- /dev/null
+++ b/src/qemu/qemu_virtiofs.h
@@ -0,0 +1,37 @@
+/*
+ * qemu_virtiofs.h: virtiofs support
+ *
+ * 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/>.
+ */
+
+#pragma once
+
+
+char *
+qemuVirtioFSCreatePidFilename(virQEMUDriverConfigPtr cfg,
+ const virDomainDef *def,
+ const char *alias);
+char *
+qemuVirtioFSCreateSocketFilename(virDomainObjPtr vm,
+ const char *alias);
+
+int
+qemuVirtioFSStart(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ virDomainFSDefPtr fs);
+void
+qemuVirtioFSStop(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ virDomainFSDefPtr fs);
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index b923590930..5a517a4982 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -496,6 +496,12 @@ testCompareXMLToArgv(const void *data)
}
}
+ for (i = 0; i < vm->def->nfss; i++) {
+ virDomainFSDefPtr fs = vm->def->fss[i];
+ char *s = g_strdup_printf("/tmp/lib/domain--1-guest/fs%zu.vhost-fs.sock", i);
+ QEMU_DOMAIN_FS_PRIVATE(fs)->vhostuser_fs_sock = s;
+ }
+
if (vm->def->vsock) {
virDomainVsockDefPtr vsock = vm->def->vsock;
qemuDomainVsockPrivatePtr vsockPriv =
--
2.21.0
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