From d4f90466fc4685b72ae9ca4bae1d022c04f0e2be Mon Sep 17 00:00:00 2001

Message-Id: <d4f90466fc4685b72ae9ca4bae1d022c04f0e2be@dist-git>

From: =?UTF-8?q?J=C3=A1n=20Tomko?= <jtomko@redhat.com>

Date: Wed, 4 Mar 2020 12:42:46 +0100

Subject: [PATCH] qemu: add code for handling virtiofsd

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit

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 a43efa34c7d7b628cbf1ec0fe60043e5c91043ea

Signed-off-by: Ján Tomko <jtomko@redhat.com>

Reviewed-by: Peter Krempa <pkrempa@redhat.com>

Tested-by: Andrea Bolognani <abologna@redhat.com>

(cherry picked from commit f0f986efa8a8e352fbdce7079ec440a4f3c8f522)

Signed-off-by: Ján Tomko <jtomko@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1694166

Message-Id: <78ba169fbe59c5307db462ad78b65b06776d64a6.1583322091.git.jtomko@redhat.com>

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

---

 po/POTFILES.in            |   1 +

 src/qemu/Makefile.inc.am  |   2 +

 src/qemu/qemu_domain.c    |   5 +-

 src/qemu/qemu_domain.h    |   2 +-

 src/qemu/qemu_extdevice.c |  20 ++-

 src/qemu/qemu_virtiofs.c  | 301 ++++++++++++++++++++++++++++++++++++++

 src/qemu/qemu_virtiofs.h  |  37 +++++

 tests/qemuxml2argvtest.c  |  11 ++

 8 files changed, 376 insertions(+), 3 deletions(-)

 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 faf173584e..29984042f4 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

+@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 79d8de2e42..3cbe7ef6e1 100644

--- a/src/qemu/qemu_domain.c

+++ b/src/qemu/qemu_domain.c

@@ -1440,8 +1440,11 @@ qemuDomainFSPrivateNew(void)

 static void

-qemuDomainFSPrivateDispose(void *obj G_GNUC_UNUSED)

+qemuDomainFSPrivateDispose(void *obj)

 {

+    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 c581b3a162..83150e4e6d 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 bb73787b8d..bfa770f45a 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"

@@ -153,7 +155,7 @@ qemuExtDevicesCleanupHost(virQEMUDriverPtr driver,

 int

 qemuExtDevicesStart(virQEMUDriverPtr driver,

                     virDomainObjPtr vm,

-                    virLogManagerPtr logManager G_GNUC_UNUSED,

+                    virLogManagerPtr logManager,

                     bool incomingMigration)

 {

     virDomainDefPtr def = vm->def;

@@ -183,6 +185,15 @@ 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(logManager, driver, vm, fs) < 0)

+                return -1;

+        }

+    }

+

     return 0;

 }

@@ -214,6 +225,13 @@ 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..09ab2cef27

--- /dev/null

+++ b/src/qemu/qemu_virtiofs.c

@@ -0,0 +1,301 @@

+/*

+ * 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 <sys/types.h>

+#include <sys/stat.h>

+#include <fcntl.h>

+

+#include "logging/log_manager.h"

+#include "virlog.h"

+#include "qemu_command.h"

+#include "qemu_conf.h"

+#include "qemu_extdevice.h"

+#include "qemu_security.h"

+#include "qemu_virtiofs.h"

+#include "virpidfile.h"

+#include "virqemu.h"

+#include "virutil.h"

+

+#define VIR_FROM_THIS VIR_FROM_QEMU

+

+

+char *

+qemuVirtioFSCreatePidFilename(virDomainObjPtr vm,

+                              const char *alias)

+{

+    qemuDomainObjPrivatePtr priv = vm->privateData;

+    g_autofree char *shortName = NULL;

+    g_autofree char *name = NULL;

+

+    if (!(shortName = virDomainDefGetShortName(vm->def)))

+        return NULL;

+

+    name = g_strdup_printf("%s-%s-virtiofsd", shortName, alias);

+

+    return virPidFileBuildPath(priv->libDir, name);

+}

+

+

+char *

+qemuVirtioFSCreateSocketFilename(virDomainObjPtr vm,

+                                 const char *alias)

+{

+    qemuDomainObjPrivatePtr priv = vm->privateData;

+

+    return virFileBuildPath(priv->libDir, alias, "-virtiofsd.sock");

+}

+

+

+static char *

+qemuVirtioFSCreateLogFilename(virQEMUDriverConfigPtr cfg,

+                              const virDomainDef *def,

+                              const char *alias)

+{

+    g_autofree char *name = NULL;

+

+    name = g_strdup_printf("%s-%s", def->name, alias);

+

+    return virFileBuildPath(cfg->logDir, name, "-virtiofsd.log");

+}

+

+

+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;

+

+    virCommandAddArgFormat(cmd, "--fd=%d", *fd);

+    virCommandPassFD(cmd, *fd, VIR_COMMAND_PASS_FD_CLOSE_PARENT);

+    *fd = -1;

+

+    virCommandAddArg(cmd, "-o");

+    virBufferAddLit(&opts, "source=");

+    virQEMUBuildBufferEscapeComma(&opts, fs->src->path);

+    if (fs->cache)

+        virBufferAsprintf(&opts, ",cache=%s", virDomainFSCacheModeTypeToString(fs->cache));

+

+    if (fs->xattr == VIR_TRISTATE_SWITCH_ON)

+        virBufferAddLit(&opts, ",xattr");

+    else if (fs->xattr == VIR_TRISTATE_SWITCH_OFF)

+        virBufferAddLit(&opts, ",no_xattr");

+

+    if (fs->flock == VIR_TRISTATE_SWITCH_ON)

+        virBufferAddLit(&opts, ",flock");

+    else if (fs->flock == VIR_TRISTATE_SWITCH_OFF)

+        virBufferAddLit(&opts, ",no_flock");

+

+    if (fs->posix_lock == VIR_TRISTATE_SWITCH_ON)

+        virBufferAddLit(&opts, ",posix_lock");

+    else if (fs->posix_lock == VIR_TRISTATE_SWITCH_OFF)

+        virBufferAddLit(&opts, ",no_posix_lock");

+

+    virCommandAddArgBuffer(cmd, &opts);

+    if (cfg->virtiofsdDebug)

+        virCommandAddArg(cmd, "-d");

+

+    return g_steal_pointer(&cmd);

+}

+

+int

+qemuVirtioFSStart(virLogManagerPtr logManager,

+                  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;

+    g_autofree char *logpath = NULL;

+    pid_t pid = (pid_t) -1;

+    VIR_AUTOCLOSE fd = -1;

+    VIR_AUTOCLOSE logfd = -1;

+    int ret = -1;

+    int rc;

+

+    if (!virFileExists(fs->src->path)) {

+        virReportError(VIR_ERR_INTERNAL_ERROR,

+                       _("the virtiofs export directory '%s' does not exist"),

+                       fs->src->path);

+        return -1;

+    }

+

+    if (!(pidfile = qemuVirtioFSCreatePidFilename(vm, 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;

+

+    logpath = qemuVirtioFSCreateLogFilename(cfg, vm->def, fs->info.alias);

+

+    if (cfg->stdioLogD) {

+        if ((logfd = virLogManagerDomainOpenLogFile(logManager,

+                                                    "qemu",

+                                                    vm->def->uuid,

+                                                    vm->def->name,

+                                                    logpath,

+                                                    0,

+                                                    NULL, NULL)) < 0)

+            goto cleanup;

+    } else {

+        if ((logfd = open(logpath, O_WRONLY | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR)) < 0) {

+            virReportSystemError(errno, _("failed to create logfile %s"),

+                                 logpath);

+            goto cleanup;

+        }

+        if (virSetCloseExec(logfd) < 0) {

+            virReportSystemError(errno, _("failed to set close-on-exec flag on %s"),

+                                 logpath);

+            goto error;

+        }

+    }

+

+    if (!(cmd = qemuVirtioFSBuildCommandLine(cfg, fs, &fd)))

+        goto cleanup;

+

+    /* so far only running as root is supported */

+    virCommandSetUID(cmd, 0);

+    virCommandSetGID(cmd, 0);

+

+    virCommandSetPidFile(cmd, pidfile);

+    virCommandSetOutputFD(cmd, &logfd);

+    virCommandSetErrorFD(cmd, &logfd);

+    virCommandNonblockingFDs(cmd);

+    virCommandDaemonize(cmd);

+

+    if (qemuExtDeviceLogCommand(driver, vm, cmd, "virtiofsd") < 0)

+        goto cleanup;

+

+    rc = virCommandRun(cmd, NULL);

+

+    if (rc < 0) {

+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",

+                       _("Could not start 'virtiofsd'"));

+        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) {

+        virReportSystemError(errno, "%s",

+                             _("virtiofsd died unexpectedly"));

+        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 G_GNUC_UNUSED,

+                    virDomainObjPtr vm,

+                    virDomainFSDefPtr fs)

+{

+    g_autofree char *pidfile = NULL;

+    virErrorPtr orig_err;

+    pid_t pid = -1;

+    int rc;

+

+    virErrorPreserveLast(&orig_err);

+

+    if (!(pidfile = qemuVirtioFSCreatePidFilename(vm, 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..b2f0c57d0c

--- /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(virDomainObjPtr vm,

+                              const char *alias);

+char *

+qemuVirtioFSCreateSocketFilename(virDomainObjPtr vm,

+                                 const char *alias);

+

+int

+qemuVirtioFSStart(virLogManagerPtr logManager,

+                  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 8215935bab..a391823090 100644

--- a/tests/qemuxml2argvtest.c

+++ b/tests/qemuxml2argvtest.c

@@ -496,6 +496,17 @@ testCompareXMLToArgv(const void *data)

         }

     }

+    for (i = 0; i < vm->def->nfss; i++) {

+        virDomainFSDefPtr fs = vm->def->fss[i];

+        char *s;

+

+        if (fs->fsdriver != VIR_DOMAIN_FS_DRIVER_TYPE_VIRTIOFS)

+            continue;

+

+        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 =

-- 

2.25.1