The current implementation fails to load on a system with
libbpf 1.0 and reports that legacy map definitions in 'maps'
section are not supported by libbpf v1.0+. This commit updates
the Makefile to add BTF (-g flag) and appropriately updates
the maps in rss.bpf.c and update the skeleton file in repo.

Signed-off-by: Shreesh Adiga <16567adigashreesh@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

Now remove all the source.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

Remove all the virtiofsd build and docs infrastructure.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20221219130205.687815-4-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Tweak the semantic patch to drop redundant parenthesis around the
return expression.

Coccinelle drops a comment in hw/rdma/vmw/pvrdma_cmd.c; restored
manually.

Coccinelle messes up vmdk_co_create(), not sure why.  Change dropped,
will be done manually in the next commit.

Line breaks in target/avr/cpu.h and hw/rdma/vmw/pvrdma_cmd.c tidied up
manually.

Whitespace in tools/virtiofsd/fuse_lowlevel.c tidied up manually.

checkpatch.pl complains "return of an errno should typically be -ve"
two times for hw/9pfs/9p-synth.c.  Preexisting, the patch merely makes
it visible to checkpatch.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221122134917.1217307-2-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

The virtiofsd currently crashes on s390x. This is because of a
`sigreturn` system call. See audit log below:

type=SECCOMP msg=audit(1669382477.611:459): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=system_u:system_r:virtd_t:s0-s0:c0.c1023 pid=6649 comm="virtiofsd" exe="/usr/libexec/virtiofsd" sig=31 arch=80000016 syscall=119 compat=0 ip=0x3fff15f748a code=0x80000000AUID="unset" UID="root" GID="root" ARCH=s390x SYSCALL=sigreturn

Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: German Maglione <gmaglione@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221125143946.27717-1-mhartmay@linux.ibm.com>

The "%f" specifier in g_date_time_format() is only available in glib
2.65.2 or later. If combined with older glib, the function returns null
and the timestamp displayed as "(null)".

For backward compatibility, g_date_time_get_microsecond should be used
to retrieve subsecond.

In this patch the g_date_time_format() leaves subsecond field as "%06d"
and let next snprintf to format with g_date_time_get_microsecond.

Signed-off-by: Yusuke Okada <okada.yusuke@jp.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 20220818184618.2205172-1-yokada.996@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Message-Id: <20220804074833.892604-1-sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

We are having bunch of issues with killpriv_v2 enabled by default. First
of all it relies on clearing suid/sgid bits as needed by dropping
capability CAP_FSETID. This does not work for remote filesystems like
NFS (and possibly others).

Secondly, we are noticing other issues related to clearing of SGID
which leads to failures for xfstests generic/355 and generic/193.

Thirdly, there are other issues w.r.t caching of metadata (suid/sgid)
bits in fuse client with killpriv_v2 enabled. Guest can cache that
data for sometime even if cleared on server.

Second and Third issue are fixable. Just that it might take a little
while to get it fixed in kernel. First one will probably not see
any movement for a long time.

Given these issues, killpriv_v2 does not seem to be a good candidate
for enabling by default. We have already disabled it by default in
rust version of virtiofsd.

Hence this patch disabled killpriv_v2 by default. User can choose to
enable it by passing option "-o killpriv_v2".

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <YuPd0itNIAz4tQRt@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220707163720.1421716-5-berrange@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>

Inspired by Julia Lawall's fixing of Linux
kernel comments, I looked at qemu, although I did it manually.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Message-Id: <20220614104045.85728-2-dgilbert@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

Header guard symbols should match their file name to make guard
collisions less likely.

Cleaned up with scripts/clean-header-guards.pl, followed by some
renaming of new guard symbols picked by the script to better ones.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20220506134911.2856099-2-armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[Change to generated file ebpf/rss.bpf.skeleton.h backed out]

When using Meson options rather than config-host.h, the "when" clauses
have to be changed to if statements (which is not necessarily great,
though at least it highlights which parts of the build are per-target
and which are not).

Do that before moving vhost logic to meson.build, though for now
the variables are just based on config-host.mak data.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

Simplify the function to only return the directory path. Callers are
adjusted to use the GLib function to build paths, g_build_filename().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220420132624.2439741-39-marcandre.lureau@redhat.com>

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20220420132624.2439741-7-marcandre.lureau@redhat.com>

virtiofsd has introduced killpriv_v2/no_killpriv_v2 for a while. Add
description of it to docs/helper.

Signed-off-by: Liu Yiding <liuyd.fnst@fujitsu.com>
Message-Id: <20220421095151.2231099-1-liuyd.fnst@fujitsu.com>

[Small documentation fixes: s/as client supports/as the client supports/
and s/.  /. /.
--Stefan]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

In virtiofsd, we assume that the presence of the STATX_MNT_ID macro
implies existence of the statx.stx_mnt_id field.  Unfortunately, that is
not necessarily the case: glibc has introduced the macro in its commit
88a2cf6c4bab6e94a65e9c0db8813709372e9180, but the statx.stx_mnt_id field
is still missing from its own headers.

Let meson.build actually chek for both STATX_MNT_ID and
statx.stx_mnt_id, and set CONFIG_STATX_MNT_ID if both are present.
Then, use this config macro in virtiofsd.

Closes: https://gitlab.com/qemu-project/qemu/-/issues/882


Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220223092340.9043-1-hreitz@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Honor the expected behavior of syncfs() to synchronously flush all data
and metadata to disk on linux systems.

If virtiofsd is started with '-o announce_submounts', the client is
expected to send a FUSE_SYNCFS request for each individual submount.
In this case, we just create a new file descriptor on the submount
inode with lo_inode_open(), call syncfs() on it and close it. The
intermediary file is needed because O_PATH descriptors aren't
backed by an actual file and syncfs() would fail with EBADF.

If virtiofsd is started without '-o announce_submounts' or if the
client doesn't have the FUSE_CAP_SUBMOUNTS capability, the client
only sends a single FUSE_SYNCFS request for the root inode. The
server would thus need to track submounts internally and call
syncfs() on each of them. This will be implemented later.

Note that syncfs() might suffer from a time penalty if the submounts
are being hammered by some unrelated workload on the host. The only
solution to prevent that is to avoid shared mounts.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20220215181529.164070-2-groug@kaod.org>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Provide an option "-o security_label/no_security_label" to enable/disable
security label functionality. By default these are turned off.

If enabled, server will indicate to client that it is capable of handling
one security label during file creation. Typically this is expected to
be a SELinux label. File server will set this label on the file. It will
try to set it atomically wherever possible. But its not possible in
all the cases.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20220208204813.682906-11-vgoyal@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

If guest and host policies can't work with each other, then guest security
context (selinux label) needs to be set into an xattr. Say remap guest
security.selinux xattr to trusted.virtiofs.security.selinux.

That means setting "fscreate" is not going to help as that's ony useful
for security.selinux xattr on host.

So we need another method which is atomic. Use O_TMPFILE to create new
file, set xattr and then linkat() to proper place.

But this works only for regular files. So dir, symlinks will continue
to be non-atomic.

Also if host filesystem does not support O_TMPFILE, we fallback to
non-atomic behavior.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20220208204813.682906-10-vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

This patch adds support for creating new file with security context
as sent by client. It basically takes three paths.

- If no security context enabled, then it continues to create files without
  security context.

- If security context is enabled and but security.selinux has not been
  remapped, then it uses /proc/thread-self/attr/fscreate knob to set
  security context and then create the file. This will make sure that
  newly created file gets the security context as set in "fscreate" and
  this is atomic w.r.t file creation.

  This is useful and host and guest SELinux policies don't conflict and
  can work with each other. In that case, guest security.selinux xattr
  is not remapped and it is passthrough as "security.selinux" xattr
  on host.

- If security context is enabled but security.selinux xattr has been
  remapped to something else, then it first creates the file and then
  uses setxattr() to set the remapped xattr with the security context.
  This is a non-atomic operation w.r.t file creation.

  This mode will be most versatile and allow host and guest to have their
  own separate SELinux xattrs and have their own separate SELinux policies.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20220208204813.682906-9-vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Soon we will be able to create and also set security context on the file
atomically using /proc/self/task/tid/attr/fscreate knob. If this knob
is available on the system, first set the knob with the desired context
and then create the file. It will be created with the context set in
fscreate. This works basically for SELinux and its per thread.

This patch just introduces the helper functions. Subsequent patches will
make use of these helpers.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20220208204813.682906-8-vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert: Manually merged gettid syscall number fixup from Vivek

Move core file creation bits in a separate function. Soon this is going
to get more complex as file creation need to set security context also.
And there will be multiple modes of file creation in next patch.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20220208204813.682906-7-vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Add capability to enable and parse security context as sent by client
and put into fuse_req. Filesystems now can get security context from
request and set it on files during creation.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20220208204813.682906-6-vgoyal@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

->capable keeps track of what capabilities kernel supports and ->wants keep
track of what capabilities filesytem wants.

Right now these fields are 32bit in size. But now fuse has run out of
bits and capabilities can now have bit number which are higher than 31.

That means 32 bit fields are not suffcient anymore. Increase size to 64
bit so that we can add newer capabilities and still be able to use existing
code to check and set the capabilities.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20220208204813.682906-5-vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Add some code to parse extended "struct fuse_init_in". And use a local
variable "flag" to represent 64 bit flags. This will make it easier
to add more features without having to worry about two 32bit flags (->flags
and ->flags2) in "fuse_struct_in".

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20220208204813.682906-4-vgoyal@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert: Fixed up long line

Kernel version 5.17 has increased the size of "struct fuse_init_in" struct.
Previously this struct was 16 bytes and now it has been extended to
64 bytes in size.

Once qemu headers are updated to latest, it will expect to receive 64 byte
size struct (for protocol version major 7 and minor > 6). But if guest is
booting older kernel (older than 5.17), then it still sends older
fuse_init_in of size 16 bytes. And do_init() fails. It is expecting
64 byte struct. And this results in mount of virtiofs failing.

Fix this by parsing 16 bytes only for now. Separate patches will be
posted which will parse rest of the bytes and enable new functionality.
Right now we don't support any of the new functionality, so we don't
lose anything by not parsing bytes beyond 16.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20220208204813.682906-2-vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

With the current implementation, blocking flock can lead to
deadlock. Thus, it's better to return EOPNOTSUPP if a user attempts
to perform a blocking flock request.

Signed-off-by: Sebastian Hasler <sebastian.hasler@stuvus.uni-stuttgart.de>
Message-Id: <20220113153249.710216-1-sebastian.hasler@stuvus.uni-stuttgart.de>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>

The method is now in 0.59, using it simplifies some conditionals.

There is a small change, which is to build virtfs-proxy-helper in a
tools-only build.  This is done for consistency with other tools,
which are not culled by the absence of system emulator binaries.

.disable_auto_if() would also be useful to check for packages,
for example

-linux_io_uring = not_found
-if not get_option('linux_io_uring').auto() or have_block
-  linux_io_uring = dependency('liburing', required: get_option('linux_io_uring'),
-                              method: 'pkg-config', kwargs: static_kwargs)
-endif
+linux_io_uring = dependency('liburing',
+  required: get_option('linux_io_uring').disable_auto_if(not have_block),
+  method: 'pkg-config', kwargs: static_kwargs)

This change however is much larger and I am not sure about the improved
readability, so I am not performing it right now.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The virtiofsd currently crashes when used with glibc 2.35.
That is due to the rseq system call being added to every thread
creation [1][2].

[1]: https://www.efficios.com/blog/2019/02/08/linux-restartable-sequences/
[2]: https://sourceware.org/pipermail/libc-alpha/2022-February/136040.html



This happens not at daemon start, but when a guest connects

    /usr/lib/qemu/virtiofsd -f --socket-path=/tmp/testvfsd -o sandbox=chroot \
        -o source=/var/guests/j-virtiofs --socket-group=kvm
    virtio_session_mount: Waiting for vhost-user socket connection...
    # start ok, now guest will connect
    virtio_session_mount: Received vhost-user socket connection
    virtio_loop: Entry
    fv_queue_set_started: qidx=0 started=1
    fv_queue_set_started: qidx=1 started=1
    Bad system call (core dumped)

We have to put rseq on the seccomp allowlist to avoid that the daemon
is crashing in this case.

Reported-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 20220209111456.3328420-1-christian.ehrhardt@canonical.com

[Moved rseq to its alphabetically ordered position in the seccomp
allowlist.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

At the start, drop membership of all supplementary groups. This is
not required.

If we have membership of "root" supplementary group and when we switch
uid/gid using setresuid/setsgid, we still retain membership of existing
supplemntary groups. And that can allow some operations which are not
normally allowed.

For example, if root in guest creates a dir as follows.

$ mkdir -m 03777 test_dir

This sets SGID on dir as well as allows unprivileged users to write into
this dir.

And now as unprivileged user open file as follows.

$ su test
$ fd = open("test_dir/priviledge_id", O_RDWR|O_CREAT|O_EXCL, 02755);

This will create SGID set executable in test_dir/.

And that's a problem because now an unpriviliged user can execute it,
get egid=0 and get access to resources owned by "root" group. This is
privilege escalation.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2044863


Fixes: CVE-2022-0358
Reported-by: JIETAO XIAO <shawtao1125@gmail.com>
Suggested-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <YfBGoriS38eBQrAb@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert: Fixed missing {}'s style nit

Make the '--socket-group=' option fail if the group name is unknown:

./tools/virtiofsd/virtiofsd .... --socket-group=zaphod
vhost socket: unable to find group 'zaphod'

Reported-by: Xiaoling Gao <xiagao@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20211014122554.34599-1-dgilbert@redhat.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Use a helper to stop all the queues. Later in the patch series I am
planning to use this helper at one more place later in the patch series.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20210930153037.1194279-6-vgoyal@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

We have open coded logic to take locks and push element on virtqueue at
three places. Add a helper and use it everywhere. Code is easier to read and
less number of lines of code.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20210930153037.1194279-5-vgoyal@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

"struct virtio_fs_config" definition seems to be unused in fuse_virtio.c.
Remove it.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20210930153037.1194279-4-vgoyal@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Right now for xattr remapping, we support types of "prefix", "ok" or "bad".
Type "bad" returns -EPERM on setxattr and hides xattr in listxattr. For
getxattr, mapping code returns -EPERM but getxattr code converts it to -ENODATA.

I need a new semantics where if an xattr is unsupported, then
getxattr()/setxattr() return -ENOTSUP and listxattr() should hide the xattr.
This is needed to simulate that security.selinux is not supported by
virtiofs filesystem and in that case client falls back to some default
label specified by policy.

So add a new type "unsupported" which returns -ENOTSUP on getxattr() and
setxattr() and hides xattrs in listxattr().

For example, one can use following mapping rule to not support
security.selinux xattr and allow others.

"-o xattrmap=/unsupported/all/security.selinux/security.selinux//ok/all///"

Suggested-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <YUt9qbmgAfCFfg5t@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

With the thread pool disabled, we add the requests in the queue to a
GList, processing by iterating over there afterwards.

For adding them, we're using "g_list_prepend()", which is more
efficient but causes the requests to be processed in reverse order,
breaking the read-ahead and request-merging optimizations in the host
for sequential operations.

According to the documentation, if you need to process the request
in-order, using "g_list_prepend()" and then reversing the list with
"g_list_reverse()" is more efficient than using "g_list_append()", so
let's do it that way.

Testing on a spinning disk (to boost the increase of read-ahead and
request-merging) shows a 4x improvement on sequential write fio test:

Test:
fio --directory=/mnt/virtio-fs --filename=fio-file1 --runtime=20
--iodepth=16 --size=4G --direct=1 --blocksize=4K --ioengine libaio
--rw write --name seqwrite-libaio

Without "g_list_reverse()":
...
Jobs: 1 (f=1): [W(1)][100.0%][w=22.4MiB/s][w=5735 IOPS][eta 00m:00s]
seqwrite-libaio: (groupid=0, jobs=1): err= 0: pid=710: Tue Aug 24 12:58:16 2021
  write: IOPS=5709, BW=22.3MiB/s (23.4MB/s)(446MiB/20002msec); 0 zone resets
...

With "g_list_reverse()":
...
Jobs: 1 (f=1): [W(1)][100.0%][w=84.0MiB/s][w=21.5k IOPS][eta 00m:00s]
seqwrite-libaio: (groupid=0, jobs=1): err= 0: pid=716: Tue Aug 24 13:00:15 2021
  write: IOPS=21.3k, BW=83.1MiB/s (87.2MB/s)(1663MiB/20001msec); 0 zone resets
...

Signed-off-by: Sergio Lopez <slp@redhat.com>
Message-Id: <20210824131158.39970-1-slp@redhat.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

The virtiofsd currently crashes on s390x when doing something like
this in the guest:

 mkdir -p /mnt/myfs
 mount -t virtiofs myfs /mnt/myfs
 touch /mnt/myfs/foo.txt
 stat -f /mnt/myfs/foo.txt

The problem is that the fstatfs64 syscall is called in this case
from the virtiofsd. We have to put it on the seccomp allowlist to
avoid that the daemon gets killed in this case.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2001728


Suggested-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210914123214.181885-1-thuth@redhat.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Signed-off-By: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <fefb5f5c-82bc-05e2-b4c1-665e9d6896ff@msgid.tls.msk.ru>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>