Since the insns here and in particular their memory access patterns
follow the usual scheme, I didn't think it was necessary to add a
contrived test specifically for them.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Since the insns here and in particular their memory access patterns
follow the usual scheme, I didn't think it was necessary to add a
contrived test specifically for them.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Since the insns here don't access memory, I didn't think it was
necessary to extend our SHA test for them.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
These are close relatives of the AVX-VNNI and AVX-VNNI-INT8 ISA
extensions. Since the insns here and in particular their memory access
patterns follow the usual scheme (and especially the word variants of
AVX-VNNI), I didn't think it was necessary to add a contrived test
specifically for them.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Instead of defining get_unaligned() and put_unaligned() in a way that
is only supporting architectures allowing unaligned accesses, use the
same approach as the Linux kernel and let the compiler do the
decision how to generate the code for probably unaligned data accesses.
Update include/xen/unaligned.h from include/asm-generic/unaligned.h of
the Linux kernel.
The generated code has been checked to be the same on x86.
Modify the Linux variant to not use underscore prefixed identifiers,
avoid unneeded parentheses and drop the 24-bit accessors.
Add the definition of __packed to xg_dom_decompress_unsafe_zstd.c in
libxenguest as it is using a cruel hack to reuse the hypervisor's
decompressing code for stubdom.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 803f4e1eab7a
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
The procedure used to customize the domain CPU policy is broken when
toolstack tries to set leaves (with subleaves) that the hypervisor didn't
need to serialise (i.e: because they where empty subleaves).
During typical domain creation xg does the following:
1. Probe Xen for max #leaves that a policy may have
2. Allocate memory for that many leaves
3. Tell the hypervisor to dump the policy in the allocated buffer
4. Deserialise it
5. Modify it
6. Reserialise it
7. Send it back to Xen
The problem is that (3) overrides nr_leaves, which then makes (6) fail in
the case where (5) has added subleaves that Xen understands but didn't need
to serialize on (3).
The fix uses an opaque CPU policy object so we can (a) avoid probing Xen
for sizes, and (b) trivially have knowledge of the actual size of the
buffer.
While at it, fix xc_cpu_policy_destroy() to preserve errno accross free()
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
This was deprecated in commit 10c88f1c18 ("tools: Install pv bootloaders in
libexec rather than /usr/bin") and caused to warn in commit c31d6a7ee2
("libxl: Warn that /usr/bin/pygrub is deprecated"), both in 2012.
New versions of RPM warn against absolute symlinks, so take out fully, 11
years later.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
When adding locking to tools/libs/evtchn/minios.c a semaphore was
used. This can result in deadlocks, as the lock is taken inside the
event handler, which can interrupt an already locked region.
The fix is rather simple, as Mini-OS is supporting a single vcpu
only. So instead of the semaphore it is enough to disable interrupts
when operating on the port list.
Fixes: bc4fe94a69 ("ools/libs/evtchn: replace assert()s in stubdom with proper locking")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Today write_messages() will call trace_io() after having written the
complete message to the ring buffer or socket.
In case the message can't be written in one go, split it by writing
one trace entry when starting the write and one when finishing it.
In order to distinguish a complete OUT message from a split one, let the
caller of trace_io specify the prefix string ("IN", "OUT", "OUT(START)",
"OUT(END)") directly instead via an int.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
In tools/libs/evtchn/minios.c there are assert()s for the current
thread being the main thread when binding an event channel.
As Mini-OS is supporting multiple threads, there is no real reason
why the binding shouldn't be allowed to happen in any other thread.
Drop the assert()s and replace them with proper locking of the
port_list.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
The "-R" (no recovery) command line option enables to omit fixing the
node store in case of detected inconsistencies.
This might have been of interest in the past, when the node data base
was kept in a file, but now the usability of this option is zero.
Remove the "-R" option.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The "-P" command line option just results in printing the PID of the
xenstored daemon to stdout before stdout is being closed. The same
information can be retrieved from the PID file via the "-F" option.
Remove the redundant "-P" option.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The "-V" (verbose) command line option is nearly completely redundant
with "io" tracing. Just the time of the printed data is a little bit
different, while the tracing is more informative.
Remove the verbose option.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Remove the "-D" command parameter, which is disabling initialization of
the mandatory domain data handling.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Right now, all tools and hypervisor will be complied with the option
-Wdeclaration-after-statement. While most of the code in the hypervisor
is controlled by us, for tools we may import external libraries.
The build will fail if one of them are using the construct we are
trying to prevent. This is the case when building against Python 3.12
and Yocto:
| In file included from /srv/storage/alex/yocto/build-virt/tmp/work/core2-64-poky-linux/xen-tools/4.17+stable/recipe-sysroot/usr/include/python3.12/Python.h:44,
| from xen/lowlevel/xc/xc.c:8:
| /srv/storage/alex/yocto/build-virt/tmp/work/core2-64-poky-linux/xen-tools/4.17+stable/recipe-sysroot/usr/include/python3.12/object.h: In function 'Py_SIZE':
| /srv/storage/alex/yocto/build-virt/tmp/work/core2-64-poky-linux/xen-tools/4.17+stable/recipe-sysroot/usr/include/python3.12/object.h:233:5: error: ISO C90 forbids mixed declarations and code [-Werror=declaration-after-statement]
| 233 | PyVarObject *var_ob = _PyVarObject_CAST(ob);
| | ^~~~~~~~~~~
| In file included from /srv/storage/alex/yocto/build-virt/tmp/work/core2-64-poky-linux/xen-tools/4.17+stable/recipe-sysroot/usr/include/python3.12/Python.h:53:
| /srv/storage/alex/yocto/build-virt/tmp/work/core2-64-poky-linux/xen-tools/4.17+stable/recipe-sysroot/usr/include/python3.12/cpython/longintrepr.h: In function '_PyLong_CompactValue':
| /srv/storage/alex/yocto/build-virt/tmp/work/core2-64-poky-linux/xen-tools/4.17+stable/recipe-sysroot/usr/include/python3.12/cpython/longintrepr.h:121:5: error: ISO C90 forbids mixed declarations and code [-Werror=declaration-after-statement]
| 121 | Py_ssize_t sign = 1 - (op->long_value.lv_tag & _PyLong_SIGN_MASK);
| | ^~~~~~~~~~
| cc1: all warnings being treated as errors
Looking at the tools directory, a fair few directory already add
-Wno-declaration-after-statement to inhibit the default behavior.
We have always build the hypervisor with the flag, so for now remove
only the flag for anything but the hypervisor. We can decide at later
time whether we want to relax.
Also remove the -Wno-declaration-after-statement in some subdirectory
as the flag is now unnecessary.
Part of the commit message was take from Alexander's first proposal:
Link: https://lore.kernel.org/xen-devel/20231128174729.3880113-1-alex@linutronix.de/
Reported-by: Alexander Kanavin <alex@linutronix.de>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Julien Grall <jgrall@amazon.com>
Introduce a handler for the PCI status register, with ability to mask
the capabilities bit. The status register contains RsvdZ bits,
read-only bits, and write-1-to-clear bits. Additionally, we use RsvdP to
mask the capabilities bit. Introduce bitmasks to handle these in vPCI.
If a bit in the bitmask is set, then the special meaning applies:
ro_mask: read normal, guest write ignore (preserve on write to hardware)
rw1c_mask: read normal, write 1 to clear
rsvdp_mask: read as zero, guest write ignore (preserve on write to hardware)
rsvdz_mask: read as zero, guest write ignore (write zero to hardware)
The RO/RW1C/RsvdP/RsvdZ naming and definitions were borrowed from the
PCI Express Base 6.1 specification. RsvdP/RsvdZ bits help Xen enforce
our view of the world. Xen preserves the value of read-only bits on
write to hardware, discarding the guests write value. This is done in
case hardware wrongly implements R/O bits as R/W.
The mask_cap_list flag will be set in a follow-on change.
Signed-off-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
They allocate two different hypercall buffers, but leak the first
allocation if the second one failed due to an early return that bypasses
cleanup.
Remove the early exit and go through _post() instead. Invoking _post() is
benign even if _pre() failed.
Fixes: 6b85e42709 ('x86/sysctl: Implement XEN_SYSCTL_get_cpu_policy')
Fixes: 60529dfeca ('x86/domctl: Implement XEN_DOMCTL_get_cpu_policy')
Fixes: 14ba07e6f8 ('x86/domctl: Implement XEN_DOMCTL_set_cpumsr_policy')
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Everywhere else the VL tests are grouped with the basic ones,
distinguished simply by the "form" specifiers.
No change to the generated test blobs, and hence no functional change.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
The env variable must be interpreted as an integer. As it is, the override
logic simply causes an exception.
Fixes: e0342ae555 ("tools/pygrub: Deprivilege pygrub")
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
This is important in order for every mount done inside a mount namespace to
go away after the namespace itself goes away. The comment referring to
unreliability in Linux 4.19 was just wrong.
This patch sets the story straight and makes the depriv pygrub a bit more
confined should a layer of the onion be vulnerable.
Fixes: e0342ae555 ("tools/pygrub: Deprivilege pygrub")
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Add a local .gitignore file for tools/python.
As at least on some systems (e.g. OpenSUSE Leap 15.5) the build will
produce a tools/python/xen.egg-info directory, add it to the new
.gitignore file, too.
Use "/dir/" as pattern for ignoring a directory and its contents, as
the "/dir/*" pattern won't ignore the directory itself (git just
doesn't complain when seeing a directory without any not ignored file
in it).
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Add a local .gitignore file for tools/pygrub.
As at least on some systems (e.g. OpenSUSE Leap 15.5) the build will
produce a tools/pygrub/pygrub.egg-info directory, add it to the new
.gitignore file, too.
Use "/dir/" as pattern for ignoring a directory and its contents, as
the "/dir/*" pattern won't ignore the directory itself (git just
doesn't complain when seeing a directory without any not ignored file
in it).
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
There's nothing else that should need doing in order for guests to be
able to use these insns, as the encodings are in what's otherwise NOP
space.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Previous change to xenstored used "%d" to format conn->id while in fact
conn->id has "unsigned int" type, so "%u" should be used.
Fixes: 97f8555acb ("xenstored: print domain id in traces")
Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
It is very helpful to see domain id why analyzing xenstored
traces. Especially when you are trying to understand which exactly
domain performs an action.
Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
[jgrall: Use %u rather than %d]
Signed-off-by: Julien Grall <jgrall@amazon.com>
These macros were hiding that the ops are not zero-initialized by the
toolstack. This is needlessly opaque for something so simple, so this patch
removes them and replaces them with explicit zero-initialising versions.
The patch also removes PHYSDEV_OP from there, as that seems to be an old
dead macro.
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
The new bootloader_restrict and bootloader_user fields in the libxl idl
change the bindings. Update them.
Fixes: 1f762642d2 ("libxl: add support for running bootloader in restricted mode")
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: George Dunlap <george.dunlap@cloud.com>
The new FF-A TEE type changed the go bindings. Update them.
Fixes: 8abdd8d528 ("tools: add Arm FF-A mediator")
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: George Dunlap <george.dunlap@cloud.com>
Commit fc2b57c9a ("xenstored: send an evtchn notification on
introduce_domain") introduced the sending of an event channel to the
guest when first introduced, so that dom0less domains waiting for the
connection would know that xenstore was ready to use.
Unfortunately, it was introduced in introduce_domain(), which 1) is
called by other functions, where such functionality is unneeded, and
2) after the main XS_INTRODUCE call, calls domain_conn_reset(). This
introduces a race condition, whereby if xenstored is delayed, a domain
can wake up, send messages to the buffer, only to have them deleted by
xenstore before finishing its processing of the XS_INTRODUCE message.
Move the connect-and-notfy call into do_introduce() instead, after the
domain_conn_rest(); predicated on the state being in the
XENSTORE_RECONNECT state.
(We don't need to check for "restoring", since that value is always
passed as "false" from do_domain_introduce()).
Also take the opportunity to add a missing wmb barrier after resetting
the indexes of the ring in domain_conn_reset.
This change will also remove an extra event channel notification for
dom0 (because the notification is now done by do_introduce which is not
called for dom0.) The extra dom0 event channel notification was only
introduced by fc2b57c9a and was never present before. It is not needed
because dom0 is the one to tell xenstored the connection parameters, so
dom0 has to know that the ring page is setup correctly by the time
xenstored starts looking at it. It is dom0 that performs the ring page
init.
Signed-off-by: George Dunlap <george.dunlap@cloud.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
CC: jgross@suse.com
CC: julien@xen.org
CC: wl@xen.org
We warn when we see data for a vcpu moving into a non-RUNNING state,
just so that people know why we're ignoring it. On full traces, this
happens only once. However, if the trace was limited to a subset of
pcpus, then this will happen every time the domain in question is
woken on that pcpu.
Add a 'delayed_init' flag to the vcpu struct to indicate when a vcpu
has experienced a delayed init. Print a warning message once when
entering the state, and once when leaving it.
Signed-off-by: George Dunlap <george.dunlap@cloud.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
EIP lists are generalized across several use cases. For many of them,
it make sense to have a cycle per sample; but not really for interrupt
EIP lists. For this reason, it normally just passes 0 as for the tsc
value, which will in turn down at the bottom of update_cycles(),
update only the summary.event_count, but nothing else.
The dump_eip() function attempted to handle this by calling the generic
cycle print handler if the summary contained *any* cycles, and by collecting
and printing its own stats, based solely on counts, if not.
Unfortunately, it used the wrong element for this: it collected the
total from samples.count rather samples.event_count; in the case that
there are no cycles, this will always be zero. It then divided by
this zero value. This results in output that looked like this:
```
ffff89d29656 : 0 -nan%
ffff89d298b6 : 0 -nan%
ffff89d298c0 : 0 -nan%
```
It's better than nothing, but a lot less informative than one would
like.
Use event_count rather than count for collecting the total, and the
reporting when there are no cycles in the summary information. This results
in output that looks like this:
```
ffff89d29656 : 2 1.21%
ffff89d298b6 : 1 0.61%
ffff89d298c0 : 1 0.61%
```
Signed-off-by: George Dunlap <george.dunlap@cloud.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
If a vmentry/exit arc unexpectedly doesn't have a handler, we throw an
error, and then log the information under HVM event 0; thus those
particular traces within the vmexit reason will have stats gathered,
and will show up with "(no handler)". This is useful in the event
that there are unusual paths through the hypervisor which don't have
trace points.
However, if there are more than one of these, then although we detect and warn
that this is happening, we subsequently continue to stuff data about all exits
into that one exit, even though we only show it in one place.
Instead, refator things to only allow a single exit reason to be
accumulated into any given event.
Also put a comment explaining what's going on, and how to fix it.
Signed-off-by: George Dunlap <george.dunlap@cloud.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Introduce a timeout for bootloader execution when running in restricted mode.
Allow overwriting the default time out with an environment provided value.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Much like the device model depriv mode, add the same kind of support for the
bootloader. Such feature allows passing a UID as a parameter for the
bootloader to run as, together with the bootloader itself taking the necessary
actions to isolate.
Note that the user to run the bootloader as must have the right permissions to
access the guest disk image (in read mode only), and that the bootloader will
be run in non-interactive mode when restricted.
If enabled bootloader restrict mode will attempt to re-use the user(s) from the
QEMU depriv implementation if no user is provided on the configuration file or
the environment. See docs/features/qemu-deprivilege.pandoc for more
information about how to setup those users.
Bootloader restrict mode is not enabled by default as it requires certain
setup to be done first (setup of the user(s) to use in restrict mode).
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Introduce a --runas=<uid> flag to deprivilege pygrub on Linux and *BSDs. It
also implicitly creates a chroot env where it drops a deprivileged forked
process. The chroot itself is cleaned up at the end.
If the --runas arg is present, then pygrub forks, leaving the child to
deprivilege itself, and waiting for it to complete. When the child exists,
the parent performs cleanup and exits with the same error code.
This is roughly what the child does:
1. Initialize libfsimage (this loads every .so in memory so the chroot
can avoid bind-mounting /{,usr}/lib*
2. Create a temporary empty chroot directory
3. Mount tmpfs in it
4. Bind mount the disk inside, because libfsimage expects a path, not a
file descriptor.
5. Remount the root tmpfs to be stricter (ro,nosuid,nodev)
6. Set RLIMIT_FSIZE to a sensibly high amount (128 MiB)
7. Depriv gid, groups and uid
With this scheme in place, the "output" files are writable (up to
RLIMIT_FSIZE octets) and the exposed filesystem is immutable and contains
the single only file we can't easily get rid of (the disk).
If running on Linux, the child process also unshares mount, IPC, and
network namespaces before dropping its privileges.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
This is work required in order to let pygrub operate in highly deprivileged
chroot mode. This patch adds a function that preloads every plugin, hence
ensuring that a on function exit, every shared library is loaded in memory.
The new "init" function is supposed to be used before depriv, but that's
fine because it's not acting on untrusted data.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
This patch allows pygrub to get ahold of every RW file descriptor it needs
early on. A later patch will clamp the filesystem it can access so it can't
obtain any others.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Small tidy up to ensure output_directory always has a trailing '/' to ease
concatenating paths and that `output` can only be a filename or None.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
There's a hypercall being issued in order to determine whether PV64 is
supported, but since Xen 4.3 that's strictly true so it's not required.
Plus, this way we can avoid mapping the privcmd interface altogether in the
depriv pygrub.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Adds the common tools include folder to the -I compile flags
of libfsimage. This allows us to use:
xen-tools/common-macros.h:BUILD_BUG_ON()
With it, statically assert a sanitized "blocklog - SECTOR_BITS" cannot
underflow.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Sanity-check the XFS superblock for wellformedness at the mount handler.
This forces pygrub to abort parsing a potentially malformed filesystem and
ensures the invariants assumed throughout the rest of the code hold.
Also, derive parameters from previously sanitized parameters where possible
(rather than reading them off the superblock)
The code doesn't try to avoid overflowing the end of the disk, because
that's an unlikely and benign error. Parameters used in calculations of
xfs_daddr_t (like the root inode index) aren't in critical need of being
sanitized.
The sanitization of agblklog is basically checking that no obvious
overflows happen on agblklog, and then ensuring agblocks is contained in
the range (2^(sb_agblklog-1), 2^sb_agblklog].
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
agblklog could plausibly be 32, but that would overflow this shift.
Perform the shift as ULL and cast to u32 at the end instead.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
xfs_info.agnolog (and related code) and XFS_INO_AGBNO_BITS are dead code
that serve no purpose.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>