Commit Graph

25 Commits

Author SHA1 Message Date
Marcel Holtmann
d87a642403 libvhost-user: Declare uffdio_register early to make it C90 compliant
When using libvhost-user source in an external project that wants to
comply with the C90 standard, it is best to declare variables before
code.

  CC       libvhost-user.o
libvhost-user.c: In function ‘generate_faults’:
libvhost-user.c:683:9: error: ISO C90 forbids mixed declarations and code [-Werror=declaration-after-statement]
  683 |         struct uffdio_register reg_struct;
      |         ^~~~~~

In this case, it is also simple enough and doesn't cause any extra
ifdef additions.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <556c2d00c01fa134d13c0371d4014c90694c2943.1671741278.git.marcel@holtmann.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 10:44:34 +01:00
Marcel Holtmann
92bf246130 libvhost-user: Use unsigned int i for some for-loop iterations
The sign-compare warning also hits some of the for-loops, but it easy
fixed by just making the iterator variable unsigned int.

  CC       libvhost-user.o
libvhost-user.c: In function ‘vu_gpa_to_va’:
libvhost-user.c:223:19: error: comparison of integer expressions of different signedness: ‘int’ and ‘uint32_t’ {aka ‘unsigned int’} [-Werror=sign-compare]
  223 |     for (i = 0; i < dev->nregions; i++) {
      |                   ^

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Message-Id: <decb925e1a6fb9538738d2570bda2804f888fa15.1671741278.git.marcel@holtmann.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 10:44:34 +01:00
Marcel Holtmann
18fa7f1e95 libvhost-user: Cast rc variable to avoid compiler warning
The assert from recvmsg() return value against an uint32_t size field
from a protocol struct throws a compiler warning.

  CC       libvhost-user.o
In file included from libvhost-user.c:27:
libvhost-user.c: In function ‘vu_message_read_default’:
libvhost-user.c:363:19: error: comparison of integer expressions of different signedness: ‘int’ and ‘uint32_t’ {aka ‘unsigned int’} [-Werror=sign-compare]
  363 |         assert(rc == vmsg->size);
      |                   ^~

This is not critical, but annoying when the libvhost-user source are
used in an external project that has this compiler warning switched on.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Message-Id: <7a791e27b7bd3e0a8b8cc8fbb15090a870d226d5.1671741278.git.marcel@holtmann.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 10:44:34 +01:00
Marcel Holtmann
aa5d395ac4 libvhost-user: Replace typeof with __typeof__
Strictly speaking only -std=gnu99 support the usage of typeof and for
easier inclusion in external projects, it is better to use __typeof__.

  CC       libvhost-user.o
libvhost-user.c: In function ‘vu_log_queue_fill’:
libvhost-user.c:86:13: error: implicit declaration of function ‘typeof’ [-Werror=implicit-function-declaration]
   86 |             typeof(x) _min1 = (x);              \
      |             ^~~~~~

Changing these two users of typeof makes the compiler happy and no extra
flags or pragmas need to be provided.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <981aa822bcaaa2b8d74f245339a99a85c25b346f.1671741278.git.marcel@holtmann.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 10:44:34 +01:00
Marcel Holtmann
dadc3d01bc libvhost-user: Provide _GNU_SOURCE when compiling outside of QEMU
Then the libvhost-user sources are used by another project, it can not
be guaranteed that _GNU_SOURCE is set by the build system. If it is for
example not set, errors like this show up.

  CC       libvhost-user.o
libvhost-user.c: In function ‘vu_panic’:
libvhost-user.c:195:9: error: implicit declaration of function ‘vasprintf’; did you mean ‘vsprintf’? [-Werror=implicit-function-declaration]
  195 |     if (vasprintf(&buf, msg, ap) < 0) {
      |         ^~~~~~~~~
      |         vsprintf

The simplest way to allow external complication of libvhost-user.[ch] is
by setting _GNU_SOURCE if it is not already set by the build system.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Message-Id: <be27dcc747a6b5cc6f8ae3f79e0b79171382bcef.1671741278.git.marcel@holtmann.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 10:44:34 +01:00
Stefan Weil via
52a57d8d1f libvhost-user: Add format attribute to local function vu_panic
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220422070144.1043697-4-sw@weilnetz.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221126152507.283271-5-sw@weilnetz.de>
2022-11-27 13:33:58 -05:00
Stefan Weil via
7d4774e681 libvhost-user: Fix two more format strings
This fix is required for 32 bit hosts. The bug was detected by CI
for arm-linux, but is also relevant for i386-linux.

Reported-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221126152507.283271-4-sw@weilnetz.de>
2022-11-27 13:33:58 -05:00
Stefan Weil via
8541bf452d libvhost-user: Fix format strings
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220422070144.1043697-3-sw@weilnetz.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221126152507.283271-3-sw@weilnetz.de>
2022-11-27 13:33:58 -05:00
Stefan Weil via
266aaedc37 libvhost-user: Fix wrong type of argument to formatting function (reported by LGTM)
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Message-Id: <20220422070144.1043697-2-sw@weilnetz.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221126152507.283271-2-sw@weilnetz.de>
2022-11-27 13:33:57 -05:00
Kevin Wolf
7f27d20ded libvhost-user: Fix VHOST_USER_ADD_MEM_REG reply
With REPLY_NEEDED, libvhost-user sends both the acutal result and an
additional ACK reply for VHOST_USER_ADD_MEM_REG. This is incorrect, the
spec mandates that it behave the same with and without REPLY_NEEDED
because it always sends a reply.

Fixes: ec94c8e621
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220627134500.94842-4-kwolf@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-06-27 18:53:18 -04:00
Kevin Wolf
69a5daec06 libvhost-user: Fix VHOST_USER_GET_MAX_MEM_SLOTS reply
With REPLY_NEEDED, libvhost-user sends both the acutal result and an
additional ACK reply for VHOST_USER_GET_MAX_MEM_SLOTS. This is
incorrect, the spec mandates that it behave the same with and without
REPLY_NEEDED because it always sends a reply.

Fixes: 6fb2e173d2
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220627134500.94842-3-kwolf@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-06-27 18:53:18 -04:00
Alex Bennée
467eeb0f80 libvhost-user: expose vu_request_to_string
This is useful for more human readable debug messages in vhost-user
programs.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220321153037.3622127-9-alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-05-16 04:38:40 -04:00
Kevin Wolf
a81d8d4a72 vhost-user: Don't pass file descriptor for VHOST_USER_REM_MEM_REG
The spec clarifies now that QEMU should not send a file descriptor in a
request to remove a memory region. Change it accordingly.

For libvhost-user, this is a bug fix that makes it compatible with
rust-vmm's implementation that doesn't send a file descriptor. Keep
accepting, but ignoring a file descriptor for compatibility with older
QEMU versions.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220407133657.155281-4-kwolf@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-05-04 15:55:23 +02:00
Kevin Wolf
5ebfdeb212 libvhost-user: Fix extra vu_add/rem_mem_reg reply
Outside of postcopy mode, neither VHOST_USER_ADD_MEM_REG nor
VHOST_USER_REM_MEM_REG are supposed to send a reply unless explicitly
requested with the need_reply flag. Their current implementation always
sends a reply, even if it isn't requested. This confuses the master
because it will interpret the reply as a reply for the next message for
which it actually expects a reply.

need_reply is already handled correctly by vu_dispatch(), so just don't
send a reply in the non-postcopy part of the message handler for these
two commands.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220407133657.155281-3-kwolf@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-05-04 15:55:23 +02:00
David Hildenbrand
eb99baa9b3 libvhost-user: Map shared RAM with MAP_NORESERVE to support virtio-mem with hugetlb
For fd-based shared memory, MAP_NORESERVE is only effective for hugetlb,
otherwise it's ignored. Older Linux versions that didn't support
reservation of huge pages ignored MAP_NORESERVE completely.

The first client to mmap a hugetlb fd without MAP_NORESERVE will
trigger reservation of huge pages for the whole mmapped range. There are
two cases to consider:

1) QEMU mapped RAM without MAP_NORESERVE

We're not dealing with a sparse mapping, huge pages for the whole range
have already been reserved by QEMU. An additional mmap() without
MAP_NORESERVE won't have any effect on the reservation.

2) QEMU mapped RAM with MAP_NORESERVE

We're delaing with a sparse mapping, no huge pages should be reserved.
Further mappings without MAP_NORESERVE should be avoided.

For 1), it doesn't matter if we set MAP_NORESERVE or not, so we can
simply set it. For 2), we'd be overriding QEMUs decision and trigger
reservation of huge pages, which might just fail if there are not
sufficient huge pages around. We must map with MAP_NORESERVE.

This change is required to support virtio-mem with hugetlb: a
virtio-mem device mapped into the guest physical memory corresponds to
a sparse memory mapping and QEMU maps this memory with MAP_NORESERVE.
Whenever memory in that sparse region will be accessed by the VM, QEMU
populates huge pages for the affected range by preallocating memory
and handling any preallocation errors gracefully.

So let's map shared RAM with MAP_NORESERVE. As libvhost-user only
supports Linux, there shouldn't be anything to take care of in regard of
other OS support.

Without this change, libvhost-user will fail mapping the region if there
are currently not enough huge pages to perform the reservation:
 fv_panic: libvhost-user: region mmap error: Cannot allocate memory

Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Raphael Norwitz <raphael.norwitz@nutanix.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20220111123939.132659-1-david@redhat.com>
Acked-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
2022-02-04 09:07:43 -05:00
Raphael Norwitz
4fafedc9da libvhost-user: handle removal of identical regions
Today if QEMU (or any other VMM) has sent multiple copies of the same
region to a libvhost-user based backend and then attempts to remove the
region, only one instance of the region will be removed, leaving stale
copies of the region in dev->regions[].

This change resolves this by having vu_rem_mem_reg() iterate through all
regions in dev->regions[] and delete all matching regions.

Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20220117041050.19718-7-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
2022-02-04 09:07:43 -05:00
Raphael Norwitz
b906a23c33 libvhost-user: prevent over-running max RAM slots
When VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS support was added to
libvhost-user, no guardrails were added to protect against QEMU
attempting to hot-add too many RAM slots to a VM with a libvhost-user
based backed attached.

This change adds the missing error handling by introducing a check on
the number of RAM slots the device has available before proceeding to
process the VHOST_USER_ADD_MEM_REG message.

Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20220117041050.19718-6-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2022-02-04 09:07:43 -05:00
David Hildenbrand
fa3d5483f0 libvhost-user: fix VHOST_USER_REM_MEM_REG not closing the fd
We end up not closing the file descriptor, resulting in leaking one
file descriptor for each VHOST_USER_REM_MEM_REG message.

Fixes: 875b9fd97b ("Support individual region unmap in libvhost-user")
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Raphael Norwitz <raphael.norwitz@nutanix.com>
Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Coiby Xu <coiby.xu@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20220117041050.19718-5-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-02-04 09:07:43 -05:00
David Hildenbrand
4fd5ca829a libvhost-user: Simplify VHOST_USER_REM_MEM_REG
Let's avoid having to manually copy all elements. Copy only the ones
necessary to close the hole and perform the operation in-place without
a second array.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20220117041050.19718-4-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-02-04 09:07:43 -05:00
Raphael Norwitz
9f4e63491b libvhost-user: Add vu_add_mem_reg input validation
Today if multiple FDs are sent from the VMM to the backend in a
VHOST_USER_ADD_MEM_REG message, one FD will be mapped and the remaining
FDs will be leaked. Therefore if multiple FDs are sent we report an
error and fail the operation, closing all FDs in the message.

Likewise in case the VMM sends a message with a size less than that
of a memory region descriptor, we add a check to gracefully report an
error and fail the operation rather than crashing.

Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20220117041050.19718-3-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
2022-02-04 09:07:43 -05:00
Raphael Norwitz
316ee11144 libvhost-user: Add vu_rem_mem_reg input validation
Today if multiple FDs are sent from the VMM to the backend in a
VHOST_USER_REM_MEM_REG message, one FD will be unmapped and the remaining
FDs will be leaked. Therefore if multiple FDs are sent we report an
error and fail the operation, closing all FDs in the message.

Likewise in case the VMM sends a message with a size less than that of a
memory region descriptor, we add a check to gracefully report an error
and fail the operation rather than crashing.

Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20220117041050.19718-2-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
2022-02-04 09:07:43 -05:00
David Hildenbrand
6889eb2d43 libvhost-user: fix VHOST_USER_REM_MEM_REG skipping mmap_addr
We end up not copying the mmap_addr of all existing regions, resulting
in a SEGFAULT once we actually try to map/access anything within our
memory regions.

Fixes: 875b9fd97b ("Support individual region unmap in libvhost-user")
Cc: qemu-stable@nongnu.org
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Raphael Norwitz <raphael.norwitz@nutanix.com>
Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Coiby Xu <coiby.xu@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20211011201047.62587-1-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-10-20 04:37:55 -04:00
Marc-André Lureau
4fe29344be libvhost-user: fix -Werror=format= warnings with __u64 fields
../subprojects/libvhost-user/libvhost-user.c:1070:12: error: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 3 has type ‘__u64’ {aka ‘long long unsigned int’} [-Werror=format=]
 1070 |     DPRINT("    desc_user_addr:   0x%016" PRIx64 "\n", vra->desc_user_addr);
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~              ~~~~~~~~~~~~~~~~~~~
      |                                                           |
      |                                                           __u64 {aka long long unsigned int}

Rather than using %llx, which may fail if __u64 is declared differently
elsewhere, let's just cast the values. Feel free to propose a better solution!

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210505151313.203258-2-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-29 10:15:52 +02:00
Marc-André Lureau
3f55f97b14 meson: fix meson 0.58 warning with libvhost-user subproject
Meson now checks that subprojects do not access files from parent
project. While we all agree this is best practice, libvhost-user also
want to share a few headers with QEMU, and libvhost-user isn't really a
standalone project at this point (although this is making the dependency
a bit more explicit).

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210505151313.203258-1-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-29 10:15:52 +02:00
Marc-André Lureau
0df750e9d3 libvhost-user: make it a meson subproject
By making libvhost-user a subproject, check it builds
standalone (without the global QEMU cflags etc).

Note that the library still relies on QEMU include/qemu/atomic.h and
linux_headers/.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20201125100640.366523-6-marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-08 13:48:58 -05:00