Commit Graph

9 Commits

Author SHA1 Message Date
Marcel Holtmann
86e61e4233 libvduse: Fix assignment in vring_set_avail_event
Since the assignment is causing a compiler warning, fix it by using
memcpy instead.

  CC       libvduse.o
libvduse.c: In function ‘vring_set_avail_event’:
libvduse.c:603:7: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasin]
  603 |     *((uint16_t *)&vq->vring.used->ring[vq->vring.num]) = htole16(val);
      |      ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Suggested-by: Xie Yongji <xieyongji@bytedance.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <4a0fe2a6436464473119fdbf0bc4076b36fbb37f.1671741278.git.marcel@holtmann.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 10:44:35 +01:00
Marcel Holtmann
85899f8e6b libvduse: Switch to unsigned int for inuse field in struct VduseVirtq
It seems there is no need to keep the inuse field signed and end up with
compiler warnings for sign-compare.

  CC       libvduse.o
libvduse.c: In function ‘vduse_queue_pop’:
libvduse.c:789:19: error: comparison of integer expressions of different signedness: ‘int’ and ‘unsigned int’ [-Werror=sign-compare]
  789 |     if (vq->inuse >= vq->vring.num) {
      |                   ^~

Instead of casting the comparison to unsigned int, just make the inuse
field unsigned int in the fist place.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Xie Yongji <xieyongji@bytedance.com>
Message-Id: <9fe3fd8b042e048bd04d506ca6e43d738b5c45b7.1671741278.git.marcel@holtmann.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 10:44:34 +01:00
Marcel Holtmann
518ac42879 libvduse: Provide _GNU_SOURCE when compiling outside of QEMU
When the libvduse 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       libvduse.o
libvduse.c: In function ‘vduse_log_get’:
libvduse.c:172:9: error: implicit declaration of function ‘ftruncate’; did you mean ‘strncat’? [-Werror=implicit-function-declaration]
  172 |     if (ftruncate(fd, size) == -1) {
      |         ^~~~~~~~~
      |         strncat

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

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Message-Id: <407f3665f0605df936e5bfe60831d180edfb8cca.1671741278.git.marcel@holtmann.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 10:44:34 +01:00
Philippe Mathieu-Daudé
57bc6e40e8 libvduse: Avoid warning about dangerous use of strncpy()
GCC 8 added a -Wstringop-truncation warning:

  The -Wstringop-truncation warning added in GCC 8.0 via r254630 for
  bug 81117 is specifically intended to highlight likely unintended
  uses of the strncpy function that truncate the terminating NUL
  character from the source string.

Here the next line indeed unconditionally zeroes the last byte, but
1/ the buffer has been calloc'd, so we don't need to add an extra
byte, and 2/ we called vduse_name_is_invalid() which checked the
string length, so we can simply call strcpy().

This fixes when using gcc (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0:

  [42/666] Compiling C object subprojects/libvduse/libvduse.a.p/libvduse.c.o
  FAILED: subprojects/libvduse/libvduse.a.p/libvduse.c.o
  cc -m64 -mcx16 -Isubprojects/libvduse/libvduse.a.p -Isubprojects/libvduse -I../../subprojects/libvduse [...] -o subprojects/libvduse/libvduse.a.p/libvduse.c.o -c ../../subprojects/libvduse/libvduse.c
  In file included from /usr/include/string.h:495,
                   from ../../subprojects/libvduse/libvduse.c:24:
  In function ‘strncpy’,
      inlined from ‘vduse_dev_create’ at ../../subprojects/libvduse/libvduse.c:1312:5:
  /usr/include/x86_64-linux-gnu/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ specified bound 256 equals destination size [-Werror=stringop-truncation]
    106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
        |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors
  ninja: build stopped: cannot make progress due to previous errors.

Fixes: d9cf16c0be ("libvduse: Replace strcpy() with strncpy()")
Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Xie Yongji <xieyongji@bytedance.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Bin Meng <bmeng@tinylab.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221111124550.35753-1-philmd@linaro.org>
2022-11-12 09:15:59 -05:00
Xie Yongji
630179b7f7 libvduse: Pass positive value to strerror()
The value passed to strerror() should be positive.
So let's fix it.

Fixes: Coverity CID 1490226, 1490223
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20220706095624.328-4-xieyongji@bytedance.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-08-02 11:01:42 +02:00
Xie Yongji
d9cf16c0be libvduse: Replace strcpy() with strncpy()
Coverity reported a string overflow issue since we copied
"name" to "dev_config->name" without checking the length.
This should be a false positive since we already checked
the length of "name" in vduse_name_is_invalid(). But anyway,
let's replace strcpy() with strncpy() (as a general library,
we'd like to minimize dependencies on other libraries, so we
didn't use g_strlcpy() here) to fix the coverity complaint.

Fixes: Coverity CID 1490224
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20220706095624.328-3-xieyongji@bytedance.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-08-02 11:01:41 +02:00
Xie Yongji
e7156ff7cb libvduse: Fix the incorrect function name
In vduse_name_is_valid(), we actually check whether
the name is invalid or not. So let's change the
function name to vduse_name_is_invalid() to match
the behavior.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20220706095624.328-2-xieyongji@bytedance.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-08-02 11:01:41 +02:00
Xie Yongji
d043e2db87 libvduse: Add support for reconnecting
To support reconnecting after restart or crash, VDUSE backend
might need to resubmit inflight I/Os. This stores the metadata
such as the index of inflight I/O's descriptors to a shm file so
that VDUSE backend can restore them during reconnecting.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Message-Id: <20220523084611.91-9-xieyongji@bytedance.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-06-24 17:07:06 +02:00
Xie Yongji
a6caeee811 libvduse: Add VDUSE (vDPA Device in Userspace) library
VDUSE [1] is a linux framework that makes it possible to implement
software-emulated vDPA devices in userspace. This adds a library
as a subproject to help implementing VDUSE backends in QEMU.

[1] https://www.kernel.org/doc/html/latest/userspace-api/vduse.html

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Message-Id: <20220523084611.91-6-xieyongji@bytedance.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-06-24 17:07:06 +02:00