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2019-09-11linux-user: add memfd_createShu-Chun Weng
Add support for the memfd_create syscall. If the host does not have the libc wrapper, translate to a direct syscall with NC-macro. Buglink: https://bugs.launchpad.net/qemu/+bug/1734792 Signed-off-by: Shu-Chun Weng <scw@google.com> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Message-Id: <20190819180947.180725-1-scw@google.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2019-03-11memfd: improve error messagesIlya Maximets
This gives more information about the failure. Additionally 'ENOSYS' returned for a non-Linux platforms instead of 'errno', which is not initilaized in this case. Signed-off-by: Ilya Maximets <i.maximets@samsung.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20190311135850.6537-5-i.maximets@samsung.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2019-03-11memfd: set up correct errno if not supportedIlya Maximets
qemu_memfd_create() prints the value of 'errno' which is not set in this case. Signed-off-by: Ilya Maximets <i.maximets@samsung.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20190311135850.6537-4-i.maximets@samsung.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2019-03-11memfd: always check for MFD_CLOEXECIlya Maximets
QEMU always sets this flag unconditionally. We need to check if it's supported. Signed-off-by: Ilya Maximets <i.maximets@samsung.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20190311135850.6537-3-i.maximets@samsung.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2018-10-02hostmem-memfd: add checks before adding hostmem-memfd & propertiesMarc-André Lureau
Run some memfd-related checks before registering hostmem-memfd & various properties. This will help libvirt to figure out what the host is supposed to be capable of. qemu_memfd_check() is changed to a less optimized version, since it is used with various flags, it no longer caches the result. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20180906161415.8543-1-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-25memfd: fix possible usage of the uninitialized file descriptorDima Stepanov
The qemu_memfd_alloc_check() routine allocates the fd variable on stack. This variable is initialized inside the qemu_memfd_alloc() function. There are several cases when *fd will be left unintialized which can lead to the unexpected close() in the qemu_memfd_free() call. Set file descriptor to -1 before calling the qemu_memfd_alloc routine. Signed-off-by: Dima Stepanov <dimastep@yandex-team.ru> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2018-06-01memfd: Avoid Coverity warning about integer overflowPeter Maydell
Coverity complains about qemu_memfd_create() (CID 1385858) because we calculate a bit position htsize which could be up to 63, but then use it in "1 << htsize" which is a 32-bit integer calculation and could push the 1 off the top of the value. Silence the complaint bu using "1ULL"; this isn't a bug in practice since a hugetlbsize of 4GB is not very plausible. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20180515172729.24564-1-peter.maydell@linaro.org> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-04-09memfd: fix vhost-user-test on non-memfd capable hostMarc-André Lureau
On RHEL7, memfd is not supported, and vhost-user-test fails: TEST: tests/vhost-user-test... (pid=10248) /x86_64/vhost-user/migrate: qemu-system-x86_64: -object memory-backend-memfd,id=mem,size=2M,: failed to create memfd FAIL There is a qemu_memfd_check() to prevent running memfd path, but it also checks for fallback implementation. Let's specialize qemu_memfd_check() to check memfd only, while qemu_memfd_alloc_check() checks for the qemu_memfd_alloc() API. Reported-by: Miroslav Rezanina <mrezanin@redhat.com> Tested-by: Miroslav Rezanina <mrezanin@redhat.com> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20180328121804.16203-1-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2018-02-07memfd: add hugetlbsize argumentMarc-André Lureau
Learn to specificy hugetlb size as qemu_memfd_create() argument. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20180201132757.23063-4-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-02-07memfd: add hugetlb supportMarc-André Lureau
Linux commit 749df87bd7bee5a79cef073f5d032ddb2b211de8 (v4.14-rc1) added a new flag MFD_HUGETLB to memfd_create() that specify the file to be created resides in the hugetlbfs filesystem. This is the generic hugetlbfs filesystem not associated with any specific mount point. hugetlbfs does not support sealing operations in v4.14, therefore specifying MFD_ALLOW_SEALING with MFD_HUGETLB will result in EINVAL. However, I added sealing support in "[PATCH v3 0/9] memfd: add sealing to hugetlb-backed memory" series, queued in -mm tree for v4.16. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20180201132757.23063-3-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-02-07memfd: add error argument, instead of perror()Marc-André Lureau
This will allow callers to silence error report when the call is allowed to failed. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20180201132757.23063-2-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-01-19memfd: remove needless includeMarc-André Lureau
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20171023141815.17709-3-marcandre.lureau@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2018-01-19memfd: split qemu_memfd_alloc()Marc-André Lureau
Add a function to only create a memfd, without mmap. The function is used in the following memory backend. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20171023141815.17709-2-marcandre.lureau@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2017-12-20memfd: fix configure testPaolo Bonzini
Recent glibc added memfd_create in sys/mman.h. This conflicts with the definition in util/memfd.c: /builddir/build/BUILD/qemu-2.11.0-rc1/util/memfd.c:40:12: error: static declaration of memfd_create follows non-static declaration Fix the configure test, and remove the sys/memfd.h inclusion since the file actually does not exist---it is a typo in the memfd_create(2) man page. Cc: Marc-André Lureau <marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16os-posix: include sys/mman.hPaolo Bonzini
qemu/osdep.h checks whether MAP_ANONYMOUS is defined, but this check is bogus without a previous inclusion of sys/mman.h. Include it in sysemu/os-posix.h and remove it from everywhere else. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-07all: Remove unnecessary glib.h includesPeter Maydell
Remove glib.h includes, as it is provided by osdep.h. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com> Tested-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-10-22vhost: add migration block if memfd failedMarc-André Lureau
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22util: add fallback for qemu_memfd_alloc()Marc-André Lureau
Add an open/unlink/mmap fallback for system that do not support memfd (only available since 3.17, ~1y ago). This patch may require additional SELinux policies to work for enforced systems, but should fail gracefully in this case. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22util: add memfd helpersMarc-André Lureau
Add qemu_memfd_alloc/free() helpers. The function helps to allocate and seal shared memory. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22util: add linux-only memfd fallbackMarc-André Lureau
Implement memfd_create() fallback if not available in system libc. memfd_create() is still not included in glibc today, atlhough it's been available since Linux 3.17 in Oct 2014. memfd has numerous advantages over traditional shm/mmap for ipc memory sharing with fd handler, which we are going to make use of for vhost-user logging memory in following patches. The next patches are going to introduce helpers to use best practices of memfd usage and provide some compatibility fallback. memfd.c is thus temporarily useless and eventually empty if memfd_create() is provided by the system. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
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