diff options
| -rw-r--r-- | backends/hostmem-file.c | 23 | ||||
| -rw-r--r-- | include/qemu/osdep.h | 13 | ||||
| -rw-r--r-- | util/oslib-posix.c | 53 | ||||
| -rw-r--r-- | util/oslib-win32.c | 5 |
4 files changed, 94 insertions, 0 deletions
diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c index ce54788048..37ac6445d2 100644 --- a/backends/hostmem-file.c +++ b/backends/hostmem-file.c @@ -56,6 +56,29 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) error_setg(errp, "mem-path property not set"); return; } + + /* + * Verify pmem file size since starting a guest with an incorrect size + * leads to confusing failures inside the guest. + */ + if (fb->is_pmem) { + Error *local_err = NULL; + uint64_t size; + + size = qemu_get_pmem_size(fb->mem_path, &local_err); + if (!size) { + error_propagate(errp, local_err); + return; + } + + if (backend->size > size) { + error_setg(errp, "size property %" PRIu64 " is larger than " + "pmem file \"%s\" size %" PRIu64, backend->size, + fb->mem_path, size); + return; + } + } + backend->force_prealloc = mem_prealloc; name = host_memory_backend_get_name(backend); memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 840af09cb0..303d315c5d 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -571,6 +571,19 @@ void os_mem_prealloc(int fd, char *area, size_t sz, int smp_cpus, Error **errp); /** + * qemu_get_pmem_size: + * @filename: path to a pmem file + * @errp: pointer to a NULL-initialized error object + * + * Determine the size of a persistent memory file. Besides supporting files on + * DAX file systems, this function also supports Linux devdax character + * devices. + * + * Returns: the size or 0 on failure + */ +uint64_t qemu_get_pmem_size(const char *filename, Error **errp); + +/** * qemu_get_pid_name: * @pid: pid of a process * diff --git a/util/oslib-posix.c b/util/oslib-posix.c index 37c5854b9c..10d90d1783 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -500,6 +500,59 @@ void os_mem_prealloc(int fd, char *area, size_t memory, int smp_cpus, } } +uint64_t qemu_get_pmem_size(const char *filename, Error **errp) +{ + struct stat st; + + if (stat(filename, &st) < 0) { + error_setg(errp, "unable to stat pmem file \"%s\"", filename); + return 0; + } + +#if defined(__linux__) + /* Special handling for devdax character devices */ + if (S_ISCHR(st.st_mode)) { + char *subsystem_path = NULL; + char *subsystem = NULL; + char *size_path = NULL; + char *size_str = NULL; + uint64_t ret = 0; + + subsystem_path = g_strdup_printf("/sys/dev/char/%d:%d/subsystem", + major(st.st_rdev), minor(st.st_rdev)); + subsystem = g_file_read_link(subsystem_path, NULL); + if (!subsystem) { + error_setg(errp, "unable to read subsystem for pmem file \"%s\"", + filename); + goto devdax_err; + } + + if (!g_str_has_suffix(subsystem, "/dax")) { + error_setg(errp, "pmem file \"%s\" is not a dax device", filename); + goto devdax_err; + } + + size_path = g_strdup_printf("/sys/dev/char/%d:%d/size", + major(st.st_rdev), minor(st.st_rdev)); + if (!g_file_get_contents(size_path, &size_str, NULL, NULL)) { + error_setg(errp, "unable to read size for pmem file \"%s\"", + size_path); + goto devdax_err; + } + + ret = g_ascii_strtoull(size_str, NULL, 0); + +devdax_err: + g_free(size_str); + g_free(size_path); + g_free(subsystem); + g_free(subsystem_path); + return ret; + } +#endif /* defined(__linux__) */ + + return st.st_size; +} char *qemu_get_pid_name(pid_t pid) { diff --git a/util/oslib-win32.c b/util/oslib-win32.c index b4c17f5dfa..bd633afab6 100644 --- a/util/oslib-win32.c +++ b/util/oslib-win32.c @@ -560,6 +560,11 @@ void os_mem_prealloc(int fd, char *area, size_t memory, int smp_cpus, } } +uint64_t qemu_get_pmem_size(const char *filename, Error **errp) +{ + error_setg(errp, "pmem support not available"); + return 0; +} char *qemu_get_pid_name(pid_t pid) { |