diff options
| -rw-r--r-- | backends/hostmem-file.c | 11 | ||||
| -rw-r--r-- | backends/hostmem-memfd.c | 1 | ||||
| -rw-r--r-- | backends/hostmem-ram.c | 1 | ||||
| -rw-r--r-- | backends/hostmem.c | 36 | ||||
| -rw-r--r-- | include/sysemu/hostmem.h | 2 | ||||
| -rw-r--r-- | qapi/qom.json | 10 |
6 files changed, 55 insertions, 6 deletions
diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c index 9b1b9f0a56..cd038024fa 100644 --- a/backends/hostmem-file.c +++ b/backends/hostmem-file.c @@ -39,6 +39,7 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) object_get_typename(OBJECT(backend))); #else HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend); + uint32_t ram_flags; gchar *name; if (!backend->size) { @@ -51,11 +52,11 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) } name = host_memory_backend_get_name(backend); - memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), - name, - backend->size, fb->align, - (backend->share ? RAM_SHARED : 0) | - (fb->is_pmem ? RAM_PMEM : 0), + ram_flags = backend->share ? RAM_SHARED : 0; + ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; + ram_flags |= fb->is_pmem ? RAM_PMEM : 0; + memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), name, + backend->size, fb->align, ram_flags, fb->mem_path, fb->readonly, errp); g_free(name); #endif diff --git a/backends/hostmem-memfd.c b/backends/hostmem-memfd.c index 3076da146d..3fc85c3db8 100644 --- a/backends/hostmem-memfd.c +++ b/backends/hostmem-memfd.c @@ -54,6 +54,7 @@ memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) name = host_memory_backend_get_name(backend); ram_flags = backend->share ? RAM_SHARED : 0; + ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend), name, backend->size, ram_flags, fd, 0, errp); g_free(name); diff --git a/backends/hostmem-ram.c b/backends/hostmem-ram.c index 741e701062..b8e55cdbd0 100644 --- a/backends/hostmem-ram.c +++ b/backends/hostmem-ram.c @@ -29,6 +29,7 @@ ram_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) name = host_memory_backend_get_name(backend); ram_flags = backend->share ? RAM_SHARED : 0; + ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; memory_region_init_ram_flags_nomigrate(&backend->mr, OBJECT(backend), name, backend->size, ram_flags, errp); g_free(name); diff --git a/backends/hostmem.c b/backends/hostmem.c index aab3de8408..4c05862ed5 100644 --- a/backends/hostmem.c +++ b/backends/hostmem.c @@ -216,6 +216,11 @@ static void host_memory_backend_set_prealloc(Object *obj, bool value, Error *local_err = NULL; HostMemoryBackend *backend = MEMORY_BACKEND(obj); + if (!backend->reserve && value) { + error_setg(errp, "'prealloc=on' and 'reserve=off' are incompatible"); + return; + } + if (!host_memory_backend_mr_inited(backend)) { backend->prealloc = value; return; @@ -267,6 +272,7 @@ static void host_memory_backend_init(Object *obj) /* TODO: convert access to globals to compat properties */ backend->merge = machine_mem_merge(machine); backend->dump = machine_dump_guest_core(machine); + backend->reserve = true; backend->prealloc_threads = 1; } @@ -425,6 +431,30 @@ static void host_memory_backend_set_share(Object *o, bool value, Error **errp) backend->share = value; } +#ifdef CONFIG_LINUX +static bool host_memory_backend_get_reserve(Object *o, Error **errp) +{ + HostMemoryBackend *backend = MEMORY_BACKEND(o); + + return backend->reserve; +} + +static void host_memory_backend_set_reserve(Object *o, bool value, Error **errp) +{ + HostMemoryBackend *backend = MEMORY_BACKEND(o); + + if (host_memory_backend_mr_inited(backend)) { + error_setg(errp, "cannot change property value"); + return; + } + if (backend->prealloc && !value) { + error_setg(errp, "'prealloc=on' and 'reserve=off' are incompatible"); + return; + } + backend->reserve = value; +} +#endif /* CONFIG_LINUX */ + static bool host_memory_backend_get_use_canonical_path(Object *obj, Error **errp) { @@ -493,6 +523,12 @@ host_memory_backend_class_init(ObjectClass *oc, void *data) host_memory_backend_get_share, host_memory_backend_set_share); object_class_property_set_description(oc, "share", "Mark the memory as private to QEMU or shared"); +#ifdef CONFIG_LINUX + object_class_property_add_bool(oc, "reserve", + host_memory_backend_get_reserve, host_memory_backend_set_reserve); + object_class_property_set_description(oc, "reserve", + "Reserve swap space (or huge pages) if applicable"); +#endif /* CONFIG_LINUX */ /* * Do not delete/rename option. This option must be considered stable * (as if it didn't have the 'x-' prefix including deprecation period) as diff --git a/include/sysemu/hostmem.h b/include/sysemu/hostmem.h index df5644723a..9ff5c16963 100644 --- a/include/sysemu/hostmem.h +++ b/include/sysemu/hostmem.h @@ -64,7 +64,7 @@ struct HostMemoryBackend { /* protected */ uint64_t size; bool merge, dump, use_canonical_path; - bool prealloc, is_mapped, share; + bool prealloc, is_mapped, share, reserve; uint32_t prealloc_threads; DECLARE_BITMAP(host_nodes, MAX_NODES + 1); HostMemPolicy policy; diff --git a/qapi/qom.json b/qapi/qom.json index f7ef30f940..652be317b8 100644 --- a/qapi/qom.json +++ b/qapi/qom.json @@ -545,6 +545,9 @@ # @share: if false, the memory is private to QEMU; if true, it is shared # (default: false) # +# @reserve: if true, reserve swap space (or huge pages) if applicable +# (default: true) (since 6.1) +# # @size: size of the memory region in bytes # # @x-use-canonical-path-for-ramblock-id: if true, the canoncial path is used @@ -556,6 +559,12 @@ # false generally, but true for machine # types <= 4.0) # +# Note: prealloc=true and reserve=false cannot be set at the same time. With +# reserve=true, the behavior depends on the operating system: for example, +# Linux will not reserve swap space for shared file mappings -- +# "not applicable". In contrast, reserve=false will bail out if it cannot +# be configured accordingly. +# # Since: 2.1 ## { 'struct': 'MemoryBackendProperties', @@ -566,6 +575,7 @@ '*prealloc': 'bool', '*prealloc-threads': 'uint32', '*share': 'bool', + '*reserve': 'bool', 'size': 'size', '*x-use-canonical-path-for-ramblock-id': 'bool' } } |