On Thu, 13 Dec 2018 01:48:50 +0400
Marc-André Lureau <marcandre.lureau@redhat.com> wrote:
> hostmem-file and hostmem-memfd use the whole object path for the
> memory region name, and hostname-ram uses only the path component (the
> object id, or canonical path basename):
>
> qemu -m 1024 -object memory-backend-file,id=mem,size=1G,mem-path=/tmp/foo -numa node,memdev=mem -monitor stdio
> (qemu) info ramblock
> Block Name PSize Offset Used Total
> /objects/mem 4 KiB 0x0000000000000000 0x0000000040000000 0x0000000040000000
>
> qemu -m 1024 -object memory-backend-memfd,id=mem,size=1G -numa node,memdev=mem -monitor stdio
> (qemu) info ramblock
> Block Name PSize Offset Used Total
> /objects/mem 4 KiB 0x0000000000000000 0x0000000040000000 0x0000000040000000
>
> qemu -m 1024 -object memory-backend-ram,id=mem,size=1G -numa node,memdev=mem -monitor stdio
> (qemu) info ramblock
> Block Name PSize Offset Used Total
> mem 4 KiB 0x0000000000000000 0x0000000040000000 0x0000000040000000
>
> For consistency, change to use object id for -file and -memfd as well
> with >= 4.0.
>
> Having a consistent naming allows to migrate to different hostmem
> backends.
With neat below fixed:
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
> include/sysemu/hostmem.h | 3 ++-
> backends/hostmem-file.c | 8 ++++----
> backends/hostmem-memfd.c | 2 +-
> backends/hostmem-ram.c | 9 ++++-----
> backends/hostmem.c | 36 ++++++++++++++++++++++++++++++++++++
> hw/core/machine.c | 12 +++++++++++-
> 6 files changed, 58 insertions(+), 12 deletions(-)
>
> diff --git a/include/sysemu/hostmem.h b/include/sysemu/hostmem.h
> index 6e6bd2c1cb..a023b372a4 100644
> --- a/include/sysemu/hostmem.h
> +++ b/include/sysemu/hostmem.h
> @@ -53,7 +53,7 @@ struct HostMemoryBackend {
>
> /* protected */
> uint64_t size;
> - bool merge, dump;
> + bool merge, dump, use_canonical_path;
> bool prealloc, force_prealloc, is_mapped, share;
> DECLARE_BITMAP(host_nodes, MAX_NODES + 1);
> HostMemPolicy policy;
> @@ -67,5 +67,6 @@ MemoryRegion *host_memory_backend_get_memory(HostMemoryBackend *backend);
> void host_memory_backend_set_mapped(HostMemoryBackend *backend, bool mapped);
> bool host_memory_backend_is_mapped(HostMemoryBackend *backend);
> size_t host_memory_backend_pagesize(HostMemoryBackend *memdev);
> +char *host_memory_backend_get_name(HostMemoryBackend *backend);
>
> #endif
> diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
> index 78f058dee2..7a34e25c43 100644
> --- a/backends/hostmem-file.c
> +++ b/backends/hostmem-file.c
> @@ -43,7 +43,7 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
> {
> HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);
> #ifdef CONFIG_POSIX
> - gchar *path;
> + gchar *name;
> #endif
>
> if (!backend->size) {
> @@ -58,14 +58,14 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
> error_setg(errp, "-mem-path not supported on this host");
> #else
> backend->force_prealloc = mem_prealloc;
> - path = object_get_canonical_path(OBJECT(backend));
> + name = host_memory_backend_get_name(backend);
> memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
> - path,
> + name,
> backend->size, fb->align,
> (backend->share ? RAM_SHARED : 0) |
> (fb->is_pmem ? RAM_PMEM : 0),
> fb->mem_path, errp);
> - g_free(path);
> + g_free(name);
> #endif
> }
>
> diff --git a/backends/hostmem-memfd.c b/backends/hostmem-memfd.c
> index 2eb9c827a5..98c9bf3240 100644
> --- a/backends/hostmem-memfd.c
> +++ b/backends/hostmem-memfd.c
> @@ -53,7 +53,7 @@ memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
> return;
> }
>
> - name = object_get_canonical_path(OBJECT(backend));
> + name = host_memory_backend_get_name(backend);
> memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend),
> name, backend->size,
> backend->share, fd, errp);
> diff --git a/backends/hostmem-ram.c b/backends/hostmem-ram.c
> index 7ddd08d370..24b65d9ae3 100644
> --- a/backends/hostmem-ram.c
> +++ b/backends/hostmem-ram.c
> @@ -16,21 +16,20 @@
>
> #define TYPE_MEMORY_BACKEND_RAM "memory-backend-ram"
>
> -
> static void
> ram_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
> {
> - char *path;
> + char *name;
>
> if (!backend->size) {
> error_setg(errp, "can't create backend with size 0");
> return;
> }
>
> - path = object_get_canonical_path_component(OBJECT(backend));
> - memory_region_init_ram_shared_nomigrate(&backend->mr, OBJECT(backend), path,
> + name = host_memory_backend_get_name(backend);
> + memory_region_init_ram_shared_nomigrate(&backend->mr, OBJECT(backend), name,
> backend->size, backend->share, errp);
> - g_free(path);
> + g_free(name);
> }
>
> static void
> diff --git a/backends/hostmem.c b/backends/hostmem.c
> index af800284e0..ff67e39c83 100644
> --- a/backends/hostmem.c
> +++ b/backends/hostmem.c
> @@ -28,6 +28,16 @@ QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_BIND != MPOL_BIND);
> QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_INTERLEAVE != MPOL_INTERLEAVE);
> #endif
>
> +char *
> +host_memory_backend_get_name(HostMemoryBackend *self)
for consistency s/self/backend/
> +{
> + if (!self->use_canonical_path) {
> + return object_get_canonical_path_component(OBJECT(self));
> + }
> +
> + return object_get_canonical_path(OBJECT(self));
> +}
> +
> static void
> host_memory_backend_get_size(Object *obj, Visitor *v, const char *name,
> void *opaque, Error **errp)
> @@ -247,6 +257,11 @@ static void host_memory_backend_init(Object *obj)
> backend->prealloc = mem_prealloc;
> }
>
> +static void host_memory_backend_post_init(Object *obj)
> +{
> + object_apply_compat_props(obj);
> +}
> +
> bool host_memory_backend_mr_inited(HostMemoryBackend *backend)
> {
> /*
> @@ -395,6 +410,23 @@ static void host_memory_backend_set_share(Object *o, bool value, Error **errp)
> backend->share = value;
> }
>
> +static bool
> +host_memory_backend_get_use_canonical_path(Object *obj, Error **errp)
> +{
> + HostMemoryBackend *self = MEMORY_BACKEND(obj);
> +
> + return self->use_canonical_path;
> +}
> +
> +static void
> +host_memory_backend_set_use_canonical_path(Object *obj, bool value,
> + Error **errp)
> +{
> + HostMemoryBackend *self = MEMORY_BACKEND(obj);
> +
> + self->use_canonical_path = value;
> +}
> +
> static void
> host_memory_backend_class_init(ObjectClass *oc, void *data)
> {
> @@ -441,6 +473,9 @@ host_memory_backend_class_init(ObjectClass *oc, void *data)
> &error_abort);
> object_class_property_set_description(oc, "share",
> "Mark the memory as private to QEMU or shared", &error_abort);
> + object_class_property_add_bool(oc, "x-use-canonical-path-for-ramblock-id",
> + host_memory_backend_get_use_canonical_path,
> + host_memory_backend_set_use_canonical_path, &error_abort);
> }
>
> static const TypeInfo host_memory_backend_info = {
> @@ -451,6 +486,7 @@ static const TypeInfo host_memory_backend_info = {
> .class_init = host_memory_backend_class_init,
> .instance_size = sizeof(HostMemoryBackend),
> .instance_init = host_memory_backend_init,
> + .instance_post_init = host_memory_backend_post_init,
> .interfaces = (InterfaceInfo[]) {
> { TYPE_USER_CREATABLE },
> { }
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index 7570408caa..cba79ef7ff 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -23,7 +23,17 @@
> #include "sysemu/qtest.h"
> #include "hw/pci/pci.h"
>
> -GlobalProperty hw_compat_3_1[] = {};
> +GlobalProperty hw_compat_3_1[] = {
> + {
> + .driver = "memory-backend-file",
> + .property = "x-use-canonical-path-for-ramblock-id",
> + .value = "true",
> + },{
> + .driver = "memory-backend-memfd",
> + .property = "x-use-canonical-path-for-ramblock-id",
> + .value = "true",
> + },
> +};
> const size_t hw_compat_3_1_len = G_N_ELEMENTS(hw_compat_3_1);
>
> GlobalProperty hw_compat_3_0[] = {};