Make qemu_mempath_getpagesize() accept NULL

qemu_mempath_getpagesize() gets the effective (host side) page size for
a block of memory backed by an mmap()ed file on the host.  It requires
the mem_path parameter to be non-NULL.

This ends up meaning all the callers need a different case for handling
anonymous memory (for memory-backend-ram or default memory with -mem-path
is not specified).

We can make all those callers a little simpler by having
qemu_mempath_getpagesize() accept NULL, and treat that as the anonymous
memory case.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
David Gibson 2018-04-03 14:55:11 +10:00
parent 8a4fd427fe
commit 0de6e2a3ca
3 changed files with 21 additions and 32 deletions

11
exec.c
View File

@ -1488,20 +1488,15 @@ void ram_block_dump(Monitor *mon)
*/
static int find_max_supported_pagesize(Object *obj, void *opaque)
{
char *mem_path;
long *hpsize_min = opaque;
if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND)) {
mem_path = object_property_get_str(obj, "mem-path", NULL);
if (mem_path) {
char *mem_path = object_property_get_str(obj, "mem-path", NULL);
long hpsize = qemu_mempath_getpagesize(mem_path);
g_free(mem_path);
if (hpsize < *hpsize_min) {
*hpsize_min = hpsize;
}
} else {
*hpsize_min = getpagesize();
}
}
return 0;
@ -1513,11 +1508,7 @@ long qemu_getrampagesize(void)
long mainrampagesize;
Object *memdev_root;
if (mem_path) {
mainrampagesize = qemu_mempath_getpagesize(mem_path);
} else {
mainrampagesize = getpagesize();
}
/* it's possible we have memory-backend objects with
* hugepage-backed RAM. these may get mapped into system

View File

@ -499,12 +499,8 @@ bool kvmppc_is_mem_backend_page_size_ok(const char *obj_path)
char *mempath = object_property_get_str(mem_obj, "mem-path", NULL);
long pagesize;
if (mempath) {
pagesize = qemu_mempath_getpagesize(mempath);
g_free(mempath);
} else {
pagesize = getpagesize();
}
return pagesize >= max_cpu_page_size;
}

View File

@ -50,6 +50,7 @@ size_t qemu_mempath_getpagesize(const char *mem_path)
struct statfs fs;
int ret;
if (mem_path) {
do {
ret = statfs(mem_path, &fs);
} while (ret != 0 && errno == EINTR);
@ -64,6 +65,7 @@ size_t qemu_mempath_getpagesize(const char *mem_path)
/* It's hugepage, return the huge page size */
return fs.f_bsize;
}
}
#ifdef __sparc__
/* SPARC Linux needs greater alignment than the pagesize */
return QEMU_VMALLOC_ALIGN;