On Mon, Jul 07, 2014 at 06:55:28PM +0800, Hu Tao wrote:
> This patch fixes two problems of memory-backend-file:
>
> 1. If user adds a memory-backend-file object using object_add command,
> specifying a non-existing directory for property mem-path, qemu
> will core dump with message:
>
> /nonexistingdir: No such file or directory
> Bad ram offset fffffffffffff000
> Aborted (core dumped)
>
> with this patch, qemu reports error message like:
>
> qemu-system-x86_64: -object
> memory-backend-file,mem-path=/nonexistingdir,id=mem-file0,size=128M:
> failed to stat file /nonexistingdir: No such file or directory
>
> 2. If user adds a memory-backend-file object using object_add command,
> specifying a size that is less than huge page size, qemu
> will core dump with message:
>
> Bad ram offset fffffffffffff000
> Aborted (core dumped)
>
> with this patch, qemu reports error message like:
>
> qemu-system-x86_64: -object
> memory-backend-file,mem-path=/hugepages,id=mem-file0,size=1M: memory
> size 0x100000 should be euqal or larger than huge page size 0x200000
>
> Signed-off-by: Hu Tao <hu...@cn.fujitsu.com>
Build fails on 32 bit host
/scm/qemu/exec.c:1037:9: error: format ‘%llx’ expects argument of type
‘long long unsigned int’, but argument 5 has type ‘long unsigned int’
[-Werror=format=]
> ---
> exec.c | 19 +++++++++++--------
> 1 file changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index ca7741b..bb97b15 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -996,7 +996,7 @@ void qemu_mutex_unlock_ramlist(void)
>
> #define HUGETLBFS_MAGIC 0x958458f6
>
> -static long gethugepagesize(const char *path)
> +static long gethugepagesize(const char *path, Error **errp)
> {
> struct statfs fs;
> int ret;
> @@ -1006,7 +1006,7 @@ static long gethugepagesize(const char *path)
> } while (ret != 0 && errno == EINTR);
>
> if (ret != 0) {
> - perror(path);
> + error_setg_errno(errp, errno, "failed to get size of file %s", path);
> return 0;
> }
>
> @@ -1024,17 +1024,20 @@ static void *file_ram_alloc(RAMBlock *block,
> char *filename;
> char *sanitized_name;
> char *c;
> - void *area;
> + void *area = NULL;
> int fd;
> unsigned long hpagesize;
>
> - hpagesize = gethugepagesize(path);
> - if (!hpagesize) {
> + hpagesize = gethugepagesize(path, errp);
> + if (errp && *errp) {
> goto error;
> }
>
> if (memory < hpagesize) {
> - return NULL;
> + error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be euqal to "
> + "or larger than huge page size 0x%" PRIx64,
> + memory, hpagesize);
> + goto error;
> }
>
> if (kvm_enabled() && !kvm_has_sync_mmu()) {
> @@ -1094,8 +1097,8 @@ static void *file_ram_alloc(RAMBlock *block,
> return area;
>
> error:
> - if (mem_prealloc) {
> - exit(1);
> + if (area && area != MAP_FAILED) {
> + munmap(area, memory);
> }
> return NULL;
> }
> --
> 1.9.3
