On 2025-05-13 03:27, Jan Beulich wrote:
On 13.05.2025 01:54, Jason Andryuk wrote:
Only access the HVM union b_info->u.hvm on HVM guests. The union
access is not guarded, so this reads and sets the default even on
non-HVM guests. Usually this doesn't matter as PV and PVH unions are
smaller and zero-initialized, but the zero default will be re-written as
a -1 boolean. Generally, it it could incorrectly set b_info->altp2m
through aliased data.
Fixes: 0291089f6ea8 ("xen: enable altp2m at create domain domctl")
Signed-off-by: Jason Andryuk <jason.andr...@amd.com>
Change-Id: Ifaca3533dcce3f409c2efa292c7e96fba6371d9d
---
tools/libs/light/libxl_x86.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/tools/libs/light/libxl_x86.c b/tools/libs/light/libxl_x86.c
index 0b1c2d3a96..b8f6663829 100644
--- a/tools/libs/light/libxl_x86.c
+++ b/tools/libs/light/libxl_x86.c
@@ -821,10 +821,12 @@ int libxl__arch_domain_build_info_setdefault(libxl__gc
*gc,
* If the legacy field info->u.hvm.altp2m is set, activate altp2m.
* Otherwise set altp2m based on the field info->altp2m.
*/
- libxl_defbool_setdefault(&b_info->u.hvm.altp2m, false);
- if (b_info->altp2m == LIBXL_ALTP2M_MODE_DISABLED &&
- libxl_defbool_val(b_info->u.hvm.altp2m))
- b_info->altp2m = libxl_defbool_val(b_info->u.hvm.altp2m);
+ if (b_info->type == LIBXL_DOMAIN_TYPE_HVM) {
+ libxl_defbool_setdefault(&b_info->u.hvm.altp2m, false);
+ if (b_info->altp2m == LIBXL_ALTP2M_MODE_DISABLED &&
+ libxl_defbool_val(b_info->u.hvm.altp2m))
+ b_info->altp2m = libxl_defbool_val(b_info->u.hvm.altp2m);
+ }
I think at least the latter half of the comment wants to move inside the
if() then.
Yes. Actually, I think the whole comment should move inside the if().
Regards,
Jason
