The limitation of shared_info being allocated below 4G to fit in the
start_info field only applies to 32bit PV guests. On 64bit PV guests the
start_info field is 64bits wide. HVM guests don't use start_info at all.
Limit the allocation address restriction to 32bit PV guests only.
Fixes: 3cadc0469d5c ("x86_64: shared_info must be allocated below 4GB as it is
advertised to 32-bit guests via a 32-bit machine address field in start_info.")
Signed-off-by: Roger Pau Monné <[email protected]>
---
xen/arch/x86/domain.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index edb76366b596..4163568043b1 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -882,10 +882,13 @@ int arch_domain_create(struct domain *d,
goto fail;
/*
- * The shared_info machine address must fit in a 32-bit field within a
- * 32-bit guest's start_info structure. Hence we specify MEMF_bits(32).
+ * For 32bit PV guests the shared_info machine address must fit in a 32-bit
+ * field within the guest's start_info structure. Hence we specify
+ * MEMF_bits(32).
*/
- if ( (d->shared_info = alloc_xenheap_pages(0, MEMF_bits(32))) == NULL )
+ if ( (d->shared_info =
+ alloc_xenheap_pages(0, is_pv_32bit_domain(d) ? MEMF_bits(32)
+ : 0)) == NULL )
goto fail;
clear_page(d->shared_info);
--
2.51.0
