The ALLOCA(3) man-page mentions its "use is discouraged".

Use autofree heap allocation instead, replacing it by a g_malloc call.

Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 target/ppc/kvm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 104a308abb5..23c4ea377e8 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -2698,11 +2698,11 @@ int kvmppc_save_htab(QEMUFile *f, int fd, size_t bufsize, int64_t max_ns)
 int kvmppc_load_htab_chunk(QEMUFile *f, int fd, uint32_t index,
                            uint16_t n_valid, uint16_t n_invalid, Error **errp)
 {
-    struct kvm_get_htab_header *buf;
+    g_autofree struct kvm_get_htab_header *buf = NULL;
     size_t chunksize = sizeof(*buf) + n_valid * HASH_PTE_SIZE_64;
     ssize_t rc;
 
-    buf = alloca(chunksize);
+    buf = g_malloc(chunksize);
     buf->index = index;
     buf->n_valid = n_valid;
     buf->n_invalid = n_invalid;
-- 
2.26.3