When running the s390x virtio machine we can potentially use uninitialized
memory for the virtio device backing ram. That can lead to weird breakge.
So let's better initialize it to 0 properly.
Reported-by: Andreas Färber <afaer...@suse.de>
Signed-off-by: Alexander Graf <ag...@suse.de>
---
hw/s390-virtio.c | 9 +++++++++
1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
index 37945d5..d936809 100644
--- a/hw/s390-virtio.c
+++ b/hw/s390-virtio.c
@@ -165,6 +165,8 @@ static void s390_init(ram_addr_t my_ram_size,
ram_addr_t initrd_size = 0;
int shift = 0;
uint8_t *storage_keys;
+ void *virtio_region;
+ target_phys_addr_t virtio_region_len;
int i;
/* s390x ram size detection needs a 16bit multiplier + an increment. So
@@ -184,6 +186,13 @@ static void s390_init(ram_addr_t my_ram_size,
memory_region_init_ram(ram, NULL, "s390.ram", my_ram_size);
memory_region_add_subregion(sysmem, 0, ram);
+ /* clear virtio region */
+ virtio_region_len = my_ram_size - ram_size;
+ virtio_region = cpu_physical_memory_map(ram_size, &virtio_region_len,
true);
+ memset(virtio_region, 0, virtio_region_len);
+ cpu_physical_memory_unmap(virtio_region, virtio_region_len, 1,
+ virtio_region_len);
+
/* allocate storage keys */
storage_keys = g_malloc0(my_ram_size / TARGET_PAGE_SIZE);
--
1.6.0.2
