qemu-kvm/SOURCES/kvm-s390x-s390-virtio-ccw-don-t-crash-on-weird-RAM-sizes.patch

64 lines
2.4 KiB
Diff

From 4ee3076ac566622929f9410636483c4f0b2da967 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@redhat.com>
Date: Thu, 19 Dec 2024 15:41:02 +0100
Subject: [PATCH 10/26] s390x/s390-virtio-ccw: don't crash on weird RAM sizes
RH-Author: Thomas Huth <thuth@redhat.com>
RH-MergeRequest: 351: Enable virtio-mem support on s390x
RH-Jira: RHEL-72977
RH-Acked-by: David Hildenbrand <david@redhat.com>
RH-Acked-by: Juraj Marcin <None>
RH-Commit: [10/26] 55738da52f3cf4746bee2b17780a10720fa05863 (thuth/qemu-kvm-cs)
KVM is not happy when starting a VM with weird RAM sizes:
# qemu-system-s390x --enable-kvm --nographic -m 1234K
qemu-system-s390x: kvm_set_user_memory_region: KVM_SET_USER_MEMORY_REGION
failed, slot=0, start=0x0, size=0x244000: Invalid argument
kvm_set_phys_mem: error registering slot: Invalid argument
Aborted (core dumped)
Let's handle that in a better way by rejecting such weird RAM sizes
right from the start:
# qemu-system-s390x --enable-kvm --nographic -m 1234K
qemu-system-s390x: ram size must be multiples of 1 MiB
Message-ID: <20241219144115.2820241-2-david@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
(cherry picked from commit 14e568ab4836347481af2e334009c385f456a734)
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
hw/s390x/s390-virtio-ccw.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 94cad1705b..82ded9666c 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -180,6 +180,17 @@ static void s390_memory_init(MemoryRegion *ram)
{
MemoryRegion *sysmem = get_system_memory();
+ if (!QEMU_IS_ALIGNED(memory_region_size(ram), 1 * MiB)) {
+ /*
+ * SCLP cannot possibly expose smaller granularity right now and KVM
+ * cannot handle smaller granularity. As we don't support NUMA, the
+ * region size directly corresponds to machine->ram_size, and the region
+ * is a single RAM memory region.
+ */
+ error_report("ram size must be multiples of 1 MiB");
+ exit(EXIT_FAILURE);
+ }
+
/* allocate RAM for core */
memory_region_add_subregion(sysmem, 0, ram);
--
2.48.1