From 84d49bc7469905877fc22f6faea1e53c8c0cbe1c Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@redhat.com>
Date: Fri, 21 Sep 2018 09:19:39 +0200
Subject: [PATCH 03/22] pc-dimm: turn alignment assert into check
RH-Author: David Hildenbrand <david@redhat.com>
Message-id: <20180921091939.4107-1-david@redhat.com>
Patchwork-id: 82227
O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH] pc-dimm: turn alignment assert into check
Bugzilla: 1629720
RH-Acked-by: Pankaj Gupta <pagupta@redhat.com>
RH-Acked-by: Igor Mammedov <imammedo@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1629720
Brew: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=18439425
Upstream: 4d8938a05db15dea2c86c4ab9c5f872f160d2188
The start of the address space indicates which maximum alignment is
supported by our machine (e.g. ppc, x86 1GB). This is helpful to
catch fragmenting guest physical memory in strange fashions.
Right now we can crash QEMU by e.g. (there might be easier examples)
qemu-system-x86_64 -m 256M,maxmem=20G,slots=2 \
-object memory-backend-file,id=mem0,size=8192M,mem-path=/dev/zero,align=8192M \
-device pc-dimm,id=dimm1,memdev=mem0
Backport conflicts:
hw/mem/memory-device.c: The memory device refactoring is part of 3.0
and probably not worth backporting to 7.X.
So fix it in previous pc-dimm code.
Note: The upstream patch missed a "x" (0% .. vs. 0x% ..), will fix that
upstream, too.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180607154705.6316-2-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 4d8938a05db15dea2c86c4ab9c5f872f160d2188)
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
hw/mem/pc-dimm.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index 51350d9..a9d7c51 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -298,14 +298,19 @@ uint64_t pc_dimm_get_free_addr(uint64_t address_space_start,
uint64_t new_addr, ret = 0;
uint64_t address_space_end = address_space_start + address_space_size;
- g_assert(QEMU_ALIGN_UP(address_space_start, align) == address_space_start);
-
if (!address_space_size) {
error_setg(errp, "memory hotplug is not enabled, "
"please add maxmem option");
goto out;
}
+ /* address_space_start indicates the maximum alignment we expect */
+ if (QEMU_ALIGN_UP(address_space_start, align) != address_space_start) {
+ error_setg(errp, "the alignment (0x%" PRIx64 ") is not supported",
+ align);
+ goto out;
+ }
+
if (hint && QEMU_ALIGN_UP(*hint, align) != *hint) {
error_setg(errp, "address must be aligned to 0x%" PRIx64 " bytes",
align);
--
1.8.3.1