[Qemu-devel] [PATCH] pc-dimm: fix checking for backend memory size

[Zhu Guihua]

If hot add 100MiB memory like this:
(monitor) object_add memory-backend-ram,id=ram0,size=100M
(monitor) device_add pc-dimm,id=d0,memdev=ram0

The hotplug operation will faile, and the guest will print error message:
Section-unaligned hotplug range: start 0x100000000, size 0x6400000
acpi PNP0C80:00: add_memory failed
acpi PNP0C80:00: acpi_memory_enable_device() error

Then I found that, according to the func check_hotplug_memory_range() in linux
kernel, backend memory size must be multiple of 128MiB, not 2MiB.

So this patch checks whether backend memory size is multiple of 128MiB.

Signed-off-by: Zhu Guihua <address@hidden>
---
 hw/mem/pc-dimm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index d431834..3b8a015 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -161,9 +161,9 @@ uint64_t pc_dimm_get_free_addr(uint64_t address_space_start,
         goto out;
     }
 
-    if (QEMU_ALIGN_UP(size, align) != size) {
+    if (QEMU_ALIGN_UP(size, align * 64) != size) {
         error_setg(errp, "backend memory size must be multiple of 0x%"
-                   PRIx64, align);
+                   PRIx64, align * 64);
         goto out;
     }
 
-- 
1.9.3