Re: [Qemu-devel] [qemu-s390x] [PULL 00/46] First batch of s390x patches for 2.12

[Christian Borntraeger]

On 12/14/2017 08:05 PM, Peter Maydell wrote:
> On 14 December 2017 at 17:09, Cornelia Huck <address@hidden> wrote:
>> The following changes since commit 0ef0583d5adceb9138bdb47494dabd1549ac5b6d:
>>
>>   Merge remote-tracking branch 'remotes/dgilbert/tags/pull-hmp-20171214' 
>> into staging (2017-12-14 15:32:32 +0000)
>>
>> are available in the git repository at:
>>
>>   git://github.com/cohuck/qemu tags/s390x-20171214
>>
>> for you to fetch changes up to a9e3065c6579df8652ce38502276ac0a13180d6f:
>>
>>   s390-ccw-virtio: allow for systems larger that 7.999TB (2017-12-14 
>> 17:56:54 +0100)
>>
>> ----------------------------------------------------------------
>> s390x changes for 2.12:
>> - Lots of tcg improvements: ccw hotplug is now working and we can run
>>   a Linux kernel built for z12 under tcg
>> - zPCI improvements to get virtio-pci working
>> - get rid of the cssid restrictions for virtual and non-virtual channel
>>   devices
>> - we now support 8TB+ systems
>> - 2.12 compat machine
>> - fixes and cleanups
>>
>> ----------------------------------------------------------------
> 
> Hi; I'm afraid this fails to build on 32-bit:
> 
> In file included from
> /usr/lib/arm-linux-gnueabihf/glib-2.0/include/glibconfig.h:9:0,
>                  from /usr/include/glib-2.0/glib/gtypes.h:32,
>                  from /usr/include/glib-2.0/glib/galloca.h:32,
>                  from /usr/include/glib-2.0/glib.h:30,
>                  from /home/peter.maydell/qemu/include/glib-compat.h:19,
>                  from /home/peter.maydell/qemu/include/qemu/osdep.h:107,
>                  from /home/peter.maydell/qemu/hw/s390x/s390-virtio-ccw.c:13:
> /home/peter.maydell/qemu/hw/s390x/s390-virtio-ccw.c: In function
> 's390_memory_init':
> /usr/include/glib-2.0/glib/gmacros.h:291:26: error: comparison is
> always true due to limited range of data type [-Werror=type-limits]
>  #define MIN(a, b)  (((a) < (b)) ? (a) : (b))
>                           ^
> /home/peter.maydell/qemu/hw/s390x/s390-virtio-ccw.c:177:17: note: in
> expansion of macro 'MIN'
>          chunk = MIN(mem_size, KVM_SLOT_MAX_BYTES);
>                  ^
> 
> (ram_addr_t can be a 32-bit type).

gcc seems to be extra clever, even a cast does not work.
Something like this seems to work.

diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 80e753a5ef..9abb8de9f9 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -172,9 +172,10 @@ static void s390_memory_init(ram_addr_t mem_size)
     name = g_strdup_printf("s390.ram");
     while (mem_size) {
         MemoryRegion *ram = g_new(MemoryRegion, 1);
+       unsigned long long size = mem_size;
 
         /* KVM does not allow memslots >= 8 TB */
-        chunk = MIN(mem_size, KVM_SLOT_MAX_BYTES);
+        chunk = MIN(size, KVM_SLOT_MAX_BYTES);
         memory_region_allocate_system_memory(ram, NULL, name, chunk);
         memory_region_add_subregion(sysmem, offset, ram);
         mem_size -= chunk;