On Fri, May 11, 2018 at 03:19:52PM +0200, David Hildenbrand wrote:
> While s390x has no real interface for communicating devices mapped into
> the physical address space of the guest, paravirtualized devices can
> easily expose the applicable address range themselves.
>
> So let's use the difference between maxram_size and ram_size as the size
> for our hotplug memory area (just as on other architectures).
>
> Signed-off-by: David Hildenbrand <da...@redhat.com>
> ---
> hw/s390x/s390-virtio-ccw.c | 28 ++++++++++++++++++++++++++--
> 1 file changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index ee0a2b124f..09b755282b 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -157,9 +157,11 @@ static void virtio_ccw_register_hcalls(void)
> #define KVM_MEM_MAX_NR_PAGES ((1ULL << 31) - 1)
> #define SEG_MSK (~0xfffffULL)
> #define KVM_SLOT_MAX_BYTES ((KVM_MEM_MAX_NR_PAGES * TARGET_PAGE_SIZE) &
> SEG_MSK)
> -static void s390_memory_init(ram_addr_t mem_size)
> +static void s390_memory_init(MachineState *machine)
> {
> + S390CcwMachineState *ms = S390_CCW_MACHINE(machine);
> MemoryRegion *sysmem = get_system_memory();
> + ram_addr_t mem_size = machine->ram_size;
> ram_addr_t chunk, offset = 0;
> unsigned int number = 0;
> gchar *name;
> @@ -181,6 +183,28 @@ static void s390_memory_init(ram_addr_t mem_size)
> }
> g_free(name);
>
> + /* always allocate the device memory information */
> + machine->device_memory = g_malloc0(sizeof(*machine->device_memory));
Is there any QEMU guideline/preference/recommendation in using g_new0
vs. g_malloc0?
I recall Paolo suggesting g_new0 instead of g_malloc0 in another patch:
http://lists.nongnu.org/archive/html/qemu-devel/2018-05/msg02372.html
> +
> + /* initialize device memory address space */
> + if (machine->ram_size < machine->maxram_size) {
> + ram_addr_t device_mem_size = machine->maxram_size -
> machine->ram_size;
> +
> + if (QEMU_ALIGN_UP(machine->maxram_size, TARGET_PAGE_SIZE) !=
> + machine->maxram_size) {
> + error_report("maximum memory size must be aligned to multiple of
> "
> + "%d bytes", TARGET_PAGE_SIZE);
> + exit(EXIT_FAILURE);
> + }
> +
> + machine->device_memory->base = machine->ram_size;
> + memory_region_init(&machine->device_memory->mr, OBJECT(ms),
> + "device-memory", device_mem_size);
> + memory_region_add_subregion(sysmem, machine->device_memory->base,
> + &machine->device_memory->mr);
> +
> + }
> +
> /* Initialize storage key device */
> s390_skeys_init();
> /* Initialize storage attributes device */
> @@ -304,7 +328,7 @@ static void ccw_init(MachineState *machine)
> DeviceState *dev;
>
> s390_sclp_init();
> - s390_memory_init(machine->ram_size);
> + s390_memory_init(machine);
>
> /* init CPUs (incl. CPU model) early so s390_has_feature() works */
> s390_init_cpus(machine);
> --
> 2.14.3
>
>
--
Murilo
