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[Qemu-devel] [PATCH v2 1/2] spapr: Accommadate alignment gaps in hotplug
From: |
Bharata B Rao |
Subject: |
[Qemu-devel] [PATCH v2 1/2] spapr: Accommadate alignment gaps in hotplug memory region |
Date: |
Mon, 26 Oct 2015 13:30:37 +0530 |
Accommodate enough space in hotplug memory region so that it will
be possible to align memory in each slot to 256M. When PowerPC memory
hotplug enables inter-dimm gaps, then we could end up having
unused/unassigned 256M memory chucks between DIMMs in the hotplug memory
region. Hence create DRC objects spanning the entire alignment-adjusted
hotplug memory region instead of just the acutal
hotpluggable size (machine->maxram_size - machine->ram_size).
In addition, pass 256M alignment to pc_dimm_memory_plug() so that
the DIMM address gets aligned to 256M.
Signed-off-by: Bharata B Rao <address@hidden>
Reviewed-by: Igor Mammedov <address@hidden>
---
hw/ppc/spapr.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index e1202ce..f29bb10 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -753,7 +753,7 @@ static int spapr_populate_drconf_memory(sPAPRMachineState
*spapr, void *fdt)
int ret, i, offset;
uint64_t lmb_size = SPAPR_MEMORY_BLOCK_SIZE;
uint32_t prop_lmb_size[] = {0, cpu_to_be32(lmb_size)};
- uint32_t nr_lmbs = (machine->maxram_size - machine->ram_size)/lmb_size;
+ uint32_t nr_lmbs = memory_region_size(&spapr->hotplug_memory.mr)/lmb_size;
uint32_t *int_buf, *cur_index, buf_len;
int nr_nodes = nb_numa_nodes ? nb_numa_nodes : 1;
@@ -1647,9 +1647,8 @@ static void spapr_drc_reset(void *opaque)
static void spapr_create_lmb_dr_connectors(sPAPRMachineState *spapr)
{
- MachineState *machine = MACHINE(spapr);
uint64_t lmb_size = SPAPR_MEMORY_BLOCK_SIZE;
- uint32_t nr_lmbs = (machine->maxram_size - machine->ram_size)/lmb_size;
+ uint32_t nr_lmbs = memory_region_size(&spapr->hotplug_memory.mr)/lmb_size;
int i;
for (i = 0; i < nr_lmbs; i++) {
@@ -1825,6 +1824,20 @@ static void ppc_spapr_init(MachineState *machine)
spapr->hotplug_memory.base = ROUND_UP(machine->ram_size,
SPAPR_HOTPLUG_MEM_ALIGN);
+
+ /*
+ * Ensure that there is enough space in the hotplug memory
+ * region to support a maximum alignment of 256M per slot.
+ * Though PowerPC has 16M and 16G huge pages, PowerKVM supports
+ * only 16M and hence 256M alignment works until we start
+ * supporting 16G hugepage.
+ *
+ * Instead of max hugepage size alignment, we go with 256M
+ * alignment because we require the DIMM address to be 256M
+ * aligned as we maintain a DRC object for every 256M memory
+ * chunk in the hotplug memory region.
+ */
+ hotplug_mem_size += SPAPR_MEMORY_BLOCK_SIZE * machine->ram_slots;
memory_region_init(&spapr->hotplug_memory.mr, OBJECT(spapr),
"hotplug-memory", hotplug_mem_size);
memory_region_add_subregion(sysmem, spapr->hotplug_memory.base,
@@ -2147,7 +2160,7 @@ static void spapr_memory_plug(HotplugHandler
*hotplug_dev, DeviceState *dev,
PCDIMMDevice *dimm = PC_DIMM(dev);
PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
MemoryRegion *mr = ddc->get_memory_region(dimm);
- uint64_t align = memory_region_get_alignment(mr);
+ uint64_t align = SPAPR_MEMORY_BLOCK_SIZE;
uint64_t size = memory_region_size(mr);
uint64_t addr;
--
2.1.0