From d0e5a8f2937de66778d94c20a8fc5cf43501fa04 Mon Sep 17 00:00:00 2001 From: Bharata B Rao Date: Fri, 10 Jun 2016 10:44:48 +0530 Subject: [PATCH] spapr: Ensure all LMBs are represented in ibm,dynamic-memory Memory hotplug can fail for some combinations of RAM and maxmem when DDW is enabled in the presence of devices like nec-usb-xhci. DDW depends on maximum addressable memory returned by guest and this value is currently being calculated wrongly by the guest kernel routine memory_hotplug_max(). While there is an attempt to fix the guest kernel, this patch works around the problem within QEMU itself. memory_hotplug_max() routine in the guest kernel arrives at max addressable memory by multiplying lmb-size with the lmb-count obtained from ibm,dynamic-memory property. There are two assumptions here: - All LMBs are part of ibm,dynamic memory: This is not true for PowerKVM where only hot-pluggable LMBs are present in this property. - The memory area comprising of RAM and hotplug region is contiguous: This needn't be true always for PowerKVM as there can be gap between boot time RAM and hotplug region. To work around this guest kernel bug, ensure that ibm,dynamic-memory has information about all the LMBs (RMA, boot-time LMBs, future hotpluggable LMBs, and dummy LMBs to cover the gap between RAM and hotpluggable region). RMA is represented separately by memory@0 node. Hence mark RMA LMBs and also the LMBs for the gap b/n RAM and hotpluggable region as reserved and as having no valid DRC so that these LMBs are not considered by the guest. Signed-off-by: Bharata B Rao Reviewed-by: Michael Roth Reviewed-by: Nathan Fontenot Signed-off-by: David Gibson --- hw/ppc/spapr.c | 55 +++++++++++++++++++++++++++--------------- include/hw/ppc/spapr.h | 6 +++-- 2 files changed, 40 insertions(+), 21 deletions(-) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 0636642341..9a4a803b17 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -762,14 +762,17 @@ 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 hotplug_lmb_start = spapr->hotplug_memory.base / lmb_size; + uint32_t nr_lmbs = (spapr->hotplug_memory.base + + 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; /* - * Don't create the node if there are no DR LMBs. + * Don't create the node if there is no hotpluggable memory */ - if (!nr_lmbs) { + if (machine->ram_size == machine->maxram_size) { return 0; } @@ -803,26 +806,40 @@ static int spapr_populate_drconf_memory(sPAPRMachineState *spapr, void *fdt) int_buf[0] = cpu_to_be32(nr_lmbs); cur_index++; for (i = 0; i < nr_lmbs; i++) { - sPAPRDRConnector *drc; - sPAPRDRConnectorClass *drck; - uint64_t addr = i * lmb_size + spapr->hotplug_memory.base;; + uint64_t addr = i * lmb_size; uint32_t *dynamic_memory = cur_index; - drc = spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_LMB, - addr/lmb_size); - g_assert(drc); - drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc); + if (i >= hotplug_lmb_start) { + sPAPRDRConnector *drc; + sPAPRDRConnectorClass *drck; - dynamic_memory[0] = cpu_to_be32(addr >> 32); - dynamic_memory[1] = cpu_to_be32(addr & 0xffffffff); - dynamic_memory[2] = cpu_to_be32(drck->get_index(drc)); - dynamic_memory[3] = cpu_to_be32(0); /* reserved */ - dynamic_memory[4] = cpu_to_be32(numa_get_node(addr, NULL)); - if (addr < machine->ram_size || - memory_region_present(get_system_memory(), addr)) { - dynamic_memory[5] = cpu_to_be32(SPAPR_LMB_FLAGS_ASSIGNED); + drc = spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_LMB, i); + g_assert(drc); + drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc); + + dynamic_memory[0] = cpu_to_be32(addr >> 32); + dynamic_memory[1] = cpu_to_be32(addr & 0xffffffff); + dynamic_memory[2] = cpu_to_be32(drck->get_index(drc)); + dynamic_memory[3] = cpu_to_be32(0); /* reserved */ + dynamic_memory[4] = cpu_to_be32(numa_get_node(addr, NULL)); + if (memory_region_present(get_system_memory(), addr)) { + dynamic_memory[5] = cpu_to_be32(SPAPR_LMB_FLAGS_ASSIGNED); + } else { + dynamic_memory[5] = cpu_to_be32(0); + } } else { - dynamic_memory[5] = cpu_to_be32(0); + /* + * LMB information for RMA, boot time RAM and gap b/n RAM and + * hotplug memory region -- all these are marked as reserved + * and as having no valid DRC. + */ + dynamic_memory[0] = cpu_to_be32(addr >> 32); + dynamic_memory[1] = cpu_to_be32(addr & 0xffffffff); + dynamic_memory[2] = cpu_to_be32(0); + dynamic_memory[3] = cpu_to_be32(0); /* reserved */ + dynamic_memory[4] = cpu_to_be32(-1); + dynamic_memory[5] = cpu_to_be32(SPAPR_LMB_FLAGS_RESERVED | + SPAPR_LMB_FLAGS_DRC_INVALID); } cur_index += SPAPR_DR_LMB_LIST_ENTRY_SIZE; diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h index 971df3d0df..3ac85c07d7 100644 --- a/include/hw/ppc/spapr.h +++ b/include/hw/ppc/spapr.h @@ -620,9 +620,11 @@ int spapr_rng_populate_dt(void *fdt); #define SPAPR_DR_LMB_LIST_ENTRY_SIZE 6 /* - * This flag value defines the LMB as assigned in ibm,dynamic-memory - * property under ibm,dynamic-reconfiguration-memory node. + * Defines for flag value in ibm,dynamic-memory property under + * ibm,dynamic-reconfiguration-memory node. */ #define SPAPR_LMB_FLAGS_ASSIGNED 0x00000008 +#define SPAPR_LMB_FLAGS_DRC_INVALID 0x00000020 +#define SPAPR_LMB_FLAGS_RESERVED 0x00000080 #endif /* !defined (__HW_SPAPR_H__) */