[Qemu-devel] [PATCH 5/5] sclp-s390: Add memory hotplug SCLPs

[Matthew Rosato]

Add memory information to read SCP info and add handlers for
Read Storage Element Information, Attach Storage Element,
Assign Storage and Unassign Storage.

Signed-off-by: Matthew Rosato <address@hidden>
---
 hw/s390x/sclp.c         |  233 +++++++++++++++++++++++++++++++++++++++++++++--
 include/hw/s390x/sclp.h |    2 +
 2 files changed, 229 insertions(+), 6 deletions(-)

diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
index cb53d7e..5d27fc3 100644
--- a/hw/s390x/sclp.c
+++ b/hw/s390x/sclp.c
@@ -15,9 +15,15 @@
 #include "cpu.h"
 #include "sysemu/kvm.h"
 #include "exec/memory.h"
-
+#include "exec/address-spaces.h"
 #include "hw/s390x/sclp.h"
 
+int shift;
+ram_addr_t standby_subregion_size;
+ram_addr_t padded_ram_size;
+ram_addr_t rzm;
+char *standby_state_map;
+
 static inline S390SCLPDevice *get_event_facility(void)
 {
     ObjectProperty *op = object_property_find(qdev_get_machine(),
@@ -31,16 +37,215 @@ static inline S390SCLPDevice *get_event_facility(void)
 static void read_SCP_info(SCCB *sccb)
 {
     ReadInfo *read_info = (ReadInfo *) sccb;
-    int shift = 0;
+    int rnsize, rnmax;
+    int max_avail_slots = MAX_AVAIL_SLOTS;
+#ifdef CONFIG_KVM
+    max_avail_slots = kvm_check_extension(kvm_state, KVM_CAP_NR_MEMSLOTS);
+#endif
+
+    read_info->facilities = 0;
+
+    if (standby_mem_size) {
+        /*
+         * The storage increment size is a multiple of 1M and is a power of 2.
+         * The number of storage increments must be 1020 or fewer.
+         */
+        while ((ram_size >> (20 + shift)) > 1020) {
+            shift++;
+        }
+        while ((standby_mem_size >> (20 + shift)) > 1020) {
+            shift++;
+        }
+
+        standby_subregion_size = MEM_SECTION_SIZE;
+        /* Deduct the memory slot already used for core */
+        while ((standby_subregion_size * (max_avail_slots - 1)
+               < standby_mem_size)) {
+            standby_subregion_size = standby_subregion_size << 1;
+        }
+        /*
+         * Initialize mapping of guest standby memory sections indicating which
+         * are and are not online. Assume all standby memory begins offline.
+         */
+        if (standby_mem_size % standby_subregion_size) {
+            standby_state_map = g_malloc0((standby_mem_size /
+                                           standby_subregion_size + 1) *
+                                          (standby_subregion_size /
+                                           MEM_SECTION_SIZE));
+        } else {
+            standby_state_map = g_malloc0(standby_mem_size / MEM_SECTION_SIZE);
+        }
+
+        padded_ram_size = ram_size + pad_size;
+        rzm = 1 << (20 + shift);
+
+    } else {
+        while ((ram_size >> (20 + shift)) > 65535) {
+            shift++;
+        }
+    }
 
-    while ((ram_size >> (20 + shift)) > 65535) {
-        shift++;
+    rnsize = 1 << shift;
+    if (rnsize <= 128) {
+        read_info->rnsize = rnsize;
+    } else {
+        read_info->rnsize = 0;
+        read_info->rnsize2 = cpu_to_be32(rnsize);
+    }
+
+    rnmax = (ram_size + standby_mem_size + pad_size) >> (20 + shift);
+    if (rnmax < 0x10000) {
+        read_info->rnmax = cpu_to_be16(rnmax);
+    } else {
+        read_info->rnmax = cpu_to_be16(0);
+        read_info->rnmax2 = cpu_to_be64(rnmax);
+    }
+
+    if (standby_mem_size) {
+        read_info->facilities |= cpu_to_be64(SCLP_FC_ASSIGN_ATTACH_READ_STOR);
     }
-    read_info->rnmax = cpu_to_be16(ram_size >> (20 + shift));
-    read_info->rnsize = 1 << shift;
     sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_READ_COMPLETION);
 }
 
+static void read_storage_element0_info(SCCB *sccb)
+{
+    int i, assigned;
+    int subincrement_id = SCLP_STARTING_SUBINCREMENT_ID;
+    ReadStorageElementInfo *storage_info = (ReadStorageElementInfo *) sccb;
+
+    if ((ram_size >> (20 + shift)) >= 0x10000) {
+        sccb->h.response_code = cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION);
+        return;
+    }
+
+    storage_info->max_id = cpu_to_be16(standby_mem_size ? 1 : 0);
+    assigned = ram_size >> (20 + shift);
+    storage_info->assigned = cpu_to_be16(assigned);
+
+    for (i = 0; i < assigned; i++) {
+        storage_info->entries[i] = cpu_to_be32(subincrement_id);
+        subincrement_id += SCLP_INCREMENT_UNIT;
+    }
+    sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_READ_COMPLETION);
+}
+
+static void read_storage_element1_info(SCCB *sccb)
+{
+    ReadStorageElementInfo *storage_info = (ReadStorageElementInfo *) sccb;
+
+    if ((standby_mem_size >> (20 + shift)) >= 0x10000) {
+        sccb->h.response_code = cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION);
+        return;
+    }
+
+    storage_info->max_id = cpu_to_be16(standby_mem_size ? 1 : 0);
+    storage_info->assigned = cpu_to_be16(standby_mem_size >> (20 + shift));
+    storage_info->standby = cpu_to_be16(standby_mem_size >> (20 + shift));
+    sccb->h.response_code = cpu_to_be16(SCLP_RC_STANDBY_READ_COMPLETION);
+}
+
+static void attach_storage_element(SCCB *sccb, uint16_t element)
+{
+    int i, assigned, subincrement_id;
+    AttachStorageElement *attach_info = (AttachStorageElement *) sccb;
+
+    if (element != 1) {
+        sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
+        return;
+    }
+
+    assigned = standby_mem_size >> (20 + shift);
+    attach_info->assigned = cpu_to_be16(assigned);
+    subincrement_id = ((ram_size >> (20 + shift)) << 16)
+                      + SCLP_STARTING_SUBINCREMENT_ID;
+    for (i = 0; i < assigned; i++) {
+        attach_info->entries[i] = cpu_to_be32(subincrement_id);
+        subincrement_id += SCLP_INCREMENT_UNIT;
+    }
+    sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
+}
+
+static void assign_storage(SCCB *sccb)
+{
+    MemoryRegion *mr = NULL;
+    int this_subregion_size;
+    AssignStorage *assign_info = (AssignStorage *) sccb;
+    ram_addr_t assign_addr = (assign_info->rn - 1) * rzm;
+    MemoryRegion *sysmem = get_system_memory();
+
+    if ((assign_addr % MEM_SECTION_SIZE == 0) &&
+        (assign_addr >= padded_ram_size)) {
+        mr = memory_region_find(sysmem, assign_addr, 1).mr;
+        if (!mr) {
+
+            MemoryRegion *standby_ram = g_new(MemoryRegion, 1);
+
+            /* offset to align to standby_subregion_size for allocation */
+            ram_addr_t offset = assign_addr -
+                                (assign_addr - padded_ram_size)
+                                % standby_subregion_size;
+
+            /* strlen("standby.ram") + 4 (Max of KVM_MEMORY_SLOTS) +  NULL */
+            char id[16];
+            snprintf(id, 16, "standby.ram%d", (int)((offset - padded_ram_size)
+                     / standby_subregion_size) + 1);
+
+            /* Allocate a subregion of the calculated standby_subregion_size */
+            if (offset + standby_subregion_size >
+                padded_ram_size + standby_mem_size) {
+                this_subregion_size = padded_ram_size + standby_mem_size
+                                      - offset;
+            } else {
+                this_subregion_size = standby_subregion_size;
+            }
+
+            memory_region_init_ram(standby_ram, NULL, id, this_subregion_size);
+            vmstate_register_ram_global(standby_ram);
+            memory_region_add_subregion(sysmem, offset, standby_ram);
+        }
+        standby_state_map[(assign_addr - padded_ram_size)
+                          / MEM_SECTION_SIZE] = 1;
+    }
+    sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
+}
+
+static void unassign_storage(SCCB *sccb)
+{
+    MemoryRegion *mr = NULL;
+    AssignStorage *assign_info = (AssignStorage *) sccb;
+    ram_addr_t unassign_addr = (assign_info->rn - 1) * rzm;
+    MemoryRegion *sysmem = get_system_memory();
+
+    /* if the addr is a multiple of 256 MB */
+    if ((unassign_addr % MEM_SECTION_SIZE == 0) &&
+        (unassign_addr >= padded_ram_size)) {
+        standby_state_map[(unassign_addr -
+                           padded_ram_size) / MEM_SECTION_SIZE] = 0;
+        mr = memory_region_find(sysmem, unassign_addr, 1).mr;
+        if (mr) {
+            int i;
+            int is_removable = 1;
+            ram_addr_t map_offset = (unassign_addr - padded_ram_size -
+                                     (unassign_addr - padded_ram_size)
+                                     % standby_subregion_size);
+            for (i = 0;
+                 i < (standby_subregion_size / MEM_SECTION_SIZE);
+                 i++) {
+
+                if (standby_state_map[i + map_offset / MEM_SECTION_SIZE]) {
+                    is_removable = 0;
+                    break;
+                }
+            }
+            if (is_removable) {
+                memory_region_del_subregion(sysmem, mr);
+                memory_region_destroy(mr);
+            }
+        }
+    }
+    sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
+}
+
 static void sclp_execute(SCCB *sccb, uint64_t code)
 {
     S390SCLPDevice *sdev = get_event_facility();
@@ -50,6 +255,22 @@ static void sclp_execute(SCCB *sccb, uint64_t code)
     case SCLP_CMDW_READ_SCP_INFO_FORCED:
         read_SCP_info(sccb);
         break;
+    case SCLP_READ_STORAGE_ELEMENT_INFO:
+        if (code & 0xff00) {
+            read_storage_element1_info(sccb);
+        } else {
+            read_storage_element0_info(sccb);
+        }
+        break;
+    case SCLP_ATTACH_STORAGE_ELEMENT:
+        attach_storage_element(sccb, (code & 0xff00) >> 8);
+        break;
+    case SCLP_ASSIGN_STORAGE:
+        assign_storage(sccb);
+        break;
+    case SCLP_UNASSIGN_STORAGE:
+        unassign_storage(sccb);
+        break;
     default:
         sdev->sclp_command_handler(sdev->ef, sccb, code);
         break;
diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h
index e80cb23..1211d69 100644
--- a/include/hw/s390x/sclp.h
+++ b/include/hw/s390x/sclp.h
@@ -143,6 +143,8 @@ static inline int sccb_data_len(SCCB *sccb)
      OBJECT_GET_CLASS(S390SCLPDeviceClass, (obj), \
              TYPE_DEVICE_S390_SCLP)
 
+extern ram_addr_t pad_size;
+
 typedef struct SCLPEventFacility SCLPEventFacility;
 
 typedef struct S390SCLPDevice {
-- 
1.7.9.5