[Qemu-devel] [PATCH 2/8] [PATCH RFC v3] s390-qemu: cpu hotplug - SCLP CPU Info

["Jason J. Herne" <jjherne@us.ibm.com>]

From: "Jason J. Herne" <jjherne@us.ibm.com>

Implement the CPU data in SCLP "Read SCP Info".  And implement "Read CPU Info"
SCLP command. This data will be used by the guest to get information about hot
plugged cpus.

Signed-off-by: Jason J. Herne <jjherne@us.ibm.com>
---
 hw/s390x/sclp.c         |   51 +++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/s390x/sclp.h |   32 +++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+)

diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
index cb53d7e..da8cf7a 100644
--- a/hw/s390x/sclp.c
+++ b/hw/s390x/sclp.c
@@ -15,6 +15,7 @@
 #include "cpu.h"
 #include "sysemu/kvm.h"
 #include "exec/memory.h"
+#include "sysemu/sysemu.h"
 
 #include "hw/s390x/sclp.h"
 
@@ -31,7 +32,26 @@ static inline S390SCLPDevice *get_event_facility(void)
 static void read_SCP_info(SCCB *sccb)
 {
     ReadInfo *read_info = (ReadInfo *) sccb;
+    CPUState *cpu;
     int shift = 0;
+    int cpu_count = 0;
+    int i = 0;
+
+    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        cpu_count++;
+    }
+
+    /* CPU information */
+    read_info->entries_cpu = cpu_to_be16(cpu_count);
+    read_info->offset_cpu = cpu_to_be16(offsetof(ReadInfo, entries));
+    read_info->highest_cpu = cpu_to_be16(max_cpus);
+
+    for (i = 0; i < cpu_count; i++) {
+        read_info->entries[i].address = i;
+        read_info->entries[i].type = 0;
+    }
+
+    read_info->facilities = cpu_to_be64(SCLP_HAS_CPU_INFO);
 
     while ((ram_size >> (20 + shift)) > 65535) {
         shift++;
@@ -41,6 +61,34 @@ static void read_SCP_info(SCCB *sccb)
     sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_READ_COMPLETION);
 }
 
+/* Provide information about the CPU */
+static void sclp_read_cpu_info(SCCB *sccb)
+{
+    ReadCpuInfo *cpu_info = (ReadCpuInfo *) sccb;
+    CPUState *cpu;
+    int cpu_count = 0;
+    int i = 0;
+
+    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        cpu_count++;
+    }
+
+    cpu_info->nr_configured = cpu_to_be16(cpu_count);
+    cpu_info->offset_configured = cpu_to_be16(offsetof(ReadCpuInfo, entries));
+    cpu_info->nr_standby = cpu_to_be16(0);
+
+    /* The standby offset is 16-byte for each CPU */
+    cpu_info->offset_standby = cpu_to_be16(cpu_info->offset_configured
+        + cpu_info->nr_configured*sizeof(CpuEntry));
+
+    for (i = 0; i < cpu_count; i++) {
+        cpu_info->entries[i].address = i;
+        cpu_info->entries[i].type = 0;
+    }
+
+    sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_READ_COMPLETION);
+}
+
 static void sclp_execute(SCCB *sccb, uint64_t code)
 {
     S390SCLPDevice *sdev = get_event_facility();
@@ -50,6 +98,9 @@ static void sclp_execute(SCCB *sccb, uint64_t code)
     case SCLP_CMDW_READ_SCP_INFO_FORCED:
         read_SCP_info(sccb);
         break;
+    case SCLP_CMDW_READ_CPU_INFO:
+        sclp_read_cpu_info(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 174097d..89ae7d1 100644
--- a/include/hw/s390x/sclp.h
+++ b/include/hw/s390x/sclp.h
@@ -79,12 +79,44 @@ typedef struct SCCBHeader {
 
 #define SCCB_DATA_LEN (SCCB_SIZE - sizeof(SCCBHeader))
 
+/* CPU information */
+typedef struct CpuEntry {
+    uint8_t address;
+    uint8_t reserved0[13];
+    uint8_t type;
+    uint8_t reserved1;
+} QEMU_PACKED CpuEntry;
+
 typedef struct ReadInfo {
     SCCBHeader h;
     uint16_t rnmax;
     uint8_t rnsize;
+    uint8_t  _reserved1[16 - 11];       /* 11-15 */
+    uint16_t entries_cpu;               /* 16-17 */
+    uint16_t offset_cpu;                /* 18-19 */
+    uint8_t  _reserved2[24 - 20];       /* 20-23 */
+    uint8_t  loadparm[8];               /* 24-31 */
+    uint8_t  _reserved3[48 - 32];       /* 32-47 */
+    uint64_t facilities;                /* 48-55 */
+    uint8_t  _reserved0[100 - 56];
+    uint32_t rnsize2;
+    uint64_t rnmax2;
+    uint8_t  _reserved4[120-112];       /* 112-119 */
+    uint16_t highest_cpu;
+    uint8_t  _reserved5[128 - 122];     /* 122-127 */
+    struct CpuEntry entries[0];
 } QEMU_PACKED ReadInfo;
 
+typedef struct ReadCpuInfo {
+    SCCBHeader h;
+    uint16_t nr_configured;         /* 8-9 */
+    uint16_t offset_configured;     /* 10-11 */
+    uint16_t nr_standby;            /* 12-13 */
+    uint16_t offset_standby;        /* 14-15 */
+    uint8_t reserved0[24-16];       /* 16-23 */
+    struct CpuEntry entries[0];
+} QEMU_PACKED ReadCpuInfo;
+
 typedef struct SCCB {
     SCCBHeader h;
     char data[SCCB_DATA_LEN];
-- 
1.7.10.4