Extend CPU hotplug interface to return architecture specific
identifier for current CPU (in case of x86, it's APIC ID).
Signed-off-by: Igor Mammedov <imamm...@redhat.com>
---
TODO:
* cripple it to behave old way on old machine types so that
new firmware started on new QEMU won't see a difference
when migrated to an old QEMU (i.e. QEMU that doesn't support
this command)
---
docs/specs/acpi_cpu_hotplug.txt | 10 +++++++++-
hw/acpi/cpu.c | 15 +++++++++++++++
hw/acpi/trace-events | 1 +
3 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/docs/specs/acpi_cpu_hotplug.txt b/docs/specs/acpi_cpu_hotplug.txt
index 43c5a193f0..0438678249 100644
--- a/docs/specs/acpi_cpu_hotplug.txt
+++ b/docs/specs/acpi_cpu_hotplug.txt
@@ -32,7 +32,9 @@ Register block size:
read access:
offset:
- [0x0-0x3] reserved
+ [0x0-0x3] Command data 2: (DWORD access)
+ upper 32 bit of 'Command data' if returned data value is 64 bit.
+ in case of error or unsupported command reads is 0x0
[0x4] CPU device status fields: (1 byte access)
bits:
0: Device is enabled and may be used by guest
@@ -87,6 +89,8 @@ write access:
2: stores value into OST status register, triggers
ACPI_DEVICE_OST QMP event from QEMU to external applications
with current values of OST event and status registers.
+ 3: OSPM reads architecture specific value identifying CPU
+ (x86: APIC ID)
other values: reserved
Selecting CPU device beyond possible range has no effect on platform:
@@ -115,3 +119,7 @@ Typical usecases:
5.2 if 'Command data' register has not changed, there is not CPU
corresponding to iterator value and the last valid iterator value
equals to 'max_cpus' + 1
+ - Get architecture specific id for a CPU
+ 1. pick a CPU to read from using 'CPU selector' register
+ 2. write 0x3 int0 'Command field' register
+ 3. read architecture specific id from 'Command data' register
diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c
index 87f30a31d7..701542d860 100644
--- a/hw/acpi/cpu.c
+++ b/hw/acpi/cpu.c
@@ -12,11 +12,13 @@
#define ACPI_CPU_FLAGS_OFFSET_RW 4
#define ACPI_CPU_CMD_OFFSET_WR 5
#define ACPI_CPU_CMD_DATA_OFFSET_RW 8
+#define ACPI_CPU_CMD_DATA2_OFFSET_RW 0
enum {
CPHP_GET_NEXT_CPU_WITH_EVENT_CMD = 0,
CPHP_OST_EVENT_CMD = 1,
CPHP_OST_STATUS_CMD = 2,
+ CPHP_GET_CPU_ID_CMD = 3,
CPHP_CMD_MAX
};
@@ -74,11 +76,24 @@ static uint64_t cpu_hotplug_rd(void *opaque, hwaddr addr,
unsigned size)
case CPHP_GET_NEXT_CPU_WITH_EVENT_CMD:
val = cpu_st->selector;
break;
+ case CPHP_GET_CPU_ID_CMD:
+ val = cpu_to_le64(cdev->arch_id) & 0xFFFFFFFF;
+ break;
default:
break;
}
trace_cpuhp_acpi_read_cmd_data(cpu_st->selector, val);
break;
+ case ACPI_CPU_CMD_DATA2_OFFSET_RW:
+ switch (cpu_st->command) {
+ case CPHP_GET_CPU_ID_CMD:
+ val = cpu_to_le64(cdev->arch_id) >> 32;
+ break;
+ default:
+ break;
+ }
+ trace_cpuhp_acpi_read_cmd_data2(cpu_st->selector, val);
+ break;
default:
break;
}
diff --git a/hw/acpi/trace-events b/hw/acpi/trace-events
index 96b8273297..afbc77de1c 100644
--- a/hw/acpi/trace-events
+++ b/hw/acpi/trace-events
@@ -23,6 +23,7 @@ cpuhp_acpi_read_flags(uint32_t idx, uint8_t flags)
"idx[0x%"PRIx32"] flags: 0x%"
cpuhp_acpi_write_idx(uint32_t idx) "set active cpu idx: 0x%"PRIx32
cpuhp_acpi_write_cmd(uint32_t idx, uint8_t cmd) "idx[0x%"PRIx32"] cmd:
0x%"PRIx8
cpuhp_acpi_read_cmd_data(uint32_t idx, uint32_t data) "idx[0x%"PRIx32"] data:
0x%"PRIx32
+cpuhp_acpi_read_cmd_data2(uint32_t idx, uint32_t data) "idx[0x%"PRIx32"] data:
0x%"PRIx32
cpuhp_acpi_cpu_has_events(uint32_t idx, bool ins, bool rm) "idx[0x%"PRIx32"]
inserting: %d, removing: %d"
cpuhp_acpi_clear_inserting_evt(uint32_t idx) "idx[0x%"PRIx32"]"
cpuhp_acpi_clear_remove_evt(uint32_t idx) "idx[0x%"PRIx32"]"
--
2.18.1
