From: Chen Fan <chen.fan.f...@cn.fujitsu.com>
When OS ejected a vcpu (like: echo 1 > /sys/bus/acpi/devices/LNXCPUXX/eject),
it would call acpi EJ0 method, the firmware need to write the new cpumap, QEMU
would know which vcpu need to be ejected.
TODO:
-confirm the hotplug result via OST if guest support it.
Signed-off-by: Chen Fan <chen.fan.f...@cn.fujitsu.com>
Signed-off-by: Gu Zheng <guz.f...@cn.fujitsu.com>
---
cpus.c | 7 ++++++
hw/acpi/cpu_hotplug.c | 40 ++++++++++++++++++++++++++++++++++++-
hw/i386/acpi-dsdt-cpu-hotplug.dsl | 6 ++++-
include/hw/acpi/cpu_hotplug.h | 1 +
include/qom/cpu.h | 9 ++++++++
5 files changed, 61 insertions(+), 2 deletions(-)
diff --git a/cpus.c b/cpus.c
index cce2744..eee693b 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1182,6 +1182,13 @@ void resume_all_vcpus(void)
}
}
+void cpu_remove(CPUState *cpu)
+{
+ cpu->stop = true;
+ cpu->exit = true;
+ qemu_cpu_kick(cpu);
+}
+
/* For temporary buffers for forming a name */
#define VCPU_THREAD_NAME_SIZE 16
diff --git a/hw/acpi/cpu_hotplug.c b/hw/acpi/cpu_hotplug.c
index 56cb316..7cbce69 100644
--- a/hw/acpi/cpu_hotplug.c
+++ b/hw/acpi/cpu_hotplug.c
@@ -20,10 +20,46 @@ static uint64_t cpu_status_read(void *opaque, hwaddr addr,
unsigned int size)
return val;
}
+static void acpi_eject_vcpu(AcpiCpuHotplug *cpus_status, int64_t cpu_id)
+{
+ CPUState *cpu;
+
+ CPU_FOREACH(cpu) {
+ CPUClass *cc = CPU_GET_CLASS(cpu);
+ int64_t id = cc->get_arch_id(cpu);
+
+ if (cpu_id == id) {
+ cpus_status->old_sts[cpu_id / 8] &= ~(1 << (cpu_id % 8));
+ cpus_status->sts[cpu_id / 8] &= ~(1 << (cpu_id % 8));
+ cpu_remove(cpu);
+ break;
+ }
+ }
+}
+
static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
unsigned int size)
{
- /* TODO: implement VCPU removal on guest signal that CPU can be removed */
+ AcpiCpuHotplug *cpus = opaque;
+ uint8_t val;
+ int i;
+ int64_t cpu_id = -1;
+
+ val = cpus->old_sts[addr] ^ data;
+
+ if (val == 0) {
+ return;
+ }
+
+ for (i = 0; i < 8; i++) {
+ if (val & 1 << i) {
+ cpu_id = 8 * addr + i;
+ }
+ }
+
+ if (cpu_id != -1) {
+ acpi_eject_vcpu(cpus, cpu_id);
+ }
}
static const MemoryRegionOps AcpiCpuHotplug_ops = {
@@ -49,6 +85,7 @@ void AcpiCpuHotplug_handle(ACPIGPE *gpe, AcpiCpuHotplug *g,
if (type == PLUG) {
g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
+ g->old_sts[cpu_id / 8] |= (1 << (cpu_id % 8));
} else {
g->sts[cpu_id / 8] &= ~(1 << (cpu_id % 8));
}
@@ -65,6 +102,7 @@ void AcpiCpuHotplug_init(MemoryRegion *parent, Object *owner,
g_assert((id / 8) < ACPI_GPE_PROC_LEN);
gpe_cpu->sts[id / 8] |= (1 << (id % 8));
+ gpe_cpu->old_sts[id / 8] |= (1 << (id % 8));
}
memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops,
gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN);
diff --git a/hw/i386/acpi-dsdt-cpu-hotplug.dsl
b/hw/i386/acpi-dsdt-cpu-hotplug.dsl
index 34aab5a..9485f12 100644
--- a/hw/i386/acpi-dsdt-cpu-hotplug.dsl
+++ b/hw/i386/acpi-dsdt-cpu-hotplug.dsl
@@ -50,7 +50,11 @@ Scope(\_SB) {
}
Method(CPEJ, 2, NotSerialized) {
// _EJ0 method - eject callback
- Sleep(200)
+ Store(Zero, Index(CPON, ToInteger(Arg0)))
+ Store(One, Local0)
+ ShiftLeft(Local0, Arg0, Local0)
+ Not(Local0, Local0)
+ And(PRS, Local0, PRS)
}
#define CPU_STATUS_LEN ACPI_GPE_PROC_LEN
diff --git a/include/hw/acpi/cpu_hotplug.h b/include/hw/acpi/cpu_hotplug.h
index 4fe0066..3bffc69 100644
--- a/include/hw/acpi/cpu_hotplug.h
+++ b/include/hw/acpi/cpu_hotplug.h
@@ -28,6 +28,7 @@ typedef struct CPUNotifier {
typedef struct AcpiCpuHotplug {
MemoryRegion io;
uint8_t sts[ACPI_GPE_PROC_LEN];
+ uint8_t old_sts[ACPI_GPE_PROC_LEN];
} AcpiCpuHotplug;
void AcpiCpuHotplug_handle(ACPIGPE *gpe, AcpiCpuHotplug *g,
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 2fc00ef..9108dc6 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -236,6 +236,7 @@ struct CPUState {
bool created;
bool stop;
bool stopped;
+ bool exit;
volatile sig_atomic_t exit_request;
uint32_t interrupt_request;
int singlestep_enabled;
@@ -600,6 +601,14 @@ void cpu_exit(CPUState *cpu);
void cpu_resume(CPUState *cpu);
/**
+ * cpu_remove:
+ * @cpu: The vCPU to remove.
+ *
+ * Requests the CPU @cpu to be removed.
+ */
+void cpu_remove(CPUState *cpu);
+
+/**
* qemu_init_vcpu:
* @cpu: The vCPU to initialize.
*
--
1.7.7
