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[Qemu-devel] [RFC qom-next v5 7/8] piix4: implement function cpu_status_
From: |
Chen Fan |
Subject: |
[Qemu-devel] [RFC qom-next v5 7/8] piix4: implement function cpu_status_write() for vcpu ejection |
Date: |
Mon, 23 Dec 2013 17:04:08 +0800 |
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: for now QEMU only supported that cpu was deleted sequentially from the
last
one in OS, in the further OS should reject vcpu arbitrarily.
Signed-off-by: Chen Fan <address@hidden>
---
cpus.c | 7 ++++++
hw/acpi/piix4.c | 48 ++++++++++++++++++++++++++++++++++++++-
hw/i386/acpi-dsdt-cpu-hotplug.dsl | 6 ++++-
include/qom/cpu.h | 10 ++++++++
4 files changed, 69 insertions(+), 2 deletions(-)
diff --git a/cpus.c b/cpus.c
index ca4c59f..5829d24 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1117,6 +1117,13 @@ void resume_all_vcpus(void)
}
}
+void cpu_remove(CPUState *cpu)
+{
+ cpu->stop = true;
+ cpu->exit = true;
+ qemu_cpu_kick(cpu);
+}
+
static void qemu_tcg_init_vcpu(CPUState *cpu)
{
/* share a single thread for all cpus with TCG */
diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index d2cd4cd..6407f8d 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -62,6 +62,7 @@ struct pci_status {
typedef struct CPUStatus {
uint8_t sts[PIIX4_PROC_LEN];
+ uint8_t old_sts[PIIX4_PROC_LEN];
} CPUStatus;
typedef struct PIIX4PMState {
@@ -651,6 +652,23 @@ static const MemoryRegionOps piix4_pci_ops = {
},
};
+static void acpi_piix_eject_vcpu(PIIX4PMState *s, int64_t cpuid)
+{
+ CPUStatus *g = &s->gpe_cpu;
+ CPUState *cpu;
+
+ CPU_FOREACH(cpu) {
+ CPUClass *cc = CPU_GET_CLASS(cpu);
+ int64_t id = cc->get_arch_id(cpu);
+
+ if (cpuid == id) {
+ g->old_sts[cpuid / 8] &= ~(1 << (cpuid % 8));
+ cpu_remove(cpu);
+ break;
+ }
+ }
+}
+
static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
{
PIIX4PMState *s = opaque;
@@ -663,7 +681,27 @@ static uint64_t cpu_status_read(void *opaque, hwaddr addr,
unsigned int size)
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 */
+ PIIX4PMState *s = opaque;
+ CPUStatus *cpus = &s->gpe_cpu;
+ uint8_t val;
+ int i;
+ int64_t cpuid = -1;
+
+ val = cpus->old_sts[addr] ^ data;
+
+ if (val == 0) {
+ return;
+ }
+
+ for (i = 0; i < 8; i++) {
+ if (val & 1 << i) {
+ cpuid = 8 * addr + i;
+ }
+ }
+
+ if (cpuid != -1) {
+ acpi_piix_eject_vcpu(s, cpuid);
+ }
}
static const MemoryRegionOps cpu_hotplug_ops = {
@@ -683,13 +721,20 @@ static void piix4_cpu_hotplug_req(PIIX4PMState *s,
CPUState *cpu,
ACPIGPE *gpe = &s->ar.gpe;
CPUClass *k = CPU_GET_CLASS(cpu);
int64_t cpu_id;
+ int i;
assert(s != NULL);
*gpe->sts = *gpe->sts | PIIX4_CPU_HOTPLUG_STATUS;
cpu_id = k->get_arch_id(CPU(cpu));
+
+ for (i = 0; i < PIIX4_PROC_LEN; i++) {
+ g->old_sts[i] = g->sts[i];
+ }
+
if (action == 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));
}
@@ -728,6 +773,7 @@ static void piix4_acpi_system_hot_add_init(MemoryRegion
*parent,
g_assert((id / 8) < PIIX4_PROC_LEN);
s->gpe_cpu.sts[id / 8] |= (1 << (id % 8));
+ s->gpe_cpu.old_sts[id / 8] |= (1 << (id % 8));
}
memory_region_init_io(&s->io_cpu, OBJECT(s), &cpu_hotplug_ops, s,
"acpi-cpu-hotplug", PIIX4_PROC_LEN);
diff --git a/hw/i386/acpi-dsdt-cpu-hotplug.dsl
b/hw/i386/acpi-dsdt-cpu-hotplug.dsl
index c96ac42..8327b0d 100644
--- a/hw/i386/acpi-dsdt-cpu-hotplug.dsl
+++ b/hw/i386/acpi-dsdt-cpu-hotplug.dsl
@@ -49,7 +49,11 @@ 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)
}
/* CPU hotplug notify method */
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 0238532..4412fb0 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -146,6 +146,7 @@ struct kvm_run;
* @halted: Nonzero if the CPU is in suspended state.
* @stop: Indicates a pending stop request.
* @stopped: Indicates the CPU has been artificially stopped.
+ * @exit: Indicates the CPU is in impending exit state.
* @tcg_exit_req: Set to force TCG to stop executing linked TBs for this
* CPU and return to its top level loop.
* @singlestep_enabled: Flags for single-stepping.
@@ -181,6 +182,7 @@ struct CPUState {
bool created;
bool stop;
bool stopped;
+ bool exit;
volatile sig_atomic_t exit_request;
volatile sig_atomic_t tcg_exit_req;
uint32_t interrupt_request;
@@ -487,6 +489,14 @@ void cpu_exit(CPUState *cpu);
void cpu_resume(CPUState *cpu);
/**
+ * qemu_remove_vcpu:
+ * @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.
*
--
1.8.1.4
- [Qemu-devel] [RFC qom-next v5 0/8] i386: add cpu hot remove support, Chen Fan, 2013/12/23
- [Qemu-devel] [RFC qom-next v5 1/8] x86: move apic_state field from CPUX86State to X86CPU, Chen Fan, 2013/12/23
- [Qemu-devel] [RFC qom-next v5 2/8] x86: add x86_cpu_unrealizefn() for cpu apic remove, Chen Fan, 2013/12/23
- [Qemu-devel] [RFC qom-next v5 8/8] cpus: reclaim allocated vCPU objects, Chen Fan, 2013/12/23
- [Qemu-devel] [RFC qom-next v5 3/8] qmp: add 'cpu-del' command support, Chen Fan, 2013/12/23
- [Qemu-devel] [RFC qom-next v5 4/8] qom cpu: rename variable 'cpu_added_notifier' to 'cpu_hotplug_notifier', Chen Fan, 2013/12/23
- [Qemu-devel] [RFC qom-next v5 7/8] piix4: implement function cpu_status_write() for vcpu ejection,
Chen Fan <=
- [Qemu-devel] [RFC qom-next v5 6/8] i386: implement pc interface cpu_common_unrealizefn() in qom/cpu.c, Chen Fan, 2013/12/23
- [Qemu-devel] [RFC qom-next v5 5/8] qom cpu: add UNPLUG cpu notifier support, Chen Fan, 2013/12/23