Avi Kivity wrote: > Dong, Eddie wrote: >> Avi Kivity wrote: >> >>> But, for an ungraceful reset, nothing prevents an AP from >>> issuing a reset? >>> >> >> Mmm, Yes, but I think current architecture can't handle this. >> The thread where AP issues "RESET" will continue run, which >> means it becomes BSP now and wake up other APs later on. >> Or We can block that AP first and then inform BSP to do >> RESET job. Here we need to block the AP in kernel >> so that we can wake up. >> > > It should call vcpu_halt() immediately after reset.
?? Can user level be able to enter kernel HALT state.
>
>> It can be a future task which is not that high priority IMO.
>> I will focus on SMP boot 1st. Your opnion?
>>
>
> Agree. But let's make it close to the complete solution.
>
Yes, halt all APs and let BSP do reset ops in user level.
Will post patch to Qemu to support SMP reboot some time later.
>
> The test for vcpu->requests already exists (and is needed for tlb
> flushes) so there is no additional performance hit.
OK, that makes sense. changed. please verify.
User level is split into libkvm and qemu.
thx,eddie
commit a0aed7040befe198491254d3459aeb5897f5f2c1
Author: root <[EMAIL PROTECTED](none)>
Date: Wed Oct 10 13:45:58 2007 +0800
Add VM reset support in kernel side to
reset the kernel devices and force APs
to enter wait for INIT/SIPI state.
Signed-off-by: Yaozu (Eddie) Dong <[EMAIL PROTECTED]>
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 4ab487c..81c9af1 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -68,6 +68,7 @@
* vcpu->requests bit members
*/
#define KVM_TLB_FLUSH 0
+#define KVM_FROZEN 1
/*
* Address types:
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 0b2894a..33f16bd 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -2189,9 +2189,17 @@ again:
vcpu->guest_mode = 1;
- if (vcpu->requests)
+ if (vcpu->requests) {
if (test_and_clear_bit(KVM_TLB_FLUSH, &vcpu->requests))
kvm_x86_ops->tlb_flush(vcpu);
+ if (test_and_clear_bit(KVM_FROZEN, &vcpu->requests)) {
+ local_irq_enable();
+ preempt_enable();
+ r = -EINTR;
+ kvm_run->exit_reason = KVM_EXIT_FROZEN;
+ goto out;
+ }
+ }
kvm_x86_ops->run(vcpu, kvm_run);
@@ -2245,6 +2253,8 @@ static int kvm_vcpu_ioctl_run(struct kvm_vcpu
*vcpu, struct kvm_run *kvm_run)
vcpu_load(vcpu);
if (unlikely(vcpu->mp_state == VCPU_MP_STATE_UNINITIALIZED)) {
+ if (irqchip_in_kernel(vcpu->kvm) && vcpu->apic)
+ kvm_lapic_reset(vcpu);
kvm_vcpu_block(vcpu);
vcpu_put(vcpu);
return -EAGAIN;
@@ -3143,6 +3153,54 @@ out:
return r;
}
+/*
+ * Reset kernel devices.
+ */
+void kvm_reset_devices(struct kvm *kvm)
+{
+ kvm_pic_reset(&pic_irqchip(kvm)->pics[1]);
+ kvm_pic_reset(&pic_irqchip(kvm)->pics[0]);
+ pic_irqchip(kvm)->output = 0;
+ kvm_ioapic_reset(kvm->vioapic);
+}
+
+/*
+ * Kernel side VM Reset.
+ * NOTE here: User level code must guarantee only the BSP
+ * thread can do this call.
+ *
+ */
+int kvm_vm_reset(struct kvm *kvm)
+{
+ struct kvm_vcpu *vcpu;
+ int i;
+
+ for (i = 0; i < KVM_MAX_VCPUS; i++) {
+ vcpu = kvm->vcpus[i];
+ if (!vcpu)
+ continue;
+ /* active VCPU */
+ if (vcpu->vcpu_id) {
+ vcpu->mp_state = VCPU_MP_STATE_UNINITIALIZED;
+ set_bit(KVM_FROZEN, &vcpu->requests);
+ kvm_vcpu_kick(vcpu);
+ /*
+ * Wait till the AP entered waiting for
+ * INIT/SIPI state
+ */
+ while (test_bit(KVM_FROZEN, &vcpu->requests))
+ schedule();
+ }
+ else {
+ vcpu->mp_state = VCPU_MP_STATE_RUNNABLE;
+ kvm_lapic_reset(vcpu);
+ }
+ }
+ /* Now only BSP is running... */
+ kvm_reset_devices(kvm);
+ return 0;
+}
+
static long kvm_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -3228,6 +3286,12 @@ static long kvm_vm_ioctl(struct file *filp,
} else
goto out;
break;
+ case KVM_RESET:
+ r = -EINVAL;
+ if (!irqchip_in_kernel(kvm))
+ goto out;
+ r = kvm_vm_reset(kvm);
+ break;
case KVM_IRQ_LINE: {
struct kvm_irq_level irq_event;
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index cd4ac12..ea9c004 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -127,7 +127,8 @@ enum kvm_exit_reason {
KVM_EXIT_SHUTDOWN = 8,
KVM_EXIT_FAIL_ENTRY = 9,
KVM_EXIT_INTR = 10,
- KVM_EXIT_SET_TPR = 11
+ KVM_EXIT_SET_TPR = 11,
+ KVM_EXIT_FROZEN = 12
};
/* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */
@@ -383,6 +384,7 @@ struct kvm_signal_mask {
#define KVM_IRQ_LINE _IOW(KVMIO, 0x61, struct
kvm_irq_level)
#define KVM_GET_IRQCHIP _IOWR(KVMIO, 0x62, struct
kvm_irqchip)
#define KVM_SET_IRQCHIP _IOR(KVMIO, 0x63, struct
kvm_irqchip)
+#define KVM_RESET _IO(KVMIO, 0x64)
/*
* ioctls for vcpu fds
rbt-u2.patch
Description: rbt-u2.patch
rbt-u1.patch
Description: rbt-u1.patch
rbt-k3.patch
Description: rbt-k3.patch
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