KVM: in-kernel LAPIC save and restore support

This patch adds a new vcpu-based IOCTL to save and restore the local
apic registers for a single vcpu. The kernel only copies the apic page as
a whole, extraction of registers is left to userspace side. On restore, the
APIC timer is restarted from the initial count, this introduces a little
delay, but works fine.

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
Eddie Dong 2007-09-06 12:22:56 +03:00 committed by Avi Kivity
parent 6bf9e962d1
commit 96ad2cc613
4 changed files with 68 additions and 0 deletions

View File

@ -149,6 +149,7 @@ int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u16 dest);
void kvm_ioapic_update_eoi(struct kvm *kvm, int vector);
int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda);
int kvm_apic_set_irq(struct kvm_lapic *apic, u8 vec, u8 trig);
void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu);
int kvm_ioapic_init(struct kvm *kvm);
void kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level);

View File

@ -2642,6 +2642,27 @@ static int kvm_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
return 0;
}
static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
struct kvm_lapic_state *s)
{
vcpu_load(vcpu);
memcpy(s->regs, vcpu->apic->regs, sizeof *s);
vcpu_put(vcpu);
return 0;
}
static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu,
struct kvm_lapic_state *s)
{
vcpu_load(vcpu);
memcpy(vcpu->apic->regs, s->regs, sizeof *s);
kvm_apic_post_state_restore(vcpu);
vcpu_put(vcpu);
return 0;
}
static long kvm_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@ -2811,6 +2832,31 @@ static long kvm_vcpu_ioctl(struct file *filp,
r = 0;
break;
}
case KVM_GET_LAPIC: {
struct kvm_lapic_state lapic;
memset(&lapic, 0, sizeof lapic);
r = kvm_vcpu_ioctl_get_lapic(vcpu, &lapic);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, &lapic, sizeof lapic))
goto out;
r = 0;
break;
}
case KVM_SET_LAPIC: {
struct kvm_lapic_state lapic;
r = -EFAULT;
if (copy_from_user(&lapic, argp, sizeof lapic))
goto out;
r = kvm_vcpu_ioctl_set_lapic(vcpu, &lapic);;
if (r)
goto out;
r = 0;
break;
}
default:
;
}

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@ -931,3 +931,16 @@ int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu)
apic_clear_irr(vector, apic);
return vector;
}
void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu)
{
struct kvm_lapic *apic = vcpu->apic;
apic->base_address = vcpu->apic_base &
MSR_IA32_APICBASE_BASE;
apic_set_reg(apic, APIC_LVR, APIC_VERSION);
apic_update_ppr(apic);
hrtimer_cancel(&apic->timer.dev);
update_divide_count(apic);
start_apic_timer(apic);
}

View File

@ -208,6 +208,12 @@ struct kvm_fpu {
__u32 pad2;
};
/* for KVM_GET_LAPIC and KVM_SET_LAPIC */
#define KVM_APIC_REG_SIZE 0x400
struct kvm_lapic_state {
char regs[KVM_APIC_REG_SIZE];
};
struct kvm_segment {
__u64 base;
__u32 limit;
@ -380,5 +386,7 @@ struct kvm_signal_mask {
#define KVM_SET_SIGNAL_MASK _IOW(KVMIO, 0x8b, struct kvm_signal_mask)
#define KVM_GET_FPU _IOR(KVMIO, 0x8c, struct kvm_fpu)
#define KVM_SET_FPU _IOW(KVMIO, 0x8d, struct kvm_fpu)
#define KVM_GET_LAPIC _IOR(KVMIO, 0x8e, struct kvm_lapic_state)
#define KVM_SET_LAPIC _IOW(KVMIO, 0x8f, struct kvm_lapic_state)
#endif