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KVM paravirt: Add async PF initialization to PV guest.

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Enable async PF in a guest if async PF capability is discovered.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Gleb Natapov 2010-10-14 11:22:51 +02:00 • committed by Avi Kivity
commit fd10cde929
3 changed files with 101 additions and 0 deletions
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3
Documentation/kernel-parameters.txt
View file

@ -1707,6 +1707,9 @@ and is between 256 and 4096 characters. It is defined in the file
no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
fault handling.
nolapic [X86-32,APIC] Do not enable or use the local APIC.
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.

6
arch/x86/include/asm/kvm_para.h
View file

@ -65,6 +65,12 @@ struct kvm_mmu_op_release_pt {
__u64 pt_phys;
};
struct kvm_vcpu_pv_apf_data {
__u32 reason;
__u8 pad[60];
__u32 enabled;
};
#ifdef __KERNEL__
#include <asm/processor.h>

92
arch/x86/kernel/kvm.c
View file

@ -27,16 +27,30 @@
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/hardirq.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <asm/timer.h>
#include <asm/cpu.h>
#define MMU_QUEUE_SIZE 1024
static int kvmapf = 1;
static int parse_no_kvmapf(char *arg)
{
kvmapf = 0;
return 0;
}
early_param("no-kvmapf", parse_no_kvmapf);
struct kvm_para_state {
u8 mmu_queue[MMU_QUEUE_SIZE];
int mmu_queue_len;
};
static DEFINE_PER_CPU(struct kvm_para_state, para_state);
static DEFINE_PER_CPU(struct kvm_vcpu_pv_apf_data, apf_reason) __aligned(64);
static struct kvm_para_state *kvm_para_state(void)
{
@ -231,12 +245,86 @@ static void __init paravirt_ops_setup(void)
#endif
}
void __cpuinit kvm_guest_cpu_init(void)
{
if (!kvm_para_available())
return;
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf) {
u64 pa = __pa(&__get_cpu_var(apf_reason));
wrmsrl(MSR_KVM_ASYNC_PF_EN, pa | KVM_ASYNC_PF_ENABLED);
__get_cpu_var(apf_reason).enabled = 1;
printk(KERN_INFO"KVM setup async PF for cpu %d\n",
smp_processor_id());
}
}
static void kvm_pv_disable_apf(void *unused)
{
if (!__get_cpu_var(apf_reason).enabled)
return;
wrmsrl(MSR_KVM_ASYNC_PF_EN, 0);
__get_cpu_var(apf_reason).enabled = 0;
printk(KERN_INFO"Unregister pv shared memory for cpu %d\n",
smp_processor_id());
}
static int kvm_pv_reboot_notify(struct notifier_block *nb,
unsigned long code, void *unused)
{
if (code == SYS_RESTART)
on_each_cpu(kvm_pv_disable_apf, NULL, 1);
return NOTIFY_DONE;
}
static struct notifier_block kvm_pv_reboot_nb = {
.notifier_call = kvm_pv_reboot_notify,
};
#ifdef CONFIG_SMP
static void __init kvm_smp_prepare_boot_cpu(void)
{
WARN_ON(kvm_register_clock("primary cpu clock"));
kvm_guest_cpu_init();
native_smp_prepare_boot_cpu();
}
static void kvm_guest_cpu_online(void *dummy)
{
kvm_guest_cpu_init();
}
static void kvm_guest_cpu_offline(void *dummy)
{
kvm_pv_disable_apf(NULL);
}
static int __cpuinit kvm_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
int cpu = (unsigned long)hcpu;
switch (action) {
case CPU_ONLINE:
case CPU_DOWN_FAILED:
case CPU_ONLINE_FROZEN:
smp_call_function_single(cpu, kvm_guest_cpu_online, NULL, 0);
break;
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
smp_call_function_single(cpu, kvm_guest_cpu_offline, NULL, 1);
break;
default:
break;
}
return NOTIFY_OK;
}
static struct notifier_block __cpuinitdata kvm_cpu_notifier = {
.notifier_call = kvm_cpu_notify,
};
#endif
void __init kvm_guest_init(void)
@ -245,7 +333,11 @@ void __init kvm_guest_init(void)
return;
paravirt_ops_setup();
register_reboot_notifier(&kvm_pv_reboot_nb);
#ifdef CONFIG_SMP
smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
register_cpu_notifier(&kvm_cpu_notifier);
#else
kvm_guest_cpu_init();
#endif
}