From fd10cde9294f73eeccbc16f3fec1ae6cde7b800c Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Thu, 14 Oct 2010 11:22:51 +0200 Subject: KVM paravirt: Add async PF initialization to PV guest. Enable async PF in a guest if async PF capability is discovered. Acked-by: Rik van Riel Signed-off-by: Gleb Natapov Signed-off-by: Marcelo Tosatti --- Documentation/kernel-parameters.txt | 3 ++ arch/x86/include/asm/kvm_para.h | 6 +++ arch/x86/kernel/kvm.c | 92 +++++++++++++++++++++++++++++++++++++ 3 files changed, 101 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 8b61c936099..369580da195 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -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. diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index 8662ae0a035..2315398230d 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -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 diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index e6db17976b8..032d03b6b54 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -27,16 +27,30 @@ #include #include #include +#include +#include #include +#include #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 } -- cgit v1.2.3