| Message ID | 1308007897-17013-8-git-send-email-glommer@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 13 Jun 2011, Glauber Costa wrote: > Register steal time within KVM. Everytime we sample the steal time > information, we update a local variable that tells what was the > last time read. We then account the difference. > > Signed-off-by: Glauber Costa <glommer@redhat.com> > CC: Rik van Riel <riel@redhat.com> > CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> > CC: Peter Zijlstra <peterz@infradead.org> > CC: Avi Kivity <avi@redhat.com> > CC: Anthony Liguori <aliguori@us.ibm.com> > CC: Eric B Munson <emunson@mgebm.net> Tested-by: Eric B Munson <emunson@mgebm.net>
On Mon, Jun 13, 2011 at 07:31:37PM -0400, Glauber Costa wrote: > Register steal time within KVM. Everytime we sample the steal time > information, we update a local variable that tells what was the > last time read. We then account the difference. > > Signed-off-by: Glauber Costa <glommer@redhat.com> > CC: Rik van Riel <riel@redhat.com> > CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> > CC: Peter Zijlstra <peterz@infradead.org> > CC: Avi Kivity <avi@redhat.com> > CC: Anthony Liguori <aliguori@us.ibm.com> > CC: Eric B Munson <emunson@mgebm.net> > --- > Documentation/kernel-parameters.txt | 4 ++ > arch/x86/include/asm/kvm_para.h | 1 + > arch/x86/kernel/kvm.c | 72 +++++++++++++++++++++++++++++++++++ > arch/x86/kernel/kvmclock.c | 2 + > 4 files changed, 79 insertions(+), 0 deletions(-) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index fd248a31..a722574 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -1737,6 +1737,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page > fault handling. > > + no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting. > + steal time is computed, but won't influence scheduler > + behaviour > + > 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 0341e61..2a8f2a5 100644 > --- a/arch/x86/include/asm/kvm_para.h > +++ b/arch/x86/include/asm/kvm_para.h > @@ -94,6 +94,7 @@ struct kvm_vcpu_pv_apf_data { > > extern void kvmclock_init(void); > extern int kvm_register_clock(char *txt); > +extern void kvm_disable_steal_time(void); > > > /* This instruction is vmcall. On non-VT architectures, it will generate a > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > index 33c07b0..5a5ac19 100644 > --- a/arch/x86/kernel/kvm.c > +++ b/arch/x86/kernel/kvm.c > @@ -51,6 +51,15 @@ static int parse_no_kvmapf(char *arg) > > early_param("no-kvmapf", parse_no_kvmapf); > > +static int steal_acc = 1; > +static int parse_no_stealacc(char *arg) > +{ > + steal_acc = 0; > + return 0; > +} > + > +early_param("no-steal-acc", parse_no_stealacc); > + > struct kvm_para_state { > u8 mmu_queue[MMU_QUEUE_SIZE]; > int mmu_queue_len; > @@ -58,6 +67,8 @@ struct kvm_para_state { > > 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 DEFINE_PER_CPU(struct kvm_steal_time, steal_time) __aligned(64); > +static int has_steal_clock = 0; > > static struct kvm_para_state *kvm_para_state(void) > { > @@ -483,23 +494,66 @@ static struct notifier_block kvm_pv_reboot_nb = { > .notifier_call = kvm_pv_reboot_notify, > }; > > +static void kvm_register_steal_time(void) > +{ > + int cpu = smp_processor_id(); > + struct kvm_steal_time *st = &per_cpu(steal_time, cpu); > + > + if (!has_steal_clock) > + return; > + > + memset(st, 0, sizeof(*st)); > + > + wrmsrl(MSR_KVM_STEAL_TIME, (__pa(st) | KVM_MSR_ENABLED)); > + printk(KERN_INFO "kvm-stealtime: cpu %d, msr %lx\n", > + cpu, __pa(st)); > +} > + > +static u64 kvm_steal_clock(int cpu) > +{ > + u64 steal; > + struct kvm_steal_time *src; > + int version; > + > + src = &per_cpu(steal_time, cpu); > + do { > + version = src->version; > + rmb(); > + steal = src->steal; > + rmb(); > + } while ((version & 1) || (version != src->version)); > + > + return steal; > +} > + > #ifdef CONFIG_SMP > static void __init kvm_smp_prepare_boot_cpu(void) > { > #ifdef CONFIG_KVM_CLOCK > WARN_ON(kvm_register_clock("primary cpu clock")); > #endif > + kvm_register_steal_time(); > kvm_guest_cpu_init(); > native_smp_prepare_boot_cpu(); > } > > static void __cpuinit kvm_guest_cpu_online(void *dummy) > { > + kvm_register_steal_time(); > kvm_guest_cpu_init(); > } > Why not call kvm_register_steal_time() from kvm_guest_cpu_init()? This way you save one line of code and steal time will be initialized in !CONFIG_SMP kernel too. > +void kvm_disable_steal_time(void) > +{ > + if (!has_steal_clock) > + return; > + > + wrmsr(MSR_KVM_STEAL_TIME, 0, 0); > +} > + > static void kvm_guest_cpu_offline(void *dummy) > { > + kvm_disable_steal_time(); > kvm_pv_disable_apf(NULL); > apf_task_wake_all(); > } > @@ -548,6 +602,11 @@ void __init kvm_guest_init(void) > if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF)) > x86_init.irqs.trap_init = kvm_apf_trap_init; > > + if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) { > + has_steal_clock = 1; > + pv_time_ops.steal_clock = kvm_steal_clock; > + } > + > #ifdef CONFIG_SMP > smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu; > register_cpu_notifier(&kvm_cpu_notifier); > @@ -555,3 +614,16 @@ void __init kvm_guest_init(void) > kvm_guest_cpu_init(); > #endif > } > + > +static __init int activate_jump_labels(void) > +{ > + if (has_steal_clock) { > + jump_label_inc(¶virt_steal_enabled); > + if (steal_acc) > + jump_label_inc(¶virt_steal_rq_enabled); > + } > + > + return 0; > +} > +arch_initcall(activate_jump_labels); > + > diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c > index 6389a6b..c1a0188 100644 > --- a/arch/x86/kernel/kvmclock.c > +++ b/arch/x86/kernel/kvmclock.c > @@ -160,6 +160,7 @@ static void __cpuinit kvm_setup_secondary_clock(void) > static void kvm_crash_shutdown(struct pt_regs *regs) > { > native_write_msr(msr_kvm_system_time, 0, 0); > + kvm_disable_steal_time(); > native_machine_crash_shutdown(regs); > } > #endif > @@ -167,6 +168,7 @@ static void kvm_crash_shutdown(struct pt_regs *regs) > static void kvm_shutdown(void) > { > native_write_msr(msr_kvm_system_time, 0, 0); > + kvm_disable_steal_time(); > native_machine_shutdown(); > } > > -- > 1.7.3.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index fd248a31..a722574 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1737,6 +1737,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page fault handling. + no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting. + steal time is computed, but won't influence scheduler + behaviour + 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 0341e61..2a8f2a5 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -94,6 +94,7 @@ struct kvm_vcpu_pv_apf_data { extern void kvmclock_init(void); extern int kvm_register_clock(char *txt); +extern void kvm_disable_steal_time(void); /* This instruction is vmcall. On non-VT architectures, it will generate a diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 33c07b0..5a5ac19 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -51,6 +51,15 @@ static int parse_no_kvmapf(char *arg) early_param("no-kvmapf", parse_no_kvmapf); +static int steal_acc = 1; +static int parse_no_stealacc(char *arg) +{ + steal_acc = 0; + return 0; +} + +early_param("no-steal-acc", parse_no_stealacc); + struct kvm_para_state { u8 mmu_queue[MMU_QUEUE_SIZE]; int mmu_queue_len; @@ -58,6 +67,8 @@ struct kvm_para_state { 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 DEFINE_PER_CPU(struct kvm_steal_time, steal_time) __aligned(64); +static int has_steal_clock = 0; static struct kvm_para_state *kvm_para_state(void) { @@ -483,23 +494,66 @@ static struct notifier_block kvm_pv_reboot_nb = { .notifier_call = kvm_pv_reboot_notify, }; +static void kvm_register_steal_time(void) +{ + int cpu = smp_processor_id(); + struct kvm_steal_time *st = &per_cpu(steal_time, cpu); + + if (!has_steal_clock) + return; + + memset(st, 0, sizeof(*st)); + + wrmsrl(MSR_KVM_STEAL_TIME, (__pa(st) | KVM_MSR_ENABLED)); + printk(KERN_INFO "kvm-stealtime: cpu %d, msr %lx\n", + cpu, __pa(st)); +} + +static u64 kvm_steal_clock(int cpu) +{ + u64 steal; + struct kvm_steal_time *src; + int version; + + src = &per_cpu(steal_time, cpu); + do { + version = src->version; + rmb(); + steal = src->steal; + rmb(); + } while ((version & 1) || (version != src->version)); + + return steal; +} + #ifdef CONFIG_SMP static void __init kvm_smp_prepare_boot_cpu(void) { #ifdef CONFIG_KVM_CLOCK WARN_ON(kvm_register_clock("primary cpu clock")); #endif + kvm_register_steal_time(); kvm_guest_cpu_init(); native_smp_prepare_boot_cpu(); } static void __cpuinit kvm_guest_cpu_online(void *dummy) { + kvm_register_steal_time(); kvm_guest_cpu_init(); } +void kvm_disable_steal_time(void) +{ + if (!has_steal_clock) + return; + + wrmsr(MSR_KVM_STEAL_TIME, 0, 0); +} + static void kvm_guest_cpu_offline(void *dummy) { + kvm_disable_steal_time(); kvm_pv_disable_apf(NULL); apf_task_wake_all(); } @@ -548,6 +602,11 @@ void __init kvm_guest_init(void) if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF)) x86_init.irqs.trap_init = kvm_apf_trap_init; + if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) { + has_steal_clock = 1; + pv_time_ops.steal_clock = kvm_steal_clock; + } + #ifdef CONFIG_SMP smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu; register_cpu_notifier(&kvm_cpu_notifier); @@ -555,3 +614,16 @@ void __init kvm_guest_init(void) kvm_guest_cpu_init(); #endif } + +static __init int activate_jump_labels(void) +{ + if (has_steal_clock) { + jump_label_inc(¶virt_steal_enabled); + if (steal_acc) + jump_label_inc(¶virt_steal_rq_enabled); + } + + return 0; +} +arch_initcall(activate_jump_labels); + diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 6389a6b..c1a0188 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -160,6 +160,7 @@ static void __cpuinit kvm_setup_secondary_clock(void) static void kvm_crash_shutdown(struct pt_regs *regs) { native_write_msr(msr_kvm_system_time, 0, 0); + kvm_disable_steal_time(); native_machine_crash_shutdown(regs); } #endif @@ -167,6 +168,7 @@ static void kvm_crash_shutdown(struct pt_regs *regs) static void kvm_shutdown(void) { native_write_msr(msr_kvm_system_time, 0, 0); + kvm_disable_steal_time(); native_machine_shutdown(); }
Register steal time within KVM. Everytime we sample the steal time information, we update a local variable that tells what was the last time read. We then account the difference. Signed-off-by: Glauber Costa <glommer@redhat.com> CC: Rik van Riel <riel@redhat.com> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Peter Zijlstra <peterz@infradead.org> CC: Avi Kivity <avi@redhat.com> CC: Anthony Liguori <aliguori@us.ibm.com> CC: Eric B Munson <emunson@mgebm.net> --- Documentation/kernel-parameters.txt | 4 ++ arch/x86/include/asm/kvm_para.h | 1 + arch/x86/kernel/kvm.c | 72 +++++++++++++++++++++++++++++++++++ arch/x86/kernel/kvmclock.c | 2 + 4 files changed, 79 insertions(+), 0 deletions(-)