| Message ID | 1463134596-19470-2-git-send-email-borntraeger@de.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 13/05/2016 12:16, Christian Borntraeger wrote: > +config HAVE_KVM_INVALID_POLLS > + bool > + I'll change the config item to HAVE_KVM_INVALID_WAKEUPS, otherwise looks good. Paolo -- 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
On 05/13/2016 02:02 PM, Paolo Bonzini wrote: > > > On 13/05/2016 12:16, Christian Borntraeger wrote: >> +config HAVE_KVM_INVALID_POLLS >> + bool >> + > > I'll change the config item to HAVE_KVM_INVALID_WAKEUPS, otherwise looks > good. Can you do that or shall I resend as pull request? Regarding 4.7 vs. 4.8 Lets do this for 4.7. In the unlikely case that there is some bigger fallout we can still revert or fix for 2 1/2 month but it really seems to help. -- 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
On 13/05/2016 14:26, Christian Borntraeger wrote: >> > >> > On 13/05/2016 12:16, Christian Borntraeger wrote: >>> >> +config HAVE_KVM_INVALID_POLLS >>> >> + bool >>> >> + >> > >> > I'll change the config item to HAVE_KVM_INVALID_WAKEUPS, otherwise looks >> > good. > Can you do that or shall I resend as pull request? I'll do this. Paolo > Regarding 4.7 vs. 4.8 > Lets do this for 4.7. In the unlikely case that there is some bigger fallout > we can still revert or fix for 2 1/2 month but it really seems to help. > > -- 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
On Fri, May 13, 2016 at 3:16 AM, Christian Borntraeger <borntraeger@de.ibm.com> wrote: > Some wakeups should not be considered a sucessful poll. For example on > s390 I/O interrupts are usually floating, which means that _ALL_ CPUs > would be considered runnable - letting all vCPUs poll all the time for > transactional like workload, even if one vCPU would be enough. > This can result in huge CPU usage for large guests. > This patch lets architectures provide a way to qualify wakeups if they > should be considered a good/bad wakeups in regard to polls. > > For s390 the implementation will fence of halt polling for anything but > known good, single vCPU events. The s390 implementation for floating > interrupts does a wakeup for one vCPU, but the interrupt will be delivered > by whatever CPU checks first for a pending interrupt. We prefer the > woken up CPU by marking the poll of this CPU as "good" poll. > This code will also mark several other wakeup reasons like IPI or > expired timers as "good". This will of course also mark some events as > not sucessful. As KVM on z runs always as a 2nd level hypervisor, > we prefer to not poll, unless we are really sure, though. > > This patch successfully limits the CPU usage for cases like uperf 1byte > transactional ping pong workload or wakeup heavy workload like OLTP > while still providing a proper speedup. > > This also introduced a new vcpu stat "halt_poll_no_tuning" that marks > wakeups that are considered not good for polling. > > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > Acked-by: Radim Kr?má? <rkrcmar@redhat.com> (for an earlier version) > Cc: David Matlack <dmatlack@google.com> Reviewed-by: David Matlack <dmatlack@google.com> > Cc: Wanpeng Li <kernellwp@gmail.com> > --- > arch/arm/include/asm/kvm_host.h | 2 ++ > arch/arm64/include/asm/kvm_host.h | 2 ++ > arch/mips/include/asm/kvm_host.h | 2 ++ > arch/mips/kvm/mips.c | 1 + > arch/powerpc/include/asm/kvm_host.h | 2 ++ > arch/powerpc/kvm/book3s.c | 1 + > arch/powerpc/kvm/booke.c | 1 + > arch/s390/include/asm/kvm_host.h | 3 +++ > arch/s390/kvm/Kconfig | 1 + > arch/s390/kvm/interrupt.c | 5 +++++ > arch/s390/kvm/kvm-s390.c | 6 ++++++ > arch/x86/include/asm/kvm_host.h | 2 ++ > arch/x86/kvm/x86.c | 1 + > include/linux/kvm_host.h | 15 +++++++++++++++ > include/trace/events/kvm.h | 11 +++++++---- > virt/kvm/Kconfig | 3 +++ > virt/kvm/kvm_main.c | 8 ++++++-- > 17 files changed, 60 insertions(+), 6 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 3850701..4cd8732 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -187,6 +187,7 @@ struct kvm_vm_stat { > struct kvm_vcpu_stat { > u32 halt_successful_poll; > u32 halt_attempted_poll; > + u32 halt_poll_invalid; > u32 halt_wakeup; > u32 hvc_exit_stat; > u64 wfe_exit_stat; > @@ -282,6 +283,7 @@ static inline void kvm_arch_hardware_unsetup(void) {} > static inline void kvm_arch_sync_events(struct kvm *kvm) {} > static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} > static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} > +static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} > > static inline void kvm_arm_init_debug(void) {} > static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index f5c6bd2..d49399d 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -293,6 +293,7 @@ struct kvm_vm_stat { > struct kvm_vcpu_stat { > u32 halt_successful_poll; > u32 halt_attempted_poll; > + u32 halt_poll_invalid; > u32 halt_wakeup; > u32 hvc_exit_stat; > u64 wfe_exit_stat; > @@ -357,6 +358,7 @@ static inline void kvm_arch_hardware_unsetup(void) {} > static inline void kvm_arch_sync_events(struct kvm *kvm) {} > static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} > static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} > +static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} > > void kvm_arm_init_debug(void); > void kvm_arm_setup_debug(struct kvm_vcpu *vcpu); > diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h > index 942b8f6..9a37a10 100644 > --- a/arch/mips/include/asm/kvm_host.h > +++ b/arch/mips/include/asm/kvm_host.h > @@ -122,6 +122,7 @@ struct kvm_vcpu_stat { > u32 flush_dcache_exits; > u32 halt_successful_poll; > u32 halt_attempted_poll; > + u32 halt_poll_invalid; > u32 halt_wakeup; > }; > > @@ -812,5 +813,6 @@ static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} > static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} > static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {} > static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} > +static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} > > #endif /* __MIPS_KVM_HOST_H__ */ > diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c > index 23b2094..dc052fb 100644 > --- a/arch/mips/kvm/mips.c > +++ b/arch/mips/kvm/mips.c > @@ -56,6 +56,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { > { "flush_dcache", VCPU_STAT(flush_dcache_exits), KVM_STAT_VCPU }, > { "halt_successful_poll", VCPU_STAT(halt_successful_poll), KVM_STAT_VCPU }, > { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll), KVM_STAT_VCPU }, > + { "halt_poll_invalid", VCPU_STAT(halt_poll_invalid), KVM_STAT_VCPU }, > { "halt_wakeup", VCPU_STAT(halt_wakeup), KVM_STAT_VCPU }, > {NULL} > }; > diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h > index a07645c..ec35af3 100644 > --- a/arch/powerpc/include/asm/kvm_host.h > +++ b/arch/powerpc/include/asm/kvm_host.h > @@ -116,6 +116,7 @@ struct kvm_vcpu_stat { > u32 ext_intr_exits; > u32 halt_successful_poll; > u32 halt_attempted_poll; > + u32 halt_poll_invalid; > u32 halt_wakeup; > u32 dbell_exits; > u32 gdbell_exits; > @@ -727,5 +728,6 @@ static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} > static inline void kvm_arch_exit(void) {} > static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {} > static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} > +static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} > > #endif /* __POWERPC_KVM_HOST_H__ */ > diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c > index b34220d2..47018fc 100644 > --- a/arch/powerpc/kvm/book3s.c > +++ b/arch/powerpc/kvm/book3s.c > @@ -54,6 +54,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { > { "queue_intr", VCPU_STAT(queue_intr) }, > { "halt_successful_poll", VCPU_STAT(halt_successful_poll), }, > { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll), }, > + { "halt_poll_invalid", VCPU_STAT(halt_poll_invalid) }, > { "halt_wakeup", VCPU_STAT(halt_wakeup) }, > { "pf_storage", VCPU_STAT(pf_storage) }, > { "sp_storage", VCPU_STAT(sp_storage) }, > diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c > index 4d66f44..4afae69 100644 > --- a/arch/powerpc/kvm/booke.c > +++ b/arch/powerpc/kvm/booke.c > @@ -64,6 +64,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { > { "ext_intr", VCPU_STAT(ext_intr_exits) }, > { "halt_successful_poll", VCPU_STAT(halt_successful_poll) }, > { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) }, > + { "halt_poll_invalid", VCPU_STAT(halt_poll_invalid) }, > { "halt_wakeup", VCPU_STAT(halt_wakeup) }, > { "doorbell", VCPU_STAT(dbell_exits) }, > { "guest doorbell", VCPU_STAT(gdbell_exits) }, > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h > index 9282ccf..53d7945 100644 > --- a/arch/s390/include/asm/kvm_host.h > +++ b/arch/s390/include/asm/kvm_host.h > @@ -247,6 +247,7 @@ struct kvm_vcpu_stat { > u32 exit_instruction; > u32 halt_successful_poll; > u32 halt_attempted_poll; > + u32 halt_poll_invalid; > u32 halt_wakeup; > u32 instruction_lctl; > u32 instruction_lctlg; > @@ -696,4 +697,6 @@ static inline void kvm_arch_flush_shadow_memslot(struct kvm *kvm, > static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {} > static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} > > +void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu); > + > #endif > diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig > index 5ea5af3..ccfe6f6 100644 > --- a/arch/s390/kvm/Kconfig > +++ b/arch/s390/kvm/Kconfig > @@ -28,6 +28,7 @@ config KVM > select HAVE_KVM_IRQCHIP > select HAVE_KVM_IRQFD > select HAVE_KVM_IRQ_ROUTING > + select HAVE_KVM_INVALID_POLLS > select SRCU > select KVM_VFIO > ---help--- > diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c > index e550404..5a80af7 100644 > --- a/arch/s390/kvm/interrupt.c > +++ b/arch/s390/kvm/interrupt.c > @@ -977,6 +977,11 @@ no_timer: > > void kvm_s390_vcpu_wakeup(struct kvm_vcpu *vcpu) > { > + /* > + * We cannot move this into the if, as the CPU might be already > + * in kvm_vcpu_block without having the waitqueue set (polling) > + */ > + vcpu->valid_wakeup = true; > if (swait_active(&vcpu->wq)) { > /* > * The vcpu gave up the cpu voluntarily, mark it as a good > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index c597201..6d8ec3a 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -65,6 +65,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { > { "exit_instr_and_program_int", VCPU_STAT(exit_instr_and_program) }, > { "halt_successful_poll", VCPU_STAT(halt_successful_poll) }, > { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) }, > + { "halt_poll_invalid", VCPU_STAT(halt_poll_invalid) }, > { "halt_wakeup", VCPU_STAT(halt_wakeup) }, > { "instruction_lctlg", VCPU_STAT(instruction_lctlg) }, > { "instruction_lctl", VCPU_STAT(instruction_lctl) }, > @@ -2992,6 +2993,11 @@ static inline unsigned long nonhyp_mask(int i) > return 0x0000ffffffffffffUL >> (nonhyp_fai << 4); > } > > +void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) > +{ > + vcpu->valid_wakeup = false; > +} > + > static int __init kvm_s390_init(void) > { > int i; > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index c66e262..c99494b 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -803,6 +803,7 @@ struct kvm_vcpu_stat { > u32 halt_exits; > u32 halt_successful_poll; > u32 halt_attempted_poll; > + u32 halt_poll_invalid; > u32 halt_wakeup; > u32 request_irq_exits; > u32 irq_exits; > @@ -1342,5 +1343,6 @@ void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e, > > static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {} > static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} > +static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} > > #endif /* _ASM_X86_KVM_HOST_H */ > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 6c774cd..bcef92f 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -161,6 +161,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { > { "halt_exits", VCPU_STAT(halt_exits) }, > { "halt_successful_poll", VCPU_STAT(halt_successful_poll) }, > { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) }, > + { "halt_poll_invalid", VCPU_STAT(halt_poll_invalid) }, > { "halt_wakeup", VCPU_STAT(halt_wakeup) }, > { "hypercalls", VCPU_STAT(hypercalls) }, > { "request_irq", VCPU_STAT(request_irq_exits) }, > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index 92a0229..f350dc9 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -229,6 +229,7 @@ struct kvm_vcpu { > sigset_t sigset; > struct kvm_vcpu_stat stat; > unsigned int halt_poll_ns; > + bool valid_wakeup; > > #ifdef CONFIG_HAS_IOMEM > int mmio_needed; > @@ -1196,4 +1197,18 @@ int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq, > uint32_t guest_irq, bool set); > #endif /* CONFIG_HAVE_KVM_IRQ_BYPASS */ > > +#ifdef CONFIG_HAVE_KVM_INVALID_POLLS > +/* If we wakeup during the poll time, was it a sucessful poll? */ > +static inline bool vcpu_valid_wakeup(struct kvm_vcpu *vcpu) > +{ > + return vcpu->valid_wakeup; > +} > + > +#else > +static inline bool vcpu_valid_wakeup(struct kvm_vcpu *vcpu) > +{ > + return true; > +} > +#endif /* CONFIG_HAVE_KVM_INVALID_POLLS */ > + > #endif > diff --git a/include/trace/events/kvm.h b/include/trace/events/kvm.h > index aa69253..526fb3d 100644 > --- a/include/trace/events/kvm.h > +++ b/include/trace/events/kvm.h > @@ -38,22 +38,25 @@ TRACE_EVENT(kvm_userspace_exit, > ); > > TRACE_EVENT(kvm_vcpu_wakeup, > - TP_PROTO(__u64 ns, bool waited), > - TP_ARGS(ns, waited), > + TP_PROTO(__u64 ns, bool waited, bool valid), > + TP_ARGS(ns, waited, valid), > > TP_STRUCT__entry( > __field( __u64, ns ) > __field( bool, waited ) > + __field( bool, valid ) > ), > > TP_fast_assign( > __entry->ns = ns; > __entry->waited = waited; > + __entry->valid = valid; > ), > > - TP_printk("%s time %lld ns", > + TP_printk("%s time %lld ns, polling %s", > __entry->waited ? "wait" : "poll", > - __entry->ns) > + __entry->ns, > + __entry->valid ? "valid" : "invalid") > ); > > #if defined(CONFIG_HAVE_KVM_IRQFD) > diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig > index 7a79b68..4451842 100644 > --- a/virt/kvm/Kconfig > +++ b/virt/kvm/Kconfig > @@ -41,6 +41,9 @@ config KVM_VFIO > config HAVE_KVM_ARCH_TLB_FLUSH_ALL > bool > > +config HAVE_KVM_INVALID_POLLS > + bool > + > config KVM_GENERIC_DIRTYLOG_READ_PROTECT > bool > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index ed3d9bb..21f6498 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -2028,6 +2028,8 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) > */ > if (kvm_vcpu_check_block(vcpu) < 0) { > ++vcpu->stat.halt_successful_poll; > + if (!vcpu_valid_wakeup(vcpu)) > + ++vcpu->stat.halt_poll_invalid; > goto out; > } > cur = ktime_get(); > @@ -2057,7 +2059,8 @@ out: > if (block_ns <= vcpu->halt_poll_ns) > ; > /* we had a long block, shrink polling */ > - else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns) > + else if (!vcpu_valid_wakeup(vcpu) || > + (vcpu->halt_poll_ns && block_ns > halt_poll_ns)) > shrink_halt_poll_ns(vcpu); > /* we had a short halt and our poll time is too small */ > else if (vcpu->halt_poll_ns < halt_poll_ns && > @@ -2066,7 +2069,8 @@ out: > } else > vcpu->halt_poll_ns = 0; > > - trace_kvm_vcpu_wakeup(block_ns, waited); > + trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu)); > + kvm_arch_vcpu_block_finish(vcpu); > } > EXPORT_SYMBOL_GPL(kvm_vcpu_block); > > -- > 2.5.5 > > -- > 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 -- 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/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 3850701..4cd8732 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -187,6 +187,7 @@ struct kvm_vm_stat { struct kvm_vcpu_stat { u32 halt_successful_poll; u32 halt_attempted_poll; + u32 halt_poll_invalid; u32 halt_wakeup; u32 hvc_exit_stat; u64 wfe_exit_stat; @@ -282,6 +283,7 @@ static inline void kvm_arch_hardware_unsetup(void) {} static inline void kvm_arch_sync_events(struct kvm *kvm) {} static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} +static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_init_debug(void) {} static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index f5c6bd2..d49399d 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -293,6 +293,7 @@ struct kvm_vm_stat { struct kvm_vcpu_stat { u32 halt_successful_poll; u32 halt_attempted_poll; + u32 halt_poll_invalid; u32 halt_wakeup; u32 hvc_exit_stat; u64 wfe_exit_stat; @@ -357,6 +358,7 @@ static inline void kvm_arch_hardware_unsetup(void) {} static inline void kvm_arch_sync_events(struct kvm *kvm) {} static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} +static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} void kvm_arm_init_debug(void); void kvm_arm_setup_debug(struct kvm_vcpu *vcpu); diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h index 942b8f6..9a37a10 100644 --- a/arch/mips/include/asm/kvm_host.h +++ b/arch/mips/include/asm/kvm_host.h @@ -122,6 +122,7 @@ struct kvm_vcpu_stat { u32 flush_dcache_exits; u32 halt_successful_poll; u32 halt_attempted_poll; + u32 halt_poll_invalid; u32 halt_wakeup; }; @@ -812,5 +813,6 @@ static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {} static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} +static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} #endif /* __MIPS_KVM_HOST_H__ */ diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index 23b2094..dc052fb 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -56,6 +56,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "flush_dcache", VCPU_STAT(flush_dcache_exits), KVM_STAT_VCPU }, { "halt_successful_poll", VCPU_STAT(halt_successful_poll), KVM_STAT_VCPU }, { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll), KVM_STAT_VCPU }, + { "halt_poll_invalid", VCPU_STAT(halt_poll_invalid), KVM_STAT_VCPU }, { "halt_wakeup", VCPU_STAT(halt_wakeup), KVM_STAT_VCPU }, {NULL} }; diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index a07645c..ec35af3 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -116,6 +116,7 @@ struct kvm_vcpu_stat { u32 ext_intr_exits; u32 halt_successful_poll; u32 halt_attempted_poll; + u32 halt_poll_invalid; u32 halt_wakeup; u32 dbell_exits; u32 gdbell_exits; @@ -727,5 +728,6 @@ static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} static inline void kvm_arch_exit(void) {} static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {} static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} +static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} #endif /* __POWERPC_KVM_HOST_H__ */ diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index b34220d2..47018fc 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -54,6 +54,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "queue_intr", VCPU_STAT(queue_intr) }, { "halt_successful_poll", VCPU_STAT(halt_successful_poll), }, { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll), }, + { "halt_poll_invalid", VCPU_STAT(halt_poll_invalid) }, { "halt_wakeup", VCPU_STAT(halt_wakeup) }, { "pf_storage", VCPU_STAT(pf_storage) }, { "sp_storage", VCPU_STAT(sp_storage) }, diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index 4d66f44..4afae69 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -64,6 +64,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "ext_intr", VCPU_STAT(ext_intr_exits) }, { "halt_successful_poll", VCPU_STAT(halt_successful_poll) }, { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) }, + { "halt_poll_invalid", VCPU_STAT(halt_poll_invalid) }, { "halt_wakeup", VCPU_STAT(halt_wakeup) }, { "doorbell", VCPU_STAT(dbell_exits) }, { "guest doorbell", VCPU_STAT(gdbell_exits) }, diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 9282ccf..53d7945 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -247,6 +247,7 @@ struct kvm_vcpu_stat { u32 exit_instruction; u32 halt_successful_poll; u32 halt_attempted_poll; + u32 halt_poll_invalid; u32 halt_wakeup; u32 instruction_lctl; u32 instruction_lctlg; @@ -696,4 +697,6 @@ static inline void kvm_arch_flush_shadow_memslot(struct kvm *kvm, static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {} static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} +void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu); + #endif diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig index 5ea5af3..ccfe6f6 100644 --- a/arch/s390/kvm/Kconfig +++ b/arch/s390/kvm/Kconfig @@ -28,6 +28,7 @@ config KVM select HAVE_KVM_IRQCHIP select HAVE_KVM_IRQFD select HAVE_KVM_IRQ_ROUTING + select HAVE_KVM_INVALID_POLLS select SRCU select KVM_VFIO ---help--- diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index e550404..5a80af7 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -977,6 +977,11 @@ no_timer: void kvm_s390_vcpu_wakeup(struct kvm_vcpu *vcpu) { + /* + * We cannot move this into the if, as the CPU might be already + * in kvm_vcpu_block without having the waitqueue set (polling) + */ + vcpu->valid_wakeup = true; if (swait_active(&vcpu->wq)) { /* * The vcpu gave up the cpu voluntarily, mark it as a good diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index c597201..6d8ec3a 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -65,6 +65,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "exit_instr_and_program_int", VCPU_STAT(exit_instr_and_program) }, { "halt_successful_poll", VCPU_STAT(halt_successful_poll) }, { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) }, + { "halt_poll_invalid", VCPU_STAT(halt_poll_invalid) }, { "halt_wakeup", VCPU_STAT(halt_wakeup) }, { "instruction_lctlg", VCPU_STAT(instruction_lctlg) }, { "instruction_lctl", VCPU_STAT(instruction_lctl) }, @@ -2992,6 +2993,11 @@ static inline unsigned long nonhyp_mask(int i) return 0x0000ffffffffffffUL >> (nonhyp_fai << 4); } +void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) +{ + vcpu->valid_wakeup = false; +} + static int __init kvm_s390_init(void) { int i; diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index c66e262..c99494b 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -803,6 +803,7 @@ struct kvm_vcpu_stat { u32 halt_exits; u32 halt_successful_poll; u32 halt_attempted_poll; + u32 halt_poll_invalid; u32 halt_wakeup; u32 request_irq_exits; u32 irq_exits; @@ -1342,5 +1343,6 @@ void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e, static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {} static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} +static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} #endif /* _ASM_X86_KVM_HOST_H */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 6c774cd..bcef92f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -161,6 +161,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "halt_exits", VCPU_STAT(halt_exits) }, { "halt_successful_poll", VCPU_STAT(halt_successful_poll) }, { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) }, + { "halt_poll_invalid", VCPU_STAT(halt_poll_invalid) }, { "halt_wakeup", VCPU_STAT(halt_wakeup) }, { "hypercalls", VCPU_STAT(hypercalls) }, { "request_irq", VCPU_STAT(request_irq_exits) }, diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 92a0229..f350dc9 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -229,6 +229,7 @@ struct kvm_vcpu { sigset_t sigset; struct kvm_vcpu_stat stat; unsigned int halt_poll_ns; + bool valid_wakeup; #ifdef CONFIG_HAS_IOMEM int mmio_needed; @@ -1196,4 +1197,18 @@ int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq, uint32_t guest_irq, bool set); #endif /* CONFIG_HAVE_KVM_IRQ_BYPASS */ +#ifdef CONFIG_HAVE_KVM_INVALID_POLLS +/* If we wakeup during the poll time, was it a sucessful poll? */ +static inline bool vcpu_valid_wakeup(struct kvm_vcpu *vcpu) +{ + return vcpu->valid_wakeup; +} + +#else +static inline bool vcpu_valid_wakeup(struct kvm_vcpu *vcpu) +{ + return true; +} +#endif /* CONFIG_HAVE_KVM_INVALID_POLLS */ + #endif diff --git a/include/trace/events/kvm.h b/include/trace/events/kvm.h index aa69253..526fb3d 100644 --- a/include/trace/events/kvm.h +++ b/include/trace/events/kvm.h @@ -38,22 +38,25 @@ TRACE_EVENT(kvm_userspace_exit, ); TRACE_EVENT(kvm_vcpu_wakeup, - TP_PROTO(__u64 ns, bool waited), - TP_ARGS(ns, waited), + TP_PROTO(__u64 ns, bool waited, bool valid), + TP_ARGS(ns, waited, valid), TP_STRUCT__entry( __field( __u64, ns ) __field( bool, waited ) + __field( bool, valid ) ), TP_fast_assign( __entry->ns = ns; __entry->waited = waited; + __entry->valid = valid; ), - TP_printk("%s time %lld ns", + TP_printk("%s time %lld ns, polling %s", __entry->waited ? "wait" : "poll", - __entry->ns) + __entry->ns, + __entry->valid ? "valid" : "invalid") ); #if defined(CONFIG_HAVE_KVM_IRQFD) diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index 7a79b68..4451842 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -41,6 +41,9 @@ config KVM_VFIO config HAVE_KVM_ARCH_TLB_FLUSH_ALL bool +config HAVE_KVM_INVALID_POLLS + bool + config KVM_GENERIC_DIRTYLOG_READ_PROTECT bool diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ed3d9bb..21f6498 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2028,6 +2028,8 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) */ if (kvm_vcpu_check_block(vcpu) < 0) { ++vcpu->stat.halt_successful_poll; + if (!vcpu_valid_wakeup(vcpu)) + ++vcpu->stat.halt_poll_invalid; goto out; } cur = ktime_get(); @@ -2057,7 +2059,8 @@ out: if (block_ns <= vcpu->halt_poll_ns) ; /* we had a long block, shrink polling */ - else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns) + else if (!vcpu_valid_wakeup(vcpu) || + (vcpu->halt_poll_ns && block_ns > halt_poll_ns)) shrink_halt_poll_ns(vcpu); /* we had a short halt and our poll time is too small */ else if (vcpu->halt_poll_ns < halt_poll_ns && @@ -2066,7 +2069,8 @@ out: } else vcpu->halt_poll_ns = 0; - trace_kvm_vcpu_wakeup(block_ns, waited); + trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu)); + kvm_arch_vcpu_block_finish(vcpu); } EXPORT_SYMBOL_GPL(kvm_vcpu_block);