search for: kvm_feature_pv_unhalt

...ONFIG_PARAVIRT_UNFAIR_LOCKS > +/* > + * Enable unfair lock if running in a real para-virtualized environment > + */ > +static __init int kvm_unfair_locks_init_jump(void) > +{ > + if (!kvm_para_available()) > + return 0; I think you also need to check for !kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)? Otherwise you might enable this, but the kicker function won't be enabled. > + > + static_key_slow_inc(&paravirt_unfairlocks_enabled); > + printk(KERN_INFO "KVM setup unfair spinlock\n"); > + > + return 0; > +} > +early_initcall(kvm_unfair_locks_init_jump);...

...ONFIG_PARAVIRT_UNFAIR_LOCKS > +/* > + * Enable unfair lock if running in a real para-virtualized environment > + */ > +static __init int kvm_unfair_locks_init_jump(void) > +{ > + if (!kvm_para_available()) > + return 0; I think you also need to check for !kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)? Otherwise you might enable this, but the kicker function won't be enabled. > + > + static_key_slow_inc(&paravirt_unfairlocks_enabled); > + printk(KERN_INFO "KVM setup unfair spinlock\n"); > + > + return 0; > +} > +early_initcall(kvm_unfair_locks_init_jump);...

The 5-patch series to follow this email extends KVM-hypervisor and Linux guest running on KVM-hypervisor to support pv-ticket spinlocks, based on Xen's implementation. One hypercall is introduced in KVM hypervisor,that allows a vcpu to kick another vcpu out of halt state. The blocking of vcpu is done using halt() in (lock_spinning) slowpath. Note: 1) patch is based on 3.4-rc3 + ticketlock

The 5-patch series to follow this email extends KVM-hypervisor and Linux guest running on KVM-hypervisor to support pv-ticket spinlocks, based on Xen's implementation. One hypercall is introduced in KVM hypervisor,that allows a vcpu to kick another vcpu out of halt state. The blocking of vcpu is done using halt() in (lock_spinning) slowpath. Note: 1) patch is based on 3.4-rc3 + ticketlock

This series forms the kvm host part of paravirtual spinlock based against kvm tree. Please refer to https://lkml.org/lkml/2013/8/9/265 for kvm guest and Xen, x86 part merged to -tip spinlocks. Please note that: kvm uapi: Add KICK_CPU and PV_UNHALT definition to uapi is a common patch for both guest and host. Changes since V12: fold the patch 3 into patch 2 for bisection. (Eric Northup)

This series forms the kvm host part of paravirtual spinlock based against kvm tree. Please refer to https://lkml.org/lkml/2013/8/9/265 for kvm guest and Xen, x86 part merged to -tip spinlocks. Please note that: kvm uapi: Add KICK_CPU and PV_UNHALT definition to uapi is a common patch for both guest and host. Changes since V12: fold the patch 3 into patch 2 for bisection. (Eric Northup)

The 6-patch series to follow this email extends KVM-hypervisor and Linux guest running on KVM-hypervisor to support pv-ticket spinlocks, based on Xen's implementation. One hypercall is introduced in KVM hypervisor,that allows a vcpu to kick another vcpu out of halt state. The blocking of vcpu is done using halt() in (lock_spinning) slowpath. one MSR is added to aid live migration. Changes

The 6-patch series to follow this email extends KVM-hypervisor and Linux guest running on KVM-hypervisor to support pv-ticket spinlocks, based on Xen's implementation. One hypercall is introduced in KVM hypervisor,that allows a vcpu to kick another vcpu out of halt state. The blocking of vcpu is done using halt() in (lock_spinning) slowpath. one MSR is added to aid live migration. Changes

This series forms the kvm host part of paravirtual spinlock based against kvm tree. Please refer https://lkml.org/lkml/2013/8/6/178 for kvm guest part of the series. Please note that: kvm uapi: Add KICK_CPU and PV_UNHALT definition to uapi is a common patch for both guest and host. Srivatsa Vaddagiri (1): kvm hypervisor : Add a hypercall to KVM hypervisor to support pv-ticketlocks

This series forms the kvm host part of paravirtual spinlock based against kvm tree. Please refer https://lkml.org/lkml/2013/8/6/178 for kvm guest part of the series. Please note that: kvm uapi: Add KICK_CPU and PV_UNHALT definition to uapi is a common patch for both guest and host. Srivatsa Vaddagiri (1): kvm hypervisor : Add a hypercall to KVM hypervisor to support pv-ticketlocks

...et(,%rdi,8), %rdx;" > +"cmpb $0, (%rdx,%rax);" > +"setne %al;" > +"pop %rdx;" > +"pop %rdi;" > +FRAME_END > +"ret;" > +".popsection"); > + > +#endif > + > /* > * Setup pv_lock_ops to exploit KVM_FEATURE_PV_UNHALT if present. > */ That should work for now. I have done something similar for __pv_queued_spin_unlock. However, this has the problem of creating a dependency on the exact layout of the steal_time structure. Maybe the constant 16 can be passed in as a parameter offsetof(struct kvm_steal_time, p...

...et(,%rdi,8), %rdx;" > +"cmpb $0, (%rdx,%rax);" > +"setne %al;" > +"pop %rdx;" > +"pop %rdi;" > +FRAME_END > +"ret;" > +".popsection"); > + > +#endif > + > /* > * Setup pv_lock_ops to exploit KVM_FEATURE_PV_UNHALT if present. > */ That should work for now. I have done something similar for __pv_queued_spin_unlock. However, this has the problem of creating a dependency on the exact layout of the steal_time structure. Maybe the constant 16 can be passed in as a parameter offsetof(struct kvm_steal_time, p...

Il 12/03/2014 19:54, Waiman Long ha scritto: > @@ -807,8 +889,13 @@ void __init kvm_spinlock_init(void) > if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) > return; > > +#ifdef CONFIG_QUEUE_SPINLOCK > + pv_lock_ops.kick_cpu = kvm_kick_cpu_type; > + pv_lock_ops.hibernate = kvm_hibernate; > +#else > pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(kvm_lock_spinning); > pv_lock_ops.unlock_kick = kvm_unlock_kick; > +#endif...

...void hang when lock info is overwritten + * in irq spinlock slowpath and no spurious interrupt occur to save us. + */ + if (arch_irqs_disabled_flags(flags)) + halt(); + else + safe_halt(); + +out: + local_irq_restore(flags); +} +#endif /* QUEUE_SPINLOCK */ /* * Setup pv_lock_ops to exploit KVM_FEATURE_PV_UNHALT if present. @@ -808,8 +854,20 @@ void __init kvm_spinlock_init(void) if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) return; +#ifdef CONFIG_QUEUE_SPINLOCK + pv_lock_ops.init_node = PV_CALLEE_SAVE(__pv_init_node); + pv_lock_ops.link_and_wait_node = PV_CALLEE_SAVE(__pv_link_and_wait_node); +...

Il 12/03/2014 19:54, Waiman Long ha scritto: > @@ -807,8 +889,13 @@ void __init kvm_spinlock_init(void) > if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) > return; > > +#ifdef CONFIG_QUEUE_SPINLOCK > + pv_lock_ops.kick_cpu = kvm_kick_cpu_type; > + pv_lock_ops.hibernate = kvm_hibernate; > +#else > pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(kvm_lock_spinning); > pv_lock_ops.unlock_kick = kvm_unlock_kick; > +#endif...

...G_FS */ +static inline void inc_kick_stats(enum pv_kick_type type) +{ +} +#endif /* CONFIG_KVM_DEBUG_FS */ + +static void kvm_kick_cpu_type(int cpu, enum pv_kick_type type) +{ + kvm_kick_cpu(cpu); + inc_kick_stats(type); +} +#endif /* !CONFIG_QUEUE_SPINLOCK */ /* * Setup pv_lock_ops to exploit KVM_FEATURE_PV_UNHALT if present. @@ -807,8 +857,12 @@ void __init kvm_spinlock_init(void) if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) return; +#ifdef CONFIG_QUEUE_SPINLOCK + pv_lock_ops.kick_cpu = kvm_kick_cpu_type; +#else pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(kvm_lock_spinning); pv_lock_ops.unloc...

KVM_HC_KICK_CPU hypercall added to wakeup halted vcpu in paravirtual spinlock enabled guest. KVM_FEATURE_PV_UNHALT enables guest to check whether pv spinlock can be enabled in guest. Thanks Vatsa for rewriting KVM_HC_KICK_CPU Cc: Rob Landley <rob at landley.net> Signed-off-by: Srivatsa Vaddagiri <vatsa at linux.vnet.ibm.com> Signed-off-by: Raghavendra K T <raghavendra.kt at linux.vnet.ibm.com&gt...

...+ */ > +static __init int kvm_unfair_locks_init_jump(void) > +{ > + if (!kvm_para_available()) > + return 0; > + kvm_kick_cpu_type() in patch 8 assumes that host has support for kick hypercall (KVM_HC_KICK_CPU). I think for that we need explicit check of this kvm_para_has_feature(KVM_FEATURE_PV_UNHALT). otherwise things may break for unlikely case of running a new guest on a old host? > + static_key_slow_inc(&paravirt_unfairlocks_enabled); > + printk(KERN_INFO "KVM setup unfair spinlock\n"); > + > + return 0; > +} > +early_initcall(kvm_unfair_locks_init_jump);...

...+ */ > +static __init int kvm_unfair_locks_init_jump(void) > +{ > + if (!kvm_para_available()) > + return 0; > + kvm_kick_cpu_type() in patch 8 assumes that host has support for kick hypercall (KVM_HC_KICK_CPU). I think for that we need explicit check of this kvm_para_has_feature(KVM_FEATURE_PV_UNHALT). otherwise things may break for unlikely case of running a new guest on a old host? > + static_key_slow_inc(&paravirt_unfairlocks_enabled); > + printk(KERN_INFO "KVM setup unfair spinlock\n"); > + > + return 0; > +} > +early_initcall(kvm_unfair_locks_init_jump);...

...raw_callee_save___kvm_vcpu_is_preempted:" +"movq __per_cpu_offset(,%rdi,8), %rax;" +"cmpb $0, " __stringify(PREEMPTED_OFFSET) "+steal_time(%rax);" +"setne %al;" +"ret;" +".popsection"); + +#endif + /* * Setup pv_lock_ops to exploit KVM_FEATURE_PV_UNHALT if present. */ void __init kvm_spinlock_init(void) { + BUILD_BUG_ON((offsetof(struct kvm_steal_time, preempted) + != PREEMPTED_OFFSET) || (sizeof(steal_time.preempted) != 1)); + if (!kvm_para_available()) return; /* Does host kernel support KVM_FEATURE_PV_UNHALT? */ -- 1.8.3.1