diff options
Diffstat (limited to 'arch/powerpc/include/asm/paravirt.h')
| -rw-r--r-- | arch/powerpc/include/asm/paravirt.h | 79 |
1 files changed, 75 insertions, 4 deletions
diff --git a/arch/powerpc/include/asm/paravirt.h b/arch/powerpc/include/asm/paravirt.h index eb7df559ae74..b78b82d66057 100644 --- a/arch/powerpc/include/asm/paravirt.h +++ b/arch/powerpc/include/asm/paravirt.h @@ -6,6 +6,7 @@ #include <asm/smp.h> #ifdef CONFIG_PPC64 #include <asm/paca.h> +#include <asm/lppaca.h> #include <asm/hvcall.h> #endif @@ -21,6 +22,18 @@ static inline bool is_shared_processor(void) return static_branch_unlikely(&shared_processor); } +#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING +extern struct static_key paravirt_steal_enabled; +extern struct static_key paravirt_steal_rq_enabled; + +u64 pseries_paravirt_steal_clock(int cpu); + +static inline u64 paravirt_steal_clock(int cpu) +{ + return pseries_paravirt_steal_clock(cpu); +} +#endif + /* If bit 0 is set, the cpu has been ceded, conferred, or preempted */ static inline u32 yield_count_of(int cpu) { @@ -58,6 +71,22 @@ static inline void yield_to_any(void) { plpar_hcall_norets_notrace(H_CONFER, -1, 0); } + +static inline bool is_vcpu_idle(int vcpu) +{ + return lppaca_of(vcpu).idle; +} + +static inline bool vcpu_is_dispatched(int vcpu) +{ + /* + * This is the yield_count. An "odd" value (low bit on) means that + * the processor is yielded (either because of an OS yield or a + * hypervisor preempt). An even value implies that the processor is + * currently executing. + */ + return (!(yield_count_of(vcpu) & 1)); +} #else static inline bool is_shared_processor(void) { @@ -87,6 +116,14 @@ static inline void prod_cpu(int cpu) ___bad_prod_cpu(); /* This would be a bug */ } +static inline bool is_vcpu_idle(int vcpu) +{ + return false; +} +static inline bool vcpu_is_dispatched(int vcpu) +{ + return true; +} #endif #define vcpu_is_preempted vcpu_is_preempted @@ -108,9 +145,23 @@ static inline bool vcpu_is_preempted(int cpu) if (!is_shared_processor()) return false; + /* + * If the hypervisor has dispatched the target CPU on a physical + * processor, then the target CPU is definitely not preempted. + */ + if (vcpu_is_dispatched(cpu)) + return false; + + /* + * if the target CPU is not dispatched and the guest OS + * has not marked the CPU idle, then it is hypervisor preempted. + */ + if (!is_vcpu_idle(cpu)) + return true; + #ifdef CONFIG_PPC_SPLPAR if (!is_kvm_guest()) { - int first_cpu; + int first_cpu, i; /* * The result of vcpu_is_preempted() is used in a @@ -130,17 +181,37 @@ static inline bool vcpu_is_preempted(int cpu) /* * The PowerVM hypervisor dispatches VMs on a whole core - * basis. So we know that a thread sibling of the local CPU + * basis. So we know that a thread sibling of the executing CPU * cannot have been preempted by the hypervisor, even if it * has called H_CONFER, which will set the yield bit. */ if (cpu_first_thread_sibling(cpu) == first_cpu) return false; + + /* + * The specific target CPU was marked by guest OS as idle, but + * then also check all other cpus in the core for PowerVM + * because it does core scheduling and one of the vcpu + * of the core getting preempted by hypervisor implies + * other vcpus can also be considered preempted. + */ + first_cpu = cpu_first_thread_sibling(cpu); + for (i = first_cpu; i < first_cpu + threads_per_core; i++) { + if (i == cpu) + continue; + if (vcpu_is_dispatched(i)) + return false; + if (!is_vcpu_idle(i)) + return true; + } } #endif - if (yield_count_of(cpu) & 1) - return true; + /* + * None of the threads in target CPU's core are running but none of + * them were preempted too. Hence assume the target CPU to be + * non-preempted. + */ return false; } |