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Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Ajay Kaher , Alexey Makhalov , Jan Kiszka , Andy Lutomirski , Peter Zijlstra , Juergen Gross , Daniel Lezcano , John Stultz Cc: Shuah Khan , "H. Peter Anvin" , Vitaly Kuznetsov , Broadcom internal kernel review list , Boris Ostrovsky , Stephen Boyd , linux-doc@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, linux-hyperv@vger.kernel.org, virtualization@lists.linux.dev, xen-devel@lists.xenproject.org, Tom Lendacky , Nikunj A Dadhania , David Woodhouse , David Woodhouse , Michael Kelley , Thomas Gleixner Content-Type: text/plain; charset="UTF-8" Pass in a PV clock's save/restore helpers when configuring sched_clock instead of relying on each PV clock to manually set the save/restore hooks. In addition to bringing sanity to the code, this will allow gracefully "rejecting" a PV sched_clock, e.g. when running as a CoCo guest that has access to a "secure" TSC. No functional change intended. Reviewed-by: David Woodhouse Signed-off-by: Sean Christopherson --- arch/x86/include/asm/timer.h | 9 ++++++--- arch/x86/kernel/cpu/vmware.c | 8 +++----- arch/x86/kernel/kvmclock.c | 6 +++--- arch/x86/kernel/tsc.c | 5 ++++- arch/x86/xen/time.c | 5 ++--- drivers/clocksource/hyperv_timer.c | 6 ++---- 6 files changed, 20 insertions(+), 19 deletions(-) diff --git a/arch/x86/include/asm/timer.h b/arch/x86/include/asm/timer.h index fe41d40a9ae6..e97cd1ae03d1 100644 --- a/arch/x86/include/asm/timer.h +++ b/arch/x86/include/asm/timer.h @@ -14,11 +14,14 @@ extern int no_timer_check; extern bool using_native_sched_clock(void); #ifdef CONFIG_PARAVIRT -void __paravirt_set_sched_clock(u64 (*func)(void), bool stable); +void __paravirt_set_sched_clock(u64 (*func)(void), bool stable, + void (*save)(void), void (*restore)(void)); -static inline void paravirt_set_sched_clock(u64 (*func)(void)) +static inline void paravirt_set_sched_clock(u64 (*func)(void), + void (*save)(void), + void (*restore)(void)) { - __paravirt_set_sched_clock(func, true); + __paravirt_set_sched_clock(func, true, save, restore); } #endif diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c index 5c1ccaf4a25e..232255279a6e 100644 --- a/arch/x86/kernel/cpu/vmware.c +++ b/arch/x86/kernel/cpu/vmware.c @@ -347,11 +347,9 @@ static void __init vmware_paravirt_ops_setup(void) vmware_cyc2ns_setup(); - if (vmw_sched_clock) { - paravirt_set_sched_clock(vmware_sched_clock); - x86_platform.save_sched_clock_state = x86_init_noop; - x86_platform.restore_sched_clock_state = x86_init_noop; - } + if (vmw_sched_clock) + paravirt_set_sched_clock(vmware_sched_clock, + x86_init_noop, x86_init_noop); if (vmware_is_stealclock_available()) { has_steal_clock = true; diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 07e875738c39..5b9955343199 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -158,7 +158,9 @@ static void kvm_restore_sched_clock_state(void) static inline void kvm_sched_clock_init(bool stable) { kvm_sched_clock_offset = kvm_clock_read(); - __paravirt_set_sched_clock(kvm_sched_clock_read, stable); + __paravirt_set_sched_clock(kvm_sched_clock_read, stable, + kvm_save_sched_clock_state, + kvm_restore_sched_clock_state); pr_info("kvm-clock: using sched offset of %llu cycles", kvm_sched_clock_offset); @@ -367,8 +369,6 @@ void __init kvmclock_init(bool prefer_tsc) #ifdef CONFIG_SMP x86_cpuinit.early_percpu_clock_init = kvm_setup_secondary_clock; #endif - x86_platform.save_sched_clock_state = kvm_save_sched_clock_state; - x86_platform.restore_sched_clock_state = kvm_restore_sched_clock_state; kvm_get_preset_lpj(); /* diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 7473dcab4775..83353d643150 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -280,12 +280,15 @@ bool using_native_sched_clock(void) return static_call_query(pv_sched_clock) == native_sched_clock; } -void __paravirt_set_sched_clock(u64 (*func)(void), bool stable) +void __paravirt_set_sched_clock(u64 (*func)(void), bool stable, + void (*save)(void), void (*restore)(void)) { if (!stable) clear_sched_clock_stable(); static_call_update(pv_sched_clock, func); + x86_platform.save_sched_clock_state = save; + x86_platform.restore_sched_clock_state = restore; } #else u64 sched_clock_noinstr(void) __attribute__((alias("native_sched_clock"))); diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 477441752f40..8cd8bfaf1320 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -566,13 +566,12 @@ static void __init xen_init_time_common(void) { xen_sched_clock_offset = xen_clocksource_read(); static_call_update(pv_steal_clock, xen_steal_clock); - paravirt_set_sched_clock(xen_sched_clock); + /* * Xen has paravirtualized suspend/resume and so doesn't use the common * x86 sched_clock save/restore hooks. */ - x86_platform.save_sched_clock_state = x86_init_noop; - x86_platform.restore_sched_clock_state = x86_init_noop; + paravirt_set_sched_clock(xen_sched_clock, x86_init_noop, x86_init_noop); x86_init.hyper.get_tsc_khz = xen_tsc_khz; x86_platform.get_wallclock = xen_get_wallclock; diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index 220668207d19..8ee7a9de0f4f 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -570,10 +570,8 @@ static void hv_restore_sched_clock_state(void) static __always_inline void hv_setup_sched_clock(void *sched_clock) { /* We're on x86/x64 *and* using PV ops */ - paravirt_set_sched_clock(sched_clock); - - x86_platform.save_sched_clock_state = hv_save_sched_clock_state; - x86_platform.restore_sched_clock_state = hv_restore_sched_clock_state; + paravirt_set_sched_clock(sched_clock, hv_save_sched_clock_state, + hv_restore_sched_clock_state); } #else /* !CONFIG_GENERIC_SCHED_CLOCK && !CONFIG_PARAVIRT */ static __always_inline void hv_setup_sched_clock(void *sched_clock) {} -- 2.55.0.rc0.799.gd6f94ed593-goog