| Message ID | 20210120135555.32594-8-jgross@suse.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | x86: major paravirt cleanup | expand |
From: Juergen Gross <jgross@suse.com> Sent: Wednesday, January 20, 2021 5:56 AM > > The time pvops functions are the only ones left which might be > used in 32-bit mode and which return a 64-bit value. > > Switch them to use the static_call() mechanism instead of pvops, as > this allows quite some simplification of the pvops implementation. > > Signed-off-by: Juergen Gross <jgross@suse.com> > --- > V4: > - drop paravirt_time.h again > - don't move Hyper-V code (Michael Kelley) > --- > arch/x86/Kconfig | 1 + > arch/x86/include/asm/mshyperv.h | 2 +- > arch/x86/include/asm/paravirt.h | 17 ++++++++++++++--- > arch/x86/include/asm/paravirt_types.h | 6 ------ > arch/x86/kernel/cpu/vmware.c | 5 +++-- > arch/x86/kernel/kvm.c | 2 +- > arch/x86/kernel/kvmclock.c | 2 +- > arch/x86/kernel/paravirt.c | 16 ++++++++++++---- > arch/x86/kernel/tsc.c | 2 +- > arch/x86/xen/time.c | 11 ++++------- > drivers/clocksource/hyperv_timer.c | 5 +++-- > drivers/xen/time.c | 2 +- > 12 files changed, 42 insertions(+), 29 deletions(-) > [snip] > diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h > index 30f76b966857..b4ee331d29a7 100644 > --- a/arch/x86/include/asm/mshyperv.h > +++ b/arch/x86/include/asm/mshyperv.h > @@ -63,7 +63,7 @@ typedef int (*hyperv_fill_flush_list_func)( > static __always_inline void hv_setup_sched_clock(void *sched_clock) > { > #ifdef CONFIG_PARAVIRT > - pv_ops.time.sched_clock = sched_clock; > + paravirt_set_sched_clock(sched_clock); > #endif > } > This looks fine. [snip] > diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c > index ba04cb381cd3..bf3bf20bc6bd 100644 > --- a/drivers/clocksource/hyperv_timer.c > +++ b/drivers/clocksource/hyperv_timer.c > @@ -18,6 +18,7 @@ > #include <linux/sched_clock.h> > #include <linux/mm.h> > #include <linux/cpuhotplug.h> > +#include <linux/static_call.h> > #include <clocksource/hyperv_timer.h> > #include <asm/hyperv-tlfs.h> > #include <asm/mshyperv.h> > @@ -445,7 +446,7 @@ static bool __init hv_init_tsc_clocksource(void) > clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100); > > hv_sched_clock_offset = hv_read_reference_counter(); > - hv_setup_sched_clock(read_hv_sched_clock_tsc); > + paravirt_set_sched_clock(read_hv_sched_clock_tsc); > > return true; > } > @@ -470,6 +471,6 @@ void __init hv_init_clocksource(void) > clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100); > > hv_sched_clock_offset = hv_read_reference_counter(); > - hv_setup_sched_clock(read_hv_sched_clock_msr); > + static_call_update(pv_sched_clock, read_hv_sched_clock_msr); > } > EXPORT_SYMBOL_GPL(hv_init_clocksource); The changes to hyperv_timer.c aren't needed and shouldn't be there, so as to preserve hyperv_timer.c as architecture neutral. With your update to hv_setup_sched_clock() in mshyperv.h, the original code works correctly. While there are two call sites for hv_setup_sched_clock(), only one is called. And once the sched clock function is set, it is never changed or overridden. Michael
On Wed, Jan 20, 2021 at 02:55:47PM +0100, Juergen Gross wrote: > The time pvops functions are the only ones left which might be > used in 32-bit mode and which return a 64-bit value. > > Switch them to use the static_call() mechanism instead of pvops, as > this allows quite some simplification of the pvops implementation. > > Signed-off-by: Juergen Gross <jgross@suse.com> > --- > V4: > - drop paravirt_time.h again > - don't move Hyper-V code (Michael Kelley) > --- > arch/x86/Kconfig | 1 + > arch/x86/include/asm/mshyperv.h | 2 +- > arch/x86/include/asm/paravirt.h | 17 ++++++++++++++--- > arch/x86/include/asm/paravirt_types.h | 6 ------ > arch/x86/kernel/cpu/vmware.c | 5 +++-- > arch/x86/kernel/kvm.c | 2 +- > arch/x86/kernel/kvmclock.c | 2 +- > arch/x86/kernel/paravirt.c | 16 ++++++++++++---- > arch/x86/kernel/tsc.c | 2 +- > arch/x86/xen/time.c | 11 ++++------- > drivers/clocksource/hyperv_timer.c | 5 +++-- > drivers/xen/time.c | 2 +- > 12 files changed, 42 insertions(+), 29 deletions(-) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 21f851179ff0..7ccd4a80788c 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -771,6 +771,7 @@ if HYPERVISOR_GUEST > > config PARAVIRT > bool "Enable paravirtualization code" > + depends on HAVE_STATIC_CALL > help > This changes the kernel so it can modify itself when it is run > under a hypervisor, potentially improving performance significantly > diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h > index 30f76b966857..b4ee331d29a7 100644 > --- a/arch/x86/include/asm/mshyperv.h > +++ b/arch/x86/include/asm/mshyperv.h > @@ -63,7 +63,7 @@ typedef int (*hyperv_fill_flush_list_func)( > static __always_inline void hv_setup_sched_clock(void *sched_clock) > { > #ifdef CONFIG_PARAVIRT > - pv_ops.time.sched_clock = sched_clock; > + paravirt_set_sched_clock(sched_clock); > #endif > } > > diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h > index 4abf110e2243..1e45b46fae84 100644 > --- a/arch/x86/include/asm/paravirt.h > +++ b/arch/x86/include/asm/paravirt.h > @@ -15,11 +15,22 @@ > #include <linux/bug.h> > #include <linux/types.h> > #include <linux/cpumask.h> > +#include <linux/static_call_types.h> > #include <asm/frame.h> > > -static inline unsigned long long paravirt_sched_clock(void) > +u64 dummy_steal_clock(int cpu); > +u64 dummy_sched_clock(void); > + > +DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock); > +DECLARE_STATIC_CALL(pv_sched_clock, dummy_sched_clock); Did you build this before sending? I'm test-applying this on rc6 + tip/master so I probably am using a different tree so it looks like something has changed in the meantime. -rc6 has a couple of Xen changes which made applying those to need some wiggling in... Maybe you should redo them ontop of tip/master. That is, *if* they're going to eventually go through tip. The diffstat has Xen stuff too so we might need some synchronization here what goes where how... ./arch/x86/include/asm/paravirt.h:24:1: warning: data definition has no type or storage class 24 | DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock); | ^~~~~~~~~~~~~~~~~~~ ./arch/x86/include/asm/paravirt.h:24:1: error: type defaults to ‘int’ in declaration of ‘DECLARE_STATIC_CALL’ [-Werror=implicit-int] ./arch/x86/include/asm/paravirt.h:24:1: warning: parameter names (without types) in function declaration ./arch/x86/include/asm/paravirt.h:25:1: warning: data definition has no type or storage class 25 | DECLARE_STATIC_CALL(pv_sched_clock, dummy_sched_clock); | ^~~~~~~~~~~~~~~~~~~ ./arch/x86/include/asm/paravirt.h:25:1: error: type defaults to ‘int’ in declaration of ‘DECLARE_STATIC_CALL’ [-Werror=implicit-int] ./arch/x86/include/asm/paravirt.h:25:1: warning: parameter names (without types) in function declaration ./arch/x86/include/asm/paravirt.h: In function ‘paravirt_sched_clock’: ./arch/x86/include/asm/paravirt.h:33:9: error: implicit declaration of function ‘static_call’ [-Werror=implicit-function-declaration] 33 | return static_call(pv_sched_clock)(); | ^~~~~~~~~~~ ./arch/x86/include/asm/paravirt.h:33:21: error: ‘pv_sched_clock’ undeclared (first use in this function); did you mean ‘dummy_sched_clock’? 33 | return static_call(pv_sched_clock)(); | ^~~~~~~~~~~~~~ | dummy_sched_clock ./arch/x86/include/asm/paravirt.h:33:21: note: each undeclared identifier is reported only once for each function it appears in ./arch/x86/include/asm/paravirt.h: In function ‘paravirt_steal_clock’: ./arch/x86/include/asm/paravirt.h:47:21: error: ‘pv_steal_clock’ undeclared (first use in this function); did you mean ‘dummy_steal_clock’? 47 | return static_call(pv_steal_clock)(cpu); | ^~~~~~~~~~~~~~ | dummy_steal_clock cc1: some warnings being treated as errors make[1]: *** [scripts/Makefile.build:117: arch/x86/kernel/asm-offsets.s] Error 1 make: *** [Makefile:1200: prepare0] Error 2 Thx.
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 21f851179ff0..7ccd4a80788c 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -771,6 +771,7 @@ if HYPERVISOR_GUEST config PARAVIRT bool "Enable paravirtualization code" + depends on HAVE_STATIC_CALL help This changes the kernel so it can modify itself when it is run under a hypervisor, potentially improving performance significantly diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 30f76b966857..b4ee331d29a7 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -63,7 +63,7 @@ typedef int (*hyperv_fill_flush_list_func)( static __always_inline void hv_setup_sched_clock(void *sched_clock) { #ifdef CONFIG_PARAVIRT - pv_ops.time.sched_clock = sched_clock; + paravirt_set_sched_clock(sched_clock); #endif } diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 4abf110e2243..1e45b46fae84 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -15,11 +15,22 @@ #include <linux/bug.h> #include <linux/types.h> #include <linux/cpumask.h> +#include <linux/static_call_types.h> #include <asm/frame.h> -static inline unsigned long long paravirt_sched_clock(void) +u64 dummy_steal_clock(int cpu); +u64 dummy_sched_clock(void); + +DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock); +DECLARE_STATIC_CALL(pv_sched_clock, dummy_sched_clock); + +extern bool paravirt_using_native_sched_clock; + +void paravirt_set_sched_clock(u64 (*func)(void)); + +static inline u64 paravirt_sched_clock(void) { - return PVOP_CALL0(unsigned long long, time.sched_clock); + return static_call(pv_sched_clock)(); } struct static_key; @@ -33,7 +44,7 @@ bool pv_is_native_vcpu_is_preempted(void); static inline u64 paravirt_steal_clock(int cpu) { - return PVOP_CALL1(u64, time.steal_clock, cpu); + return static_call(pv_steal_clock)(cpu); } /* The paravirtualized I/O functions */ diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index de87087d3bde..1fff349e4792 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -95,11 +95,6 @@ struct pv_lazy_ops { } __no_randomize_layout; #endif -struct pv_time_ops { - unsigned long long (*sched_clock)(void); - unsigned long long (*steal_clock)(int cpu); -} __no_randomize_layout; - struct pv_cpu_ops { /* hooks for various privileged instructions */ void (*io_delay)(void); @@ -291,7 +286,6 @@ struct pv_lock_ops { * what to patch. */ struct paravirt_patch_template { struct pv_init_ops init; - struct pv_time_ops time; struct pv_cpu_ops cpu; struct pv_irq_ops irq; struct pv_mmu_ops mmu; diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c index c6ede3b3d302..84fb8e3f3d1b 100644 --- a/arch/x86/kernel/cpu/vmware.c +++ b/arch/x86/kernel/cpu/vmware.c @@ -27,6 +27,7 @@ #include <linux/clocksource.h> #include <linux/cpu.h> #include <linux/reboot.h> +#include <linux/static_call.h> #include <asm/div64.h> #include <asm/x86_init.h> #include <asm/hypervisor.h> @@ -336,11 +337,11 @@ static void __init vmware_paravirt_ops_setup(void) vmware_cyc2ns_setup(); if (vmw_sched_clock) - pv_ops.time.sched_clock = vmware_sched_clock; + paravirt_set_sched_clock(vmware_sched_clock); if (vmware_is_stealclock_available()) { has_steal_clock = true; - pv_ops.time.steal_clock = vmware_steal_clock; + static_call_update(pv_steal_clock, vmware_steal_clock); /* We use reboot notifier only to disable steal clock */ register_reboot_notifier(&vmware_pv_reboot_nb); diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 5e78e01ca3b4..351ba99f6009 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -650,7 +650,7 @@ static void __init kvm_guest_init(void) if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) { has_steal_clock = 1; - pv_ops.time.steal_clock = kvm_steal_clock; + static_call_update(pv_steal_clock, kvm_steal_clock); } if (pv_tlb_flush_supported()) { diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index aa593743acf6..01e7c1839ace 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -106,7 +106,7 @@ static inline void kvm_sched_clock_init(bool stable) if (!stable) clear_sched_clock_stable(); kvm_sched_clock_offset = kvm_clock_read(); - pv_ops.time.sched_clock = kvm_sched_clock_read; + paravirt_set_sched_clock(kvm_sched_clock_read); pr_info("kvm-clock: using sched offset of %llu cycles", kvm_sched_clock_offset); diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index c60222ab8ab9..44e5b0fe28cb 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -14,6 +14,7 @@ #include <linux/highmem.h> #include <linux/kprobes.h> #include <linux/pgtable.h> +#include <linux/static_call.h> #include <asm/bug.h> #include <asm/paravirt.h> @@ -167,6 +168,17 @@ static u64 native_steal_clock(int cpu) return 0; } +DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock); +DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock); + +bool paravirt_using_native_sched_clock = true; + +void paravirt_set_sched_clock(u64 (*func)(void)) +{ + static_call_update(pv_sched_clock, func); + paravirt_using_native_sched_clock = (func == native_sched_clock); +} + /* These are in entry.S */ extern void native_iret(void); @@ -272,10 +284,6 @@ struct paravirt_patch_template pv_ops = { /* Init ops. */ .init.patch = native_patch, - /* Time ops. */ - .time.sched_clock = native_sched_clock, - .time.steal_clock = native_steal_clock, - /* Cpu ops. */ .cpu.io_delay = native_io_delay, diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index f70dffc2771f..b6f7853d8077 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -254,7 +254,7 @@ unsigned long long sched_clock(void) bool using_native_sched_clock(void) { - return pv_ops.time.sched_clock == native_sched_clock; + return paravirt_using_native_sched_clock; } #else unsigned long long diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 91f5b330dcc6..01930e182e99 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -379,11 +379,6 @@ void xen_timer_resume(void) } } -static const struct pv_time_ops xen_time_ops __initconst = { - .sched_clock = xen_sched_clock, - .steal_clock = xen_steal_clock, -}; - static struct pvclock_vsyscall_time_info *xen_clock __read_mostly; static u64 xen_clock_value_saved; @@ -528,7 +523,8 @@ static void __init xen_time_init(void) void __init xen_init_time_ops(void) { xen_sched_clock_offset = xen_clocksource_read(); - pv_ops.time = xen_time_ops; + static_call_update(pv_steal_clock, xen_steal_clock); + paravirt_set_sched_clock(xen_sched_clock); x86_init.timers.timer_init = xen_time_init; x86_init.timers.setup_percpu_clockev = x86_init_noop; @@ -570,7 +566,8 @@ void __init xen_hvm_init_time_ops(void) } xen_sched_clock_offset = xen_clocksource_read(); - pv_ops.time = xen_time_ops; + static_call_update(pv_steal_clock, xen_steal_clock); + paravirt_set_sched_clock(xen_sched_clock); x86_init.timers.setup_percpu_clockev = xen_time_init; x86_cpuinit.setup_percpu_clockev = xen_hvm_setup_cpu_clockevents; diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index ba04cb381cd3..bf3bf20bc6bd 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -18,6 +18,7 @@ #include <linux/sched_clock.h> #include <linux/mm.h> #include <linux/cpuhotplug.h> +#include <linux/static_call.h> #include <clocksource/hyperv_timer.h> #include <asm/hyperv-tlfs.h> #include <asm/mshyperv.h> @@ -445,7 +446,7 @@ static bool __init hv_init_tsc_clocksource(void) clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100); hv_sched_clock_offset = hv_read_reference_counter(); - hv_setup_sched_clock(read_hv_sched_clock_tsc); + paravirt_set_sched_clock(read_hv_sched_clock_tsc); return true; } @@ -470,6 +471,6 @@ void __init hv_init_clocksource(void) clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100); hv_sched_clock_offset = hv_read_reference_counter(); - hv_setup_sched_clock(read_hv_sched_clock_msr); + static_call_update(pv_sched_clock, read_hv_sched_clock_msr); } EXPORT_SYMBOL_GPL(hv_init_clocksource); diff --git a/drivers/xen/time.c b/drivers/xen/time.c index 108edbcbc040..199c016834ed 100644 --- a/drivers/xen/time.c +++ b/drivers/xen/time.c @@ -175,7 +175,7 @@ void __init xen_time_setup_guest(void) xen_runstate_remote = !HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_runstate_update_flag); - pv_ops.time.steal_clock = xen_steal_clock; + static_call_update(pv_steal_clock, xen_steal_clock); static_key_slow_inc(¶virt_steal_enabled); if (xen_runstate_remote)
The time pvops functions are the only ones left which might be used in 32-bit mode and which return a 64-bit value. Switch them to use the static_call() mechanism instead of pvops, as this allows quite some simplification of the pvops implementation. Signed-off-by: Juergen Gross <jgross@suse.com> --- V4: - drop paravirt_time.h again - don't move Hyper-V code (Michael Kelley) --- arch/x86/Kconfig | 1 + arch/x86/include/asm/mshyperv.h | 2 +- arch/x86/include/asm/paravirt.h | 17 ++++++++++++++--- arch/x86/include/asm/paravirt_types.h | 6 ------ arch/x86/kernel/cpu/vmware.c | 5 +++-- arch/x86/kernel/kvm.c | 2 +- arch/x86/kernel/kvmclock.c | 2 +- arch/x86/kernel/paravirt.c | 16 ++++++++++++---- arch/x86/kernel/tsc.c | 2 +- arch/x86/xen/time.c | 11 ++++------- drivers/clocksource/hyperv_timer.c | 5 +++-- drivers/xen/time.c | 2 +- 12 files changed, 42 insertions(+), 29 deletions(-)