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x86/paravirt: Switch time pvops functions to use static_call()

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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>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210311142319.4723-5-jgross@suse.com
This commit is contained in:
Juergen Gross 2021-03-11 15:23:09 +01:00 committed by Borislav Petkov
parent 6ea312d95e
commit a0e2bf7cb7
15 changed files with 71 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
arch/arm/include/asm/paravirt.h
View File

@ -3,23 +3,19 @@
#define _ASM_ARM_PARAVIRT_H
#ifdef CONFIG_PARAVIRT
#include <linux/static_call_types.h>
struct static_key;
extern struct static_key paravirt_steal_enabled;
extern struct static_key paravirt_steal_rq_enabled;
struct pv_time_ops {
unsigned long long (*steal_clock)(int cpu);
};
u64 dummy_steal_clock(int cpu);
struct paravirt_patch_template {
struct pv_time_ops time;
};
extern struct paravirt_patch_template pv_ops;
DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock);
static inline u64 paravirt_steal_clock(int cpu)
{
return pv_ops.time.steal_clock(cpu);
return static_call(pv_steal_clock)(cpu);
}
#endif

9
arch/arm/kernel/paravirt.c
View File

@ -9,10 +9,15 @@
#include <linux/export.h>
#include <linux/jump_label.h>
#include <linux/types.h>
#include <linux/static_call.h>
#include <asm/paravirt.h>
struct static_key paravirt_steal_enabled;
struct static_key paravirt_steal_rq_enabled;
struct paravirt_patch_template pv_ops;
EXPORT_SYMBOL_GPL(pv_ops);
static u64 native_steal_clock(int cpu)
{
return 0;
}
DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);

14
arch/arm64/include/asm/paravirt.h
View File

@ -3,23 +3,19 @@
#define _ASM_ARM64_PARAVIRT_H
#ifdef CONFIG_PARAVIRT
#include <linux/static_call_types.h>
struct static_key;
extern struct static_key paravirt_steal_enabled;
extern struct static_key paravirt_steal_rq_enabled;
struct pv_time_ops {
unsigned long long (*steal_clock)(int cpu);
};
u64 dummy_steal_clock(int cpu);
struct paravirt_patch_template {
struct pv_time_ops time;
};
extern struct paravirt_patch_template pv_ops;
DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock);
static inline u64 paravirt_steal_clock(int cpu)
{
return pv_ops.time.steal_clock(cpu);
return static_call(pv_steal_clock)(cpu);
}
int __init pv_time_init(void);

13
arch/arm64/kernel/paravirt.c
View File

@ -18,6 +18,7 @@
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/static_call.h>
#include <asm/paravirt.h>
#include <asm/pvclock-abi.h>
@ -26,8 +27,12 @@
struct static_key paravirt_steal_enabled;
struct static_key paravirt_steal_rq_enabled;
struct paravirt_patch_template pv_ops;
EXPORT_SYMBOL_GPL(pv_ops);
static u64 native_steal_clock(int cpu)
{
return 0;
}
DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);
struct pv_time_stolen_time_region {
struct pvclock_vcpu_stolen_time *kaddr;
@ -45,7 +50,7 @@ static int __init parse_no_stealacc(char *arg)
early_param("no-steal-acc", parse_no_stealacc);
/* return stolen time in ns by asking the hypervisor */
static u64 pv_steal_clock(int cpu)
static u64 para_steal_clock(int cpu)
{
struct pv_time_stolen_time_region *reg;
@ -150,7 +155,7 @@ int __init pv_time_init(void)
if (ret)
return ret;
pv_ops.time.steal_clock = pv_steal_clock;
static_call_update(pv_steal_clock, para_steal_clock);
static_key_slow_inc(&paravirt_steal_enabled);
if (steal_acc)

1
arch/x86/Kconfig
View File

@ -777,6 +777,7 @@ 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

2
arch/x86/include/asm/mshyperv.h
View File

@ -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
}

15
arch/x86/include/asm/paravirt.h
View File

@ -15,11 +15,20 @@
#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);
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 +42,7 @@ 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 */

6
arch/x86/include/asm/paravirt_types.h
View File

@ -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;

5
arch/x86/kernel/cpu/vmware.c
View File

@ -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);

2
arch/x86/kernel/kvm.c
View File

@ -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()) {

2
arch/x86/kernel/kvmclock.c
View File

@ -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);

13
arch/x86/kernel/paravirt.c
View File

@ -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 +168,14 @@ 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);
void paravirt_set_sched_clock(u64 (*func)(void))
{
static_call_update(pv_sched_clock, func);
}
/* These are in entry.S */
extern void native_iret(void);
@ -272,10 +281,6 @@ 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,

3
arch/x86/kernel/tsc.c
View File

@ -14,6 +14,7 @@
#include <linux/percpu.h>
#include <linux/timex.h>
#include <linux/static_key.h>
#include <linux/static_call.h>
#include <asm/hpet.h>
#include <asm/timer.h>
@ -254,7 +255,7 @@ unsigned long long sched_clock(void)
bool using_native_sched_clock(void)
{
return pv_ops.time.sched_clock == native_sched_clock;
return static_call_query(pv_sched_clock) == native_sched_clock;
}
#else
unsigned long long

26
arch/x86/xen/time.c
View File

@ -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;
@ -525,17 +520,24 @@ static void __init xen_time_init(void)
pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
}
void __init xen_init_time_ops(void)
static void __init xen_init_time_common(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_platform.calibrate_tsc = xen_tsc_khz;
x86_platform.get_wallclock = xen_get_wallclock;
}
void __init xen_init_time_ops(void)
{
xen_init_time_common();
x86_init.timers.timer_init = xen_time_init;
x86_init.timers.setup_percpu_clockev = x86_init_noop;
x86_cpuinit.setup_percpu_clockev = x86_init_noop;
x86_platform.calibrate_tsc = xen_tsc_khz;
x86_platform.get_wallclock = xen_get_wallclock;
/* Dom0 uses the native method to set the hardware RTC. */
if (!xen_initial_domain())
x86_platform.set_wallclock = xen_set_wallclock;
@ -569,13 +571,11 @@ void __init xen_hvm_init_time_ops(void)
return;
}
xen_sched_clock_offset = xen_clocksource_read();
pv_ops.time = xen_time_ops;
xen_init_time_common();
x86_init.timers.setup_percpu_clockev = xen_time_init;
x86_cpuinit.setup_percpu_clockev = xen_hvm_setup_cpu_clockevents;
x86_platform.calibrate_tsc = xen_tsc_khz;
x86_platform.get_wallclock = xen_get_wallclock;
x86_platform.set_wallclock = xen_set_wallclock;
}
#endif

3
drivers/xen/time.c
View File

@ -7,6 +7,7 @@
#include <linux/math64.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/static_call.h>
#include <asm/paravirt.h>
#include <asm/xen/hypervisor.h>
@ -175,7 +176,7 @@ 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(&paravirt_steal_enabled);
if (xen_runstate_remote)