[tip:x86/timers] x86/kvmclock: Remove page size requirement from wall_clock

From: tip-bot for Thomas Gleixner
Date: Thu Jul 19 2018 - 18:23:01 EST


Commit-ID: 7ef363a39514ed8a6f2333fbae1875ac0953715a
Gitweb: https://git.kernel.org/tip/7ef363a39514ed8a6f2333fbae1875ac0953715a
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Thu, 19 Jul 2018 16:55:21 -0400
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 20 Jul 2018 00:02:36 +0200

x86/kvmclock: Remove page size requirement from wall_clock

There is no requirement for wall_clock data to be page aligned or page
sized.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: steven.sistare@xxxxxxxxxx
Cc: daniel.m.jordan@xxxxxxxxxx
Cc: linux@xxxxxxxxxxxxxxx
Cc: schwidefsky@xxxxxxxxxx
Cc: heiko.carstens@xxxxxxxxxx
Cc: john.stultz@xxxxxxxxxx
Cc: sboyd@xxxxxxxxxxxxxx
Cc: hpa@xxxxxxxxx
Cc: douly.fnst@xxxxxxxxxxxxxx
Cc: peterz@xxxxxxxxxxxxx
Cc: prarit@xxxxxxxxxx
Cc: feng.tang@xxxxxxxxx
Cc: pmladek@xxxxxxxx
Cc: gnomes@xxxxxxxxxxxxxxxxxxx
Cc: linux-s390@xxxxxxxxxxxxxxx
Cc: boris.ostrovsky@xxxxxxxxxx
Cc: jgross@xxxxxxxx
Link: https://lkml.kernel.org/r/20180719205545.16512-3-pasha.tatashin@xxxxxxxxxx

---
arch/x86/kernel/kvmclock.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 1f6ac5aaa904..a995d7d7164c 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -46,14 +46,12 @@ early_param("no-kvmclock", parse_no_kvmclock);

/* Aligned to page sizes to match whats mapped via vsyscalls to userspace */
#define HV_CLOCK_SIZE (sizeof(struct pvclock_vsyscall_time_info) * NR_CPUS)
-#define WALL_CLOCK_SIZE (sizeof(struct pvclock_wall_clock))

static u8 hv_clock_mem[PAGE_ALIGN(HV_CLOCK_SIZE)] __aligned(PAGE_SIZE);
-static u8 wall_clock_mem[PAGE_ALIGN(WALL_CLOCK_SIZE)] __aligned(PAGE_SIZE);

/* The hypervisor will put information about time periodically here */
static struct pvclock_vsyscall_time_info *hv_clock;
-static struct pvclock_wall_clock *wall_clock;
+static struct pvclock_wall_clock wall_clock;

/*
* The wallclock is the time of day when we booted. Since then, some time may
@@ -66,15 +64,15 @@ static void kvm_get_wallclock(struct timespec64 *now)
int low, high;
int cpu;

- low = (int)slow_virt_to_phys(wall_clock);
- high = ((u64)slow_virt_to_phys(wall_clock) >> 32);
+ low = (int)slow_virt_to_phys(&wall_clock);
+ high = ((u64)slow_virt_to_phys(&wall_clock) >> 32);

native_write_msr(msr_kvm_wall_clock, low, high);

cpu = get_cpu();

vcpu_time = &hv_clock[cpu].pvti;
- pvclock_read_wallclock(wall_clock, vcpu_time, now);
+ pvclock_read_wallclock(&wall_clock, vcpu_time, now);

put_cpu();
}
@@ -267,12 +265,10 @@ void __init kvmclock_init(void)
} else if (!(kvmclock && kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE)))
return;

- wall_clock = (struct pvclock_wall_clock *)wall_clock_mem;
hv_clock = (struct pvclock_vsyscall_time_info *)hv_clock_mem;

if (kvm_register_clock("primary cpu clock")) {
hv_clock = NULL;
- wall_clock = NULL;
return;
}