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@linutronix.de>
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: peterz@infradead.org
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Link: https://lkml.kernel.org/r/20180719205545.16512-3-pasha.tatashin@oracle.com

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 1f6ac5a..a995d7d 100644 (file)
--- 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;
        }