x86/pvclock: add setter for pvclock_pvti_cpu0_va

Right now there is only a pvclock_pvti_cpu0_va() which is defined
on kvmclock since:

commit dac16fba6fc5
("x86/vdso: Get pvclock data from the vvar VMA instead of the fixmap")

The only user of this interface so far is kvm. This commit adds a
setter function for the pvti page and moves pvclock_pvti_cpu0_va
to pvclock, which is a more generic place to have it; and would
allow other PV clocksources to use it, such as Xen.

While moving pvclock_pvti_cpu0_va into pvclock, rename also this
function to pvclock_get_pvti_cpu0_va (including its call sites)
to be symmetric with the setter (pvclock_set_pvti_cpu0_va).

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 1911310959f8b475cf42ef51a7c8d31780f7bc4b..a77fd3c8d8241c15e34da8af3eea4d48e47c75a8 100644 (file)
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -112,7 +112,7 @@ static int vvar_fault(const struct vm_special_mapping *sm,
                                    __pa_symbol(&__vvar_page) >> PAGE_SHIFT);
        } else if (sym_offset == image->sym_pvclock_page) {
                struct pvclock_vsyscall_time_info *pvti =
-                       pvclock_pvti_cpu0_va();
+                       pvclock_get_pvti_cpu0_va();
                if (pvti && vclock_was_used(VCLOCK_PVCLOCK)) {
                        ret = vm_insert_pfn(
                                vma,

diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index 448cfe1b48cf02b46c76b76cf2aa0be93b3df0bc..55325f934d714d8989569fac4c7e9863b0fb290d 100644 (file)
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -4,15 +4,6 @@
 #include <linux/clocksource.h>
 #include <asm/pvclock-abi.h>
 
-#ifdef CONFIG_KVM_GUEST
-extern struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void);
-#else
-static inline struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void)
-{
-       return NULL;
-}
-#endif
-
 /* some helper functions for xen and kvm pv clock sources */
 u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
 u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);
@@ -101,4 +92,14 @@ struct pvclock_vsyscall_time_info {
 
 #define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)
 
+#ifdef CONFIG_PARAVIRT_CLOCK
+void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti);
+struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void);
+#else
+static inline struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void)
+{
+       return NULL;
+}
+#endif
+
 #endif /* _ASM_X86_PVCLOCK_H */

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index d88967659098b59478633d9707e0045562fdd85c..538738047ff5cb6d5a59bb927cd9fd254cce40f0 100644 (file)
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -47,12 +47,6 @@ early_param("no-kvmclock", parse_no_kvmclock);
 static struct pvclock_vsyscall_time_info *hv_clock;
 static struct pvclock_wall_clock wall_clock;
 
-struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void)
-{
-       return hv_clock;
-}
-EXPORT_SYMBOL_GPL(pvclock_pvti_cpu0_va);
-
 /*
  * The wallclock is the time of day when we booted. Since then, some time may
  * have elapsed since the hypervisor wrote the data. So we try to account for
@@ -334,6 +328,7 @@ int __init kvm_setup_vsyscall_timeinfo(void)
                return 1;
        }
 
+       pvclock_set_pvti_cpu0_va(hv_clock);
        put_cpu();
 
        kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK;

diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
index 5c3f6d6a5078338e0a0806026e9465f057c92285..761f6af6efa5c972d084bbe5055398989772c702 100644 (file)
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -25,8 +25,10 @@
 
 #include <asm/fixmap.h>
 #include <asm/pvclock.h>
+#include <asm/vgtod.h>
 
 static u8 valid_flags __read_mostly = 0;
+static struct pvclock_vsyscall_time_info *pvti_cpu0_va __read_mostly;
 
 void pvclock_set_flags(u8 flags)
 {
@@ -144,3 +146,15 @@ void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock,
 
        set_normalized_timespec(ts, now.tv_sec, now.tv_nsec);
 }
+
+void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti)
+{
+       WARN_ON(vclock_was_used(VCLOCK_PVCLOCK));
+       pvti_cpu0_va = pvti;
+}
+
+struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void)
+{
+       return pvti_cpu0_va;
+}
+EXPORT_SYMBOL_GPL(pvclock_get_pvti_cpu0_va);

diff --git a/drivers/ptp/ptp_kvm.c b/drivers/ptp/ptp_kvm.c
index e04d7b2ecb3afb71d7f8a9b1f3e3718e6e26afac..c67dd11e08b1f5033edd14856172270f08cf5fad 100644 (file)
--- a/drivers/ptp/ptp_kvm.c
+++ b/drivers/ptp/ptp_kvm.c
@@ -182,7 +182,7 @@ static int __init ptp_kvm_init(void)
                return -ENODEV;
 
        clock_pair_gpa = slow_virt_to_phys(&clock_pair);
-       hv_clock = pvclock_pvti_cpu0_va();
+       hv_clock = pvclock_get_pvti_cpu0_va();
 
        if (!hv_clock)
                return -ENODEV;