[PATCH v3 1/3] x86/pvclock: add setter for pvclock_pvti_cpu0_va
From: Joao Martins <hidden>
Date: 2017-09-27 12:01:19
Also in:
lkml
Subsystem:
kvm paravirt (kvm/paravirt), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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.
Signed-off-by: Joao Martins <redacted>
Acked-by: Andy Lutomirski <luto@kernel.org>
---
Changes since v1:
* Rebased: the only conflict was that I had move the export
pvclock_pvti_cpu0_va() symbol as it is used by kvm PTP driver.
* Do not initialize pvti_cpu0_va to NULL (checkpatch error)
( Comments from Andy Lutomirski )
* Removed asm/pvclock.h 'pvclock_set_pvti_cpu0_va' definition
for non !PARAVIRT_CLOCK to better track screwed Kconfig stuff.
* Add his Acked-by (provided the previous adjustment was made)
Changes since RFC:
(Comments from Andy Lutomirski)
* Add __init to pvclock_set_pvti_cpu0_va
* Add WARN_ON(vclock_was_used(VCLOCK_PVCLOCK)) to
pvclock_set_pvti_cpu0_va
---
arch/x86/include/asm/pvclock.h | 19 ++++++++++---------
arch/x86/kernel/kvmclock.c | 7 +------
arch/x86/kernel/pvclock.c | 14 ++++++++++++++
3 files changed, 25 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index 448cfe1b48cf..6f228f90cdd7 100644
--- 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_pvti_cpu0_va(void); +#else +static inline struct pvclock_vsyscall_time_info *pvclock_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 d88967659098..538738047ff5 100644
--- 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 5c3f6d6a5078..cb7d6d9c9c2d 100644
--- 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_pvti_cpu0_va(void) +{ + return pvti_cpu0_va; +} +EXPORT_SYMBOL_GPL(pvclock_pvti_cpu0_va);
--
2.11.0