Messages in this thread Patch in this message | | | From | Borislav Petkov <> | Subject | [PATCH 02/19] x86/msr, kvm: Remove vget_cycles() | Date | Thu, 25 Jun 2015 18:43:56 +0200 |
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From: Andy Lutomirski <luto@kernel.org>
The only caller was KVM's read_tsc(). The only difference between vget_cycles() and native_read_tsc() was that vget_cycles() returned zero instead of crashing on TSC-less systems. KVM already checks vclock_mode() before calling that function, so the extra check is unnecessary. Also, KVM (host-side) requires the TSC to exist.
Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: kvm ML <kvm@vger.kernel.org> Cc: x86-ml <x86@kernel.org> Link: http://lkml.kernel.org/r/20615df14ae2eb713ea7a5f5123c1dc4c7ca993d.1434501121.git.luto@kernel.org Signed-off-by: Borislav Petkov <bp@suse.de> --- arch/x86/include/asm/tsc.h | 13 ------------- arch/x86/kvm/x86.c | 2 +- 2 files changed, 1 insertion(+), 14 deletions(-)
diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h index fd11128faf25..3da1cc1218ac 100644 --- a/arch/x86/include/asm/tsc.h +++ b/arch/x86/include/asm/tsc.h @@ -32,19 +32,6 @@ static inline cycles_t get_cycles(void) return ret; } -static __always_inline cycles_t vget_cycles(void) -{ - /* - * We only do VDSOs on TSC capable CPUs, so this shouldn't - * access boot_cpu_data (which is not VDSO-safe): - */ -#ifndef CONFIG_X86_TSC - if (!cpu_has_tsc) - return 0; -#endif - return (cycles_t)native_read_tsc(); -} - extern void tsc_init(void); extern void mark_tsc_unstable(char *reason); extern int unsynchronized_tsc(void); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 26eaeb522cab..c26faf408bce 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1430,7 +1430,7 @@ static cycle_t read_tsc(void) * but no one has ever seen it happen. */ rdtsc_barrier(); - ret = (cycle_t)vget_cycles(); + ret = (cycle_t)native_read_tsc(); last = pvclock_gtod_data.clock.cycle_last; -- 2.3.5
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