From 424c32f1aa3112632a657d45698c8e7666668f78 Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Tue, 11 May 2010 12:17:39 -0400 Subject: x86, paravirt: Enable pvclock flags in vcpu_time_info structure This patch removes one padding byte and transform it into a flags field. New versions of guests using pvclock will query these flags upon each read. Flags, however, will only be interpreted when the guest decides to. It uses the pvclock_valid_flags function to signal that a specific set of flags should be taken into consideration. Which flags are valid are usually devised via HV negotiation. Signed-off-by: Glauber Costa CC: Jeremy Fitzhardinge Acked-by: Zachary Amsden Signed-off-by: Marcelo Tosatti --- arch/x86/include/asm/pvclock-abi.h | 3 ++- arch/x86/include/asm/pvclock.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/pvclock-abi.h b/arch/x86/include/asm/pvclock-abi.h index 6d93508..ec5c41a 100644 --- a/arch/x86/include/asm/pvclock-abi.h +++ b/arch/x86/include/asm/pvclock-abi.h @@ -29,7 +29,8 @@ struct pvclock_vcpu_time_info { u64 system_time; u32 tsc_to_system_mul; s8 tsc_shift; - u8 pad[3]; + u8 flags; + u8 pad[2]; } __attribute__((__packed__)); /* 32 bytes */ struct pvclock_wall_clock { diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h index 53235fd..cd02f32 100644 --- a/arch/x86/include/asm/pvclock.h +++ b/arch/x86/include/asm/pvclock.h @@ -6,6 +6,7 @@ /* some helper functions for xen and kvm pv clock sources */ cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); +void pvclock_set_flags(u8 flags); unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); void pvclock_read_wallclock(struct pvclock_wall_clock *wall, struct pvclock_vcpu_time_info *vcpu, -- cgit v1.1