On 05/03/2010 06:52 PM, Glauber Costa wrote:
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<glom...@redhat.com> CC: Jeremy Fitzhardinge<jer...@goop.org> --- arch/x86/include/asm/pvclock-abi.h | 3 ++- arch/x86/include/asm/pvclock.h | 1 + arch/x86/kernel/pvclock.c | 9 +++++++++ 3 files changed, 12 insertions(+), 1 deletions(-) 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, diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c index 03801f2..aa2262b 100644 --- a/arch/x86/kernel/pvclock.c +++ b/arch/x86/kernel/pvclock.c @@ -31,8 +31,16 @@ struct pvclock_shadow_time { u32 tsc_to_nsec_mul; int tsc_shift; u32 version; + u8 flags; }; +static u8 valid_flags = 0; +
Minor optimization: __read_mostly. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
