diff options
author | Glauber Costa <glommer@redhat.com> | 2010-05-11 12:17:39 -0400 |
---|---|---|
committer | Avi Kivity <avi@redhat.com> | 2010-05-19 04:40:59 -0400 |
commit | 424c32f1aa3112632a657d45698c8e7666668f78 (patch) | |
tree | c63fd6d83b6f2cbcb979b3f55c9a07425b13053f | |
parent | b69e8caef5b190af48c525f6d715e7b7728a77f6 (diff) |
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 <glommer@redhat.com>
CC: Jeremy Fitzhardinge <jeremy@goop.org>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
-rw-r--r-- | arch/x86/include/asm/pvclock-abi.h | 3 | ||||
-rw-r--r-- | arch/x86/include/asm/pvclock.h | 1 | ||||
-rw-r--r-- | 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 6d93508f2626..ec5c41ac4bef 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 { | |||
29 | u64 system_time; | 29 | u64 system_time; |
30 | u32 tsc_to_system_mul; | 30 | u32 tsc_to_system_mul; |
31 | s8 tsc_shift; | 31 | s8 tsc_shift; |
32 | u8 pad[3]; | 32 | u8 flags; |
33 | u8 pad[2]; | ||
33 | } __attribute__((__packed__)); /* 32 bytes */ | 34 | } __attribute__((__packed__)); /* 32 bytes */ |
34 | 35 | ||
35 | struct pvclock_wall_clock { | 36 | struct pvclock_wall_clock { |
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h index 53235fd5f8ce..cd02f324aa6b 100644 --- a/arch/x86/include/asm/pvclock.h +++ b/arch/x86/include/asm/pvclock.h | |||
@@ -6,6 +6,7 @@ | |||
6 | 6 | ||
7 | /* some helper functions for xen and kvm pv clock sources */ | 7 | /* some helper functions for xen and kvm pv clock sources */ |
8 | cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); | 8 | cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); |
9 | void pvclock_set_flags(u8 flags); | ||
9 | unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); | 10 | unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); |
10 | void pvclock_read_wallclock(struct pvclock_wall_clock *wall, | 11 | void pvclock_read_wallclock(struct pvclock_wall_clock *wall, |
11 | struct pvclock_vcpu_time_info *vcpu, | 12 | struct pvclock_vcpu_time_info *vcpu, |
diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c index 03801f2f761f..f7fdd56bc0ab 100644 --- a/arch/x86/kernel/pvclock.c +++ b/arch/x86/kernel/pvclock.c | |||
@@ -31,8 +31,16 @@ struct pvclock_shadow_time { | |||
31 | u32 tsc_to_nsec_mul; | 31 | u32 tsc_to_nsec_mul; |
32 | int tsc_shift; | 32 | int tsc_shift; |
33 | u32 version; | 33 | u32 version; |
34 | u8 flags; | ||
34 | }; | 35 | }; |
35 | 36 | ||
37 | static u8 valid_flags __read_mostly = 0; | ||
38 | |||
39 | void pvclock_set_flags(u8 flags) | ||
40 | { | ||
41 | valid_flags = flags; | ||
42 | } | ||
43 | |||
36 | /* | 44 | /* |
37 | * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, | 45 | * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, |
38 | * yielding a 64-bit result. | 46 | * yielding a 64-bit result. |
@@ -91,6 +99,7 @@ static unsigned pvclock_get_time_values(struct pvclock_shadow_time *dst, | |||
91 | dst->system_timestamp = src->system_time; | 99 | dst->system_timestamp = src->system_time; |
92 | dst->tsc_to_nsec_mul = src->tsc_to_system_mul; | 100 | dst->tsc_to_nsec_mul = src->tsc_to_system_mul; |
93 | dst->tsc_shift = src->tsc_shift; | 101 | dst->tsc_shift = src->tsc_shift; |
102 | dst->flags = src->flags; | ||
94 | rmb(); /* test version after fetching data */ | 103 | rmb(); /* test version after fetching data */ |
95 | } while ((src->version & 1) || (dst->version != src->version)); | 104 | } while ((src->version & 1) || (dst->version != src->version)); |
96 | 105 | ||