* [patch 0/4] KVM virtual PTP driver (v5)
@ 2017-01-24 17:09 Marcelo Tosatti
2017-01-24 17:09 ` [patch 1/4] KVM: x86: provide realtime host clock via vsyscall notifiers Marcelo Tosatti
` (3 more replies)
0 siblings, 4 replies; 14+ messages in thread
From: Marcelo Tosatti @ 2017-01-24 17:09 UTC (permalink / raw)
To: kvm, linux-kernel
Cc: Paolo Bonzini, Radim Krcmar, Richard Cochran, Miroslav Lichvar
This patchset implements a virtual PTP driver which allows guest to sync
its clock to the host clock with high precision
(error is < 1us on an idle guest).
Changelog from v4
Drop PTP_SYS_OFFSET emulation via ->crosstimestamp callback (Richard).
Emulate ->gettime directly without TSC offset (Radim).
Changelog from v3
Patch3:
v2: export kvmclock clocksource structure directly (Paolo)
Patch4:
v2: drop timekeeper spinlock, move back to drivers/ptp/ptp_chardev.c (Paolo)
ptp_clock_gettime: support drivers with crosstimestamp but not
gettime64 callbacks (Paolo)
Patch5:
v4: remove gettime64 callback (Paolo)
Changelog from v2
Cross timestamping, emulation of PTP_SYS_OFFSET with cross timestamping
(Paolo, Miroslav, Radim).
Changelog from v1
Patch1:
v2: unify nsec_base (Radim)
Patch2:
v2: improve documentation (Radim)
change hypercall name to KVM_HC_CLOCK_PAIRING (Radim)
increase padding size
Patch3:
v2: check for kvmclock (Radim)
initialize global variables before device registration (Radim)
30 second output of a idle guest:
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 9 -1ns[ -1ns] +/- 2ns
Tue Jan 24 11:46:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 7 -0ns[ -1ns] +/- 2ns
Tue Jan 24 11:47:06 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 5 -1ns[ +0ns] +/- 2ns
Tue Jan 24 11:47:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 11 +0ns[ -2ns] +/- 2ns
Tue Jan 24 11:48:06 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 10 -0ns[ -0ns] +/- 2ns
Tue Jan 24 11:48:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 7 -0ns[ -0ns] +/- 2ns
Tue Jan 24 11:49:06 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 5 -3ns[ -4ns] +/- 2ns
Tue Jan 24 11:49:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 11 +2ns[ +2ns] +/- 2ns
Tue Jan 24 11:50:06 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 9 -1ns[ +1ns] +/- 2ns
Tue Jan 24 11:50:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 6 +0ns[ +0ns] +/- 2ns
Tue Jan 24 11:51:06 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 5 +1ns[ +10ns] +/- 2ns
Tue Jan 24 11:51:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 11 -5ns[ -6ns] +/- 2ns
Tue Jan 24 11:52:06 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 9 -0ns[ -1ns] +/- 2ns
Tue Jan 24 11:52:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 6 +0ns[ -5ns] +/- 2ns
Tue Jan 24 11:53:06 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 4 -0ns[ -0ns] +/- 2ns
Tue Jan 24 11:53:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 10 -0ns[ -0ns] +/- 2ns
Tue Jan 24 11:54:06 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 9 -1ns[ -1ns] +/- 2ns
Tue Jan 24 11:54:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 6 -1ns[ -2ns] +/- 2ns
Tue Jan 24 11:55:06 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 4 -0ns[ +3ns] +/- 2ns
Tue Jan 24 11:55:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 10 -3ns[ -6ns] +/- 2ns
Tue Jan 24 11:56:06 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 8 +2ns[ +3ns] +/- 2ns
Tue Jan 24 11:56:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 6 +0ns[ -2ns] +/- 2ns
Tue Jan 24 11:57:06 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 4 -0ns[ +1ns] +/- 2ns
Tue Jan 24 11:57:36 EST 2017
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#* PHC0 0 3 377 10 -1ns[ +1ns] +/- 2ns
^ permalink raw reply [flat|nested] 14+ messages in thread* [patch 1/4] KVM: x86: provide realtime host clock via vsyscall notifiers 2017-01-24 17:09 [patch 0/4] KVM virtual PTP driver (v5) Marcelo Tosatti @ 2017-01-24 17:09 ` Marcelo Tosatti 2017-01-25 12:30 ` Paolo Bonzini 2017-01-24 17:09 ` [patch 2/4] KVM: x86: add KVM_HC_CLOCK_OFFSET hypercall Marcelo Tosatti ` (2 subsequent siblings) 3 siblings, 1 reply; 14+ messages in thread From: Marcelo Tosatti @ 2017-01-24 17:09 UTC (permalink / raw) To: kvm, linux-kernel Cc: Paolo Bonzini, Radim Krcmar, Richard Cochran, Miroslav Lichvar, Marcelo Tosatti [-- Attachment #1: kvm-do-realtime --] [-- Type: text/plain, Size: 2010 bytes --] Expose the realtime host clock and save the TSC value used for the clock calculation. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> --- arch/x86/kvm/x86.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) v2: unify nsec_base (Radim) Index: kvm-ptpdriver/arch/x86/kvm/x86.c =================================================================== --- kvm-ptpdriver.orig/arch/x86/kvm/x86.c 2017-01-13 16:43:15.013244682 -0200 +++ kvm-ptpdriver/arch/x86/kvm/x86.c 2017-01-20 09:56:41.404534904 -0200 @@ -1139,6 +1139,7 @@ u64 boot_ns; u64 nsec_base; + u64 wall_time_sec; }; static struct pvclock_gtod_data pvclock_gtod_data; @@ -1162,6 +1163,8 @@ vdata->boot_ns = boot_ns; vdata->nsec_base = tk->tkr_mono.xtime_nsec; + vdata->wall_time_sec = tk->xtime_sec; + write_seqcount_end(&vdata->seq); } #endif @@ -1623,6 +1626,28 @@ return mode; } +static int do_realtime(struct timespec *ts, cycle_t *cycle_now) +{ + struct pvclock_gtod_data *gtod = &pvclock_gtod_data; + unsigned long seq; + int mode; + u64 ns; + + do { + seq = read_seqcount_begin(>od->seq); + mode = gtod->clock.vclock_mode; + ts->tv_sec = gtod->wall_time_sec; + ns = gtod->nsec_base; + ns += vgettsc(cycle_now); + ns >>= gtod->clock.shift; + } while (unlikely(read_seqcount_retry(>od->seq, seq))); + + ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns); + ts->tv_nsec = ns; + + return mode; +} + /* returns true if host is using tsc clocksource */ static bool kvm_get_time_and_clockread(s64 *kernel_ns, cycle_t *cycle_now) { @@ -1632,6 +1657,17 @@ return do_monotonic_boot(kernel_ns, cycle_now) == VCLOCK_TSC; } + +/* returns true if host is using tsc clocksource */ +static bool kvm_get_walltime_and_clockread(struct timespec *ts, + cycle_t *cycle_now) +{ + /* checked again under seqlock below */ + if (pvclock_gtod_data.clock.vclock_mode != VCLOCK_TSC) + return false; + + return do_realtime(ts, cycle_now) == VCLOCK_TSC; +} #endif /* ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [patch 1/4] KVM: x86: provide realtime host clock via vsyscall notifiers 2017-01-24 17:09 ` [patch 1/4] KVM: x86: provide realtime host clock via vsyscall notifiers Marcelo Tosatti @ 2017-01-25 12:30 ` Paolo Bonzini 0 siblings, 0 replies; 14+ messages in thread From: Paolo Bonzini @ 2017-01-25 12:30 UTC (permalink / raw) To: Marcelo Tosatti, kvm, linux-kernel Cc: Radim Krcmar, Richard Cochran, Miroslav Lichvar On 24/01/2017 18:09, Marcelo Tosatti wrote: > Expose the realtime host clock and save the TSC value > used for the clock calculation. > > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> > > --- > arch/x86/kvm/x86.c | 36 ++++++++++++++++++++++++++++++++++++ > 1 file changed, 36 insertions(+) > > v2: unify nsec_base (Radim) > > Index: kvm-ptpdriver/arch/x86/kvm/x86.c > =================================================================== > --- kvm-ptpdriver.orig/arch/x86/kvm/x86.c 2017-01-13 16:43:15.013244682 -0200 > +++ kvm-ptpdriver/arch/x86/kvm/x86.c 2017-01-20 09:56:41.404534904 -0200 > @@ -1139,6 +1139,7 @@ > > u64 boot_ns; > u64 nsec_base; > + u64 wall_time_sec; > }; > > static struct pvclock_gtod_data pvclock_gtod_data; > @@ -1162,6 +1163,8 @@ > vdata->boot_ns = boot_ns; > vdata->nsec_base = tk->tkr_mono.xtime_nsec; > > + vdata->wall_time_sec = tk->xtime_sec; > + > write_seqcount_end(&vdata->seq); > } > #endif > @@ -1623,6 +1626,28 @@ > return mode; > } > > +static int do_realtime(struct timespec *ts, cycle_t *cycle_now) > +{ > + struct pvclock_gtod_data *gtod = &pvclock_gtod_data; > + unsigned long seq; > + int mode; > + u64 ns; > + > + do { > + seq = read_seqcount_begin(>od->seq); > + mode = gtod->clock.vclock_mode; > + ts->tv_sec = gtod->wall_time_sec; > + ns = gtod->nsec_base; > + ns += vgettsc(cycle_now); > + ns >>= gtod->clock.shift; > + } while (unlikely(read_seqcount_retry(>od->seq, seq))); > + > + ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns); > + ts->tv_nsec = ns; > + > + return mode; > +} > + > /* returns true if host is using tsc clocksource */ > static bool kvm_get_time_and_clockread(s64 *kernel_ns, cycle_t *cycle_now) > { > @@ -1632,6 +1657,17 @@ > > return do_monotonic_boot(kernel_ns, cycle_now) == VCLOCK_TSC; > } > + > +/* returns true if host is using tsc clocksource */ > +static bool kvm_get_walltime_and_clockread(struct timespec *ts, > + cycle_t *cycle_now) > +{ > + /* checked again under seqlock below */ > + if (pvclock_gtod_data.clock.vclock_mode != VCLOCK_TSC) > + return false; > + > + return do_realtime(ts, cycle_now) == VCLOCK_TSC; > +} > #endif > > /* > > > Only used in the next patch, will squash. Also, cycle_t is gone now so use u64 instead. Paolo ^ permalink raw reply [flat|nested] 14+ messages in thread
* [patch 2/4] KVM: x86: add KVM_HC_CLOCK_OFFSET hypercall 2017-01-24 17:09 [patch 0/4] KVM virtual PTP driver (v5) Marcelo Tosatti 2017-01-24 17:09 ` [patch 1/4] KVM: x86: provide realtime host clock via vsyscall notifiers Marcelo Tosatti @ 2017-01-24 17:09 ` Marcelo Tosatti 2017-01-25 12:30 ` Paolo Bonzini 2017-01-24 17:09 ` [patch 3/4] kvmclock: export kvmclock clocksource pointer Marcelo Tosatti 2017-01-24 17:09 ` [patch 4/4] PTP: add kvm PTP driver Marcelo Tosatti 3 siblings, 1 reply; 14+ messages in thread From: Marcelo Tosatti @ 2017-01-24 17:09 UTC (permalink / raw) To: kvm, linux-kernel Cc: Paolo Bonzini, Radim Krcmar, Richard Cochran, Miroslav Lichvar, Marcelo Tosatti [-- Attachment #1: kvm-hv-clock-offset --] [-- Type: text/plain, Size: 5057 bytes --] Add a hypercall to retrieve the host realtime clock and the TSC value used to calculate that clock read. Used to implement clock synchronization between host and guest. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> --- Documentation/virtual/kvm/hypercalls.txt | 33 ++++++++++++++++++++++++ arch/x86/include/uapi/asm/kvm_para.h | 9 ++++++ arch/x86/kvm/x86.c | 41 +++++++++++++++++++++++++++++++ include/uapi/linux/kvm_para.h | 3 ++ 4 files changed, 86 insertions(+) v2: improve documentation (Radim) change hypercall name to KVM_HC_CLOCK_PAIRING (Radim) increase padding size Index: kvm-ptpdriver/arch/x86/include/uapi/asm/kvm_para.h =================================================================== --- kvm-ptpdriver.orig/arch/x86/include/uapi/asm/kvm_para.h 2017-01-13 16:43:11.947240575 -0200 +++ kvm-ptpdriver/arch/x86/include/uapi/asm/kvm_para.h 2017-01-13 16:43:25.038258187 -0200 @@ -50,6 +50,15 @@ __u32 pad[11]; }; +#define KVM_CLOCK_PAIRING_WALLCLOCK 0 +struct kvm_clock_offset { + __s64 sec; + __s64 nsec; + __u64 tsc; + __u32 flags; + __u32 pad[9]; +}; + #define KVM_STEAL_ALIGNMENT_BITS 5 #define KVM_STEAL_VALID_BITS ((-1ULL << (KVM_STEAL_ALIGNMENT_BITS + 1))) #define KVM_STEAL_RESERVED_MASK (((1 << KVM_STEAL_ALIGNMENT_BITS) - 1 ) << 1) Index: kvm-ptpdriver/Documentation/virtual/kvm/hypercalls.txt =================================================================== --- kvm-ptpdriver.orig/Documentation/virtual/kvm/hypercalls.txt 2017-01-13 16:43:11.947240575 -0200 +++ kvm-ptpdriver/Documentation/virtual/kvm/hypercalls.txt 2017-01-13 16:43:25.038258187 -0200 @@ -81,3 +81,36 @@ same guest can wakeup the sleeping vcpu by issuing KVM_HC_KICK_CPU hypercall, specifying APIC ID (a1) of the vcpu to be woken up. An additional argument (a0) is used in the hypercall for future use. + + +6. KVM_HC_CLOCK_PAIRING +------------------------ +Architecture: x86 +Status: active +Purpose: Hypercall used to synchronize host and guest clocks. +Usage: + +a0: guest physical address where host copies +"struct kvm_clock_offset" structure. + +a1: clock_type, ATM only KVM_CLOCK_PAIRING_WALLCLOCK (0) +is supported (hosts CLOCK_REALTIME clock). + + struct kvm_clock_offset { + __s64 sec; + __s64 nsec; + __u64 tsc; + __u32 flags; + __u32 pad[9]; + }; + + Where: + * sec: seconds from clock_type clock. + * nsec: nanoseconds from clock_type clock. + * tsc: TSC value used to calculate sec/nsec pair + (this hypercall only works when host uses TSC clocksource). + * flags: flags, unused (0) at the moment. + +Returns KVM_EOPNOTSUPP if the host does not use TSC clocksource, +or if clock type is different than KVM_CLOCK_PAIRING_WALLCLOCK. + Index: kvm-ptpdriver/arch/x86/kvm/x86.c =================================================================== --- kvm-ptpdriver.orig/arch/x86/kvm/x86.c 2017-01-13 16:43:20.898252596 -0200 +++ kvm-ptpdriver/arch/x86/kvm/x86.c 2017-01-13 16:43:25.041258191 -0200 @@ -6119,6 +6119,44 @@ } EXPORT_SYMBOL_GPL(kvm_emulate_halt); +static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr, + unsigned long clock_type) +{ + struct kvm_clock_offset *clock_offset; + struct timespec ts; + cycle_t cycle; + int ret; + + if (clock_type != KVM_CLOCK_PAIRING_WALLCLOCK) + return -KVM_EOPNOTSUPP; + + if (pvclock_gtod_data.clock.vclock_mode != VCLOCK_TSC) + return -KVM_EOPNOTSUPP; + + clock_offset = kzalloc(sizeof(struct kvm_clock_offset), GFP_KERNEL); + if (clock_offset == NULL) + return -KVM_ENOMEM; + + if (kvm_get_walltime_and_clockread(&ts, &cycle) == false) { + kfree(clock_offset); + return -KVM_EOPNOTSUPP; + } + + clock_offset->sec = ts.tv_sec; + clock_offset->nsec = ts.tv_nsec; + clock_offset->tsc = kvm_read_l1_tsc(vcpu, cycle); + clock_offset->flags = 0; + + ret = 0; + if (kvm_write_guest(vcpu->kvm, paddr, clock_offset, + sizeof(struct kvm_clock_offset))) + ret = -KVM_EFAULT; + + kfree(clock_offset); + + return ret; +} + /* * kvm_pv_kick_cpu_op: Kick a vcpu. * @@ -6183,6 +6221,9 @@ kvm_pv_kick_cpu_op(vcpu->kvm, a0, a1); ret = 0; break; + case KVM_HC_CLOCK_PAIRING: + ret = kvm_pv_clock_pairing(vcpu, a0, a1); + break; default: ret = -KVM_ENOSYS; break; Index: kvm-ptpdriver/include/uapi/linux/kvm_para.h =================================================================== --- kvm-ptpdriver.orig/include/uapi/linux/kvm_para.h 2017-01-13 16:43:11.947240575 -0200 +++ kvm-ptpdriver/include/uapi/linux/kvm_para.h 2017-01-13 16:43:25.042258192 -0200 @@ -14,6 +14,8 @@ #define KVM_EFAULT EFAULT #define KVM_E2BIG E2BIG #define KVM_EPERM EPERM +#define KVM_EOPNOTSUPP EOPNOTSUPP +#define KVM_ENOMEM ENOMEM #define KVM_HC_VAPIC_POLL_IRQ 1 #define KVM_HC_MMU_OP 2 @@ -23,6 +25,7 @@ #define KVM_HC_MIPS_GET_CLOCK_FREQ 6 #define KVM_HC_MIPS_EXIT_VM 7 #define KVM_HC_MIPS_CONSOLE_OUTPUT 8 +#define KVM_HC_CLOCK_PAIRING 9 /* * hypercalls use architecture specific ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [patch 2/4] KVM: x86: add KVM_HC_CLOCK_OFFSET hypercall 2017-01-24 17:09 ` [patch 2/4] KVM: x86: add KVM_HC_CLOCK_OFFSET hypercall Marcelo Tosatti @ 2017-01-25 12:30 ` Paolo Bonzini 2017-01-25 12:55 ` Marcelo Tosatti 0 siblings, 1 reply; 14+ messages in thread From: Paolo Bonzini @ 2017-01-25 12:30 UTC (permalink / raw) To: Marcelo Tosatti, kvm, linux-kernel Cc: Radim Krcmar, Richard Cochran, Miroslav Lichvar On 24/01/2017 18:09, Marcelo Tosatti wrote: > Add a hypercall to retrieve the host realtime clock > and the TSC value used to calculate that clock read. > > Used to implement clock synchronization between > host and guest. > > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> > > --- > Documentation/virtual/kvm/hypercalls.txt | 33 ++++++++++++++++++++++++ > arch/x86/include/uapi/asm/kvm_para.h | 9 ++++++ > arch/x86/kvm/x86.c | 41 +++++++++++++++++++++++++++++++ > include/uapi/linux/kvm_para.h | 3 ++ > 4 files changed, 86 insertions(+) > > v2: improve documentation (Radim) > change hypercall name to KVM_HC_CLOCK_PAIRING (Radim) > increase padding size > > Index: kvm-ptpdriver/arch/x86/include/uapi/asm/kvm_para.h > =================================================================== > --- kvm-ptpdriver.orig/arch/x86/include/uapi/asm/kvm_para.h 2017-01-13 16:43:11.947240575 -0200 > +++ kvm-ptpdriver/arch/x86/include/uapi/asm/kvm_para.h 2017-01-13 16:43:25.038258187 -0200 > @@ -50,6 +50,15 @@ > __u32 pad[11]; > }; > > +#define KVM_CLOCK_PAIRING_WALLCLOCK 0 > +struct kvm_clock_offset { The struct still has the old name. > + __s64 sec; > + __s64 nsec; > + __u64 tsc; > + __u32 flags; > + __u32 pad[9]; > +}; > + > #define KVM_STEAL_ALIGNMENT_BITS 5 > #define KVM_STEAL_VALID_BITS ((-1ULL << (KVM_STEAL_ALIGNMENT_BITS + 1))) > #define KVM_STEAL_RESERVED_MASK (((1 << KVM_STEAL_ALIGNMENT_BITS) - 1 ) << 1) > Index: kvm-ptpdriver/Documentation/virtual/kvm/hypercalls.txt > =================================================================== > --- kvm-ptpdriver.orig/Documentation/virtual/kvm/hypercalls.txt 2017-01-13 16:43:11.947240575 -0200 > +++ kvm-ptpdriver/Documentation/virtual/kvm/hypercalls.txt 2017-01-13 16:43:25.038258187 -0200 > @@ -81,3 +81,36 @@ > same guest can wakeup the sleeping vcpu by issuing KVM_HC_KICK_CPU hypercall, > specifying APIC ID (a1) of the vcpu to be woken up. An additional argument (a0) > is used in the hypercall for future use. > + > + > +6. KVM_HC_CLOCK_PAIRING > +------------------------ > +Architecture: x86 > +Status: active > +Purpose: Hypercall used to synchronize host and guest clocks. > +Usage: > + > +a0: guest physical address where host copies > +"struct kvm_clock_offset" structure. > + > +a1: clock_type, ATM only KVM_CLOCK_PAIRING_WALLCLOCK (0) > +is supported (hosts CLOCK_REALTIME clock). > + > + struct kvm_clock_offset { Name of the struct not adjusted. > + __s64 sec; > + __s64 nsec; > + __u64 tsc; > + __u32 flags; > + __u32 pad[9]; I'd just leave one element of padding and put the struct on the stack, since we have no reason to think we'll need a lot of padding. > + }; > + > + Where: > + * sec: seconds from clock_type clock. > + * nsec: nanoseconds from clock_type clock. > + * tsc: TSC value used to calculate sec/nsec pair > + (this hypercall only works when host uses TSC clocksource). This is already mentioned below, and it's not clear that tsc is a guest TSC value. > + * flags: flags, unused (0) at the moment. > + > +Returns KVM_EOPNOTSUPP if the host does not use TSC clocksource, > +or if clock type is different than KVM_CLOCK_PAIRING_WALLCLOCK. > + > Index: kvm-ptpdriver/arch/x86/kvm/x86.c > =================================================================== > --- kvm-ptpdriver.orig/arch/x86/kvm/x86.c 2017-01-13 16:43:20.898252596 -0200 > +++ kvm-ptpdriver/arch/x86/kvm/x86.c 2017-01-13 16:43:25.041258191 -0200 > @@ -6119,6 +6119,44 @@ > } > EXPORT_SYMBOL_GPL(kvm_emulate_halt); > > +static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr, > + unsigned long clock_type) > +{ > + struct kvm_clock_offset *clock_offset; > + struct timespec ts; > + cycle_t cycle; > + int ret; > + > + if (clock_type != KVM_CLOCK_PAIRING_WALLCLOCK) > + return -KVM_EOPNOTSUPP; > + > + if (pvclock_gtod_data.clock.vclock_mode != VCLOCK_TSC) > + return -KVM_EOPNOTSUPP; Already checked in kvm_get_walltime_and_clockread. > + clock_offset = kzalloc(sizeof(struct kvm_clock_offset), GFP_KERNEL); > + if (clock_offset == NULL) > + return -KVM_ENOMEM; > + > + if (kvm_get_walltime_and_clockread(&ts, &cycle) == false) { > + kfree(clock_offset); > + return -KVM_EOPNOTSUPP; > + } > + clock_offset->sec = ts.tv_sec; > + clock_offset->nsec = ts.tv_nsec; > + clock_offset->tsc = kvm_read_l1_tsc(vcpu, cycle); > + clock_offset->flags = 0; > + > + ret = 0; > + if (kvm_write_guest(vcpu->kvm, paddr, clock_offset, > + sizeof(struct kvm_clock_offset))) > + ret = -KVM_EFAULT; > + > + kfree(clock_offset); > + > + return ret; > +} > + > /* > * kvm_pv_kick_cpu_op: Kick a vcpu. > * > @@ -6183,6 +6221,9 @@ > kvm_pv_kick_cpu_op(vcpu->kvm, a0, a1); > ret = 0; > break; > + case KVM_HC_CLOCK_PAIRING: > + ret = kvm_pv_clock_pairing(vcpu, a0, a1); > + break; > default: > ret = -KVM_ENOSYS; > break; > Index: kvm-ptpdriver/include/uapi/linux/kvm_para.h > =================================================================== > --- kvm-ptpdriver.orig/include/uapi/linux/kvm_para.h 2017-01-13 16:43:11.947240575 -0200 > +++ kvm-ptpdriver/include/uapi/linux/kvm_para.h 2017-01-13 16:43:25.042258192 -0200 > @@ -14,6 +14,8 @@ > #define KVM_EFAULT EFAULT > #define KVM_E2BIG E2BIG > #define KVM_EPERM EPERM > +#define KVM_EOPNOTSUPP EOPNOTSUPP > +#define KVM_ENOMEM ENOMEM This file could potentially be used across multiple architectures (it's not in arch/x86/include/uapi/asm), but EOPNOTSUPP is not the same on all systems. Better use "95" which is the value it has on x86. All this gives: diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt index 55eb3e1ca494..cd35de84999f 100644 --- a/Documentation/virtual/kvm/hypercalls.txt +++ b/Documentation/virtual/kvm/hypercalls.txt @@ -94,9 +94,9 @@ a0: guest physical address where host copies "struct kvm_clock_offset" structure. a1: clock_type, ATM only KVM_CLOCK_PAIRING_WALLCLOCK (0) -is supported (hosts CLOCK_REALTIME clock). +is supported (corresponding to the host's CLOCK_REALTIME clock). - struct kvm_clock_offset { + struct kvm_clock_pairing { __s64 sec; __s64 nsec; __u64 tsc; @@ -107,10 +107,12 @@ is supported (hosts CLOCK_REALTIME clock). Where: * sec: seconds from clock_type clock. * nsec: nanoseconds from clock_type clock. - * tsc: TSC value used to calculate sec/nsec pair - (this hypercall only works when host uses TSC clocksource). + * tsc: guest TSC value used to calculate sec/nsec pair * flags: flags, unused (0) at the moment. +The hypercall lets a guest compute a precise timestamp across +host and guest. The guest can use the returned TSC value to +compute the CLOCK_REALTIME for its clock, at the same instant. + Returns KVM_EOPNOTSUPP if the host does not use TSC clocksource, or if clock type is different than KVM_CLOCK_PAIRING_WALLCLOCK. - diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h index ce7b411e28bc..3641d8b7dba9 100644 --- a/arch/x86/include/uapi/asm/kvm_para.h +++ b/arch/x86/include/uapi/asm/kvm_para.h @@ -51,12 +51,12 @@ struct kvm_steal_time { }; #define KVM_CLOCK_PAIRING_WALLCLOCK 0 -struct kvm_clock_offset { +struct kvm_clock_pairing { __s64 sec; __s64 nsec; __u64 tsc; __u32 flags; - __u32 pad[9]; + __u32 pad[1]; }; #define KVM_STEAL_ALIGNMENT_BITS 5 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 4ecc3145ea4b..09e5d31dac98 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6149,9 +6149,9 @@ int kvm_emulate_halt(struct kvm_vcpu *vcpu) EXPORT_SYMBOL_GPL(kvm_emulate_halt); static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr, - unsigned long clock_type) + unsigned long clock_type) { - struct kvm_clock_offset *clock_offset; + struct kvm_clock_pairing clock_pairing; struct timespec ts; cycle_t cycle; int ret; @@ -6159,30 +6159,19 @@ static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr, if (clock_type != KVM_CLOCK_PAIRING_WALLCLOCK) return -KVM_EOPNOTSUPP; - if (pvclock_gtod_data.clock.vclock_mode != VCLOCK_TSC) - return -KVM_EOPNOTSUPP; - - clock_offset = kzalloc(sizeof(struct kvm_clock_offset), GFP_KERNEL); - if (clock_offset == NULL) - return -KVM_ENOMEM; - - if (kvm_get_walltime_and_clockread(&ts, &cycle) == false) { - kfree(clock_offset); + if (kvm_get_walltime_and_clockread(&ts, &cycle) == false) return -KVM_EOPNOTSUPP; - } - clock_offset->sec = ts.tv_sec; - clock_offset->nsec = ts.tv_nsec; - clock_offset->tsc = kvm_read_l1_tsc(vcpu, cycle); - clock_offset->flags = 0; + clock_pairing.sec = ts.tv_sec; + clock_pairing.nsec = ts.tv_nsec; + clock_pairing.tsc = kvm_read_l1_tsc(vcpu, cycle); + clock_pairing.flags = 0; ret = 0; - if (kvm_write_guest(vcpu->kvm, paddr, clock_offset, - sizeof(struct kvm_clock_offset))) + if (kvm_write_guest(vcpu->kvm, paddr, &clock_pairing, + sizeof(struct kvm_clock_pairing))) ret = -KVM_EFAULT; - kfree(clock_offset); - return ret; } diff --git a/include/uapi/linux/kvm_para.h b/include/uapi/linux/kvm_para.h index 68da60e7f519..c72128527377 100644 --- a/include/uapi/linux/kvm_para.h +++ b/include/uapi/linux/kvm_para.h @@ -14,7 +14,7 @@ #define KVM_EFAULT EFAULT #define KVM_E2BIG E2BIG #define KVM_EPERM EPERM -#define KVM_EOPNOTSUPP EOPNOTSUPP +#define KVM_EOPNOTSUPP 95 #define KVM_ENOMEM ENOMEM #define KVM_HC_VAPIC_POLL_IRQ 1 Okay? Paolo > #define KVM_HC_VAPIC_POLL_IRQ 1 > #define KVM_HC_MMU_OP 2 > @@ -23,6 +25,7 @@ > #define KVM_HC_MIPS_GET_CLOCK_FREQ 6 > #define KVM_HC_MIPS_EXIT_VM 7 > #define KVM_HC_MIPS_CONSOLE_OUTPUT 8 > +#define KVM_HC_CLOCK_PAIRING 9 > > /* > * hypercalls use architecture specific > > > ^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [patch 2/4] KVM: x86: add KVM_HC_CLOCK_OFFSET hypercall 2017-01-25 12:30 ` Paolo Bonzini @ 2017-01-25 12:55 ` Marcelo Tosatti 2017-01-25 12:59 ` Paolo Bonzini 0 siblings, 1 reply; 14+ messages in thread From: Marcelo Tosatti @ 2017-01-25 12:55 UTC (permalink / raw) To: Paolo Bonzini Cc: kvm, linux-kernel, Radim Krcmar, Richard Cochran, Miroslav Lichvar On Wed, Jan 25, 2017 at 01:30:49PM +0100, Paolo Bonzini wrote: > > > On 24/01/2017 18:09, Marcelo Tosatti wrote: > > Add a hypercall to retrieve the host realtime clock > > and the TSC value used to calculate that clock read. > > > > Used to implement clock synchronization between > > host and guest. > > > > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> > > > > --- > > Documentation/virtual/kvm/hypercalls.txt | 33 ++++++++++++++++++++++++ > > arch/x86/include/uapi/asm/kvm_para.h | 9 ++++++ > > arch/x86/kvm/x86.c | 41 +++++++++++++++++++++++++++++++ > > include/uapi/linux/kvm_para.h | 3 ++ > > 4 files changed, 86 insertions(+) > > > > v2: improve documentation (Radim) > > change hypercall name to KVM_HC_CLOCK_PAIRING (Radim) > > increase padding size > > > > Index: kvm-ptpdriver/arch/x86/include/uapi/asm/kvm_para.h > > =================================================================== > > --- kvm-ptpdriver.orig/arch/x86/include/uapi/asm/kvm_para.h 2017-01-13 16:43:11.947240575 -0200 > > +++ kvm-ptpdriver/arch/x86/include/uapi/asm/kvm_para.h 2017-01-13 16:43:25.038258187 -0200 > > @@ -50,6 +50,15 @@ > > __u32 pad[11]; > > }; > > > > +#define KVM_CLOCK_PAIRING_WALLCLOCK 0 > > +struct kvm_clock_offset { > > The struct still has the old name. > > > + __s64 sec; > > + __s64 nsec; > > + __u64 tsc; > > + __u32 flags; > > + __u32 pad[9]; > > +}; That was on purpose: "to pair" is the operation. "struct kvm_clock_pairing" makes no sense to me (because pairing is an "action"). (if you'd prefer that name, let me know). > > #define KVM_STEAL_ALIGNMENT_BITS 5 > > #define KVM_STEAL_VALID_BITS ((-1ULL << (KVM_STEAL_ALIGNMENT_BITS + 1))) > > #define KVM_STEAL_RESERVED_MASK (((1 << KVM_STEAL_ALIGNMENT_BITS) - 1 ) << 1) > > Index: kvm-ptpdriver/Documentation/virtual/kvm/hypercalls.txt > > =================================================================== > > --- kvm-ptpdriver.orig/Documentation/virtual/kvm/hypercalls.txt 2017-01-13 16:43:11.947240575 -0200 > > +++ kvm-ptpdriver/Documentation/virtual/kvm/hypercalls.txt 2017-01-13 16:43:25.038258187 -0200 > > @@ -81,3 +81,36 @@ > > same guest can wakeup the sleeping vcpu by issuing KVM_HC_KICK_CPU hypercall, > > specifying APIC ID (a1) of the vcpu to be woken up. An additional argument (a0) > > is used in the hypercall for future use. > > + > > + > > +6. KVM_HC_CLOCK_PAIRING > > +------------------------ > > +Architecture: x86 > > +Status: active > > +Purpose: Hypercall used to synchronize host and guest clocks. > > +Usage: > > + > > +a0: guest physical address where host copies > > +"struct kvm_clock_offset" structure. > > + > > +a1: clock_type, ATM only KVM_CLOCK_PAIRING_WALLCLOCK (0) > > +is supported (hosts CLOCK_REALTIME clock). > > + > > + struct kvm_clock_offset { > > Name of the struct not adjusted. > > + __s64 sec; > > + __s64 nsec; > > + __u64 tsc; > > + __u32 flags; > > + __u32 pad[9]; > > I'd just leave one element of padding and put the struct on the stack, > since we have no reason to think we'll need a lot of padding. Well you don't know: we could implement it in case of HPET clocksource hosts. > > + }; > > + > > + Where: > > + * sec: seconds from clock_type clock. > > + * nsec: nanoseconds from clock_type clock. > > + * tsc: TSC value used to calculate sec/nsec pair > > + (this hypercall only works when host uses TSC clocksource). > > This is already mentioned below, and it's not clear that tsc is a guest > TSC value. Ok fixed. > > + * flags: flags, unused (0) at the moment. > > + > > +Returns KVM_EOPNOTSUPP if the host does not use TSC clocksource, > > +or if clock type is different than KVM_CLOCK_PAIRING_WALLCLOCK. > > + > > Index: kvm-ptpdriver/arch/x86/kvm/x86.c > > =================================================================== > > --- kvm-ptpdriver.orig/arch/x86/kvm/x86.c 2017-01-13 16:43:20.898252596 -0200 > > +++ kvm-ptpdriver/arch/x86/kvm/x86.c 2017-01-13 16:43:25.041258191 -0200 > > @@ -6119,6 +6119,44 @@ > > } > > EXPORT_SYMBOL_GPL(kvm_emulate_halt); > > > > +static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr, > > + unsigned long clock_type) > > +{ > > + struct kvm_clock_offset *clock_offset; > > + struct timespec ts; > > + cycle_t cycle; > > + int ret; > > + > > + if (clock_type != KVM_CLOCK_PAIRING_WALLCLOCK) > > + return -KVM_EOPNOTSUPP; > > + > > + if (pvclock_gtod_data.clock.vclock_mode != VCLOCK_TSC) > > + return -KVM_EOPNOTSUPP; > > Already checked in kvm_get_walltime_and_clockread. Fixed. > > + clock_offset = kzalloc(sizeof(struct kvm_clock_offset), GFP_KERNEL); > > + if (clock_offset == NULL) > > + return -KVM_ENOMEM; > > + > > + if (kvm_get_walltime_and_clockread(&ts, &cycle) == false) { > > + kfree(clock_offset); > > + return -KVM_EOPNOTSUPP; > > + } > > + clock_offset->sec = ts.tv_sec; > > + clock_offset->nsec = ts.tv_nsec; > > + clock_offset->tsc = kvm_read_l1_tsc(vcpu, cycle); > > + clock_offset->flags = 0; > > + > > + ret = 0; > > + if (kvm_write_guest(vcpu->kvm, paddr, clock_offset, > > + sizeof(struct kvm_clock_offset))) > > + ret = -KVM_EFAULT; > > + > > + kfree(clock_offset); > > + > > + return ret; > > +} > > + > > /* > > * kvm_pv_kick_cpu_op: Kick a vcpu. > > * > > @@ -6183,6 +6221,9 @@ > > kvm_pv_kick_cpu_op(vcpu->kvm, a0, a1); > > ret = 0; > > break; > > + case KVM_HC_CLOCK_PAIRING: > > + ret = kvm_pv_clock_pairing(vcpu, a0, a1); > > + break; > > default: > > ret = -KVM_ENOSYS; > > break; > > Index: kvm-ptpdriver/include/uapi/linux/kvm_para.h > > =================================================================== > > --- kvm-ptpdriver.orig/include/uapi/linux/kvm_para.h 2017-01-13 16:43:11.947240575 -0200 > > +++ kvm-ptpdriver/include/uapi/linux/kvm_para.h 2017-01-13 16:43:25.042258192 -0200 > > @@ -14,6 +14,8 @@ > > #define KVM_EFAULT EFAULT > > #define KVM_E2BIG E2BIG > > #define KVM_EPERM EPERM > > +#define KVM_EOPNOTSUPP EOPNOTSUPP > > +#define KVM_ENOMEM ENOMEM > > This file could potentially be used across multiple architectures (it's > not in arch/x86/include/uapi/asm), but EOPNOTSUPP is not the same on > all systems. Better use "95" which is the value it has on x86. Fixed. > All this gives: > > diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt > index 55eb3e1ca494..cd35de84999f 100644 > --- a/Documentation/virtual/kvm/hypercalls.txt > +++ b/Documentation/virtual/kvm/hypercalls.txt > @@ -94,9 +94,9 @@ a0: guest physical address where host copies > "struct kvm_clock_offset" structure. > > a1: clock_type, ATM only KVM_CLOCK_PAIRING_WALLCLOCK (0) > -is supported (hosts CLOCK_REALTIME clock). > +is supported (corresponding to the host's CLOCK_REALTIME clock). > > - struct kvm_clock_offset { > + struct kvm_clock_pairing { > __s64 sec; > __s64 nsec; > __u64 tsc; > @@ -107,10 +107,12 @@ is supported (hosts CLOCK_REALTIME clock). > Where: > * sec: seconds from clock_type clock. > * nsec: nanoseconds from clock_type clock. > - * tsc: TSC value used to calculate sec/nsec pair > - (this hypercall only works when host uses TSC clocksource). > + * tsc: guest TSC value used to calculate sec/nsec pair > * flags: flags, unused (0) at the moment. > > +The hypercall lets a guest compute a precise timestamp across > +host and guest. The guest can use the returned TSC value to > +compute the CLOCK_REALTIME for its clock, at the same instant. > + > Returns KVM_EOPNOTSUPP if the host does not use TSC clocksource, > or if clock type is different than KVM_CLOCK_PAIRING_WALLCLOCK. > - > diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h > index ce7b411e28bc..3641d8b7dba9 100644 > --- a/arch/x86/include/uapi/asm/kvm_para.h > +++ b/arch/x86/include/uapi/asm/kvm_para.h > @@ -51,12 +51,12 @@ struct kvm_steal_time { > }; > > #define KVM_CLOCK_PAIRING_WALLCLOCK 0 > -struct kvm_clock_offset { > +struct kvm_clock_pairing { > __s64 sec; > __s64 nsec; > __u64 tsc; > __u32 flags; > - __u32 pad[9]; > + __u32 pad[1]; > }; > > #define KVM_STEAL_ALIGNMENT_BITS 5 > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 4ecc3145ea4b..09e5d31dac98 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -6149,9 +6149,9 @@ int kvm_emulate_halt(struct kvm_vcpu *vcpu) > EXPORT_SYMBOL_GPL(kvm_emulate_halt); > > static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr, > - unsigned long clock_type) > + unsigned long clock_type) > { > - struct kvm_clock_offset *clock_offset; > + struct kvm_clock_pairing clock_pairing; > struct timespec ts; > cycle_t cycle; > int ret; > @@ -6159,30 +6159,19 @@ static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr, > if (clock_type != KVM_CLOCK_PAIRING_WALLCLOCK) > return -KVM_EOPNOTSUPP; > > - if (pvclock_gtod_data.clock.vclock_mode != VCLOCK_TSC) > - return -KVM_EOPNOTSUPP; > - > - clock_offset = kzalloc(sizeof(struct kvm_clock_offset), GFP_KERNEL); > - if (clock_offset == NULL) > - return -KVM_ENOMEM; > - > - if (kvm_get_walltime_and_clockread(&ts, &cycle) == false) { > - kfree(clock_offset); > + if (kvm_get_walltime_and_clockread(&ts, &cycle) == false) > return -KVM_EOPNOTSUPP; > - } > > - clock_offset->sec = ts.tv_sec; > - clock_offset->nsec = ts.tv_nsec; > - clock_offset->tsc = kvm_read_l1_tsc(vcpu, cycle); > - clock_offset->flags = 0; > + clock_pairing.sec = ts.tv_sec; > + clock_pairing.nsec = ts.tv_nsec; > + clock_pairing.tsc = kvm_read_l1_tsc(vcpu, cycle); > + clock_pairing.flags = 0; > > ret = 0; > - if (kvm_write_guest(vcpu->kvm, paddr, clock_offset, > - sizeof(struct kvm_clock_offset))) > + if (kvm_write_guest(vcpu->kvm, paddr, &clock_pairing, > + sizeof(struct kvm_clock_pairing))) > ret = -KVM_EFAULT; > > - kfree(clock_offset); > - > return ret; > } > > diff --git a/include/uapi/linux/kvm_para.h b/include/uapi/linux/kvm_para.h > index 68da60e7f519..c72128527377 100644 > --- a/include/uapi/linux/kvm_para.h > +++ b/include/uapi/linux/kvm_para.h > @@ -14,7 +14,7 @@ > #define KVM_EFAULT EFAULT > #define KVM_E2BIG E2BIG > #define KVM_EPERM EPERM > -#define KVM_EOPNOTSUPP EOPNOTSUPP > +#define KVM_EOPNOTSUPP 95 > #define KVM_ENOMEM ENOMEM > > #define KVM_HC_VAPIC_POLL_IRQ 1 > > Okay? Just not the padding please, the rest is fine. > > Paolo > > > #define KVM_HC_VAPIC_POLL_IRQ 1 > > #define KVM_HC_MMU_OP 2 > > @@ -23,6 +25,7 @@ > > #define KVM_HC_MIPS_GET_CLOCK_FREQ 6 > > #define KVM_HC_MIPS_EXIT_VM 7 > > #define KVM_HC_MIPS_CONSOLE_OUTPUT 8 > > +#define KVM_HC_CLOCK_PAIRING 9 > > > > /* > > * hypercalls use architecture specific > > > > > > ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [patch 2/4] KVM: x86: add KVM_HC_CLOCK_OFFSET hypercall 2017-01-25 12:55 ` Marcelo Tosatti @ 2017-01-25 12:59 ` Paolo Bonzini 2017-01-25 13:06 ` Marcelo Tosatti 0 siblings, 1 reply; 14+ messages in thread From: Paolo Bonzini @ 2017-01-25 12:59 UTC (permalink / raw) To: Marcelo Tosatti Cc: kvm, linux-kernel, Radim Krcmar, Richard Cochran, Miroslav Lichvar On 25/01/2017 13:55, Marcelo Tosatti wrote: > On Wed, Jan 25, 2017 at 01:30:49PM +0100, Paolo Bonzini wrote: >> >> >> On 24/01/2017 18:09, Marcelo Tosatti wrote: >>> Add a hypercall to retrieve the host realtime clock >>> and the TSC value used to calculate that clock read. >>> >>> Used to implement clock synchronization between >>> host and guest. >>> >>> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> >>> >>> --- >>> Documentation/virtual/kvm/hypercalls.txt | 33 ++++++++++++++++++++++++ >>> arch/x86/include/uapi/asm/kvm_para.h | 9 ++++++ >>> arch/x86/kvm/x86.c | 41 +++++++++++++++++++++++++++++++ >>> include/uapi/linux/kvm_para.h | 3 ++ >>> 4 files changed, 86 insertions(+) >>> >>> v2: improve documentation (Radim) >>> change hypercall name to KVM_HC_CLOCK_PAIRING (Radim) >>> increase padding size >>> >>> Index: kvm-ptpdriver/arch/x86/include/uapi/asm/kvm_para.h >>> =================================================================== >>> --- kvm-ptpdriver.orig/arch/x86/include/uapi/asm/kvm_para.h 2017-01-13 16:43:11.947240575 -0200 >>> +++ kvm-ptpdriver/arch/x86/include/uapi/asm/kvm_para.h 2017-01-13 16:43:25.038258187 -0200 >>> @@ -50,6 +50,15 @@ >>> __u32 pad[11]; >>> }; >>> >>> +#define KVM_CLOCK_PAIRING_WALLCLOCK 0 >>> +struct kvm_clock_offset { >> >> The struct still has the old name. >> >>> + __s64 sec; >>> + __s64 nsec; >>> + __u64 tsc; >>> + __u32 flags; >>> + __u32 pad[9]; >>> +}; > > That was on purpose: "to pair" is the operation. > > "struct kvm_clock_pairing" makes no sense to me > (because pairing is an "action"). > > (if you'd prefer that name, let me know). A "pairing" is a union of two things, in this case a sec/nsec value and a TSC value. (I had to look it up in the dictionary though :)). >>> #define KVM_STEAL_ALIGNMENT_BITS 5 >>> #define KVM_STEAL_VALID_BITS ((-1ULL << (KVM_STEAL_ALIGNMENT_BITS + 1))) >>> #define KVM_STEAL_RESERVED_MASK (((1 << KVM_STEAL_ALIGNMENT_BITS) - 1 ) << 1) >>> Index: kvm-ptpdriver/Documentation/virtual/kvm/hypercalls.txt >>> =================================================================== >>> --- kvm-ptpdriver.orig/Documentation/virtual/kvm/hypercalls.txt 2017-01-13 16:43:11.947240575 -0200 >>> +++ kvm-ptpdriver/Documentation/virtual/kvm/hypercalls.txt 2017-01-13 16:43:25.038258187 -0200 >>> @@ -81,3 +81,36 @@ >>> same guest can wakeup the sleeping vcpu by issuing KVM_HC_KICK_CPU hypercall, >>> specifying APIC ID (a1) of the vcpu to be woken up. An additional argument (a0) >>> is used in the hypercall for future use. >>> + >>> + >>> +6. KVM_HC_CLOCK_PAIRING >>> +------------------------ >>> +Architecture: x86 >>> +Status: active >>> +Purpose: Hypercall used to synchronize host and guest clocks. >>> +Usage: >>> + >>> +a0: guest physical address where host copies >>> +"struct kvm_clock_offset" structure. >>> + >>> +a1: clock_type, ATM only KVM_CLOCK_PAIRING_WALLCLOCK (0) >>> +is supported (hosts CLOCK_REALTIME clock). >>> + >>> + struct kvm_clock_offset { >> >> Name of the struct not adjusted. >>> + __s64 sec; >>> + __s64 nsec; >>> + __u64 tsc; >>> + __u32 flags; >>> + __u32 pad[9]; >> >> I'd just leave one element of padding and put the struct on the stack, >> since we have no reason to think we'll need a lot of padding. > > Well you don't know: we could implement it in case of HPET clocksource > hosts. But then the guest wouldn't have a TSC value to use, would it? Also, how would it use more padding? Paolo >>> + }; >>> + >>> + Where: >>> + * sec: seconds from clock_type clock. >>> + * nsec: nanoseconds from clock_type clock. >>> + * tsc: TSC value used to calculate sec/nsec pair >>> + (this hypercall only works when host uses TSC clocksource). >> >> This is already mentioned below, and it's not clear that tsc is a guest >> TSC value. > > Ok fixed. > >>> + * flags: flags, unused (0) at the moment. >>> + >>> +Returns KVM_EOPNOTSUPP if the host does not use TSC clocksource, >>> +or if clock type is different than KVM_CLOCK_PAIRING_WALLCLOCK. >>> + >>> Index: kvm-ptpdriver/arch/x86/kvm/x86.c >>> =================================================================== >>> --- kvm-ptpdriver.orig/arch/x86/kvm/x86.c 2017-01-13 16:43:20.898252596 -0200 >>> +++ kvm-ptpdriver/arch/x86/kvm/x86.c 2017-01-13 16:43:25.041258191 -0200 >>> @@ -6119,6 +6119,44 @@ >>> } >>> EXPORT_SYMBOL_GPL(kvm_emulate_halt); >>> >>> +static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr, >>> + unsigned long clock_type) >>> +{ >>> + struct kvm_clock_offset *clock_offset; >>> + struct timespec ts; >>> + cycle_t cycle; >>> + int ret; >>> + >>> + if (clock_type != KVM_CLOCK_PAIRING_WALLCLOCK) >>> + return -KVM_EOPNOTSUPP; >>> + >>> + if (pvclock_gtod_data.clock.vclock_mode != VCLOCK_TSC) >>> + return -KVM_EOPNOTSUPP; >> >> Already checked in kvm_get_walltime_and_clockread. > > Fixed. > >>> + clock_offset = kzalloc(sizeof(struct kvm_clock_offset), GFP_KERNEL); >>> + if (clock_offset == NULL) >>> + return -KVM_ENOMEM; >>> + >>> + if (kvm_get_walltime_and_clockread(&ts, &cycle) == false) { >>> + kfree(clock_offset); >>> + return -KVM_EOPNOTSUPP; >>> + } >>> + clock_offset->sec = ts.tv_sec; >>> + clock_offset->nsec = ts.tv_nsec; >>> + clock_offset->tsc = kvm_read_l1_tsc(vcpu, cycle); >>> + clock_offset->flags = 0; >>> + >>> + ret = 0; >>> + if (kvm_write_guest(vcpu->kvm, paddr, clock_offset, >>> + sizeof(struct kvm_clock_offset))) >>> + ret = -KVM_EFAULT; >>> + >>> + kfree(clock_offset); >>> + >>> + return ret; >>> +} >>> + >>> /* >>> * kvm_pv_kick_cpu_op: Kick a vcpu. >>> * >>> @@ -6183,6 +6221,9 @@ >>> kvm_pv_kick_cpu_op(vcpu->kvm, a0, a1); >>> ret = 0; >>> break; >>> + case KVM_HC_CLOCK_PAIRING: >>> + ret = kvm_pv_clock_pairing(vcpu, a0, a1); >>> + break; >>> default: >>> ret = -KVM_ENOSYS; >>> break; >>> Index: kvm-ptpdriver/include/uapi/linux/kvm_para.h >>> =================================================================== >>> --- kvm-ptpdriver.orig/include/uapi/linux/kvm_para.h 2017-01-13 16:43:11.947240575 -0200 >>> +++ kvm-ptpdriver/include/uapi/linux/kvm_para.h 2017-01-13 16:43:25.042258192 -0200 >>> @@ -14,6 +14,8 @@ >>> #define KVM_EFAULT EFAULT >>> #define KVM_E2BIG E2BIG >>> #define KVM_EPERM EPERM >>> +#define KVM_EOPNOTSUPP EOPNOTSUPP >>> +#define KVM_ENOMEM ENOMEM >> >> This file could potentially be used across multiple architectures (it's >> not in arch/x86/include/uapi/asm), but EOPNOTSUPP is not the same on >> all systems. Better use "95" which is the value it has on x86. > > Fixed. > >> All this gives: >> >> diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt >> index 55eb3e1ca494..cd35de84999f 100644 >> --- a/Documentation/virtual/kvm/hypercalls.txt >> +++ b/Documentation/virtual/kvm/hypercalls.txt >> @@ -94,9 +94,9 @@ a0: guest physical address where host copies >> "struct kvm_clock_offset" structure. >> >> a1: clock_type, ATM only KVM_CLOCK_PAIRING_WALLCLOCK (0) >> -is supported (hosts CLOCK_REALTIME clock). >> +is supported (corresponding to the host's CLOCK_REALTIME clock). >> >> - struct kvm_clock_offset { >> + struct kvm_clock_pairing { >> __s64 sec; >> __s64 nsec; >> __u64 tsc; >> @@ -107,10 +107,12 @@ is supported (hosts CLOCK_REALTIME clock). >> Where: >> * sec: seconds from clock_type clock. >> * nsec: nanoseconds from clock_type clock. >> - * tsc: TSC value used to calculate sec/nsec pair >> - (this hypercall only works when host uses TSC clocksource). >> + * tsc: guest TSC value used to calculate sec/nsec pair >> * flags: flags, unused (0) at the moment. >> >> +The hypercall lets a guest compute a precise timestamp across >> +host and guest. The guest can use the returned TSC value to >> +compute the CLOCK_REALTIME for its clock, at the same instant. >> + >> Returns KVM_EOPNOTSUPP if the host does not use TSC clocksource, >> or if clock type is different than KVM_CLOCK_PAIRING_WALLCLOCK. >> - >> diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h >> index ce7b411e28bc..3641d8b7dba9 100644 >> --- a/arch/x86/include/uapi/asm/kvm_para.h >> +++ b/arch/x86/include/uapi/asm/kvm_para.h >> @@ -51,12 +51,12 @@ struct kvm_steal_time { >> }; >> >> #define KVM_CLOCK_PAIRING_WALLCLOCK 0 >> -struct kvm_clock_offset { >> +struct kvm_clock_pairing { >> __s64 sec; >> __s64 nsec; >> __u64 tsc; >> __u32 flags; >> - __u32 pad[9]; >> + __u32 pad[1]; >> }; >> >> #define KVM_STEAL_ALIGNMENT_BITS 5 >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> index 4ecc3145ea4b..09e5d31dac98 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -6149,9 +6149,9 @@ int kvm_emulate_halt(struct kvm_vcpu *vcpu) >> EXPORT_SYMBOL_GPL(kvm_emulate_halt); >> >> static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr, >> - unsigned long clock_type) >> + unsigned long clock_type) >> { >> - struct kvm_clock_offset *clock_offset; >> + struct kvm_clock_pairing clock_pairing; >> struct timespec ts; >> cycle_t cycle; >> int ret; >> @@ -6159,30 +6159,19 @@ static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr, >> if (clock_type != KVM_CLOCK_PAIRING_WALLCLOCK) >> return -KVM_EOPNOTSUPP; >> >> - if (pvclock_gtod_data.clock.vclock_mode != VCLOCK_TSC) >> - return -KVM_EOPNOTSUPP; >> - >> - clock_offset = kzalloc(sizeof(struct kvm_clock_offset), GFP_KERNEL); >> - if (clock_offset == NULL) >> - return -KVM_ENOMEM; >> - >> - if (kvm_get_walltime_and_clockread(&ts, &cycle) == false) { >> - kfree(clock_offset); >> + if (kvm_get_walltime_and_clockread(&ts, &cycle) == false) >> return -KVM_EOPNOTSUPP; >> - } >> >> - clock_offset->sec = ts.tv_sec; >> - clock_offset->nsec = ts.tv_nsec; >> - clock_offset->tsc = kvm_read_l1_tsc(vcpu, cycle); >> - clock_offset->flags = 0; >> + clock_pairing.sec = ts.tv_sec; >> + clock_pairing.nsec = ts.tv_nsec; >> + clock_pairing.tsc = kvm_read_l1_tsc(vcpu, cycle); >> + clock_pairing.flags = 0; >> >> ret = 0; >> - if (kvm_write_guest(vcpu->kvm, paddr, clock_offset, >> - sizeof(struct kvm_clock_offset))) >> + if (kvm_write_guest(vcpu->kvm, paddr, &clock_pairing, >> + sizeof(struct kvm_clock_pairing))) >> ret = -KVM_EFAULT; >> >> - kfree(clock_offset); >> - >> return ret; >> } >> >> diff --git a/include/uapi/linux/kvm_para.h b/include/uapi/linux/kvm_para.h >> index 68da60e7f519..c72128527377 100644 >> --- a/include/uapi/linux/kvm_para.h >> +++ b/include/uapi/linux/kvm_para.h >> @@ -14,7 +14,7 @@ >> #define KVM_EFAULT EFAULT >> #define KVM_E2BIG E2BIG >> #define KVM_EPERM EPERM >> -#define KVM_EOPNOTSUPP EOPNOTSUPP >> +#define KVM_EOPNOTSUPP 95 >> #define KVM_ENOMEM ENOMEM >> >> #define KVM_HC_VAPIC_POLL_IRQ 1 >> >> Okay? > > Just not the padding please, the rest is fine. > >> >> Paolo >> >>> #define KVM_HC_VAPIC_POLL_IRQ 1 >>> #define KVM_HC_MMU_OP 2 >>> @@ -23,6 +25,7 @@ >>> #define KVM_HC_MIPS_GET_CLOCK_FREQ 6 >>> #define KVM_HC_MIPS_EXIT_VM 7 >>> #define KVM_HC_MIPS_CONSOLE_OUTPUT 8 >>> +#define KVM_HC_CLOCK_PAIRING 9 >>> >>> /* >>> * hypercalls use architecture specific >>> >>> >>> ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [patch 2/4] KVM: x86: add KVM_HC_CLOCK_OFFSET hypercall 2017-01-25 12:59 ` Paolo Bonzini @ 2017-01-25 13:06 ` Marcelo Tosatti 2017-01-25 13:15 ` Paolo Bonzini 0 siblings, 1 reply; 14+ messages in thread From: Marcelo Tosatti @ 2017-01-25 13:06 UTC (permalink / raw) To: Paolo Bonzini Cc: kvm, linux-kernel, Radim Krcmar, Richard Cochran, Miroslav Lichvar On Wed, Jan 25, 2017 at 01:59:34PM +0100, Paolo Bonzini wrote: > > > On 25/01/2017 13:55, Marcelo Tosatti wrote: > > On Wed, Jan 25, 2017 at 01:30:49PM +0100, Paolo Bonzini wrote: > >> > >> > >> On 24/01/2017 18:09, Marcelo Tosatti wrote: > >>> Add a hypercall to retrieve the host realtime clock > >>> and the TSC value used to calculate that clock read. > >>> > >>> Used to implement clock synchronization between > >>> host and guest. > >>> > >>> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> > >>> > >>> --- > >>> Documentation/virtual/kvm/hypercalls.txt | 33 ++++++++++++++++++++++++ > >>> arch/x86/include/uapi/asm/kvm_para.h | 9 ++++++ > >>> arch/x86/kvm/x86.c | 41 +++++++++++++++++++++++++++++++ > >>> include/uapi/linux/kvm_para.h | 3 ++ > >>> 4 files changed, 86 insertions(+) > >>> > >>> v2: improve documentation (Radim) > >>> change hypercall name to KVM_HC_CLOCK_PAIRING (Radim) > >>> increase padding size > >>> > >>> Index: kvm-ptpdriver/arch/x86/include/uapi/asm/kvm_para.h > >>> =================================================================== > >>> --- kvm-ptpdriver.orig/arch/x86/include/uapi/asm/kvm_para.h 2017-01-13 16:43:11.947240575 -0200 > >>> +++ kvm-ptpdriver/arch/x86/include/uapi/asm/kvm_para.h 2017-01-13 16:43:25.038258187 -0200 > >>> @@ -50,6 +50,15 @@ > >>> __u32 pad[11]; > >>> }; > >>> > >>> +#define KVM_CLOCK_PAIRING_WALLCLOCK 0 > >>> +struct kvm_clock_offset { > >> > >> The struct still has the old name. > >> > >>> + __s64 sec; > >>> + __s64 nsec; > >>> + __u64 tsc; > >>> + __u32 flags; > >>> + __u32 pad[9]; > >>> +}; > > > > That was on purpose: "to pair" is the operation. > > > > "struct kvm_clock_pairing" makes no sense to me > > (because pairing is an "action"). > > > > (if you'd prefer that name, let me know). > > A "pairing" is a union of two things, in this case a sec/nsec value and > a TSC value. (I had to look it up in the dictionary though :)). > > >>> #define KVM_STEAL_ALIGNMENT_BITS 5 > >>> #define KVM_STEAL_VALID_BITS ((-1ULL << (KVM_STEAL_ALIGNMENT_BITS + 1))) > >>> #define KVM_STEAL_RESERVED_MASK (((1 << KVM_STEAL_ALIGNMENT_BITS) - 1 ) << 1) > >>> Index: kvm-ptpdriver/Documentation/virtual/kvm/hypercalls.txt > >>> =================================================================== > >>> --- kvm-ptpdriver.orig/Documentation/virtual/kvm/hypercalls.txt 2017-01-13 16:43:11.947240575 -0200 > >>> +++ kvm-ptpdriver/Documentation/virtual/kvm/hypercalls.txt 2017-01-13 16:43:25.038258187 -0200 > >>> @@ -81,3 +81,36 @@ > >>> same guest can wakeup the sleeping vcpu by issuing KVM_HC_KICK_CPU hypercall, > >>> specifying APIC ID (a1) of the vcpu to be woken up. An additional argument (a0) > >>> is used in the hypercall for future use. > >>> + > >>> + > >>> +6. KVM_HC_CLOCK_PAIRING > >>> +------------------------ > >>> +Architecture: x86 > >>> +Status: active > >>> +Purpose: Hypercall used to synchronize host and guest clocks. > >>> +Usage: > >>> + > >>> +a0: guest physical address where host copies > >>> +"struct kvm_clock_offset" structure. > >>> + > >>> +a1: clock_type, ATM only KVM_CLOCK_PAIRING_WALLCLOCK (0) > >>> +is supported (hosts CLOCK_REALTIME clock). > >>> + > >>> + struct kvm_clock_offset { > >> > >> Name of the struct not adjusted. > >>> + __s64 sec; > >>> + __s64 nsec; > >>> + __u64 tsc; > >>> + __u32 flags; > >>> + __u32 pad[9]; > >> > >> I'd just leave one element of padding and put the struct on the stack, > >> since we have no reason to think we'll need a lot of padding. > > > > Well you don't know: we could implement it in case of HPET clocksource > > hosts. > > But then the guest wouldn't have a TSC value to use, would it? > > Also, how would it use more padding? I don't know, maybe pass the TSC and host HPET read in the structure? (after exposing the HPET to the guest). Or maybe you want to sync CLOCK_MONOTONIC and that requires other data. Not sure. Just some space if new features are necessary. ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [patch 2/4] KVM: x86: add KVM_HC_CLOCK_OFFSET hypercall 2017-01-25 13:06 ` Marcelo Tosatti @ 2017-01-25 13:15 ` Paolo Bonzini 0 siblings, 0 replies; 14+ messages in thread From: Paolo Bonzini @ 2017-01-25 13:15 UTC (permalink / raw) To: Marcelo Tosatti Cc: kvm, linux-kernel, Radim Krcmar, Richard Cochran, Miroslav Lichvar On 25/01/2017 14:06, Marcelo Tosatti wrote: >>> Well you don't know: we could implement it in case of HPET clocksource >>> hosts. >> But then the guest wouldn't have a TSC value to use, would it? >> >> Also, how would it use more padding? > I don't know, maybe pass the TSC and host HPET read in the structure? > (after exposing the HPET to the guest). > > Or maybe you want to sync CLOCK_MONOTONIC and that requires other data. > > Not sure. > > Just some space if new features are necessary. Fair enough. Paolo ^ permalink raw reply [flat|nested] 14+ messages in thread
* [patch 3/4] kvmclock: export kvmclock clocksource pointer 2017-01-24 17:09 [patch 0/4] KVM virtual PTP driver (v5) Marcelo Tosatti 2017-01-24 17:09 ` [patch 1/4] KVM: x86: provide realtime host clock via vsyscall notifiers Marcelo Tosatti 2017-01-24 17:09 ` [patch 2/4] KVM: x86: add KVM_HC_CLOCK_OFFSET hypercall Marcelo Tosatti @ 2017-01-24 17:09 ` Marcelo Tosatti 2017-01-24 17:09 ` [patch 4/4] PTP: add kvm PTP driver Marcelo Tosatti 3 siblings, 0 replies; 14+ messages in thread From: Marcelo Tosatti @ 2017-01-24 17:09 UTC (permalink / raw) To: kvm, linux-kernel Cc: Paolo Bonzini, Radim Krcmar, Richard Cochran, Miroslav Lichvar, Marcelo Tosatti [-- Attachment #1: kvmclock-export-clocksource --] [-- Type: text/plain, Size: 1367 bytes --] To be used by KVM PTP driver. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> --- arch/x86/include/asm/kvmclock.h | 6 ++++++ arch/x86/kernel/kvmclock.c | 3 ++- 2 files changed, 8 insertions(+), 1 deletion(-) v2: export kvmclock clocksource structure directly (Paolo) Index: kvm-ptpdriver/arch/x86/include/asm/kvmclock.h =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ kvm-ptpdriver/arch/x86/include/asm/kvmclock.h 2017-01-20 11:05:28.720038512 -0200 @@ -0,0 +1,6 @@ +#ifndef _ASM_X86_KVM_CLOCK_H +#define _ASM_X86_KVM_CLOCK_H + +extern struct clocksource kvm_clock; + +#endif /* _ASM_X86_KVM_CLOCK_H */ Index: kvm-ptpdriver/arch/x86/kernel/kvmclock.c =================================================================== --- kvm-ptpdriver.orig/arch/x86/kernel/kvmclock.c 2017-01-20 10:03:44.750489955 -0200 +++ kvm-ptpdriver/arch/x86/kernel/kvmclock.c 2017-01-20 11:05:03.137971637 -0200 @@ -28,6 +28,7 @@ #include <asm/x86_init.h> #include <asm/reboot.h> +#include <asm/kvmclock.h> static int kvmclock __ro_after_init = 1; static int msr_kvm_system_time = MSR_KVM_SYSTEM_TIME; @@ -174,7 +175,7 @@ return ret; } -static struct clocksource kvm_clock = { +struct clocksource kvm_clock = { .name = "kvm-clock", .read = kvm_clock_get_cycles, .rating = 400, ^ permalink raw reply [flat|nested] 14+ messages in thread
* [patch 4/4] PTP: add kvm PTP driver 2017-01-24 17:09 [patch 0/4] KVM virtual PTP driver (v5) Marcelo Tosatti ` (2 preceding siblings ...) 2017-01-24 17:09 ` [patch 3/4] kvmclock: export kvmclock clocksource pointer Marcelo Tosatti @ 2017-01-24 17:09 ` Marcelo Tosatti 2017-01-24 18:11 ` Richard Cochran 2017-01-25 12:56 ` Paolo Bonzini 3 siblings, 2 replies; 14+ messages in thread From: Marcelo Tosatti @ 2017-01-24 17:09 UTC (permalink / raw) To: kvm, linux-kernel Cc: Paolo Bonzini, Radim Krcmar, Richard Cochran, Miroslav Lichvar, Marcelo Tosatti [-- Attachment #1: kvm-ptpdriver --] [-- Type: text/plain, Size: 7426 bytes --] Add a driver with gettime method returning hosts realtime clock. This allows Chrony to synchronize host and guest clocks with high precision (see results below). chronyc> sources MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== #* PHC0 0 3 377 4 +162ns[ -683ns] +/- 11ns To configure Chronyd to use PHC refclock, add the following line to its configuration file: refclock PHC /dev/ptpX poll 3 dpoll -2 offset 0 Where /dev/ptpX is the kvmclock PTP clock. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> --- drivers/ptp/Kconfig | 12 ++ drivers/ptp/Makefile | 1 drivers/ptp/ptp_kvm.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 215 insertions(+) v2: check for kvmclock (Radim) initialize global variables before device registration (Radim) v3: use cross timestamps callback (Paolo, Miroslav, Radim) v4: remove gettime64 callback (Paolo) v5: drop useless nsec assignment (Radim) Index: kvm-ptpdriver/drivers/ptp/Kconfig =================================================================== --- kvm-ptpdriver.orig/drivers/ptp/Kconfig 2017-01-24 09:03:47.604586098 -0200 +++ kvm-ptpdriver/drivers/ptp/Kconfig 2017-01-24 09:05:06.321704124 -0200 @@ -90,4 +90,16 @@ To compile this driver as a module, choose M here: the module will be called ptp_pch. +config PTP_1588_CLOCK_KVM + tristate "KVM virtual PTP clock" + depends on PTP_1588_CLOCK + depends on KVM_GUEST + default y + help + This driver adds support for using kvm infrastructure as a PTP + clock. This clock is only useful if you are using KVM guests. + + To compile this driver as a module, choose M here: the module + will be called ptp_kvm. + endmenu Index: kvm-ptpdriver/drivers/ptp/Makefile =================================================================== --- kvm-ptpdriver.orig/drivers/ptp/Makefile 2017-01-24 09:03:47.604586098 -0200 +++ kvm-ptpdriver/drivers/ptp/Makefile 2017-01-24 09:05:06.322704125 -0200 @@ -6,3 +6,4 @@ obj-$(CONFIG_PTP_1588_CLOCK) += ptp.o obj-$(CONFIG_PTP_1588_CLOCK_IXP46X) += ptp_ixp46x.o obj-$(CONFIG_PTP_1588_CLOCK_PCH) += ptp_pch.o +obj-$(CONFIG_PTP_1588_CLOCK_KVM) += ptp_kvm.o Index: kvm-ptpdriver/drivers/ptp/ptp_kvm.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ kvm-ptpdriver/drivers/ptp/ptp_kvm.c 2017-01-24 09:05:06.322704125 -0200 @@ -0,0 +1,202 @@ +/* + * Virtual PTP 1588 clock for use with KVM guests + * + * Copyright (C) 2017 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ +#include <linux/device.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <uapi/linux/kvm_para.h> +#include <asm/kvm_para.h> +#include <asm/pvclock.h> +#include <asm/kvmclock.h> +#include <uapi/asm/kvm_para.h> + +#include <linux/ptp_clock_kernel.h> + +struct kvm_ptp_clock { + struct ptp_clock *ptp_clock; + struct ptp_clock_info caps; +}; + +DEFINE_SPINLOCK(kvm_ptp_lock); + +static struct pvclock_vsyscall_time_info *hv_clock; + +static struct kvm_clock_offset clock_off; +static phys_addr_t clock_off_gpa; + +static int ptp_kvm_get_time_fn(ktime_t *device_time, + struct system_counterval_t *system_counter, + void *ctx) +{ + unsigned long ret; + struct timespec64 tspec; + unsigned version; + u8 flags; + int cpu; + struct pvclock_vcpu_time_info *src; + + preempt_disable_notrace(); + cpu = smp_processor_id(); + src = &hv_clock[cpu].pvti; + + spin_lock(&kvm_ptp_lock); + + do { + /* + * We are using a TSC value read in the hosts + * kvm_hc_clock_pairing handling. + * So any changes to tsc_to_system_mul + * and tsc_shift or any other pvclock + * data invalidate that measurement. + */ + version = pvclock_read_begin(src); + + ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, + clock_off_gpa, + KVM_CLOCK_PAIRING_WALLCLOCK); + if (ret != 0) { + pr_err("clock offset hypercall ret %lu\n", ret); + spin_unlock(&kvm_ptp_lock); + preempt_enable_notrace(); + return -EOPNOTSUPP; + } + + tspec.tv_sec = clock_off.sec; + tspec.tv_nsec = clock_off.nsec; + ret = __pvclock_read_cycles(src, clock_off.tsc); + flags = src->flags; + } while (pvclock_read_retry(src, version)); + + preempt_enable_notrace(); + + system_counter->cycles = ret; + system_counter->cs = &kvm_clock; + + *device_time = timespec_to_ktime(tspec); + + spin_unlock(&kvm_ptp_lock); + + return 0; +} + +static int ptp_kvm_getcrosststamp(struct ptp_clock_info *ptp, + struct system_device_crosststamp *xtstamp) +{ + return get_device_system_crosststamp(ptp_kvm_get_time_fn, NULL, + NULL, xtstamp); +} + +/* + * PTP clock operations + */ + +static int ptp_kvm_adjfreq(struct ptp_clock_info *ptp, s32 ppb) +{ + return -EOPNOTSUPP; +} + +static int ptp_kvm_adjtime(struct ptp_clock_info *ptp, s64 delta) +{ + return -EOPNOTSUPP; +} + +static int ptp_kvm_settime(struct ptp_clock_info *ptp, + const struct timespec64 *ts) +{ + return -EOPNOTSUPP; +} + +static int ptp_kvm_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts) +{ + unsigned long ret; + struct timespec64 tspec; + + spin_lock(&kvm_ptp_lock); + + ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, + clock_off_gpa, + KVM_CLOCK_PAIRING_WALLCLOCK); + if (ret != 0) { + pr_err("clock offset hypercall ret %lu\n", ret); + spin_unlock(&kvm_ptp_lock); + return -EOPNOTSUPP; + } + + tspec.tv_sec = clock_off.sec; + tspec.tv_nsec = clock_off.nsec; + spin_unlock(&kvm_ptp_lock); + + memcpy(ts, &tspec, sizeof(struct timespec64)); + + return 0; +} + +static int ptp_kvm_enable(struct ptp_clock_info *ptp, + struct ptp_clock_request *rq, int on) +{ + return -EOPNOTSUPP; +} + +static struct ptp_clock_info ptp_kvm_caps = { + .owner = THIS_MODULE, + .name = "KVM virtual PTP", + .max_adj = 0, + .n_ext_ts = 0, + .n_pins = 0, + .pps = 0, + .adjfreq = ptp_kvm_adjfreq, + .adjtime = ptp_kvm_adjtime, + .gettime64 = ptp_kvm_gettime, + .settime64 = ptp_kvm_settime, + .enable = ptp_kvm_enable, + .getcrosststamp = ptp_kvm_getcrosststamp, +}; + +/* module operations */ + +static struct kvm_ptp_clock kvm_ptp_clock; + +static void __exit ptp_kvm_exit(void) +{ + ptp_clock_unregister(kvm_ptp_clock.ptp_clock); +} + +static int __init ptp_kvm_init(void) +{ + clock_off_gpa = slow_virt_to_phys(&clock_off); + hv_clock = pvclock_pvti_cpu0_va(); + + if (!hv_clock) + return -ENODEV; + + kvm_ptp_clock.caps = ptp_kvm_caps; + + kvm_ptp_clock.ptp_clock = ptp_clock_register(&kvm_ptp_clock.caps, NULL); + + if (IS_ERR(kvm_ptp_clock.ptp_clock)) + return PTR_ERR(kvm_ptp_clock.ptp_clock); + + return 0; +} + +module_init(ptp_kvm_init); +module_exit(ptp_kvm_exit); + +MODULE_AUTHOR("Marcelo Tosatti <mtosatti@redhat.com>"); +MODULE_DESCRIPTION("PTP clock using KVMCLOCK"); +MODULE_LICENSE("GPL"); ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [patch 4/4] PTP: add kvm PTP driver 2017-01-24 17:09 ` [patch 4/4] PTP: add kvm PTP driver Marcelo Tosatti @ 2017-01-24 18:11 ` Richard Cochran 2017-01-25 12:56 ` Paolo Bonzini 1 sibling, 0 replies; 14+ messages in thread From: Richard Cochran @ 2017-01-24 18:11 UTC (permalink / raw) To: Marcelo Tosatti Cc: kvm, linux-kernel, Paolo Bonzini, Radim Krcmar, Miroslav Lichvar On Tue, Jan 24, 2017 at 03:09:42PM -0200, Marcelo Tosatti wrote: > Add a driver with gettime method returning hosts realtime clock. > This allows Chrony to synchronize host and guest clocks with > high precision (see results below). > > chronyc> sources > MS Name/IP address Stratum Poll Reach LastRx Last sample > =============================================================================== > #* PHC0 0 3 377 4 +162ns[ -683ns] +/- 11ns > > To configure Chronyd to use PHC refclock, add the > following line to its configuration file: > > refclock PHC /dev/ptpX poll 3 dpoll -2 offset 0 > > Where /dev/ptpX is the kvmclock PTP clock. > > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Acked-by: Richard Cochran <richardcochran@gmail.com> ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [patch 4/4] PTP: add kvm PTP driver 2017-01-24 17:09 ` [patch 4/4] PTP: add kvm PTP driver Marcelo Tosatti 2017-01-24 18:11 ` Richard Cochran @ 2017-01-25 12:56 ` Paolo Bonzini 2017-01-25 13:03 ` Marcelo Tosatti 1 sibling, 1 reply; 14+ messages in thread From: Paolo Bonzini @ 2017-01-25 12:56 UTC (permalink / raw) To: Marcelo Tosatti, kvm, linux-kernel Cc: Radim Krcmar, Richard Cochran, Miroslav Lichvar On 24/01/2017 18:09, Marcelo Tosatti wrote: > Add a driver with gettime method returning hosts realtime clock. > This allows Chrony to synchronize host and guest clocks with > high precision (see results below). > > chronyc> sources > MS Name/IP address Stratum Poll Reach LastRx Last sample > =============================================================================== > #* PHC0 0 3 377 4 +162ns[ -683ns] +/- 11ns > > To configure Chronyd to use PHC refclock, add the > following line to its configuration file: > > refclock PHC /dev/ptpX poll 3 dpoll -2 offset 0 > > Where /dev/ptpX is the kvmclock PTP clock. > > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> > > --- > drivers/ptp/Kconfig | 12 ++ > drivers/ptp/Makefile | 1 > drivers/ptp/ptp_kvm.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 215 insertions(+) > > v2: check for kvmclock (Radim) > initialize global variables before device registration (Radim) > v3: use cross timestamps callback (Paolo, Miroslav, Radim) > v4: remove gettime64 callback (Paolo) > v5: drop useless nsec assignment (Radim) > > Index: kvm-ptpdriver/drivers/ptp/Kconfig > =================================================================== > --- kvm-ptpdriver.orig/drivers/ptp/Kconfig 2017-01-24 09:03:47.604586098 -0200 > +++ kvm-ptpdriver/drivers/ptp/Kconfig 2017-01-24 09:05:06.321704124 -0200 > @@ -90,4 +90,16 @@ > To compile this driver as a module, choose M here: the module > will be called ptp_pch. > > +config PTP_1588_CLOCK_KVM > + tristate "KVM virtual PTP clock" > + depends on PTP_1588_CLOCK > + depends on KVM_GUEST > + default y > + help > + This driver adds support for using kvm infrastructure as a PTP > + clock. This clock is only useful if you are using KVM guests. > + > + To compile this driver as a module, choose M here: the module > + will be called ptp_kvm. > + > endmenu > Index: kvm-ptpdriver/drivers/ptp/Makefile > =================================================================== > --- kvm-ptpdriver.orig/drivers/ptp/Makefile 2017-01-24 09:03:47.604586098 -0200 > +++ kvm-ptpdriver/drivers/ptp/Makefile 2017-01-24 09:05:06.322704125 -0200 > @@ -6,3 +6,4 @@ > obj-$(CONFIG_PTP_1588_CLOCK) += ptp.o > obj-$(CONFIG_PTP_1588_CLOCK_IXP46X) += ptp_ixp46x.o > obj-$(CONFIG_PTP_1588_CLOCK_PCH) += ptp_pch.o > +obj-$(CONFIG_PTP_1588_CLOCK_KVM) += ptp_kvm.o > Index: kvm-ptpdriver/drivers/ptp/ptp_kvm.c > =================================================================== > --- /dev/null 1970-01-01 00:00:00.000000000 +0000 > +++ kvm-ptpdriver/drivers/ptp/ptp_kvm.c 2017-01-24 09:05:06.322704125 -0200 > @@ -0,0 +1,202 @@ > +/* > + * Virtual PTP 1588 clock for use with KVM guests > + * > + * Copyright (C) 2017 Red Hat Inc. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + */ > +#include <linux/device.h> > +#include <linux/err.h> > +#include <linux/init.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <uapi/linux/kvm_para.h> > +#include <asm/kvm_para.h> > +#include <asm/pvclock.h> > +#include <asm/kvmclock.h> > +#include <uapi/asm/kvm_para.h> > + > +#include <linux/ptp_clock_kernel.h> > + > +struct kvm_ptp_clock { > + struct ptp_clock *ptp_clock; > + struct ptp_clock_info caps; > +}; > + > +DEFINE_SPINLOCK(kvm_ptp_lock); > + > +static struct pvclock_vsyscall_time_info *hv_clock; > + > +static struct kvm_clock_offset clock_off; > +static phys_addr_t clock_off_gpa; > + > +static int ptp_kvm_get_time_fn(ktime_t *device_time, > + struct system_counterval_t *system_counter, > + void *ctx) > +{ > + unsigned long ret; > + struct timespec64 tspec; > + unsigned version; > + u8 flags; > + int cpu; > + struct pvclock_vcpu_time_info *src; > + > + preempt_disable_notrace(); > + cpu = smp_processor_id(); > + src = &hv_clock[cpu].pvti; > + > + spin_lock(&kvm_ptp_lock); Any reason to take the spinlock in the non-preemptable region? This would be worse for RT kernels than taking it outside. > + do { > + /* > + * We are using a TSC value read in the hosts > + * kvm_hc_clock_pairing handling. > + * So any changes to tsc_to_system_mul > + * and tsc_shift or any other pvclock > + * data invalidate that measurement. > + */ > + version = pvclock_read_begin(src); > + > + ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, > + clock_off_gpa, > + KVM_CLOCK_PAIRING_WALLCLOCK); > + if (ret != 0) { > + pr_err("clock offset hypercall ret %lu\n", ret); Need ratelimiting in case something goes wrong and the host stops using the TSC clocksource? > + spin_unlock(&kvm_ptp_lock); > + preempt_enable_notrace(); > + return -EOPNOTSUPP; > + } > + > + tspec.tv_sec = clock_off.sec; > + tspec.tv_nsec = clock_off.nsec; > + ret = __pvclock_read_cycles(src, clock_off.tsc); > + flags = src->flags; Flags written and not read. Also, I think I disagree with Radim, gettime64 should use the TSC correction. It's the right thing to do for the POSIX clock interface. It's a bit arbitrary for PTP_SYS_OFFSET (though you cannot really argue with better precision), but chrony is now using PTP_SYS_OFFSET_PRECISE (and again you cannot really argue with better precision anyway). I'll test this a bit and then push it to kvm/queue. Please take a look! Paolo ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [patch 4/4] PTP: add kvm PTP driver 2017-01-25 12:56 ` Paolo Bonzini @ 2017-01-25 13:03 ` Marcelo Tosatti 0 siblings, 0 replies; 14+ messages in thread From: Marcelo Tosatti @ 2017-01-25 13:03 UTC (permalink / raw) To: Paolo Bonzini Cc: kvm, linux-kernel, Radim Krcmar, Richard Cochran, Miroslav Lichvar On Wed, Jan 25, 2017 at 01:56:45PM +0100, Paolo Bonzini wrote: > > > On 24/01/2017 18:09, Marcelo Tosatti wrote: > > Add a driver with gettime method returning hosts realtime clock. > > This allows Chrony to synchronize host and guest clocks with > > high precision (see results below). > > > > chronyc> sources > > MS Name/IP address Stratum Poll Reach LastRx Last sample > > =============================================================================== > > #* PHC0 0 3 377 4 +162ns[ -683ns] +/- 11ns > > > > To configure Chronyd to use PHC refclock, add the > > following line to its configuration file: > > > > refclock PHC /dev/ptpX poll 3 dpoll -2 offset 0 > > > > Where /dev/ptpX is the kvmclock PTP clock. > > > > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> > > > > --- > > drivers/ptp/Kconfig | 12 ++ > > drivers/ptp/Makefile | 1 > > drivers/ptp/ptp_kvm.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 215 insertions(+) > > > > v2: check for kvmclock (Radim) > > initialize global variables before device registration (Radim) > > v3: use cross timestamps callback (Paolo, Miroslav, Radim) > > v4: remove gettime64 callback (Paolo) > > v5: drop useless nsec assignment (Radim) > > > > Index: kvm-ptpdriver/drivers/ptp/Kconfig > > =================================================================== > > --- kvm-ptpdriver.orig/drivers/ptp/Kconfig 2017-01-24 09:03:47.604586098 -0200 > > +++ kvm-ptpdriver/drivers/ptp/Kconfig 2017-01-24 09:05:06.321704124 -0200 > > @@ -90,4 +90,16 @@ > > To compile this driver as a module, choose M here: the module > > will be called ptp_pch. > > > > +config PTP_1588_CLOCK_KVM > > + tristate "KVM virtual PTP clock" > > + depends on PTP_1588_CLOCK > > + depends on KVM_GUEST > > + default y > > + help > > + This driver adds support for using kvm infrastructure as a PTP > > + clock. This clock is only useful if you are using KVM guests. > > + > > + To compile this driver as a module, choose M here: the module > > + will be called ptp_kvm. > > + > > endmenu > > Index: kvm-ptpdriver/drivers/ptp/Makefile > > =================================================================== > > --- kvm-ptpdriver.orig/drivers/ptp/Makefile 2017-01-24 09:03:47.604586098 -0200 > > +++ kvm-ptpdriver/drivers/ptp/Makefile 2017-01-24 09:05:06.322704125 -0200 > > @@ -6,3 +6,4 @@ > > obj-$(CONFIG_PTP_1588_CLOCK) += ptp.o > > obj-$(CONFIG_PTP_1588_CLOCK_IXP46X) += ptp_ixp46x.o > > obj-$(CONFIG_PTP_1588_CLOCK_PCH) += ptp_pch.o > > +obj-$(CONFIG_PTP_1588_CLOCK_KVM) += ptp_kvm.o > > Index: kvm-ptpdriver/drivers/ptp/ptp_kvm.c > > =================================================================== > > --- /dev/null 1970-01-01 00:00:00.000000000 +0000 > > +++ kvm-ptpdriver/drivers/ptp/ptp_kvm.c 2017-01-24 09:05:06.322704125 -0200 > > @@ -0,0 +1,202 @@ > > +/* > > + * Virtual PTP 1588 clock for use with KVM guests > > + * > > + * Copyright (C) 2017 Red Hat Inc. > > + * > > + * This program is free software; you can redistribute it and/or modify > > + * it under the terms of the GNU General Public License as published by > > + * the Free Software Foundation; either version 2 of the License, or > > + * (at your option) any later version. > > + * > > + * This program is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > + * GNU General Public License for more details. > > + * > > + */ > > +#include <linux/device.h> > > +#include <linux/err.h> > > +#include <linux/init.h> > > +#include <linux/kernel.h> > > +#include <linux/module.h> > > +#include <uapi/linux/kvm_para.h> > > +#include <asm/kvm_para.h> > > +#include <asm/pvclock.h> > > +#include <asm/kvmclock.h> > > +#include <uapi/asm/kvm_para.h> > > + > > +#include <linux/ptp_clock_kernel.h> > > + > > +struct kvm_ptp_clock { > > + struct ptp_clock *ptp_clock; > > + struct ptp_clock_info caps; > > +}; > > + > > +DEFINE_SPINLOCK(kvm_ptp_lock); > > + > > +static struct pvclock_vsyscall_time_info *hv_clock; > > + > > +static struct kvm_clock_offset clock_off; > > +static phys_addr_t clock_off_gpa; > > + > > +static int ptp_kvm_get_time_fn(ktime_t *device_time, > > + struct system_counterval_t *system_counter, > > + void *ctx) > > +{ > > + unsigned long ret; > > + struct timespec64 tspec; > > + unsigned version; > > + u8 flags; > > + int cpu; > > + struct pvclock_vcpu_time_info *src; > > + > > + preempt_disable_notrace(); > > + cpu = smp_processor_id(); > > + src = &hv_clock[cpu].pvti; > > + > > + spin_lock(&kvm_ptp_lock); > > Any reason to take the spinlock in the non-preemptable region? > This would be worse for RT kernels than taking it outside. Not really, can move it before. > > > + do { > > + /* > > + * We are using a TSC value read in the hosts > > + * kvm_hc_clock_pairing handling. > > + * So any changes to tsc_to_system_mul > > + * and tsc_shift or any other pvclock > > + * data invalidate that measurement. > > + */ > > + version = pvclock_read_begin(src); > > + > > + ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, > > + clock_off_gpa, > > + KVM_CLOCK_PAIRING_WALLCLOCK); > > + if (ret != 0) { > > + pr_err("clock offset hypercall ret %lu\n", ret); > > Need ratelimiting in case something goes wrong and the host stops using > the TSC clocksource? Yes wise. > > + spin_unlock(&kvm_ptp_lock); > > + preempt_enable_notrace(); > > + return -EOPNOTSUPP; > > + } > > + > > + tspec.tv_sec = clock_off.sec; > > + tspec.tv_nsec = clock_off.nsec; > > + ret = __pvclock_read_cycles(src, clock_off.tsc); > > + flags = src->flags; > > Flags written and not read. > > Also, I think I disagree with Radim, gettime64 should use the TSC > correction. It's the right thing to do for the POSIX clock interface. > It's a bit arbitrary for PTP_SYS_OFFSET (though you cannot really argue > with better precision), but chrony is now using PTP_SYS_OFFSET_PRECISE > (and again you cannot really argue with better precision anyway). > > I'll test this a bit and then push it to kvm/queue. Please take a > look! > > Paolo Ok cool thanks Paolo, will review and ping if necessary. ^ permalink raw reply [flat|nested] 14+ messages in thread
end of thread, other threads:[~2017-01-25 13:15 UTC | newest] Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2017-01-24 17:09 [patch 0/4] KVM virtual PTP driver (v5) Marcelo Tosatti 2017-01-24 17:09 ` [patch 1/4] KVM: x86: provide realtime host clock via vsyscall notifiers Marcelo Tosatti 2017-01-25 12:30 ` Paolo Bonzini 2017-01-24 17:09 ` [patch 2/4] KVM: x86: add KVM_HC_CLOCK_OFFSET hypercall Marcelo Tosatti 2017-01-25 12:30 ` Paolo Bonzini 2017-01-25 12:55 ` Marcelo Tosatti 2017-01-25 12:59 ` Paolo Bonzini 2017-01-25 13:06 ` Marcelo Tosatti 2017-01-25 13:15 ` Paolo Bonzini 2017-01-24 17:09 ` [patch 3/4] kvmclock: export kvmclock clocksource pointer Marcelo Tosatti 2017-01-24 17:09 ` [patch 4/4] PTP: add kvm PTP driver Marcelo Tosatti 2017-01-24 18:11 ` Richard Cochran 2017-01-25 12:56 ` Paolo Bonzini 2017-01-25 13:03 ` Marcelo Tosatti
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