From: Pavel Tatashin <pasha.tatashin@oracle.com>
To: boris.ostrovsky@oracle.com
Cc: Steven Sistare <steven.sistare@oracle.com>,
Daniel Jordan <daniel.m.jordan@oracle.com>,
linux@armlinux.org.uk, schwidefsky@de.ibm.com,
Heiko Carstens <heiko.carstens@de.ibm.com>,
John Stultz <john.stultz@linaro.org>,
sboyd@codeaurora.org, x86@kernel.org,
LKML <linux-kernel@vger.kernel.org>,
mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com,
douly.fnst@cn.fujitsu.com, peterz@infradead.org,
prarit@redhat.com, feng.tang@intel.com,
Petr Mladek <pmladek@suse.com>,
gnomes@lxorguk.ukuu.org.uk, linux-s390@vger.kernel.org,
jgross@suse.com
Subject: Re: [PATCH v13 06/18] x86/xen/time: initialize pv xen time in init_hypervisor_platform
Date: Tue, 17 Jul 2018 21:38:02 -0400 [thread overview]
Message-ID: <CAGM2reZTfuMhKZLApidBcenbeJTYt6n_56htaK5YkDPseb_Bqw@mail.gmail.com> (raw)
In-Reply-To: <cf7ef6d0-8650-3e8a-0e15-5150b58d1b50@oracle.com>
> > + set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_start_info->shared_info);
> > + HYPERVISOR_shared_info = (void *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
> > +
> > + /* xen clock uses per-cpu vcpu_info, need to init it for boot cpu */
> > + xen_vcpu_info_reset(0);
>
>
> I don't believe this is necessary, it has been done in
> xen_start_kernel() for PV guests.
We need it, because HYPERVISOR_shared_info has changed from dummy.
And, to output timestamps we must have access to the actual shared
page.
> > +
> > + /* pvclock is in shared info area */
> > + xen_init_time_ops();
> > +}
> > +
>
>
>
> > }
> >
> > -void __ref xen_init_time_ops(void)
> > +void __init xen_init_time_ops(void)
> > {
> > pv_time_ops = xen_time_ops;
> >
> > @@ -542,17 +542,11 @@ void __init xen_hvm_init_time_ops(void)
> > return;
> >
> > if (!xen_feature(XENFEAT_hvm_safe_pvclock)) {
> > - printk(KERN_INFO "Xen doesn't support pvclock on HVM,"
> > - "disable pv timer\n");
> > + pr_info("Xen doesn't support pvclock on HVM, disable pv timer");
> > return;
> > }
> > -
> > - pv_time_ops = xen_time_ops;
> > + xen_init_time_ops();
>
>
> As we discussed elsewhere, now that HVM guests call this routine as well
> we need to make sure that x86_init.timers.timer_init is not updated
> there for HVM since those guests expect a "real" timer to be connected
> to IO-APIC.
Yes, I decided to keep xen_init_time_ops() and xen_hvm_init_time_ops()
separate. The unification does not save that many LOC, but increase
the complexity.
Thank you,
Pavel
next prev parent reply other threads:[~2018-07-18 1:38 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-12 0:04 [PATCH v13 00/18] Early boot time stamps Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 01/18] x86: text_poke() may access uninitialized struct pages Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 02/18] x86: initialize static branching early Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 03/18] x86/CPU: Call detect_nopl() only on the BSP Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 04/18] x86/tsc: redefine notsc to behave as tsc=unstable Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 05/18] kvm/x86: remove kvm memblock dependency Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 06/18] x86/xen/time: initialize pv xen time in init_hypervisor_platform Pavel Tatashin
2018-07-13 1:57 ` Pavel Tatashin
2018-07-17 15:28 ` Boris Ostrovsky
2018-07-18 1:38 ` Pavel Tatashin [this message]
2018-07-12 0:04 ` [PATCH v13 07/18] x86/xen/time: output xen sched_clock time from 0 Pavel Tatashin
2018-07-17 15:43 ` Boris Ostrovsky
2018-07-18 1:59 ` Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 08/18] s390/time: add read_persistent_wall_and_boot_offset() Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 09/18] time: replace read_boot_clock64() with read_persistent_wall_and_boot_offset() Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 10/18] time: default boot time offset to local_clock() Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 11/18] s390/time: remove read_boot_clock64() Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 12/18] ARM/time: " Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 13/18] x86/tsc: calibrate tsc only once Pavel Tatashin
2018-07-13 7:22 ` Dou Liyang
2018-07-13 11:30 ` Pavel Tatashin
2018-07-16 9:32 ` Dou Liyang
2018-07-16 13:35 ` Pavel Tatashin
2018-07-17 8:59 ` Dou Liyang
2018-07-17 14:36 ` Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 14/18] x86/tsc: initialize cyc2ns when tsc freq. is determined Pavel Tatashin
2018-07-13 9:11 ` Dou Liyang
2018-07-13 11:39 ` Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 15/18] x86/tsc: use tsc early Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 16/18] sched: move sched clock initialization and merge with generic clock Pavel Tatashin
2018-07-12 23:50 ` kbuild test robot
2018-07-12 0:04 ` [PATCH v13 17/18] sched: early boot clock Pavel Tatashin
2018-07-12 0:04 ` [PATCH v13 18/18] sched: use static key for sched_clock_running Pavel Tatashin
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