From: Marcelo Tosatti <mtosatti@redhat.com>
To: kvm-devel <kvm@vger.kernel.org>
Cc: Glauber Costa <glommer@gmail.com>
Subject: KVM: x86: perform kvmclock updates in lockstep
Date: Mon, 6 May 2013 23:49:54 -0300 [thread overview]
Message-ID: <20130507024954.GA17711@amt.cnet> (raw)
It is necessary for each vcpus system_timestamp memory copy to be
updated from one sample of the nanosecond kernel clock.
If this is not the case, and NTP changes frequency adjustment, different
vcpus will make use of different time bases.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 94f35d2..1ef4287 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1965,7 +1965,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
kvmclock_reset(vcpu);
vcpu->arch.time = data;
- kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
+ kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
/* we verify if the enable bit is set... */
if (!(data & 1))
@@ -2665,7 +2665,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
if (unlikely(vcpu->arch.tsc_offset_adjustment)) {
adjust_tsc_offset_host(vcpu, vcpu->arch.tsc_offset_adjustment);
vcpu->arch.tsc_offset_adjustment = 0;
- set_bit(KVM_REQ_CLOCK_UPDATE, &vcpu->requests);
+ set_bit(KVM_REQ_MASTERCLOCK_UPDATE, &vcpu->requests);
}
if (unlikely(vcpu->cpu != cpu) || check_tsc_unstable()) {
@@ -2684,7 +2684,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
* kvmclock on vcpu->cpu migration
*/
if (!vcpu->kvm->arch.use_master_clock || vcpu->cpu == -1)
- kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
+ kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
if (vcpu->cpu != cpu)
kvm_migrate_timers(vcpu);
vcpu->cpu = cpu;
@@ -5092,7 +5092,7 @@ static int kvmclock_cpufreq_notifier(struct notifier_block *nb, unsigned long va
kvm_for_each_vcpu(i, vcpu, kvm) {
if (vcpu->cpu != freq->cpu)
continue;
- kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
+ kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
if (vcpu->cpu != smp_processor_id())
send_ipi = 1;
}
reply other threads:[~2013-05-07 2:50 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20130507024954.GA17711@amt.cnet \
--to=mtosatti@redhat.com \
--cc=glommer@gmail.com \
--cc=kvm@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.