From: Peng Hao <peng.hao2@zte.com.cn>
To: pbonzini@redhat.com, rkrcmar@redhat.com, tglx@linutronix.de,
x86@kernel.org, peterz@infradead.org, mingo@redhat.com
Cc: linux-kernel@vger.kernel.org, zhong.weidong@zte.com.cn,
Peng Hao <peng.hao2@zte.com.cn>
Subject: [PATCH v2] kvmclock: fix nested guest always in tsc_early clocksource
Date: Sat, 14 Jul 2018 23:28:29 +0800 [thread overview]
Message-ID: <1531582109-73498-1-git-send-email-peng.hao2@zte.com.cn> (raw)
In nested guest tsc_read_refs always return ULLONG_MAX, and that will
call tsc_refine_calibration_work periodly. So nested guest will read
acpi timer port 0x608 periodly.
The patch set X86_FEATURE_TSC_KNOWN_FREQ for kvmclock to avoid
'refine' operation.
Thanks for PeterZijlstra's advice.
Signed-off-by: Peng Hao <peng.hao2@zte.com.cn>
---
arch/x86/kernel/kvmclock.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 8b26c9e..fc1562e 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -138,6 +138,7 @@ static unsigned long kvm_get_tsc_khz(void)
src = &hv_clock[cpu].pvti;
tsc_khz = pvclock_tsc_khz(src);
put_cpu();
+ setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
return tsc_khz;
}
--
1.8.3.1
reply other threads:[~2018-07-14 7:27 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=1531582109-73498-1-git-send-email-peng.hao2@zte.com.cn \
--to=peng.hao2@zte.com.cn \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=rkrcmar@redhat.com \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
--cc=zhong.weidong@zte.com.cn \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).