From: Paolo Bonzini <pbonzini@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Luwei Kang <luwei.kang@intel.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
hpa@zytor.com, x86@kernel.org, songliubraving@fb.com,
rkrcmar@redhat.com, zsm@chromium.org,
alexander.shishkin@linux.intel.com, konrad.wilk@oracle.com,
ak@linux.intel.com
Subject: Re: [PATCH 2/3] perf/x86/intel/pt: Inject PMI for KVM guest
Date: Thu, 7 Feb 2019 09:42:03 +0100 [thread overview]
Message-ID: <d78063c8-8f0d-31ec-0626-a4a4ab013d5b@redhat.com> (raw)
In-Reply-To: <20190206163423.GI17564@hirez.programming.kicks-ass.net>
On 06/02/19 17:34, Peter Zijlstra wrote:
>
> How about we extend perf_guest_info_callback with an arch section and
> add:
>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 5aeb4c74fb99..76ce804e72c1 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -5835,6 +5835,9 @@ struct perf_guest_info_callbacks *perf_guest_cbs;
>
> int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
> {
> + if (WARN_ON_ONCE(perf_guest_cbs))
> + return -EBUSY;
> +
> perf_guest_cbs = cbs;
> return 0;
> }
> @@ -5842,6 +5845,9 @@ EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
>
> int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
> {
> + if (WARN_ON_ONCE(perf_guest_cbs != cbs))
> + return -EINVAL;
> +
> perf_guest_cbs = NULL;
> return 0;
> }
Makes total sense.
Paolo
next prev parent reply other threads:[~2019-02-07 8:42 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-19 20:04 [PATCH 0/3] Inject a PMI for KVM Guest when ToPA buffer is filled Luwei Kang
2019-01-19 20:04 ` [PATCH 1/3] perf/x86/intel/pt: Move pt structure to global header Luwei Kang
2019-01-19 20:04 ` [PATCH 2/3] perf/x86/intel/pt: Inject PMI for KVM guest Luwei Kang
2019-01-30 17:02 ` Paolo Bonzini
2019-02-06 16:34 ` Peter Zijlstra
2019-02-07 8:42 ` Paolo Bonzini [this message]
2019-01-19 20:04 ` [PATCH 3/3] KVM: x86: Add support of clear Trace_ToPA_PMI status Luwei Kang
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=d78063c8-8f0d-31ec-0626-a4a4ab013d5b@redhat.com \
--to=pbonzini@redhat.com \
--cc=ak@linux.intel.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=bp@alien8.de \
--cc=hpa@zytor.com \
--cc=konrad.wilk@oracle.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luwei.kang@intel.com \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rkrcmar@redhat.com \
--cc=songliubraving@fb.com \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
--cc=zsm@chromium.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 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).