From: Stefan Hajnoczi <stefanha@redhat.com>
To: "Lluís Vilanova" <vilanova@ac.upc.edu>
Cc: qemu-devel@nongnu.org, Daniel P Berrange <berrange@redhat.com>,
Luiz Capitulino <lcapitulino@redhat.com>,
Eric Blake <eblake@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v4 0/6] hypertrace: Lightweight guest-to-QEMU trace channel
Date: Mon, 9 Jan 2017 16:28:47 +0000 [thread overview]
Message-ID: <20170109162847.GI30228@stefanha-x1.localdomain> (raw)
In-Reply-To: <148278447806.8988.12706825771606357198.stgit@fimbulvetr.bsc.es>
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On Mon, Dec 26, 2016 at 09:34:38PM +0100, Lluís Vilanova wrote:
> The hypertrace channel allows guest code to emit events in QEMU (the host) using
> its tracing infrastructure (see "docs/trace.txt"). This works in both 'system'
> and 'user' modes, is architecture-agnostic and introduces minimal noise on the
> guest.
>
> See first commit for a full description, use-cases and an example.
As mentioned previously, the -system mode "1 vmexit per trace event"
approach is too heavyweight for for performance analysis or high
frequency tracing. It might be useful for things like system bringup or
TCG development though.
The -user approach is more promising because overheads are lower when
guest code really just jumps into QEMU code.
I have left comments on the patches.
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prev parent reply other threads:[~2017-01-09 16:37 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-26 20:34 [Qemu-devel] [PATCH v4 0/6] hypertrace: Lightweight guest-to-QEMU trace channel Lluís Vilanova
2016-12-26 20:34 ` [Qemu-devel] [PATCH v4 1/6] hypertrace: Add documentation Lluís Vilanova
2016-12-26 20:34 ` [Qemu-devel] [PATCH v4 2/6] hypertrace: Add tracing event "guest_hypertrace" Lluís Vilanova
2016-12-26 20:34 ` [Qemu-devel] [PATCH v4 3/6] hypertrace: [*-user] Add QEMU-side proxy to "guest_hypertrace" event Lluís Vilanova
2017-01-09 15:44 ` Stefan Hajnoczi
2017-01-16 17:05 ` Lluís Vilanova
2017-01-17 9:46 ` Stefan Hajnoczi
2017-01-17 23:35 ` Lluís Vilanova
2017-01-16 17:10 ` Lluís Vilanova
2017-01-09 16:35 ` Stefan Hajnoczi
2017-01-09 18:20 ` Lluís Vilanova
2017-01-10 14:47 ` Stefan Hajnoczi
2016-12-26 20:34 ` [Qemu-devel] [PATCH v4 4/6] hypertrace: [softmmu] " Lluís Vilanova
2017-01-09 16:12 ` Stefan Hajnoczi
2016-12-26 20:35 ` [Qemu-devel] [PATCH v4 5/6] hypertrace: Add guest-side user-level library Lluís Vilanova
2016-12-26 20:35 ` [Qemu-devel] [PATCH v4 6/6] hypertrace: Add guest-side Linux module Lluís Vilanova
2017-01-09 16:17 ` Stefan Hajnoczi
2017-01-15 2:10 ` Lluís Vilanova
2017-01-16 10:37 ` Stefan Hajnoczi
2016-12-26 20:47 ` [Qemu-devel] [PATCH v4 0/6] hypertrace: Lightweight guest-to-QEMU trace channel no-reply
2017-01-09 16:28 ` Stefan Hajnoczi [this message]
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