From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58309) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dPBQv-0005YQ-LA for qemu-devel@nongnu.org; Sun, 25 Jun 2017 13:34:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dPBQr-0000VA-60 for qemu-devel@nongnu.org; Sun, 25 Jun 2017 13:34:49 -0400 Received: from mail-wr0-x22b.google.com ([2a00:1450:400c:c0c::22b]:36398) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dPBQq-0000UT-Ub for qemu-devel@nongnu.org; Sun, 25 Jun 2017 13:34:45 -0400 Received: by mail-wr0-x22b.google.com with SMTP id c11so124738026wrc.3 for ; Sun, 25 Jun 2017 10:34:43 -0700 (PDT) References: <8760fqorbp.fsf@frigg.lan> <87mv91tn7d.fsf@linaro.org> <87r2y8gsy1.fsf@frigg.lan> From: Alex =?utf-8?Q?Benn=C3=A9e?= In-reply-to: <87r2y8gsy1.fsf@frigg.lan> Date: Sun, 25 Jun 2017 18:35:30 +0100 Message-ID: <87efu89di5.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] Tracing guest virtual addresses List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?utf-8?Q?Llu=C3=ADs?= Vilanova Cc: Peter Maydell , Jayanto Minocha , QEMU Developers Lluís Vilanova writes: > Alex Bennée writes: > >> Peter Maydell writes: > >>> On 20 June 2017 at 12:02, Lluís Vilanova wrote: >>>> Jayanto Minocha writes: >>>>> But that is only used to instrument the cpu_ld/cpu_st macros, which is only >>>>> called in the case of a tlb miss. >>>> >>>>> I've been going over the archives, and it looks like I need to instrument >>>>> tcg_out_tlb_load. Am I on the right path ? >>>> >>>> That event should trace all guest memory accesses performed by the CPU. If you >>>> found any case where this does not hold, it is likely a bug and I'd appreciate >>>> it if you can point me to the smallest possible failing example. >>> >>> Does it catch memory accesses that are performed via helper functions, >>> or only ones done by inline TCG code? > >> AFAICT it inserts a helper call on the TCG ld/st ops. I wonder why not >> just ensure we always take the slow path and put the helpers in the >> access functions there? You could even apply an address mask if you only >> want to look at certain address ranges. > > It also catches accesses performed by helpers. Don't helper accesses also pass through the SoftMMU? Or are we talking about user-space access as well here? > > > Cheers, > Lluis -- Alex Bennée