From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47232) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g9oHs-0005yp-OW for qemu-devel@nongnu.org; Tue, 09 Oct 2018 05:26:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g9oHo-00084n-4h for qemu-devel@nongnu.org; Tue, 09 Oct 2018 05:26:44 -0400 Received: from mail-wm1-x332.google.com ([2a00:1450:4864:20::332]:55952) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1g9oHn-00083Q-Ng for qemu-devel@nongnu.org; Tue, 09 Oct 2018 05:26:40 -0400 Received: by mail-wm1-x332.google.com with SMTP id 206-v6so1092729wmb.5 for ; Tue, 09 Oct 2018 02:26:39 -0700 (PDT) References: <20181005154910.3099-1-alex.bennee@linaro.org> <001201d45f99$4f710930$ee531b90$@ru> <87tvlvmsgg.fsf@linaro.org> <002501d45fab$71487f90$53d97eb0$@ru> From: Alex =?utf-8?Q?Benn=C3=A9e?= In-reply-to: <002501d45fab$71487f90$53d97eb0$@ru> Date: Tue, 09 Oct 2018 10:26:36 +0100 Message-ID: <87sh1fmpwz.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [RFC PATCH 00/21] Trace updates and plugin RFC List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Pavel Dovgalyuk Cc: qemu-devel@nongnu.org, Pavel.Dovgaluk@ispras.ru, vilanova@ac.upc.edu, cota@braap.org Pavel Dovgalyuk writes: >> From: Alex Benn=C3=A9e [mailto:alex.bennee@linaro.org] >> Pavel Dovgalyuk writes: >> >> >> From: Alex Benn=C3=A9e [mailto:alex.bennee@linaro.org] >> >> Any serious analysis tool should allow for us to track all memory >> >> accesses so I think the guest_mem_before trace point should probably >> >> be split into guest_mem_before_store and guest_mem_after_load. We >> >> could go the whole hog and add potential trace points for start/end of >> >> all memory operations. >> > >> > I wanted to ask about memory tracing and found this one. >> > Is it possible to use tracepoints for capturing all memory accesses? >> > In our implementation we insert helpers before and after tcg >> > read/write operations. >> >> The current tracepoint isn't enough but yes I think we could. The first >> thing I need to do is de-macrofy the atomic helpers a little just to >> make it a bit simpler to add the before/after tracepoints. > > But memory accesses can use 'fast path' without the helpers. > Thus you still need inserting the new helper for that case. trace_guest_mem_before_tcg in tcg-op.c already does this but currently only before operations. That's why I want to split it and pass the load/store value register values into the helpers. > > Pavel Dovgalyuk -- Alex Benn=C3=A9e