From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36340) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g0oei-0001w4-IU for qemu-devel@nongnu.org; Fri, 14 Sep 2018 10:01:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g0oef-0004lN-6Z for qemu-devel@nongnu.org; Fri, 14 Sep 2018 10:01:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37298) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1g0oee-0004ju-U5 for qemu-devel@nongnu.org; Fri, 14 Sep 2018 10:01:05 -0400 References: <20180912081747.3228.21861.stgit@pasha-VirtualBox> <20180912081950.3228.68987.stgit@pasha-VirtualBox> <002101d44bee$9edf9720$dc9ec560$@ru> From: John Snow Message-ID: Date: Fri, 14 Sep 2018 10:00:53 -0400 MIME-Version: 1.0 In-Reply-To: <002101d44bee$9edf9720$dc9ec560$@ru> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v6 21/25] replay: replay BH for IDE trim operation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Pavel Dovgalyuk , 'Pavel Dovgalyuk' , qemu-devel@nongnu.org Cc: kwolf@redhat.com, peter.maydell@linaro.org, war2jordan@live.com, pbonzini@redhat.com, quintela@redhat.com, ciro.santilli@gmail.com, jasowang@redhat.com, crosthwaite.peter@gmail.com, zuban32s@gmail.com, armbru@redhat.com, maria.klimushenkova@ispras.ru, mst@redhat.com, kraxel@redhat.com, boost.lists@gmail.com, thomas.dullien@googlemail.com, mreitz@redhat.com, alex.bennee@linaro.org, dgilbert@redhat.com, rth@twiddle.net On 09/14/2018 01:48 AM, Pavel Dovgalyuk wrote: >> From: John Snow [mailto:jsnow@redhat.com] >> On 09/12/2018 04:19 AM, Pavel Dovgalyuk wrote: >>> This patch makes IDE trim BH deterministic, because it affects >>> the device state. Therefore its invocation should be replayed >>> instead of running at the random moment. >>> >>> Signed-off-by: Pavel Dovgalyuk >>> Reviewed-by: Paolo Bonzini >>> --- >>> hw/ide/core.c | 3 ++- >>> 1 file changed, 2 insertions(+), 1 deletion(-) >>> >>> diff --git a/hw/ide/core.c b/hw/ide/core.c >>> index 2c62efc..04e22e7 100644 >>> --- a/hw/ide/core.c >>> +++ b/hw/ide/core.c >>> @@ -35,6 +35,7 @@ >>> #include "sysemu/block-backend.h" >>> #include "qapi/error.h" >>> #include "qemu/cutils.h" >>> +#include "sysemu/replay.h" >>> >>> #include "hw/ide/internal.h" >>> #include "trace.h" >>> @@ -479,7 +480,7 @@ static void ide_issue_trim_cb(void *opaque, int ret) >>> done: >>> iocb->aiocb = NULL; >>> if (iocb->bh) { >>> - qemu_bh_schedule(iocb->bh); >>> + replay_bh_schedule_event(iocb->bh); >>> } >>> } >>> >> Just passing by: Why do we need to change this call, but nothing else in >> IDE? > > This call is responsible for a bug that was reproducible. > >> I don't mind conceptually, but it's odd to me that of all the calls I >> make in this emulator that change state somewhere that this is the only >> one you need to hijack for the replay feature. >> >> Is this a necessarily complete change? > > Maybe not. We can hardly analyze all peripheral devices code and fix all the calls. > But I think we can improve that patch and at least look through ide core to fix other calls. > > Pavel Dovgalyuk > It just seems odd that if you're working on a replay mechanism that requires you to intercept my QEMU API calls that you're only changing a trim callback. I'd kind of expect that you don't need to intercept any, unless these are legacy calls that I shouldn't be making at all and you have a more generic intercept somewhere deeper in the codebase. In that case, I really ought to hustle off of my use of legacy calls. What are the criteria for things you need to intercept/wrap?