From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:54028)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <nikunj@linux.vnet.ibm.com>) id 1bk2S7-000693-4F
	for qemu-devel@nongnu.org; Wed, 14 Sep 2016 01:09:44 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <nikunj@linux.vnet.ibm.com>) id 1bk2S2-000568-W4
	for qemu-devel@nongnu.org; Wed, 14 Sep 2016 01:09:42 -0400
Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:44901)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <nikunj@linux.vnet.ibm.com>) id 1bk2S2-00055j-Mq
	for qemu-devel@nongnu.org; Wed, 14 Sep 2016 01:09:38 -0400
Received: from pps.filterd (m0098393.ppops.net [127.0.0.1])
	by mx0a-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id
	u8E58Tv8075916
	for <qemu-devel@nongnu.org>; Wed, 14 Sep 2016 01:09:38 -0400
Received: from e28smtp05.in.ibm.com (e28smtp05.in.ibm.com [125.16.236.5])
	by mx0a-001b2d01.pphosted.com with ESMTP id 25eupkc1ty-1
	(version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT)
	for <qemu-devel@nongnu.org>; Wed, 14 Sep 2016 01:09:37 -0400
Received: from localhost
	by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use
	Only! Violators will be prosecuted
	for <qemu-devel@nongnu.org> from <nikunj@linux.vnet.ibm.com>;
	Wed, 14 Sep 2016 10:39:34 +0530
From: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
In-Reply-To: <1473827823.8689.329.camel@kernel.crashing.org>
References: <1473659314-11813-1-git-send-email-nikunj@linux.vnet.ibm.com>
	<1473659314-11813-3-git-send-email-nikunj@linux.vnet.ibm.com>
	<20160914030941.GE15077@voom.fritz.box>
	<87twdj2l3y.fsf@abhimanyu.i-did-not-set--mail-host-address--so-tickle-me>
	<1473827823.8689.329.camel@kernel.crashing.org>
Date: Wed, 14 Sep 2016 10:39:26 +0530
MIME-Version: 1.0
Content-Type: text/plain
Message-Id: <87oa3r2hkp.fsf@abhimanyu.i-did-not-set--mail-host-address--so-tickle-me>
Subject: Re: [Qemu-devel] [PATCH v3 2/3] target-ppc: add flag in
 chech_tlb_flush()
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>, David Gibson <david@gibson.dropbear.id.au>
Cc: qemu-ppc@nongnu.org, alex.bennee@linaro.org, qemu-devel@nongnu.org, rth@twiddle.net

Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:

> On Wed, 2016-09-14 at 09:23 +0530, Nikunj A Dadhania wrote:
>
> Hr... this is confusing, let me rephrase ;-)
>
>> Due to lazy tlb flushes, propagation of the tlb flush is delayed.
> Moreover, certain operations need to do broadcast flush, this too can
> be
>> delayed until we hit the operation that warrant a broadcast.
>
> Instead:
>
> We flush the qemu TLB lazily. check_tlb_flush is called whenever we
> hit a context synchronizing event or instruction that requires a pending
> flush to be performed.
>
> However, we fail to handle broadcast TLB flush operations. In order
> to fix that efficiently, we want to differenciate whether check_tlb_flush()
> needs to only apply pending local flushes (isync instructions,
> interrupts, ...) or also global pending flush operations. The latter
> is only needed when executing instructions that are defined architecturally
> as synchronizing global TLB flush operations. This in our case is ptesync
> on BookS and tlbsync on BookE along with the paravirtualized hypervisor
> calls.

Nice ;-)

Regards
Nikunj