From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:41119) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gmcO4-0007pH-Mf for qemu-devel@nongnu.org; Thu, 24 Jan 2019 05:37:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gmcNr-0000Pj-00 for qemu-devel@nongnu.org; Thu, 24 Jan 2019 05:37:19 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54930 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gmcNq-0000Nx-GP for qemu-devel@nongnu.org; Thu, 24 Jan 2019 05:37:18 -0500 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x0OAYYOk024116 for ; Thu, 24 Jan 2019 05:37:17 -0500 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2q79m9xt1r-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 24 Jan 2019 05:37:17 -0500 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 24 Jan 2019 10:37:15 -0000 Date: Thu, 24 Jan 2019 11:37:08 +0100 From: Halil Pasic In-Reply-To: <20190124110637.2e2e3c4c.cohuck@redhat.com> References: <20190121110354.2247-1-cohuck@redhat.com> <20190121110354.2247-6-cohuck@redhat.com> <20190123165148.55aba88b@oc2783563651> <20190124110637.2e2e3c4c.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-Id: <20190124113708.2b024784@oc2783563651> Subject: Re: [Qemu-devel] [PATCH v2 5/5] vfio-ccw: add handling for async channel instructions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Cornelia Huck Cc: Eric Farman , Farhan Ali , Pierre Morel , linux-s390@vger.kernel.org, kvm@vger.kernel.org, qemu-devel@nongnu.org, qemu-s390x@nongnu.org, Alex Williamson On Thu, 24 Jan 2019 11:06:37 +0100 Cornelia Huck wrote: > On Wed, 23 Jan 2019 16:51:48 +0100 > Halil Pasic wrote: > > > On Mon, 21 Jan 2019 12:03:54 +0100 > > Cornelia Huck wrote: > > > > > Add a region to the vfio-ccw device that can be used to submit > > > asynchronous I/O instructions. ssch continues to be handled by the > > > existing I/O region; the new region handles hsch and csch. > > > > > > Interrupt status continues to be reported through the same channels > > > as for ssch. > > > > > > Signed-off-by: Cornelia Huck > > > > I had a look, and I don't have any new concerns.(New like not raised > > before.) > > So, what was raised before that I did not address? > I had the cp->initialized in mind here. My understanding is that this is the point at which safe accessors are necessary. But I consider that addressed. I'm still not a fan of this try_lock() and -EAGAIN in write (and just lock() in read approach), for the reasons I stated before. But it ain't a deal-breaker for me. It is just that I don't get the benefit of the busy looping userspace. Regards, Halil