From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:57442 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727216AbfFDNXG (ORCPT ); Tue, 4 Jun 2019 09:23:06 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x54DEtl7142808 for ; Tue, 4 Jun 2019 09:23:04 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 2swrv8201u-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 04 Jun 2019 09:23:04 -0400 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 4 Jun 2019 14:23:03 +0100 Date: Tue, 4 Jun 2019 15:22:56 +0200 From: Halil Pasic Subject: Re: [PATCH v3 4/8] s390/airq: use DMA memory for adapter interrupts In-Reply-To: <20190603172740.1023e078.cohuck@redhat.com> References: <20190529122657.166148-1-mimu@linux.ibm.com> <20190529122657.166148-5-mimu@linux.ibm.com> <20190603172740.1023e078.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-Id: <20190604152256.158d688c.pasic@linux.ibm.com> Sender: linux-s390-owner@vger.kernel.org List-ID: To: Cornelia Huck Cc: Michael Mueller , KVM Mailing List , Linux-S390 Mailing List , Sebastian Ott , Heiko Carstens , virtualization@lists.linux-foundation.org, "Michael S . Tsirkin" , Christoph Hellwig , Thomas Huth , Christian Borntraeger , Viktor Mihajlovski , Vasily Gorbik , Janosch Frank , Claudio Imbrenda , Farhan Ali , Eric Farman , Pierre Morel On Mon, 3 Jun 2019 17:27:40 +0200 Cornelia Huck wrote: > On Wed, 29 May 2019 14:26:53 +0200 > Michael Mueller wrote: > > > From: Halil Pasic > > > > Protected virtualization guests have to use shared pages for airq > > notifier bit vectors, because hypervisor needs to write these bits. > > > > Let us make sure we allocate DMA memory for the notifier bit vectors by > > replacing the kmem_cache with a dma_cache and kalloc() with > > cio_dma_zalloc(). > > > > Signed-off-by: Halil Pasic > > Reviewed-by: Sebastian Ott > > Signed-off-by: Michael Mueller > > --- > > arch/s390/include/asm/airq.h | 2 ++ > > drivers/s390/cio/airq.c | 32 ++++++++++++++++++++------------ > > drivers/s390/cio/cio.h | 2 ++ > > drivers/s390/cio/css.c | 1 + > > 4 files changed, 25 insertions(+), 12 deletions(-) > > Apologies if that already has been answered (and I missed it in my mail > pile...), but two things had come to my mind previously: > > - CHSC... does anything need to be done there? Last time I asked: > "Anyway, css_bus_init() uses some chscs > early (before cio_dma_pool_init), so we could not use the pools > there, even if we wanted to. Do chsc commands either work, or else > fail benignly on a protected virt guest?" Protected virt won't support all CHSC. The supported ones won't requre use of shared memory. So we are fine. > - PCI indicators... does this interact with any dma configuration on > the pci device? (I know pci is not supported yet, and I don't really > expect any problems.) > It does but, I'm pretty confident we don't have a problem with PCI. IMHO Sebastian is the guy who needs to be paranoid about this, and he r-b-ed the respective patches. Regards, Halil