From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:52020 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730937AbfGOUOe (ORCPT ); Mon, 15 Jul 2019 16:14:34 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x6FKBusl100352 for ; Mon, 15 Jul 2019 16:14:33 -0400 Received: from e16.ny.us.ibm.com (e16.ny.us.ibm.com [129.33.205.206]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ts037rkme-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 15 Jul 2019 16:14:33 -0400 Received: from localhost by e16.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 15 Jul 2019 21:14:32 +0100 References: <20190712053631.9814-1-bauerman@linux.ibm.com> <20190712053631.9814-4-bauerman@linux.ibm.com> <20190712150912.3097215e.pasic@linux.ibm.com> <87tvbqgboc.fsf@morokweng.localdomain> <20190715160317.7e3dfb33.pasic@linux.ibm.com> <20190715143039.GA6892@lst.de> From: Thiago Jung Bauermann Subject: Re: [PATCH 3/3] fs/core/vmcore: Move sev_active() reference to x86 arch code In-reply-to: <20190715143039.GA6892@lst.de> Date: Mon, 15 Jul 2019 17:14:04 -0300 MIME-Version: 1.0 Content-Type: text/plain Message-Id: <875zo3njhv.fsf@morokweng.localdomain> Sender: linux-s390-owner@vger.kernel.org List-ID: To: Christoph Hellwig Cc: Halil Pasic , Janosch Frank , x86@kernel.org, iommu@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Marek Szyprowski , Robin Murphy , Konrad Rzeszutek Wilk , Alexey Dobriyan , Mike Anderson , Ram Pai , "Lendacky, Thomas" Christoph Hellwig writes: > On Mon, Jul 15, 2019 at 04:03:17PM +0200, Halil Pasic wrote: >> > I thought about that but couldn't put my finger on a general concept. >> > Is it "guest with memory inaccessible to the host"? >> > >> >> Well, force_dma_unencrypted() is a much better name thatn sev_active(): >> s390 has no AMD SEV, that is sure, but for virtio to work we do need to >> make our dma accessible to the hypervisor. Yes, your "guest with memory >> inaccessible to the host" shows into the right direction IMHO. >> Unfortunately I don't have too many cycles to spend on this right now. > > In x86 it means that we need to remove dma encryption using > set_memory_decrypted before using it for DMA purposes. In the SEV > case that seems to be so that the hypervisor can access it, in the SME > case that Tom just fixes it is because there is an encrypted bit set > in the physical address, and if the device doesn't support a large > enough DMA address the direct mapping code has to encrypt the pages > used for the contigous allocation. > >> Being on cc for your patch made me realize that things got broken on >> s390. Thanks! I've sent out a patch that fixes protvirt, but we are going >> to benefit from your cleanups. I think with your cleanups and that patch >> of mine both sev_active() and sme_active() can be removed. Feel free to >> do so. If not, I can attend to it as well. > > Yes, I think with the dma-mapping fix and this series sme_active and > sev_active should be gone from common code. We should also be able > to remove the exports x86 has for them. > > I'll wait a few days and will then feed the dma-mapping fix to Linus, > it might make sense to either rebase Thiagos series on top of the > dma-mapping for-next branch, or wait a few days before reposting. I'll rebase on top of dma-mapping/for-next and do the break up of patch 2 that you mentioned as well. -- Thiago Jung Bauermann IBM Linux Technology Center