From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDC5CC4338F for ; Mon, 2 Aug 2021 11:53:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AAC8461050 for ; Mon, 2 Aug 2021 11:53:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233513AbhHBLxp (ORCPT ); Mon, 2 Aug 2021 07:53:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233341AbhHBLxo (ORCPT ); Mon, 2 Aug 2021 07:53:44 -0400 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8AB45C06175F; Mon, 2 Aug 2021 04:53:35 -0700 (PDT) Received: by theia.8bytes.org (Postfix, from userid 1000) id 835EB379; Mon, 2 Aug 2021 13:53:32 +0200 (CEST) Date: Mon, 2 Aug 2021 13:53:26 +0200 From: Joerg Roedel To: Tianyu Lan Cc: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, jgross@suse.com, sstabellini@kernel.org, will@kernel.org, davem@davemloft.net, kuba@kernel.org, jejb@linux.ibm.com, martin.petersen@oracle.com, arnd@arndb.de, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com, thomas.lendacky@amd.com, brijesh.singh@amd.com, ardb@kernel.org, Tianyu.Lan@microsoft.com, rientjes@google.com, martin.b.radev@gmail.com, akpm@linux-foundation.org, rppt@kernel.org, kirill.shutemov@linux.intel.com, aneesh.kumar@linux.ibm.com, krish.sadhukhan@oracle.com, saravanand@fb.com, xen-devel@lists.xenproject.org, pgonda@google.com, david@redhat.com, keescook@chromium.org, hannes@cmpxchg.org, sfr@canb.auug.org.au, michael.h.kelley@microsoft.com, iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, netdev@vger.kernel.org, vkuznets@redhat.com, anparri@microsoft.com Subject: Re: [PATCH 01/13] x86/HV: Initialize GHCB page in Isolation VM Message-ID: References: <20210728145232.285861-1-ltykernel@gmail.com> <20210728145232.285861-2-ltykernel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210728145232.285861-2-ltykernel@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Wed, Jul 28, 2021 at 10:52:16AM -0400, Tianyu Lan wrote: > +static int hyperv_init_ghcb(void) > +{ > + u64 ghcb_gpa; > + void *ghcb_va; > + void **ghcb_base; > + > + if (!ms_hyperv.ghcb_base) > + return -EINVAL; > + > + rdmsrl(MSR_AMD64_SEV_ES_GHCB, ghcb_gpa); > + ghcb_va = memremap(ghcb_gpa, HV_HYP_PAGE_SIZE, MEMREMAP_WB); This deserves a comment. As I understand it, the GHCB pa is set by Hyper-V or the paravisor, so the page does not need to be allocated by Linux. And it is not mapped unencrypted because the GHCB page is allocated above the VTOM boundary? > @@ -167,6 +190,31 @@ static int hv_cpu_die(unsigned int cpu) > { > struct hv_reenlightenment_control re_ctrl; > unsigned int new_cpu; > + unsigned long flags; > + void **input_arg; > + void *pg; > + void **ghcb_va = NULL; > + > + local_irq_save(flags); > + input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg); > + pg = *input_arg; Pg is never used later on, why is it set?