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=-14.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 D020DC43461 for ; Wed, 16 Sep 2020 15:59:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BC57224B2 for ; Wed, 16 Sep 2020 15:59:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600271962; bh=2j8mpLmTdSm4XACnnRoHEu45HVrZc3Vq4b+ln1x7Qy0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=olX1a/vqnp0zFUf59OkrbC+Vp7cSrs5ahLMXmpglcxoR6Tc3DqqPchcyNonmlAfWA RTJYYnYRnGZO+hgsZYz0+f6/cgpjmzbQv3+JwTQUF4FWn6aGx8M907cvPyAoE0S55e pxCOXPED758YOvAl5viwgvReBVCMXv4hLINR39TA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726280AbgIPP6s (ORCPT ); Wed, 16 Sep 2020 11:58:48 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:38782 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726312AbgIPPzb (ORCPT ); Wed, 16 Sep 2020 11:55:31 -0400 Received: by mail-wm1-f66.google.com with SMTP id l9so3575148wme.3; Wed, 16 Sep 2020 08:54:07 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=G2L3TW2WxV4GsWXWBBVjTC9AR//at+StzHS5DH3Oqf0=; b=qrw8Ba/B+s/J7oSklTMNE3a9uHuAanOV8+WQoQXByMQXcUpvMWSrGrT/xxdTaYjCYk FJzn1I/AKIZ1nDIWlnDE2EvdLCCB0yq1L4Y63CZyguE54kTH019MjRzFw/TcgMH9Sdrn vtLNYCNlHSY0+lQgcMY17h/BV9NV0g55WThHVXWhuZn2PuRvuAdQwwLJjzLW5krq3T3M EC66/uv6aHNiN2Zk+JkwBKn94HaIMmzUOHqMnuVnbOAF9raOPfptH8W4YkpH26vtq4XM 3vuwJHaMI1G3uAZ4ISXygX3vwsW02ifU6EGhV399y+0uGWvDmrGDbl62pm5ugeuoxhIo N6vQ== X-Gm-Message-State: AOAM530qcBSLVmvKsRYIUhJN+JbR4RvuiC8JLatg93+/dki4z6YhB21T rLANbY3DFmeoTRbVR9dQI7g0Hk9LWME= X-Google-Smtp-Source: ABdhPJwKDhptBJ/g7u54/YxLQysgEgYHB3c+TuF55KTGGzFdShYpmn2p1D0pmCSDGTuWaA29gAzqPw== X-Received: by 2002:a05:600c:410e:: with SMTP id j14mr5699106wmi.13.1600270923209; Wed, 16 Sep 2020 08:42:03 -0700 (PDT) Received: from liuwe-devbox-debian-v2 ([51.145.34.42]) by smtp.gmail.com with ESMTPSA id t22sm7228468wmt.1.2020.09.16.08.42.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Sep 2020 08:42:02 -0700 (PDT) Date: Wed, 16 Sep 2020 15:42:00 +0000 From: Wei Liu To: Vitaly Kuznetsov Cc: Wei Liu , Linux on Hyper-V List , virtualization@lists.linux-foundation.org, Linux Kernel List , Michael Kelley , Vineeth Pillai , Sunil Muthuswamy , Nuno Das Neves , Lillian Grassin-Drake , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "H. Peter Anvin" Subject: Re: [PATCH RFC v1 06/18] x86/hyperv: allocate output arg pages if required Message-ID: <20200916154200.7nf74vjmqu3f6sfq@liuwe-devbox-debian-v2> References: <20200914112802.80611-1-wei.liu@kernel.org> <20200914112802.80611-7-wei.liu@kernel.org> <871rj3l4yt.fsf@vitty.brq.redhat.com> <20200915124318.z6tisek5y4d7e254@liuwe-devbox-debian-v2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200915124318.z6tisek5y4d7e254@liuwe-devbox-debian-v2> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 15, 2020 at 12:43:18PM +0000, Wei Liu wrote: > On Tue, Sep 15, 2020 at 12:16:58PM +0200, Vitaly Kuznetsov wrote: > > Wei Liu writes: > > > > > When Linux runs as the root partition, it will need to make hypercalls > > > which return data from the hypervisor. > > > > > > Allocate pages for storing results when Linux runs as the root > > > partition. > > > > > > Signed-off-by: Lillian Grassin-Drake > > > Co-Developed-by: Lillian Grassin-Drake > > > Signed-off-by: Wei Liu > > > --- > > > arch/x86/hyperv/hv_init.c | 45 +++++++++++++++++++++++++++++---- > > > arch/x86/include/asm/mshyperv.h | 1 + > > > 2 files changed, 41 insertions(+), 5 deletions(-) > > > > > > diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c > > > index cac8e4c56261..ebba4be4185d 100644 > > > --- a/arch/x86/hyperv/hv_init.c > > > +++ b/arch/x86/hyperv/hv_init.c > > > @@ -45,6 +45,9 @@ EXPORT_SYMBOL_GPL(hv_vp_assist_page); > > > void __percpu **hyperv_pcpu_input_arg; > > > EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg); > > > > > > +void __percpu **hyperv_pcpu_output_arg; > > > +EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg); > > > + > > > u32 hv_max_vp_index; > > > EXPORT_SYMBOL_GPL(hv_max_vp_index); > > > > > > @@ -75,14 +78,29 @@ static int hv_cpu_init(unsigned int cpu) > > > u64 msr_vp_index; > > > struct hv_vp_assist_page **hvp = &hv_vp_assist_page[smp_processor_id()]; > > > void **input_arg; > > > - struct page *pg; > > > + struct page *input_pg; > > > > > > input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg); > > > /* hv_cpu_init() can be called with IRQs disabled from hv_resume() */ > > > - pg = alloc_page(irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL); > > > - if (unlikely(!pg)) > > > + input_pg = alloc_page(irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL); > > > + if (unlikely(!input_pg)) > > > return -ENOMEM; > > > - *input_arg = page_address(pg); > > > + *input_arg = page_address(input_pg); > > > + > > > + if (hv_root_partition) { > > > + struct page *output_pg; > > > + void **output_arg; > > > + > > > + output_pg = alloc_page(irqs_disabled() ? GFP_ATOMIC : > > > GFP_KERNEL); > > > > To simplify the code, can we just rename 'input_arg' to 'hypercall_args' > > and do alloc_pages(rqs_disabled() ? GFP_ATOMIC : GFP_KERNEL, 1) to > > allocate two pages above? > > It should be doable, but I need to code it up and test it to be 100% > sure. > I switch to alloc_pages to allocate an order of 2 page if necessary, but I keep input_arg and output_arg separate because I want to avoid code churn in other places. Wei. > > > > > > [...] > > > + /* Allocate the per-CPU state for output arg for root */ > > > + if (hv_root_partition) { > > > + hyperv_pcpu_output_arg = alloc_percpu(void *); > > redundant space ^^^^^ > > Fixed. Thanks. This is in fact copied from the input_arg code, so there > is a similar issue there to be fixed. But that's going to wait till > another day. > > Wei.