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=-5.5 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 2D163C4361B for ; Tue, 15 Dec 2020 16:44:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DCC1222571 for ; Tue, 15 Dec 2020 16:44:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729034AbgLOQnj (ORCPT ); Tue, 15 Dec 2020 11:43:39 -0500 Received: from mail-wm1-f67.google.com ([209.85.128.67]:38960 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728878AbgLOQna (ORCPT ); Tue, 15 Dec 2020 11:43:30 -0500 Received: by mail-wm1-f67.google.com with SMTP id 3so19131337wmg.4; Tue, 15 Dec 2020 08:43:13 -0800 (PST) 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:content-transfer-encoding :in-reply-to:user-agent; bh=L1u7EdyvwjxUG6AtNBhGBQuSsNPPWKR8uMS0CeSCWPI=; b=tKHDhk6Na/4Fvu356sigICGFDeEDt69aVB+b0l2DvIbd1N/24nJ32hDpklYIrqZMUN x8xkSBKei+GPVjLDgN2DQmgpnTKdm619L3f81dF+1tPhIos+IeQiNUpTYgeg2pE8zgz3 DlGxigc6NwKPUuXDnaFBprdh2bw/6q4Da7G+OORzklmks3hsgQ5cGheIvsOKNF6cHG5U VESI0mcrTlQMBaWvO8sqljFG1KgT2i281UCCcTqI6h2CZedIaysZbJV4mJcrp735n9Gm GFHGsMZUP7dp7NsWrxi1WJHk4nX9/qi3/9QchG1zx0o4mbdjPeMXREBxCSPVZBbDh6ZO eEow== X-Gm-Message-State: AOAM533LGiC1GtJFihEKoTIyS0zMhM9huDW+4tU1LQDaXXTeblal+2Pq Rv7hxs0GeZgUzOXGp+puIVw= X-Google-Smtp-Source: ABdhPJwgY7ozOUvVEU2mB6HgEBLM+BmFB6W5nXAhhCCRGC8cO7GIumbuf96N4iTTB9cRb1PUX8fSIQ== X-Received: by 2002:a7b:c8da:: with SMTP id f26mr33871783wml.50.1608050567677; Tue, 15 Dec 2020 08:42:47 -0800 (PST) Received: from liuwe-devbox-debian-v2 ([51.145.34.42]) by smtp.gmail.com with ESMTPSA id b13sm31680755wrt.31.2020.12.15.08.42.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Dec 2020 08:42:46 -0800 (PST) Date: Tue, 15 Dec 2020 16:42:45 +0000 From: Wei Liu To: "Enrico Weigelt, metux IT consult" 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 , sameo@linux.intel.com, robert.bradford@intel.com, sebastien.boeuf@intel.com Subject: Re: [PATCH v3 00/17] Introducing Linux root partition support for Microsoft Hypervisor Message-ID: <20201215164245.yrorpipw2476w35e@liuwe-devbox-debian-v2> References: <20201124170744.112180-1-wei.liu@kernel.org> <227127cf-bfea-4a06-fcbc-f6c46102e9e6@metux.net> <20201202232234.5buzu5wysiaro3hc@liuwe-devbox-debian-v2> <87d94c39-e801-fbc6-8f7f-1f1b00fa719d@metux.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87d94c39-e801-fbc6-8f7f-1f1b00fa719d@metux.net> User-Agent: NeoMutt/20180716 Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Tue, Dec 15, 2020 at 04:25:03PM +0100, Enrico Weigelt, metux IT consult wrote: > On 03.12.20 00:22, Wei Liu wrote: > > Hi, > > > I don't follow. Do you mean reusing /dev/kvm but with a different set of > > APIs underneath? I don't think that will work. > > My idea was using the same uapi for both hypervisors, so that we can use > the same userlands for both. > > Are the semantis so different that we can't provide the same API ? We can provide some similar APIs for ease of porting, but can't provide 1:1 mappings. By definition KVM and MSHV are two different things. There is no goal to make one ABI / API compatible with the other. > > > In any case, the first version of /dev/mshv was posted a few days ago > > [0]. While we've chosen to follow closely KVM's model, Microsoft > > Hypervisor has its own APIs. > > I have to admit, I don't know much about hyperv - what are the main > differences (from userland perspective) between hyperv and kvm ? > They have different architecture and hence different ways to deal with things. The difference will inevitably make its way to userland. Without going into all the details, you can have a look how Xen and KVM differ architecturally. That will give you a pretty good idea on the differences. Wei. > > --mtx > > -- > --- > Hinweis: unverschlüsselte E-Mails können leicht abgehört und manipuliert > werden ! Für eine vertrauliche Kommunikation senden Sie bitte ihren > GPG/PGP-Schlüssel zu. > --- > Enrico Weigelt, metux IT consult > Free software and Linux embedded engineering > info@metux.net -- +49-151-27565287