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 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0556AC9EC7D for ; Mon, 12 Jan 2026 12:48:11 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.1200193.1516182 (Exim 4.92) (envelope-from ) id 1vfHKt-0001CS-5u; Mon, 12 Jan 2026 12:47:55 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 1200193.1516182; Mon, 12 Jan 2026 12:47:55 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1vfHKt-0001CL-1K; Mon, 12 Jan 2026 12:47:55 +0000 Received: by outflank-mailman (input) for mailman id 1200193; Mon, 12 Jan 2026 12:47:53 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1vfHKr-0001CF-L9 for xen-devel@lists.xenproject.org; Mon, 12 Jan 2026 12:47:53 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.96) (envelope-from ) id 1vfHKr-000480-14; Mon, 12 Jan 2026 12:47:52 +0000 Received: from [2a01:cb15:80df:da00:e2a9:ff82:7bde:38cd] (helo=l14) by xenbits.xenproject.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vfHKq-000Cn4-20; Mon, 12 Jan 2026 12:47:52 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xenproject.org; s=20200302mail; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date; bh=B1ZjuILSJSpX8cg9BDkGUVHLqYxlznCrFFIKjmQsCyo=; b=5DEElnsTDUOBFFmlK1M8+5vEyx xhXETqrZkeL4BZQao6A2TaEcwTBr1TKA0q9X1I2FXC+dWhUol1ExTDPpKiq0wMRngerR9NZydxccW Il58ViFdrMf6Ppr8MoDJPJI7dgCAH1WpeL3/YAu7noB+8Q5RukWOcDHYsm0NtyAUpEX0=; Date: Mon, 12 Jan 2026 13:47:50 +0100 From: Anthony PERARD To: Roger Pau =?iso-8859-1?Q?Monn=E9?= Cc: Teddy Astie , xen-devel@lists.xenproject.org, Andrew Cooper , Anthony PERARD , Michal Orzel , Jan Beulich , Julien Grall , Stefano Stabellini Subject: Re: [RFC PATCH] pvh: Introduce SIF_HVM_GHCB for SEV-ES/SNP guests Message-ID: References: <3b6f5146287d3402a09836b7cf876d4f8dc9eee1.1766889890.git.teddy.astie@vates.tech> <0c9c1dbb-28e1-479b-a680-e99150b3f0da@vates.tech> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Jan 09, 2026 at 12:37:30PM +0100, Roger Pau Monné wrote: > On Fri, Jan 09, 2026 at 10:31:57AM +0000, Teddy Astie wrote: > > It would be easier to not use hvmloader, especially since only UEFI > > supports SEV and guests would still need to support (Xen-specific) SEV > > bits to begin with. > > I would be very happy to relegate hvmloader to be used with SeaBIOS > only, and to load OVMF directly for HVM guests. But I don't know > what's missing for OVMF to be capable of that. I would think not > much, since it's already almost working for PVH guests AFAIK. OvmfXen works in PVH, and you can start guest ;-), the last change was to remove the use of the hypercall page so the shutdown hypercall could be called from UEFI Runtime Service. > Maybe PCI enumeration, but OVMF must have a way of doing that already > for other platforms I expect. Yes, that would probably be the main thing, I believe. It might just be a setting to enable enumeration when OvmfXen is started via the PVH entry point, I haven't really try to boot OVMF in HVM without hvmloader yet, and we would need to change the tool stack to boot an HVM guest via the PVH entry point. But, I already have a prototype of OvmfXen that could boot (modified) Linux in an SEV guest, it's based on SEV work from sometime ago so might not work anymore (and I don't remember if linux could start userspace): https://xenbits.xenproject.org/gitweb/?p=people/aperard/ovmf.git;a=log;h=refs/heads/wip.sev Cheers, -- Anthony PERARD