From owner-freebsd-virtualization@freebsd.org Fri Feb 17 18:34:41 2017 Return-Path: Delivered-To: freebsd-virtualization@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 9B1D0CE3DDD for ; Fri, 17 Feb 2017 18:34:41 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 706791A98 for ; Fri, 17 Feb 2017 18:34:41 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id v1HIYbHL050490 for ; Fri, 17 Feb 2017 18:34:41 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-virtualization@FreeBSD.org Subject: [Bug 211746] [Hyper-V] UEFI VM can't boot from the iso installation disk Date: Fri, 17 Feb 2017 18:34:37 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: marcel@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-virtualization@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Feb 2017 18:34:41 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D211746 --- Comment #17 from Marcel Moolenaar --- I think the complexity of having the kernel at any other physical address is what has us do the staging/copying. It was a quick-n-dirty mechanism that avoided a lot of work and complexity -- which is ok if you don't know it's worth/needed to go through all that hassle. And I guess it looks like we now hit a case that warrants us to start looking at a real solution. As an example (for inspiration): For Itanium I had the kernel link against a fixed virtual address. The load= er built the VA-to-PA mapping based on where EFI allocated blobs of memory. The mapping was loaded/activated prior to booting the kernel and the loader gave the kernel all the information it needed to work with the mapping. This mak= es it possible to allocate memory before the VM system is up and running. Ultimately the mapping needs to be incorporated into the VM system and this= is where different CPU architectures have different challenges and solutions. Note that there are advantages to having the kernel link against a virtual address. In general it makes it easier to load or relocate the kernel anywh= ere and this enables a few capabilities that other OSes already have and then s= ome. There are also downsides. You may need to support a large VA range if you w= ant to support pre-loading CD-ROM images or run entirely form a memory disk tha= t's preloaded. A few GB of address space would be good to have. Anyway: It's probably time that to you restate this bug into an architectur= al (x86-specific for now) problem and have a discussion on the arch@ mailing l= ist. We need a more people involved to bring this to a closure. Good luck --=20 You are receiving this mail because: You are the assignee for the bug.=