From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46503) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQsW1-000546-34 for qemu-devel@nongnu.org; Thu, 07 Jun 2018 06:51:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fQsVz-0003To-KZ for qemu-devel@nongnu.org; Thu, 07 Jun 2018 06:51:36 -0400 Message-ID: From: Andrea Bolognani Date: Thu, 07 Jun 2018 12:51:21 +0200 In-Reply-To: <20180607103218.GC1455@redhat.com> References: <20180606111406.GD2660@work-vm> <9e8b49fb-0162-bf35-21bb-acc0dc28555f@redhat.com> <20180606120050.GB2661@work-vm> <61a301dd-8e50-8799-8328-341d6ab744f5@redhat.com> <20180606143134.GG2660@work-vm> <39bcee27-329a-61d8-47fa-678b431b0a79@redhat.com> <20180606150507.GJ2660@work-vm> <66727986-1cf1-c12e-d78c-d56cc15eaf00@redhat.com> <20180606163246.GL3064@redhat.com> <20180607103218.GC1455@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] storing machine data in qcow images? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Richard W.M. Jones" Cc: "Daniel P. =?ISO-8859-1?Q?Berrang=E9?=" , Eric Blake , Kevin Wolf , qemu-block@nongnu.org, "Michael S. Tsirkin" , qemu-devel@nongnu.org, armbru@redhat.com, "Dr. David Alan Gilbert" , stefanha@redhat.com, Max Reitz On Thu, 2018-06-07 at 11:32 +0100, Richard W.M. Jones wrote: > On Thu, Jun 07, 2018 at 12:02:29PM +0200, Andrea Bolognani wrote: > > Something that I haven't seen mentioned in the thread - and this > > looks like as good a point as any to jump in - is that for q35 > > guests using EFI as well as aarch64 guests the "one click import" > > experience requires not only hints about the machine (and firmware!) > > type, but also a copy of the EFI variable store: > >=20 > > $ virt-builder fedora-27 --arch aarch64 --notes > > Fedora=C2=AE 27 Server (aarch64) > >=20 > > [...] > >=20 > > You will need to use the associated UEFI NVRAM variables file: > > http://libguestfs.org/download/builder/fedora-27-aarch64-nvram.xz >=20 > This is true, although only sometimes. If the bootloader[*] has a > working fallback path then usually it is able to boot and reset the > UEFI varstore back to the correct values. We have had bugs before > where the fallback path was not working, eg: >=20 > https://bugzilla.redhat.com/show_bug.cgi?id=3D1353689 (yours!) > https://bugzilla.redhat.com/show_bug.cgi?id=3D1558793 [...] > [*] I'm not sure exactly which bit of the bootloader does this, > whether it's UEFI itself, or the grub-efi in the guest. IIUC the UEFI spec itself reserves certain file names in the ESP for this fallback mechanism; it's then up to the guest operating system to actually install something appropriate there. In Fedora and RHEL, shim is what takes care of it (except when it doesn't ;), but in Debian and Ubuntu AFAIK shim is not included and the fallback path doesn't work at all, which makes providing the NVRAM file a hard requirement to boot such guests. --=20 Andrea Bolognani / Red Hat / Virtualization