From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59902) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wjte1-0007g4-Gu for qemu-devel@nongnu.org; Mon, 12 May 2014 13:04:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wjtdw-0006ZF-VS for qemu-devel@nongnu.org; Mon, 12 May 2014 13:04:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36255) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wjtdw-0006Z9-MK for qemu-devel@nongnu.org; Mon, 12 May 2014 13:04:00 -0400 Message-ID: <5370FEF8.5010108@redhat.com> Date: Mon, 12 May 2014 11:03:52 -0600 From: Eric Blake MIME-Version: 1.0 References: <1399630869-920-1-git-send-email-arei.gonglei@huawei.com> <20140509111807.GA22335@work-vm> In-Reply-To: <20140509111807.GA22335@work-vm> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="S67gMutEIDF0u0BTUDPXrWm54X5kjacKV" Subject: Re: [Qemu-devel] [PATCH] cirrus_vga: adding sanity check for vram size List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" , arei.gonglei@huawei.com Cc: weidong.huang@huawei.com, mst@redhat.com, qemu-devel@nongnu.org, kraxel@redhat.com, pbonzini@redhat.com, afaerber@suse.de This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --S67gMutEIDF0u0BTUDPXrWm54X5kjacKV Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 05/09/2014 05:18 AM, Dr. David Alan Gilbert wrote: > * arei.gonglei@huawei.com (arei.gonglei@huawei.com) wrote: >> From: Gonglei >> >> when configure a invalid vram size for cirrus card, such as less >> 2 MB, which will crash qemu. Follow the real hardware, the cirrus >> card has 4 MB video memory. Also for backward compatibility, accept >> 8 MB and 16 MB vram size. >=20 > virt-manager/libvirt seems to default to 9 MByte of Vram for cirrus, > so this would break a lot of setups. I think it was virt-manager that made the mistake, but it is indeed a historical wart that we are now stuck with (unless you argue that taking the user's request and silently rounding up to the next power of 2 will not be a guest-visible change). >=20 > Looking at datasheets on the web seems to say the chips actually went > down to 1 MB or less. >=20 > I think before doing this change, it would be good to understand where > the weird 9MB in libvirt/virt-manager came from, and what the limits of= > the emulator/drivers are. >=20 --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --S67gMutEIDF0u0BTUDPXrWm54X5kjacKV Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJTcP74AAoJEKeha0olJ0NqwH4H/ia3uPd99YABBVXiBnhacBKK SBA5Qr7wFXOjU28NTmvnTGHlZUinexpiwerxHw6b7qHAF5WSy6WBWK5puNgoSCCZ f78Yqzo4ToVoZSSDTGkcEYXXPQNgF/8mgM321BF1zZzHL6+d+BAwiUzI1z9/exQm eLAAK9Gz+Uu8B/TNWWcdhygwt4Jdan6pHJXpBcwWNTLVTWX3vOrvXRsqMiw/QmAd 5ZQedBAoZ7tZ9hNYJ8YvLgsPdhtq2TJ2H5BlpUvET5DL5Ax+3GheLvOCBD/sB+qj Cw3URb/mgNH0K7iFsZIWdQG3OFWydw8yeGadcn89ThkGYYkUJKu/M2T7d7h/JDg= =D/oj -----END PGP SIGNATURE----- --S67gMutEIDF0u0BTUDPXrWm54X5kjacKV--