From: Gerd Hoffmann <kraxel@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: seabios@seabios.org, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH v2 02/22] virtio: run drivers in 32bit mode
Date: Wed, 01 Jul 2015 14:30:29 +0200 [thread overview]
Message-ID: <1435753829.4160.41.camel@redhat.com> (raw)
In-Reply-To: <20150701100623-mutt-send-email-mst@redhat.com>
On Mi, 2015-07-01 at 10:08 +0200, Michael S. Tsirkin wrote:
> On Tue, Jun 30, 2015 at 10:38:53AM +0200, Gerd Hoffmann wrote:
> > virtio version 1.0 registers can (and actually do in the qemu
> > implementation) live in mmio space. So we must run the blk and
> > scsi virtio drivers in 32bit mode, otherwise we can't access them.
> >
> > This also allows to drop a bunch of GET_LOWFLAT calls from the virtio
> > code in the following patches.
> >
> > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
>
> Is there an advantage to running them in a 16 bit mode?
Not really any more. Switching from 32bit mode back to
whatever-was-active-before used to be problematic before we had smm mode
support. In theory. Because you can't save/restore the complete x86
processor state. In practice we had surprisingly few problems,
appearently linux boot loaders simply don't play dirty tricks.
cheers,
Gerd
next prev parent reply other threads:[~2015-07-01 12:30 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-30 8:38 [Qemu-devel] [PATCH v2 00/22] virtio: add version 1.0 support Gerd Hoffmann
2015-06-30 8:38 ` [Qemu-devel] [PATCH v2 01/22] pci: allow to loop over capabilities Gerd Hoffmann
2015-06-30 8:38 ` [Qemu-devel] [PATCH v2 02/22] virtio: run drivers in 32bit mode Gerd Hoffmann
2015-06-30 14:36 ` [Qemu-devel] [SeaBIOS] " Kevin O'Connor
2015-07-01 7:27 ` Gerd Hoffmann
2015-07-01 8:08 ` [Qemu-devel] " Michael S. Tsirkin
2015-07-01 12:30 ` Gerd Hoffmann [this message]
2015-07-01 13:50 ` Michael S. Tsirkin
2015-07-01 13:59 ` Michael S. Tsirkin
2015-07-01 14:03 ` Gerd Hoffmann
2015-07-01 14:13 ` [Qemu-devel] [SeaBIOS] " Kevin O'Connor
2015-06-30 8:38 ` [Qemu-devel] [PATCH v2 03/22] virtio: add struct vp_device Gerd Hoffmann
2015-06-30 14:33 ` [Qemu-devel] [SeaBIOS] " Kevin O'Connor
2015-07-01 7:34 ` Gerd Hoffmann
2015-06-30 8:38 ` [Qemu-devel] [PATCH v2 04/22] virtio: pass struct pci_device to vp_init_simple Gerd Hoffmann
2015-06-30 8:38 ` [Qemu-devel] [PATCH v2 05/22] virtio: add version 1.0 structs and #defines Gerd Hoffmann
2015-06-30 8:38 ` [Qemu-devel] [PATCH v2 06/22] virtio: add version 0.9.5 struct Gerd Hoffmann
2015-06-30 8:38 ` [Qemu-devel] [PATCH v2 07/22] virtio: find version 1.0 virtio capabilities Gerd Hoffmann
2015-07-01 11:43 ` Michael S. Tsirkin
2015-07-01 12:24 ` Gerd Hoffmann
2015-07-01 12:28 ` Michael S. Tsirkin
2015-07-01 12:49 ` Gerd Hoffmann
2015-07-01 13:49 ` Michael S. Tsirkin
2015-06-30 8:38 ` [Qemu-devel] [PATCH v2 08/22] virtio: create vp_cap struct for legacy bar Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 09/22] virtio: add version 0.9.5 struct [fixup] Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 10/22] virtio: add read/write functions and macros Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 11/22] virtio: make features 64bit, support version 1.0 features Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 12/22] virtio: add version 1.0 support to vp_{get, set}_status Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 13/22] virtio: add version 1.0 support to vp_get_isr Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 14/22] virtio: add version 1.0 support to vp_reset Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 15/22] virtio: add version 1.0 support to vp_notify Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 16/22] virtio: remove unused vp_del_vq Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 17/22] virtio: add version 1.0 support to vp_find_vq Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 18/22] virtio-scsi: fix initialization for version 1.0 Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 19/22] virtio-blk: " Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 20/22] virtio: use version 1.0 if available (flip the big switch) Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 21/22] virtio: also probe version 1.0 pci ids Gerd Hoffmann
2015-06-30 8:39 ` [Qemu-devel] [PATCH v2 22/22] virtio: legacy cleanup Gerd Hoffmann
2015-07-01 11:48 ` [Qemu-devel] [PATCH v2 00/22] virtio: add version 1.0 support Michael S. Tsirkin
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