From: Tim Olson <tim@io.com>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] qemu-system-* using mmap?
Date: Wed, 13 Dec 2006 08:40:29 -0600 [thread overview]
Message-ID: <9cfca86c3aa677137448f7a0a85e3ccb@io.com> (raw)
In-Reply-To: <56d259a00612130526u214987e6kfbe926d8bba018f0@mail.gmail.com>
I am using qemu 0.8.2 built from source. In the qemu technical
documentation for features under full system emulation, it says:
"QEMU can either use a full software MMU for maximum portability or use
the host system call mmap() to simulate the target MMU."
However, I cannot find a way to build a full system simulator which
does not define SOFTMMU -- in fact, the configure parameters
"--disable-system" and "--enable-system" directly control the softmmu
switch. There are some mmap() calls in the kqemu code, but to use that
requires full kqemu support code in the kernel.
I think there is a big performance hit using the software mmu, as each
target load or store instruction is expanded into 20-30 host
instructions to perform the translation. Is there a way to build the
qemu-system-* emulators using the mmap() feature mentioned in the
documentation?
-- Tim Olson
next prev parent reply other threads:[~2006-12-13 14:40 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-13 8:09 [Qemu-devel] About performance of qemu-system-arm PianoPan
2006-12-13 10:32 ` [Qemu-devel] " Ross Burton
2006-12-13 11:22 ` [Qemu-devel] " Màrius Montón
2006-12-13 14:17 ` PianoPan
2006-12-13 15:23 ` Màrius Montón
2006-12-13 13:26 ` Martin Guy
2006-12-13 14:40 ` Tim Olson [this message]
2006-12-13 15:32 ` [Qemu-devel] qemu-system-* using mmap? Paul Brook
2006-12-13 16:04 ` Joseph Miller
2006-12-14 14:50 ` Tim Olson
2006-12-14 17:01 ` [Qemu-devel] " Joseph Miller
2006-12-14 16:45 ` Paul Brook
2006-12-15 16:21 ` [Qemu-devel] Qemu speed vs vmplayer? Joseph Miller
2006-12-15 16:13 ` Paul Brook
2006-12-15 22:20 ` Joseph Miller
2006-12-15 21:33 ` Lonnie Mendez
2006-12-15 21:38 ` Paul Brook
2006-12-15 21:48 ` Christian MICHON
2006-12-15 21:57 ` Lonnie Mendez
2006-12-15 22:18 ` Paul Brook
2006-12-15 22:34 ` Christian MICHON
2006-12-15 22:47 ` Paul Brook
[not found] ` <Pine.LNX.4.64.0612160028590.758@home.oyster.ru>
[not found] ` <25199.71.51.225.120.1166272989.squirrel@secure.emarketingnc.com>
[not found] ` <Pine.LNX.4.64.0612161732560.630@home.oyster.ru>
2006-12-17 4:37 ` it
2006-12-17 5:18 ` Lonnie Mendez
2006-12-19 16:00 ` [Qemu-devel] Qemu speed w/ USB tablet emulation Joseph Miller
2006-12-16 5:27 ` [Qemu-devel] Qemu speed vs vmplayer? Jamie Lokier
2006-12-15 16:32 ` [Qemu-devel] using mmap? Mark Williamson
2006-12-15 21:22 ` [Qemu-devel] " Anthony Liguori
2006-12-13 15:10 ` [Qemu-devel] About performance of qemu-system-arm Martin Guy
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