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From: Jamie Lokier <jamie@shareable.org>
To: Avi Kivity <avi@redhat.com>
Cc: Gerhard Wiesinger <lists@wiesinger.com>,
	qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: Re: [Qemu-devel] Re: QEMU-KVM and video performance
Date: Wed, 21 Apr 2010 19:39:31 +0100	[thread overview]
Message-ID: <20100421183930.GL27575@shareable.org> (raw)
In-Reply-To: <4BCED82C.9020702@redhat.com>

Avi Kivity wrote:
> Writes to vga in 16-color mode don't change set a memory location to a 
> value, instead they change multiple memory locations.

While code is just writing to the VGA memory, not reading(*) and not
touching the VGA I/O register that control the write latches, is it
possible in principle to swizzle the format around in memory to make
regular writes work?

(*) Reading should be ok for some settings of the write latches, I
think.

I wonder if guests of interest behave like that.

> >Is this a case where TCG would run significantly faster for code blocks
> >that have been detected to access the VGA memory?
> 
> Yes.

$ date
Wed Apr 21 19:37:38 2015
$ modprobe ktcg
;-)

-- Jamie

  parent reply	other threads:[~2010-04-21 18:39 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-19 19:14 QEMU-KVM and video performance Gerhard Wiesinger
2010-04-21  8:59 ` Avi Kivity
2010-04-21 10:08   ` [Qemu-devel] " Jamie Lokier
2010-04-21 10:49     ` Avi Kivity
2010-04-21 18:14       ` Gerhard Wiesinger
2010-04-21 20:49         ` [Qemu-devel] " Avi Kivity
2010-04-22  5:37           ` Gerhard Wiesinger
2010-04-22  6:57             ` Avi Kivity
2010-04-21 18:39       ` Jamie Lokier [this message]
2010-04-21 20:51         ` Avi Kivity
2010-04-21 21:19           ` Jamie Lokier
2010-04-22  5:44           ` Gerhard Wiesinger
2010-05-12 10:34             ` Jamie Lokier
2010-04-21 18:09   ` Gerhard Wiesinger
2010-04-21 18:33     ` Jamie Lokier
2010-04-21 18:50       ` Gerhard Wiesinger
2010-04-21 18:53         ` Jamie Lokier
2010-04-21 19:08           ` Gerhard Wiesinger
2010-04-21 21:30             ` Jamie Lokier
2010-04-22  6:12               ` Gerhard Wiesinger
2010-05-12 10:23                 ` Jamie Lokier
2010-04-21 20:56         ` Avi Kivity
2010-04-22  6:04           ` Gerhard Wiesinger
2010-04-22  7:03             ` Avi Kivity
2010-05-09 19:35               ` Gerhard Wiesinger
2010-05-10  7:32                 ` Avi Kivity
2010-05-12  6:14                   ` Gerhard Wiesinger
2010-05-12  6:39                     ` [Qemu-devel] " Avi Kivity
2011-02-18  7:32                       ` [Qemu-devel] Re: QEMU-KVM and video performance - Update Gerhard Wiesinger

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