From: Avi Kivity <avi@redhat.com>
To: Gerhard Wiesinger <lists@wiesinger.com>
Cc: Jamie Lokier <jamie@shareable.org>,
qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: Re: [Qemu-devel] Re: QEMU-KVM and video performance
Date: Wed, 21 Apr 2010 23:49:45 +0300 [thread overview]
Message-ID: <4BCF64E9.4090909@redhat.com> (raw)
In-Reply-To: <alpine.LFD.2.00.1004212010270.14758@bbs.intern>
On 04/21/2010 09:14 PM, Gerhard Wiesinger wrote:
>
> Can you explain which code files/functions of KVM is involved in
> handling VGA memory window and page switching through the port write
> to the VGA window register (or is that part handled through QEMU), so
> a little bit architecture explaination would be nice?
qemu hw/vga.c and hw/cirrus_vga.c. Boring functions like
vbe_ioport_write_data() and vga_ioport_write().
>
> BTW: In which KVM code parts is decided where "direct code" or an
> "emulated device code" is used?
>
Same place. Look for calls to cpu_register_physical_memory(). If the
last argument was obtained by a call to cpu_register_io_memory(), then
all writes trap. Otherwise, it was obtained by qemu_ram_alloc() and
writes will not trap (except the first write to a page in a 30ms window,
used to note that the page is dirty and needs redrawing).
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
WARNING: multiple messages have this Message-ID (diff)
From: Avi Kivity <avi@redhat.com>
To: Gerhard Wiesinger <lists@wiesinger.com>
Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: Re: [Qemu-devel] Re: QEMU-KVM and video performance
Date: Wed, 21 Apr 2010 23:49:45 +0300 [thread overview]
Message-ID: <4BCF64E9.4090909@redhat.com> (raw)
In-Reply-To: <alpine.LFD.2.00.1004212010270.14758@bbs.intern>
On 04/21/2010 09:14 PM, Gerhard Wiesinger wrote:
>
> Can you explain which code files/functions of KVM is involved in
> handling VGA memory window and page switching through the port write
> to the VGA window register (or is that part handled through QEMU), so
> a little bit architecture explaination would be nice?
qemu hw/vga.c and hw/cirrus_vga.c. Boring functions like
vbe_ioport_write_data() and vga_ioport_write().
>
> BTW: In which KVM code parts is decided where "direct code" or an
> "emulated device code" is used?
>
Same place. Look for calls to cpu_register_physical_memory(). If the
last argument was obtained by a call to cpu_register_io_memory(), then
all writes trap. Otherwise, it was obtained by qemu_ram_alloc() and
writes will not trap (except the first write to a page in a 30ms window,
used to note that the page is dirty and needs redrawing).
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next prev parent reply other threads:[~2010-04-21 20:49 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-19 19:14 QEMU-KVM and video performance Gerhard Wiesinger
2010-04-19 19:14 ` [Qemu-devel] " Gerhard Wiesinger
2010-04-21 8:59 ` Avi Kivity
2010-04-21 8:59 ` [Qemu-devel] " Avi Kivity
2010-04-21 10:08 ` Jamie Lokier
2010-04-21 10:49 ` Avi Kivity
2010-04-21 18:14 ` Gerhard Wiesinger
2010-04-21 18:14 ` [Qemu-devel] " Gerhard Wiesinger
2010-04-21 20:49 ` Avi Kivity [this message]
2010-04-21 20:49 ` Avi Kivity
2010-04-22 5:37 ` Gerhard Wiesinger
2010-04-22 5:37 ` Gerhard Wiesinger
2010-04-22 6:57 ` Avi Kivity
2010-04-22 6:57 ` Avi Kivity
2010-04-21 18:39 ` Jamie Lokier
2010-04-21 20:51 ` Avi Kivity
2010-04-21 21:19 ` Jamie Lokier
2010-04-22 5:44 ` Gerhard Wiesinger
2010-04-22 5:44 ` Gerhard Wiesinger
2010-05-12 10:34 ` Jamie Lokier
2010-05-12 10:34 ` Jamie Lokier
2010-04-21 18:09 ` Gerhard Wiesinger
2010-04-21 18:33 ` Jamie Lokier
2010-04-21 18:33 ` Jamie Lokier
2010-04-21 18:50 ` Gerhard Wiesinger
2010-04-21 18:50 ` Gerhard Wiesinger
2010-04-21 18:53 ` Jamie Lokier
2010-04-21 18:53 ` Jamie Lokier
2010-04-21 19:08 ` Gerhard Wiesinger
2010-04-21 19:08 ` Gerhard Wiesinger
2010-04-21 21:30 ` Jamie Lokier
2010-04-21 21:30 ` Jamie Lokier
2010-04-22 6:12 ` Gerhard Wiesinger
2010-04-22 6:12 ` Gerhard Wiesinger
2010-05-12 10:23 ` Jamie Lokier
2010-05-12 10:23 ` Jamie Lokier
2010-04-21 20:56 ` Avi Kivity
2010-04-21 20:56 ` Avi Kivity
2010-04-22 6:04 ` Gerhard Wiesinger
2010-04-22 6:04 ` Gerhard Wiesinger
2010-04-22 7:03 ` Avi Kivity
2010-04-22 7:03 ` Avi Kivity
2010-05-09 19:35 ` Gerhard Wiesinger
2010-05-09 19:35 ` Gerhard Wiesinger
2010-05-10 7:32 ` Avi Kivity
2010-05-10 7:32 ` Avi Kivity
2010-05-12 6:14 ` Gerhard Wiesinger
2010-05-12 6:14 ` [Qemu-devel] " Gerhard Wiesinger
2010-05-12 6:39 ` Avi Kivity
2010-05-12 6:39 ` Avi Kivity
2011-02-18 7:32 ` [Qemu-devel] Re: QEMU-KVM and video performance - Update Gerhard Wiesinger
2011-02-18 7:32 ` Gerhard Wiesinger
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