From: "Andreas Färber" <andreas.faerber@web.de>
To: Avi Kivity <avi@redhat.com>
Cc: qemu-devel Developers <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] Memory read/write issues
Date: Sun, 27 Nov 2011 23:16:01 +0100 [thread overview]
Message-ID: <4ED2B6A1.7000102@web.de> (raw)
In-Reply-To: <4ED2465E.9010709@redhat.com>
Am 27.11.2011 15:17, schrieb Avi Kivity:
> On 11/27/2011 04:07 PM, Andreas Färber wrote:
>> Thanks a lot! You were right, setting TARGET_PAGE_BITS to 8 solves this
>> issue.
>>
>> I'd still like to fix this subpage case for others' benefit. Do you have
>> any pointer where I should set breakpoints / review code?
>
> The subpage code (scheduled for demolition in 1.1) lives in exec.c. See
> subpage_init() and subpage_register(). I'd start with enabling
> DEBUG_SUBPAGE, fixing all the build errors, and looking at the output of
> subpage_readlen() and subpage_writelen().
With these hints I've figured out what's actually happening here:
subpage_writelen() is reading a wrong index 2 == IO_MEM_UNASSIGNED from
subpage_t and performing an unassigned memory write, confirmed by
DEBUG_UNASSIGNED.
In subpage_register(), we're taking the (memory & ~TARGET_PAGE_MASK) ==
IO_MEM_RAM path and setting IO_MEM_UNASSIGNED in subpage_t.
Will investigate further tomorrow.
Andreas
prev parent reply other threads:[~2011-11-27 22:16 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-23 23:59 [Qemu-devel] Initializing PC from memory on reset? Andreas Färber
2011-11-24 7:47 ` Peter Maydell
2011-11-24 21:24 ` Andreas Färber
2011-11-25 16:25 ` [Qemu-devel] Memory read/write issues (was: Initializing PC from memory on reset?) Andreas Färber
2011-11-27 8:32 ` [Qemu-devel] Memory read/write issues Avi Kivity
2011-11-27 14:07 ` Andreas Färber
2011-11-27 14:17 ` Avi Kivity
2011-11-27 22:16 ` Andreas Färber [this message]
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