From: "陳韋任 (Wei-Ren Chen)" <chenwj@iis.sinica.edu.tw>
To: Blue Swirl <blauwirbel@gmail.com>
Cc: qemu-devel@nongnu.org, "陳韋任 (Wei-Ren Chen)" <chenwj@iis.sinica.edu.tw>
Subject: Re: [Qemu-devel] Dump guest page table inside QEMU makes system hang
Date: Wed, 22 Aug 2012 10:20:26 +0800 [thread overview]
Message-ID: <20120822022026.GA11966@cs.nctu.edu.tw> (raw)
In-Reply-To: <CAAu8pHsy6WvzE1sCGnZ1e4aYadS2eXVcwsa92j0oTLPG1f5DVw@mail.gmail.com>
> > The system will hang while booting. However, if I comment
> > cpu_physical_memory_read in function dump_guest_pgtable, there
> > is no problem. What I am missing here? Thanks.
>
> cpu_physical_memory_read() can cause faults or other side effects like
> MMIO. Using cpu_get_phys_page_debug() may help.
PMM also suggest me looking on cpu_get_phys_page_debug. When I read
the code, I found something suspicious.
---
target_phys_addr_t cpu_get_phys_page_debug(CPUX86State *env, target_ulong addr)
{
target_ulong pde_addr, pte_addr;
...
pde = ldq_phys(pde_addr);
...
}
---
The address of pde and pte should be (guest) physical address, right?
If so, then target_ulong should be replaced with target_phys_addr_t.
The other clue is the type of ldq_phys's parameter is target_phys_addr_t.
Regards,
chenwj
--
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj
next prev parent reply other threads:[~2012-08-22 2:20 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-21 7:21 [Qemu-devel] Dump guest page table inside QEMU makes system hang 陳韋任 (Wei-Ren Chen)
2012-08-21 18:19 ` Blue Swirl
2012-08-22 2:20 ` 陳韋任 (Wei-Ren Chen) [this message]
2012-08-22 12:06 ` Max Filippov
2012-08-23 2:53 ` 陳韋任 (Wei-Ren Chen)
2012-08-23 3:55 ` 陳韋任 (Wei-Ren Chen)
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