qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: blauwirbel@gmail.com, Alexander Graf <alex@csgraf.de>,
	Alexander Graf <agraf@suse.de>
Subject: Re: [Qemu-devel] [PATCH 7/7] PPC64: Don't fault at lwsync
Date: Thu, 5 Mar 2009 16:44:30 +0000	[thread overview]
Message-ID: <200903051644.30883.paul@codesourcery.com> (raw)
In-Reply-To: <1236262454-6293-8-git-send-email-agraf@suse.de>

> If anyone knows how to really fix this, please step forward and do
> so. This only makes things work at all for me :-).

I bet lwsync being a nop is a clue.

When an MMU exception occurs, qemu figures out the guest location from the 
location of the MMU access in guest code (see cpu_restore_state). My guess is 
that this breaks when two guest instructions have the same location. I'm not 
entirely sure what the correct fix is, or where the bug lies 
(cpu_restore_state,  gen_intermediate_code_pc, or tcg_gen_code_search_pc) but 
hopefully this will point you in the right direction.

One thing to try (to confirm this theory) is make lwsync do domething (write 
to a dummy register or call a helper function) and see if the problem goes 
away.

Paul

  parent reply	other threads:[~2009-03-05 16:44 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-05 14:14 [Qemu-devel] [PATCH 0/7] PPC64 Linux bringup patches v2 Alexander Graf
2009-03-05 14:14 ` [Qemu-devel] [PATCH 1/7] PPC64: Implement slbmte Alexander Graf
2009-03-05 14:14   ` [Qemu-devel] [PATCH 2/7] PPC64: Implement large pages Alexander Graf
2009-03-05 14:14     ` [Qemu-devel] [PATCH 3/7] PPC64: Implment tlbiel Alexander Graf
2009-03-05 14:14       ` [Qemu-devel] [PATCH 4/7] Activate uninorth AGP bridge Alexander Graf
2009-03-05 14:14         ` [Qemu-devel] [PATCH 5/7] PPC64: Nop some SPRs on 970fx Alexander Graf
2009-03-05 14:14           ` [Qemu-devel] [PATCH 6/7] PPC64: Enable 64bit mode on interrupts Alexander Graf
2009-03-05 14:14             ` [Qemu-devel] [PATCH 7/7] PPC64: Don't fault at lwsync Alexander Graf
2009-03-05 15:07               ` Paul Brook
2009-03-05 15:57                 ` Alexander Graf
2009-03-05 16:09                   ` Alexander Graf
2009-03-05 16:29                     ` Paul Brook
2009-03-05 16:44               ` Paul Brook [this message]
2009-03-05 19:42                 ` Daniel Jacobowitz
2009-03-06  0:53                   ` Paul Brook
2009-03-05 21:21                 ` Alexander Graf

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=200903051644.30883.paul@codesourcery.com \
    --to=paul@codesourcery.com \
    --cc=agraf@suse.de \
    --cc=alex@csgraf.de \
    --cc=blauwirbel@gmail.com \
    --cc=qemu-devel@nongnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).