From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:58189) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SXNg3-00012h-EF for qemu-devel@nongnu.org; Wed, 23 May 2012 22:21:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SXNg0-0003dP-Ed for qemu-devel@nongnu.org; Wed, 23 May 2012 22:21:23 -0400 Received: from fmmailgate03.web.de ([217.72.192.234]:36740) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SXNg0-0003bU-43 for qemu-devel@nongnu.org; Wed, 23 May 2012 22:21:20 -0400 Received: from moweb002.kundenserver.de (moweb002.kundenserver.de [172.19.20.108]) by fmmailgate03.web.de (Postfix) with ESMTP id 55E311B4EAF47 for ; Thu, 24 May 2012 04:21:18 +0200 (CEST) Message-ID: <4FBD9B18.70600@web.de> Date: Wed, 23 May 2012 23:21:12 -0300 From: Jan Kiszka MIME-Version: 1.0 References: <4FBC5C67.1080007@suse.de> <4FBCC877.30003@siemens.com> <4FBD0A0B.1060106@siemens.com> <4FBD2038.7070007@siemens.com> <4FBD964C.4080401@web.de> In-Reply-To: <4FBD964C.4080401@web.de> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigDF47E689917A7E929B4676E5" Subject: Re: [Qemu-devel] [PATCH] exec: fix breakpoint_invalidate() breakage List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: TeLeMan Cc: Avi Kivity , qemu-devel , =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigDF47E689917A7E929B4676E5 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 2012-05-23 23:00, Jan Kiszka wrote: > On 2012-05-23 22:29, TeLeMan wrote: >> On Thu, May 24, 2012 at 1:36 AM, Jan Kiszka w= rote: >>> On 2012-05-23 13:02, Jan Kiszka wrote: >>>> On 2012-05-23 11:11, TeLeMan wrote: >>>>> On Wed, May 23, 2012 at 7:22 PM, Jan Kiszka wrote: >>>>>> On 2012-05-23 04:09, TeLeMan wrote: >>>>>>> On Wed, May 23, 2012 at 11:41 AM, Andreas F=C3=A4rber wrote: >>>>>>>> Am 18.05.2012 11:49, schrieb TeLeMan: >>>>>>>>> This breakage was introduced by the commit "memory: make >>>>>>>>> phys_page_find() return an unadjusted". >>>>>>>> >>>>>>>> You seem to have found the origin of your problem. If you also m= ention >>>>>>>> the commit hash in your commit message then certain frontends (g= itk, >>>>>>>> repo.or.cz) will display it as a handy hyperlink to that commit.= >>>>>>>> >>>>>>>>> >>>>>>>>> Signed-off-by: TeLeMan >>>>>>>> >>>>>>>> Signed-off-by is a legal statement of origin and must not be a p= seudonym. >>>>>>> Ok, please ignore this patch. I won't submit any patch just repor= t bugs. >>>>>> >>>>>> Then please describe this bug in more details, e.g. how to reprodu= ce. >>>>> I think its evident. cpu_get_phys_page_debug(env, pc) is not the >>>>> physical address of pc but the physical page base address of pc. >>>> >>>> ...so this bites us if the instruction spans two pages as >>>> tb_invalidate_phys_addr requests invalidation on a page granularity.= >>> >>> In fact, this is irrelevant. We only need to flush the address at whi= ch >>> the instruction starts, and that is achieved by flushing all TB that >>> relate to that page as the current code does. >> >> But the instruction start is wrong and its TB may not be found. For ex= ample, >> the pc is 0x1234 and its physical address is 0x1234. The correct >> "start" and "end" of tb_invalidate_phys_page_range() is 0x1234 and >> 0x1235. But now the "start" and "end" is 0x1000 and 0x1001. >> If 0x1000 is not translated yet, the real TB won't be invalidated. >=20 > The tb containing 0x1234 would be linked to the list of TBs that are > related to the 0x1000 page. As we declare that page invalid, all > affected TBs are dropped, not just the one containing the breakpoint. > See tb_invalidate_phys_page_range. Oops, too fast: in fact the introductory comment of tb_invalidate_phys_page_range is misleading, there is a sub-page-level range check. And now my test also actually triggers. Was probably running the wrong qemu version before. Jan --------------enigDF47E689917A7E929B4676E5 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk+9mxgACgkQitSsb3rl5xR64wCg0d7S8JkOpMD41a2fNNYUOEIX oxYAoMUbJIAznDep1zzfJtJU2jiPl780 =jH02 -----END PGP SIGNATURE----- --------------enigDF47E689917A7E929B4676E5--