From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Bader Subject: Re: [PATCH] xen/x86: Force removal of memory range when not covered by MTRRs Date: Fri, 15 Feb 2013 17:45:02 +0100 Message-ID: <511E660E.7000107@canonical.com> References: <1360861916-21243-1-git-send-email-stefan.bader@canonical.com> <511E0BBE02000078000BE9A8@nat28.tlf.novell.com> <511E0F34.6010107@canonical.com> <511E268002000078000BE9FA@nat28.tlf.novell.com> <20130215134720.GG11777@phenom.dumpdata.com> <511E59C902000078000BEC18@nat28.tlf.novell.com> <20130215164010.GE13775@phenom.dumpdata.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0733904675662248270==" Return-path: In-Reply-To: <20130215164010.GE13775@phenom.dumpdata.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Konrad Rzeszutek Wilk Cc: Jan Beulich , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --===============0733904675662248270== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="------------enigDCA60700F5CE5FB7743BCB99" This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigDCA60700F5CE5FB7743BCB99 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 15.02.2013 17:40, Konrad Rzeszutek Wilk wrote: > On Fri, Feb 15, 2013 at 02:52:41PM +0000, Jan Beulich wrote: >>>>> On 15.02.13 at 14:47, Konrad Rzeszutek Wilk wrote: >>>>>> Since when is E820_UNUSABLE memory being used as guest >>>>>> memory? If that's indeed the case, that's the bug to fix. The >>>>>> above data to me shows, however, that the range above >>>>>> 228000000 is considered invalid. So then the question is why the >>>>>> kernel tries to map that memory in the first place (the hypervisor= >>>>>> rejecting the attempt, despite Dom0 being privileged, seems >>>>>> correct to me, as the range is also known not to be MMIO). >>> >>> B/c it gets the E820 from the hypervisor, which shows that area as >>> E820_UNUSABLE. And dom0 (or rather, the generic memory code) ends up >>> creating pagetables for it. >> >> That would be wrong even on native, and I don't see how that >> would happen: memblock_add() gets called from >> memblock_x86_fill() only for E820_RAM and E820_RESERVED_KERN >> ranges. >=20 > Hm, the bug report shows that the ranges (which are E820_UNUSABLE) > do get called with init_memory_mapping. >=20 Not sure it makes the difference but keep in mind that the report is abou= t a 3.2 kernel. They initially claimed that 3.5 works, but then some comments see= m to say that was when using dom0_mem=3D which would in that case work around = the bug. Maybe time to go back and ask whether a recent kernel without dom0_mem on= the same machine still crashes... --------------enigDCA60700F5CE5FB7743BCB99 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with undefined - http://www.enigmail.net/ iQIcBAEBCgAGBQJRHmYOAAoJEOhnXe7L7s6j8m8P/0VwnsL5XKGc6JFZtLw5EsyJ woWvstEUGzp15oMVtJB5wn8puyN6iC91GZaVnVA2XrkQ7wUluk1r/dyXWjkXjr2N rG6tWteKGCyidCbmS6DEr6Z1GzKmBUaA7kPjBlD2PH4BEatZrOmyK8HZ2m/+f08/ 4k+r3GnmlfEd1L/c6hpaq0S5CH77Ijk9gnAB/oSm5GXMX/7Pcwl/6Z4ChLSZYenQ sFwgQXv1AludSC7NqToSSlgF2OWJMLq2OI5fcsvTYMRB0IL7blo9dVJ0cSP4YIFO 0lHiz+q+lLcOQPRXJwg5Q+Z8jd8052dFBhcYP98PhH6oIwjUhcAqf+hYmsqDbBnR qr7zVrJ7o/d2kAj5UjtZgcmdeCmG6TutYtGpE03FWpPPxfuuSln0V9PA88VXGYwI hxTO8/gi9fpMZ2YxiFvwmAt+s780Qbc5D7nrPVsb2GfquD2VWVHoGfmEArrnmYOW +QuugLGhxNAiIBXmYDndZ7Gt8cjYajZTtMvKusCOQe0Dq/7V5E4TYBRHVPLk8m4w qc71/OONsCX56USkfITld9uMzKsZqjd+t3mnDGi2sYOt+TCOMxX+MLR95zJPKXgX lTSq6T1qklfabtm3+sxzSo1n9ccbqhnYkRA28jhBr8horv0FGZgFI+WH9it+NTj/ 79Q/e23YlMyQxS9P9PTw =7od/ -----END PGP SIGNATURE----- --------------enigDCA60700F5CE5FB7743BCB99-- --===============0733904675662248270== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel --===============0733904675662248270==--