From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56400) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XM74S-00049L-Ns for qemu-devel@nongnu.org; Mon, 25 Aug 2014 23:05:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XM74K-0007FJ-M6 for qemu-devel@nongnu.org; Mon, 25 Aug 2014 23:05:20 -0400 Date: Tue, 26 Aug 2014 13:01:19 +1000 From: David Gibson Message-ID: <20140826030119.GM9923@voom.redhat.com> References: <1408667050-10789-1-git-send-email-sam.mj@au1.ibm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="dp9QYJgVRVEW2bsm" Content-Disposition: inline In-Reply-To: <1408667050-10789-1-git-send-email-sam.mj@au1.ibm.com> Subject: Re: [Qemu-devel] [PATCH V5] spapr: Fix stale HTAB during live migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Samuel Mendoza-Jonas Cc: aik@ozlabs.ru, qemu-ppc@nongnu.org, qemu-devel@nongnu.org --dp9QYJgVRVEW2bsm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Aug 22, 2014 at 10:24:10AM +1000, Samuel Mendoza-Jonas wrote: > If a guest reboots during a running migration, changes to the > hash page table are not necessarily updated on the destination. > Opening a new file descriptor to the HTAB forces the migration > handler to resend the entire table. Of course, arguably this is a kernel bug - the htab fd should probably start re-reporting things if the htab reset ioctl() is called. But I guess we need a workaround for existing kernels anyway. However, don't we still have the bug for TCG mode? spapr_reset_htab() just memset()s the whole hashtable in that case, which will actually clear all the dirty bits, whereas we need to set them. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --dp9QYJgVRVEW2bsm Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJT+/h/AAoJEGw4ysog2bOSJSoP/2Gm4Nf1o50/s/Dfrh/F8ChM MsKGWxmrn6FW7C+IH14iJm1dPZOM5ys3+WVoI6+Yxo5yp7TfSL3SAVkXVheV4WJF qOJPsapdJS2K++PRp5mfq7gR1mqbZ1nsqva3cXwncSqaJqhNrIAazVEKULJ0o+Bd JLG3iiUk41JssT8+KyyHyfDZhnuvqqP22GT+eq88En1CKLO5YggyufzUB0ry/YOR ttJWbF/LhQHKAHw+tRm/n0dfBJ7br/H3mlGRLQV9o/7rLnrbNqpgpvlraUWCtM7U 9fABsq10zFNbbEiUvksrPAG9ZcwBWnM0kRqw5KdoHxKXaYF8ZsxyRUgbMwsOyf4k lGsNhtjuKSArEsqMcY2yio1tUv2cCG3kU3Thj7nEqwYgovMW3V8607PM4HNBLNt3 mxSqZuwR0c5lb94tJduOVtG0o3nycUL65I9GvA1L1VqJfO/JQgZw0+mWLMZIv07I vj/Et3JJE6nrVh2WEbcaRUl5G5FIx+YrzJOqFaOpefTBEyTauzyXA2M7mx1gIDr+ 5C59ZxY1S9PP+CmZyJ1zFUw7W0V04ZJN6OJmcCloFNipXgyRqzvlH2vU1QRpa2DF 7V569du+xeGYdKwImokf79BNTzrmGFclBkNCfzrrRyWIDki4o7/I50EL0ZU6D6AR Gc0mtyEY3j5upgvbzDUF =Gy75 -----END PGP SIGNATURE----- --dp9QYJgVRVEW2bsm--