From nobody Sun Feb 8 23:05:14 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1488287148484956.932490683662; Tue, 28 Feb 2017 05:05:48 -0800 (PST) Received: from localhost ([::1]:60828 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cihTN-0004Ig-2C for importer@patchew.org; Tue, 28 Feb 2017 08:05:45 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40177) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cih65-0008WK-6n for qemu-devel@nongnu.org; Tue, 28 Feb 2017 07:41:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cih62-0000Px-92 for qemu-devel@nongnu.org; Tue, 28 Feb 2017 07:41:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34454) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cih62-0000PE-0a for qemu-devel@nongnu.org; Tue, 28 Feb 2017 07:41:38 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 17E4461E4C; Tue, 28 Feb 2017 12:41:38 +0000 (UTC) Received: from dgilbert-t530.redhat.com (ovpn-117-149.ams2.redhat.com [10.36.117.149]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v1SCewtJ019858; Tue, 28 Feb 2017 07:41:36 -0500 From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org Date: Tue, 28 Feb 2017 12:40:48 +0000 Message-Id: <20170228124056.5074-20-dgilbert@redhat.com> In-Reply-To: <20170228124056.5074-1-dgilbert@redhat.com> References: <20170228124056.5074-1-dgilbert@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Tue, 28 Feb 2017 12:41:38 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 19/27] postcopy: Use temporary for placing zero huge pages X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lvivier@redhat.com, pasic@linux.vnet.ibm.com, vsementsov@virtuozzo.com, quintela@redhat.com, ashijeetacharya@gmail.com, marcandre.lureau@redhat.com, danielhb@linux.vnet.ibm.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: "Dr. David Alan Gilbert" The kernel can't do UFFDIO_ZEROPAGE for huge pages, so we have to allocate a temporary (always zero) page and use UFFDIO_COPYPAGE on it. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela Reviewed-by: Laurent Vivier Message-Id: <20170224182844.32452-9-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert --- include/migration/migration.h | 1 + migration/postcopy-ram.c | 23 +++++++++++++++++++++-- 2 files changed, 22 insertions(+), 2 deletions(-) diff --git a/include/migration/migration.h b/include/migration/migration.h index 08b98e9..5720c88 100644 --- a/include/migration/migration.h +++ b/include/migration/migration.h @@ -109,6 +109,7 @@ struct MigrationIncomingState { QEMUFile *to_src_file; QemuMutex rp_mutex; /* We send replies from multiple threads */ void *postcopy_tmp_page; + void *postcopy_tmp_zero_page; =20 QEMUBH *bh; =20 diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index a8b7fed..4c736d2 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -324,6 +324,10 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingSta= te *mis) munmap(mis->postcopy_tmp_page, mis->largest_page_size); mis->postcopy_tmp_page =3D NULL; } + if (mis->postcopy_tmp_zero_page) { + munmap(mis->postcopy_tmp_zero_page, mis->largest_page_size); + mis->postcopy_tmp_zero_page =3D NULL; + } trace_postcopy_ram_incoming_cleanup_exit(); return 0; } @@ -593,8 +597,23 @@ int postcopy_place_page_zero(MigrationIncomingState *m= is, void *host, return -e; } } else { - /* TODO: The kernel can't use UFFDIO_ZEROPAGE for hugepages */ - assert(0); + /* The kernel can't use UFFDIO_ZEROPAGE for hugepages */ + if (!mis->postcopy_tmp_zero_page) { + mis->postcopy_tmp_zero_page =3D mmap(NULL, mis->largest_page_s= ize, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, + -1, 0); + if (mis->postcopy_tmp_zero_page =3D=3D MAP_FAILED) { + int e =3D errno; + mis->postcopy_tmp_zero_page =3D NULL; + error_report("%s: %s mapping large zero page", + __func__, strerror(e)); + return -e; + } + memset(mis->postcopy_tmp_zero_page, '\0', mis->largest_page_si= ze); + } + return postcopy_place_page(mis, host, mis->postcopy_tmp_zero_page, + pagesize); } =20 return 0; --=20 2.9.3