From nobody Mon May 6 18:47:30 2024 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 1495040390621230.33939779971; Wed, 17 May 2017 09:59:50 -0700 (PDT) Received: from localhost ([::1]:50001 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dB2If-00023h-1o for importer@patchew.org; Wed, 17 May 2017 12:59:49 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35884) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dB2HE-0001Cl-09 for qemu-devel@nongnu.org; Wed, 17 May 2017 12:58:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dB2HC-0000F2-0U for qemu-devel@nongnu.org; Wed, 17 May 2017 12:58:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37674) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dB2HB-0000El-Q6 for qemu-devel@nongnu.org; Wed, 17 May 2017 12:58:17 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 94B5C369C4 for ; Wed, 17 May 2017 16:58:16 +0000 (UTC) Received: from dgilbert-t530.redhat.com (ovpn-117-220.ams2.redhat.com [10.36.117.220]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9268E5C54A; Wed, 17 May 2017 16:58:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 94B5C369C4 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=dgilbert@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 94B5C369C4 From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, quintela@redhat.com, peterx@redhat.com, lvivier@redhat.com Date: Wed, 17 May 2017 17:58:09 +0100 Message-Id: <20170517165810.18164-2-dgilbert@redhat.com> In-Reply-To: <20170517165810.18164-1-dgilbert@redhat.com> References: <20170517165810.18164-1-dgilbert@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Wed, 17 May 2017 16:58:16 +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] [PATCH 1/2] migration: Fix non-multiple of page size migration 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: , 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" Unfortunately it's legal to create a VM with a RAM size that's not a multiple of the underlying host page or huge page size. Recently I'd changed things to always send host sized pages, and that breaks if we have say a 1025MB guest on 2MB hugepages. Unfortunately we can't just make that illegal since it would break migration from/to existing oddly configured VMs. Symptom: qemu-system-x86_64: Illegal RAM offset 40100000 as it transmits the fraction of the hugepage after the end of the RAMBlock (may also cause a crash on the source - possibly due to clearing bits after the bitmap) Reported-by: Yumei Huang Red Hat bug: https://bugzilla.redhat.com/show_bug.cgi?id=3D1449037 Signed-off-by: Dr. David Alan Gilbert --- migration/ram.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index 293d27ce83..cea8924c02 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1305,6 +1305,8 @@ static int ram_save_target_page(RAMState *rs, PageSea= rchStatus *pss, * a host page in which case the remainder of the hostpage is sent. * Only dirty target pages are sent. Note that the host page size may * be a huge page for this block. + * The saving stops at the boundary of the used_length of the block + * if the RAMBlock isn't a multiple of the host page size. * * Returns the number of pages written or negative on error * @@ -1328,7 +1330,8 @@ static int ram_save_host_page(RAMState *rs, PageSearc= hStatus *pss, =20 pages +=3D tmppages; pss->page++; - } while (pss->page & (pagesize_bits - 1)); + } while ((pss->page & (pagesize_bits - 1)) && + offset_in_ramblock(pss->block, pss->page << TARGET_PAGE_BITS)= ); =20 /* The offset we leave with is the last one we looked at */ pss->page--; --=20 2.13.0 From nobody Mon May 6 18:47:30 2024 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 1495040388352906.0345481775302; Wed, 17 May 2017 09:59:48 -0700 (PDT) Received: from localhost ([::1]:50000 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dB2Ib-00020r-35 for importer@patchew.org; Wed, 17 May 2017 12:59:45 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35885) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dB2HE-0001Cm-0T for qemu-devel@nongnu.org; Wed, 17 May 2017 12:58:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dB2HD-0000FD-3q for qemu-devel@nongnu.org; Wed, 17 May 2017 12:58:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42486) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dB2HC-0000F6-V6 for qemu-devel@nongnu.org; Wed, 17 May 2017 12:58:19 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DEB3183F46 for ; Wed, 17 May 2017 16:58:17 +0000 (UTC) Received: from dgilbert-t530.redhat.com (ovpn-117-220.ams2.redhat.com [10.36.117.220]) by smtp.corp.redhat.com (Postfix) with ESMTP id DB13C5C884; Wed, 17 May 2017 16:58:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com DEB3183F46 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=dgilbert@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com DEB3183F46 From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, quintela@redhat.com, peterx@redhat.com, lvivier@redhat.com Date: Wed, 17 May 2017 17:58:10 +0100 Message-Id: <20170517165810.18164-3-dgilbert@redhat.com> In-Reply-To: <20170517165810.18164-1-dgilbert@redhat.com> References: <20170517165810.18164-1-dgilbert@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 17 May 2017 16:58:18 +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] [PATCH 2/2] postcopy: Require RAMBlocks that are whole 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: , 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" It turns out that it's legal to create a VM with RAMBlocks that aren't a multiple of the pagesize in use; e.g. a 1025M main memory using 2M host pages. That breaks postcopy's atomic placement of pages, so disallow it. Signed-off-by: Dr. David Alan Gilbert --- migration/postcopy-ram.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index cdadaf6578..e8f43e7bd1 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -96,14 +96,24 @@ static bool ufd_version_check(int ufd) =20 /* Callback from postcopy_ram_supported_by_host block iterator. */ -static int test_range_shared(const char *block_name, void *host_addr, +static int test_ramblock_postcopiable(const char *block_name, void *host_a= ddr, ram_addr_t offset, ram_addr_t length, void *o= paque) { - if (qemu_ram_is_shared(qemu_ram_block_by_name(block_name))) { + RAMBlock *rb =3D qemu_ram_block_by_name(block_name); + size_t pagesize =3D qemu_ram_pagesize(rb); + + if (qemu_ram_is_shared(rb)) { error_report("Postcopy on shared RAM (%s) is not yet supported", block_name); return 1; } + + if (length % pagesize) { + error_report("Postcopy requires RAM blocks to be a page size multi= ple," + " block %s is 0x" RAM_ADDR_FMT " bytes with a " + "page size of 0x%zx", block_name, length, pagesize); + return 1; + } return 0; } =20 @@ -140,7 +150,7 @@ bool postcopy_ram_supported_by_host(void) } =20 /* We don't support postcopy with shared RAM yet */ - if (qemu_ram_foreach_block(test_range_shared, NULL)) { + if (qemu_ram_foreach_block(test_ramblock_postcopiable, NULL)) { goto out; } =20 --=20 2.13.0