From mboxrd@z Thu Jan 1 00:00:00 1970 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) From: "Dr. David Alan Gilbert (git)" 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> Subject: [Qemu-devel] [PATCH 2/2] postcopy: Require RAMBlocks that are whole pages List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, quintela@redhat.com, peterx@redhat.com, lvivier@redhat.com 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) /* 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_addr, ram_addr_t offset, ram_addr_t length, void *opaque) { - if (qemu_ram_is_shared(qemu_ram_block_by_name(block_name))) { + RAMBlock *rb = qemu_ram_block_by_name(block_name); + size_t pagesize = 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 multiple," + " block %s is 0x" RAM_ADDR_FMT " bytes with a " + "page size of 0x%zx", block_name, length, pagesize); + return 1; + } return 0; } @@ -140,7 +150,7 @@ bool postcopy_ram_supported_by_host(void) } /* 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; } -- 2.13.0