From patchwork Tue Apr 23 14:24:24 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Cody X-Patchwork-Id: 238921 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id DFB562C008C for ; Wed, 24 Apr 2013 00:25:32 +1000 (EST) Received: from localhost ([::1]:43596 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UUe9z-0004Bs-3E for incoming@patchwork.ozlabs.org; Tue, 23 Apr 2013 10:25:31 -0400 Received: from eggs.gnu.org ([208.118.235.92]:46521) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UUe9H-00045E-Rp for qemu-devel@nongnu.org; Tue, 23 Apr 2013 10:24:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UUe9E-0006AY-E3 for qemu-devel@nongnu.org; Tue, 23 Apr 2013 10:24:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60660) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UUe9E-0006AU-79 for qemu-devel@nongnu.org; Tue, 23 Apr 2013 10:24:44 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r3NEOhmE001419 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 23 Apr 2013 10:24:43 -0400 Received: from localhost ([10.3.112.13]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id r3NEOfMw007217 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Tue, 23 Apr 2013 10:24:42 -0400 From: Jeff Cody To: qemu-devel@nongnu.org Date: Tue, 23 Apr 2013 10:24:24 -0400 Message-Id: <4fe304399e0d00138fefcfffaae97ae5a16de552.1366726446.git.jcody@redhat.com> In-Reply-To: References: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, stefanha@redhat.com Subject: [Qemu-devel] [PATCH v2 5/5] block: add header update capability for VHDX images. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This adds the ability to update the headers in a VHDX image, including generating a new MS-compatible GUID. As VHDX depends on uuid.h, VHDX is now a configurable build option. If VHDX support is enabled, that will also enable uuid as well. To enable/disable VHDX: --enable-vhdx, --disable-vhdx Signed-off-by: Jeff Cody --- block/Makefile.objs | 2 +- block/vhdx.c | 157 +++++++++++++++++++++++++++++++++++++++++++++++++++- configure | 13 +++++ 3 files changed, 169 insertions(+), 3 deletions(-) diff --git a/block/Makefile.objs b/block/Makefile.objs index 5f0358a..da0a990 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -2,7 +2,7 @@ block-obj-y += raw.o cow.o qcow.o vdi.o vmdk.o cloop.o dmg.o bochs.o vpc.o vvfat block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-cache.o block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o block-obj-y += qed-check.o -block-obj-y += vhdx.o +block-obj-$(CONFIG_VHDX) += vhdx.o block-obj-y += parallels.o blkdebug.o blkverify.o block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o block-obj-$(CONFIG_POSIX) += raw-posix.o diff --git a/block/vhdx.c b/block/vhdx.c index ca4a298..272304d 100644 --- a/block/vhdx.c +++ b/block/vhdx.c @@ -21,6 +21,7 @@ #include "qemu/crc32c.h" #include "block/vhdx.h" +#include /* Several metadata and region table data entries are identified by * guids in a MS-specific GUID format. */ @@ -156,11 +157,40 @@ typedef struct BDRVVHDXState { vhdx_bat_entry *bat; uint64_t bat_offset; + ms_guid session_guid; + + vhdx_parent_locator_header parent_header; vhdx_parent_locator_entry *parent_entries; } BDRVVHDXState; +/* Calculates new checksum. + * + * Zero is substituted during crc calculation for the original crc field + * crc_offset: byte offset in buf of the buffer crc + * buf: buffer pointer + * size: size of buffer (must be > crc_offset+4) + * + * Note: The resulting checksum is in the CPU endianness, not necessarily + * in the file format endianness (LE). Any header export to disk should + * make sure that vhdx_header_le_export() is used to convert to the + * correct endianness + */ +static uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset) +{ + uint32_t crc; + + assert(buf != NULL); + assert(size > (crc_offset+4)); + + memset(buf+crc_offset, 0, sizeof(crc)); + crc = crc32c(0xffffffff, buf, size); + memcpy(buf+crc_offset, &crc, sizeof(crc)); + + return crc; +} + uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size, int crc_offset) { @@ -212,6 +242,24 @@ bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset) /* + * This generates a UUID that is compliant with the MS GUIDs used + * in the VHDX spec (and elsewhere). + * + * We can do this with uuid_generate if uuid.h is present, + * however not all systems have uuid and the generation is + * pretty straightforward for the DCE + random usage case + * + */ +static void vhdx_guid_generate(ms_guid *guid) +{ + uuid_t uuid; + assert(guid != NULL); + + uuid_generate(uuid); + memcpy(guid, uuid, 16); +} + +/* * Per the MS VHDX Specification, for every VHDX file: * - The header section is fixed size - 1 MB * - The header section is always the first "object" @@ -249,6 +297,107 @@ static void vhdx_header_le_import(vhdx_header *h) le64_to_cpus(&h->log_offset); } +/* All VHDX structures on disk are little endian */ +static void vhdx_header_le_export(vhdx_header *orig_h, vhdx_header *new_h) +{ + assert(orig_h != NULL); + assert(new_h != NULL); + + new_h->signature = cpu_to_le32(orig_h->signature); + new_h->checksum = cpu_to_le32(orig_h->checksum); + new_h->sequence_number = cpu_to_le64(orig_h->sequence_number); + + memcpy(&new_h->file_write_guid, &orig_h->file_write_guid, sizeof(ms_guid)); + memcpy(&new_h->data_write_guid, &orig_h->data_write_guid, sizeof(ms_guid)); + memcpy(&new_h->log_guid, &orig_h->log_guid, sizeof(ms_guid)); + + cpu_to_leguids(&new_h->file_write_guid); + cpu_to_leguids(&new_h->data_write_guid); + cpu_to_leguids(&new_h->log_guid); + + new_h->log_version = cpu_to_le16(orig_h->log_version); + new_h->version = cpu_to_le16(orig_h->version); + new_h->log_length = cpu_to_le32(orig_h->log_length); + new_h->log_offset = cpu_to_le64(orig_h->log_offset); +} + +/* Update the VHDX headers + * + * This follows the VHDX spec procedures for header updates. + * + * - non-current header is updated with largest sequence number + */ +static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, bool rw) +{ + int ret = 0; + int hdr_idx = 0; + uint64_t header_offset = VHDX_HEADER1_OFFSET; + + vhdx_header *active_header; + vhdx_header *inactive_header; + vhdx_header header_le; + uint8_t *buffer; + + /* operate on the non-current header */ + if (s->curr_header == 0) { + hdr_idx = 1; + header_offset = VHDX_HEADER2_OFFSET; + } + + active_header = s->headers[s->curr_header]; + inactive_header = s->headers[hdr_idx]; + + inactive_header->sequence_number = active_header->sequence_number + 1; + + /* a new file guid must be generate before any file write, including + * headers */ + memcpy(&inactive_header->file_write_guid, &s->session_guid, + sizeof(ms_guid)); + + /* a new data guid only needs to be generate before any guest-visisble + * writes, so update it if the image is opened r/w. */ + if (rw) { + vhdx_guid_generate(&inactive_header->data_write_guid); + } + + /* the header checksum is not over just the packed size of vhdx_header, + * but rather over the entire 'reserved' range for the header, which is + * 4KB (VHDX_HEADER_SIZE). */ + + buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE); + /* we can't assume the extra reserved bytes are 0 */ + ret = bdrv_pread(bs->file, header_offset, buffer, VHDX_HEADER_SIZE); + if (ret < 0) { + goto fail; + } + /* overwrite the actual vhdx_header portion */ + memcpy(buffer, inactive_header, sizeof(vhdx_header)); + inactive_header->checksum = vhdx_update_checksum(buffer, + VHDX_HEADER_SIZE, 4); + vhdx_header_le_export(inactive_header, &header_le); + bdrv_pwrite_sync(bs->file, header_offset, &header_le, sizeof(vhdx_header)); + s->curr_header = hdr_idx; + +fail: + qemu_vfree(buffer); + return ret; +} + +/* + * The VHDX spec calls for header updates to be performed twice, so that both + * the current and non-current header have valid info + */ +static int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, bool rw) +{ + int ret; + + ret = vhdx_update_header(bs, s, rw); + if (ret < 0) { + return ret; + } + ret = vhdx_update_header(bs, s, rw); + return ret; +} /* opens the specified header block from the VHDX file header section */ static int vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s) @@ -680,6 +829,11 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags) qemu_co_mutex_init(&s->lock); + /* This is used for any header updates, for the file_write_guid. + * The spec dictates that a new value should be used for the first + * header update */ + vhdx_guid_generate(&s->session_guid); + ret = vhdx_parse_header(bs, s); if (ret) { goto fail; @@ -716,8 +870,7 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags) } if (flags & BDRV_O_RDWR) { - ret = -ENOTSUP; - goto fail; + vhdx_update_headers(bs, s, false); } /* TODO: differencing files, write */ diff --git a/configure b/configure index 51a6c56..9b048ab 100755 --- a/configure +++ b/configure @@ -242,6 +242,7 @@ gtk="" gtkabi="2.0" tpm="no" libssh2="" +vhdx="no" # parse CC options first for opt do @@ -934,6 +935,11 @@ for opt do ;; --enable-libssh2) libssh2="yes" ;; + --enable-vhdx) vhdx="yes" ; + uuid="yes" + ;; + --disable-vhdx) vhdx="no" + ;; *) echo "ERROR: unknown option $opt"; show_help="yes" ;; esac @@ -1201,6 +1207,8 @@ echo " --gcov=GCOV use specified gcov [$gcov_tool]" echo " --enable-tpm enable TPM support" echo " --disable-libssh2 disable ssh block device support" echo " --enable-libssh2 enable ssh block device support" +echo " --disable-vhdx disables support for the Microsoft VHDX image format" +echo " --enable-vhdx enable support for the Microsoft VHDX image format" echo "" echo "NOTE: The object files are built at the place where configure is launched" exit 1 @@ -3580,6 +3588,7 @@ echo "gcov enabled $gcov" echo "TPM support $tpm" echo "libssh2 support $libssh2" echo "TPM passthrough $tpm_passthrough" +echo "vhdx $vhdx" if test "$sdl_too_old" = "yes"; then echo "-> Your SDL version is too old - please upgrade to have SDL support" @@ -3968,6 +3977,10 @@ if test "$virtio_blk_data_plane" = "yes" ; then echo 'CONFIG_VIRTIO_BLK_DATA_PLANE=$(CONFIG_VIRTIO)' >> $config_host_mak fi +if test "$vhdx" = "yes" ; then + echo "CONFIG_VHDX=y" >> $config_host_mak +fi + # USB host support case "$usb" in linux)