From patchwork Tue Jan 31 23:04:50 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Charles Arnold X-Patchwork-Id: 138874 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 5A157B6F98 for ; Wed, 1 Feb 2012 10:05:18 +1100 (EST) Received: from localhost ([::1]:46498 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RsMlD-0003MG-Ga for incoming@patchwork.ozlabs.org; Tue, 31 Jan 2012 18:05:11 -0500 Received: from eggs.gnu.org ([140.186.70.92]:34627) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RsMky-0003LC-CD for qemu-devel@nongnu.org; Tue, 31 Jan 2012 18:05:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RsMkw-0002Nx-KI for qemu-devel@nongnu.org; Tue, 31 Jan 2012 18:04:56 -0500 Received: from novprvoes0310.provo.novell.com ([137.65.248.74]:41959) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RsMkw-0002No-8Q for qemu-devel@nongnu.org; Tue, 31 Jan 2012 18:04:54 -0500 Received: from INET-PRV-MTA by novprvoes0310.provo.novell.com with Novell_GroupWise; Tue, 31 Jan 2012 16:04:52 -0700 Message-Id: <4F2811220200009100079C4A@novprvoes0310.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 12.0.0 Date: Tue, 31 Jan 2012 16:04:50 -0700 From: "Charles Arnold" To: "=?UTF-8?Q?Andreas=20F=C3=A4rber?=" References: <4F27D8A00200009100079C3A@novprvoes0310.provo.novell.com> <4F286659.6060300@suse.de> In-Reply-To: <4F286659.6060300@suse.de> Mime-Version: 1.0 Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) X-Received-From: 137.65.248.74 Cc: Kevin Wolf , qemu-devel@nongnu.org Subject: Re: [Qemu-devel] [PATCH] block: Add support for vpc Fixed Disk type 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 Thanks Andreas, The 'TODO uuid is missing' comment in the patch is from the original sources (as well as many '//' comments). The vhd footer and header data structures contain a field for a UUID but no code was ever developed to generate one. The revised patch is below after running scripts/checkpatch.pl and fixing the 32 bit issues. - Charles The Virtual Hard Disk Image Format Specification allows for three types of hard disk formats, Fixed, Dynamic, and Differencing. Qemu currently only supports Dynamic disks. This patch adds support for the Fixed Disk format. Usage: Example 1: qemu-img create -f vpc -o type=fixed [size] Example 2: qemu-img convert -O vpc -o type=fixed While it is also allowed to specify '-o type=dynamic', the default disk type remains Dynamic and is what is used when the type is left unspecified. Signed-off-by: Charles Arnold Reviewed-by: Andreas Färber diff --git a/block/vpc.c b/block/vpc.c index 89a5ee2..04db372 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -160,14 +160,25 @@ static int vpc_open(BlockDriverState *bs, int flags) struct vhd_dyndisk_header* dyndisk_header; uint8_t buf[HEADER_SIZE]; uint32_t checksum; + int disk_type = VHD_DYNAMIC; int err = -1; if (bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE) != HEADER_SIZE) goto fail; footer = (struct vhd_footer*) s->footer_buf; - if (strncmp(footer->creator, "conectix", 8)) - goto fail; + if (strncmp(footer->creator, "conectix", 8)) { + int64_t offset = bdrv_getlength(bs->file); + /* If a fixed disk, the footer is found only at the end of the file */ + if (bdrv_pread(bs->file, offset-HEADER_SIZE, s->footer_buf, HEADER_SIZE) + != HEADER_SIZE) { + goto fail; + } + if (strncmp(footer->creator, "conectix", 8)) { + goto fail; + } + disk_type = VHD_FIXED; + } checksum = be32_to_cpu(footer->checksum); footer->checksum = 0; @@ -186,6 +197,14 @@ static int vpc_open(BlockDriverState *bs, int flags) goto fail; } + /* The footer is all that is needed for fixed disks */ + if (disk_type == VHD_FIXED) { + /* The fixed disk format doesn't use footer->data_offset but it + should be initialized */ + footer->data_offset = be64_to_cpu(0xFFFFFFFFFFFFFFFFULL); + return 0; + } + if (bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE) != HEADER_SIZE) goto fail; @@ -533,10 +552,10 @@ static int calculate_geometry(int64_t total_sectors, uint16_t* cyls, return 0; } -static int vpc_create(const char *filename, QEMUOptionParameter *options) +static int vpc_create_dynamic_disk(const char *filename, int64_t total_size) { uint8_t buf[1024]; - struct vhd_footer* footer = (struct vhd_footer*) buf; + struct vhd_footer* footer = (struct vhd_footer *) buf; struct vhd_dyndisk_header* dyndisk_header = (struct vhd_dyndisk_header*) buf; int fd, i; @@ -544,13 +563,9 @@ static int vpc_create(const char *filename, QEMUOptionParameter *options) uint8_t heads = 0; uint8_t secs_per_cyl = 0; size_t block_size, num_bat_entries; - int64_t total_sectors = 0; + int64_t total_sectors = total_size / BDRV_SECTOR_SIZE; int ret = -EIO; - // Read out options - total_sectors = get_option_parameter(options, BLOCK_OPT_SIZE)->value.n / - BDRV_SECTOR_SIZE; - // Create the file fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); if (fd < 0) @@ -657,6 +672,101 @@ static int vpc_create(const char *filename, QEMUOptionParameter *options) return ret; } +static int vpc_create_fixed_disk(const char *filename, int64_t total_size) +{ + uint8_t buf[1024]; + struct vhd_footer* footer = (struct vhd_footer *) buf; + int fd; + uint16_t cyls = 0; + uint8_t heads = 0; + uint8_t secs_per_cyl = 0; + int64_t total_sectors = total_size / BDRV_SECTOR_SIZE; + int ret = -EIO; + + /* Create the file */ + fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); + if (fd < 0) { + return -EIO; + } + + /* Calculate matching total_size and geometry. */ + if (calculate_geometry(total_sectors, &cyls, &heads, &secs_per_cyl)) { + ret = -EFBIG; + goto fail; + } + total_sectors = (int64_t) cyls * heads * secs_per_cyl; + + /* Prepare the Hard Disk Footer */ + memset(buf, 0, 1024); + + memcpy(footer->creator, "conectix", 8); + /* TODO Check if "qemu" creator_app is ok for VPC */ + memcpy(footer->creator_app, "qemu", 4); + memcpy(footer->creator_os, "Wi2k", 4); + + footer->features = be32_to_cpu(0x02); + footer->version = be32_to_cpu(0x00010000); + footer->data_offset = be64_to_cpu(0xFFFFFFFFFFFFFFFFULL); + footer->timestamp = be32_to_cpu(time(NULL) - VHD_TIMESTAMP_BASE); + + /* Version of Virtual PC 2007 */ + footer->major = be16_to_cpu(0x0005); + footer->minor = be16_to_cpu(0x0003); + footer->orig_size = be64_to_cpu(total_size); + footer->size = be64_to_cpu(total_size); + footer->cyls = be16_to_cpu(cyls); + footer->heads = heads; + footer->secs_per_cyl = secs_per_cyl; + + footer->type = be32_to_cpu(VHD_FIXED); + + /* TODO uuid is missing */ + + footer->checksum = be32_to_cpu(vpc_checksum(buf, HEADER_SIZE)); + + total_size += 512; + if (ftruncate(fd, total_size) != 0) { + ret = -errno; + goto fail; + } + if (lseek(fd, -512, SEEK_END) < 0) { + goto fail; + } + if (write(fd, buf, HEADER_SIZE) != HEADER_SIZE) { + goto fail; + } + + ret = 0; + + fail: + close(fd); + return ret; +} + +static int vpc_create(const char *filename, QEMUOptionParameter *options) +{ + int64_t total_size = 0; + QEMUOptionParameter *disk_type_param; + int ret = -EIO; + + /* Read out options */ + total_size = get_option_parameter(options, BLOCK_OPT_SIZE)->value.n; + + disk_type_param = get_option_parameter(options, BLOCK_OPT_TYPE); + if (disk_type_param && disk_type_param->value.s) { + if (!strcmp(disk_type_param->value.s, "dynamic")) { + ret = vpc_create_dynamic_disk(filename, total_size); + } else if (!strcmp(disk_type_param->value.s, "fixed")) { + ret = vpc_create_fixed_disk(filename, total_size); + } else { + ret = -EINVAL; + } + } else { + ret = vpc_create_dynamic_disk(filename, total_size); + } + return ret; +} + static void vpc_close(BlockDriverState *bs) { BDRVVPCState *s = bs->opaque; @@ -675,6 +785,13 @@ static QEMUOptionParameter vpc_create_options[] = { .type = OPT_SIZE, .help = "Virtual disk size" }, + { + .name = BLOCK_OPT_TYPE, + .type = OPT_STRING, + .help = + "Type of virtual hard disk format. Supported formats are " + "{dynamic (default) | fixed} " + }, { NULL } }; diff --git a/block_int.h b/block_int.h index 311bd2a..6d6cc96 100644 --- a/block_int.h +++ b/block_int.h @@ -50,6 +50,7 @@ #define BLOCK_OPT_TABLE_SIZE "table_size" #define BLOCK_OPT_PREALLOC "preallocation" #define BLOCK_OPT_SUBFMT "subformat" +#define BLOCK_OPT_TYPE "type" typedef struct BdrvTrackedRequest BdrvTrackedRequest;