From 7a736bfa4e0a58087054cad68a1d4b3804bbb708 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 16 Aug 2012 10:34:10 +0200 Subject: vmdk: Fix header structure Commit bb45ded9 swapped gd_offset and rgd_offset. This is wrong. Signed-off-by: Kevin Wolf --- block/vmdk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/vmdk.c b/block/vmdk.c index daee4268be..9648398822 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -57,8 +57,8 @@ typedef struct { int64_t desc_offset; int64_t desc_size; int32_t num_gtes_per_gte; - int64_t gd_offset; int64_t rgd_offset; + int64_t gd_offset; int64_t grain_offset; char filler[1]; char check_bytes[4]; -- cgit v1.2.1 From 65bd155c7356d448ffee7f89149c4d473076b0ba Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 16 Aug 2012 10:39:33 +0200 Subject: vmdk: Read footer for streamOptimized images The footer takes precedence over the header when it exists. It contains the real grain directory offset that is missing in the header. Without this patch, streamOptimized images with a footer cannot be read. Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi Reviewed-by: Jeff Cody --- block/vmdk.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/block/vmdk.c b/block/vmdk.c index 9648398822..bba4c61a74 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -35,6 +35,7 @@ #define VMDK4_FLAG_RGD (1 << 1) #define VMDK4_FLAG_COMPRESS (1 << 16) #define VMDK4_FLAG_MARKER (1 << 17) +#define VMDK4_GD_AT_END 0xffffffffffffffffULL typedef struct { uint32_t version; @@ -115,6 +116,13 @@ typedef struct VmdkGrainMarker { uint8_t data[0]; } VmdkGrainMarker; +enum { + MARKER_END_OF_STREAM = 0, + MARKER_GRAIN_TABLE = 1, + MARKER_GRAIN_DIRECTORY = 2, + MARKER_FOOTER = 3, +}; + static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename) { uint32_t magic; @@ -451,6 +459,54 @@ static int vmdk_open_vmdk4(BlockDriverState *bs, if (header.capacity == 0 && header.desc_offset) { return vmdk_open_desc_file(bs, flags, header.desc_offset << 9); } + + if (le64_to_cpu(header.gd_offset) == VMDK4_GD_AT_END) { + /* + * The footer takes precedence over the header, so read it in. The + * footer starts at offset -1024 from the end: One sector for the + * footer, and another one for the end-of-stream marker. + */ + struct { + struct { + uint64_t val; + uint32_t size; + uint32_t type; + uint8_t pad[512 - 16]; + } QEMU_PACKED footer_marker; + + uint32_t magic; + VMDK4Header header; + uint8_t pad[512 - 4 - sizeof(VMDK4Header)]; + + struct { + uint64_t val; + uint32_t size; + uint32_t type; + uint8_t pad[512 - 16]; + } QEMU_PACKED eos_marker; + } QEMU_PACKED footer; + + ret = bdrv_pread(file, + bs->file->total_sectors * 512 - 1536, + &footer, sizeof(footer)); + if (ret < 0) { + return ret; + } + + /* Some sanity checks for the footer */ + if (be32_to_cpu(footer.magic) != VMDK4_MAGIC || + le32_to_cpu(footer.footer_marker.size) != 0 || + le32_to_cpu(footer.footer_marker.type) != MARKER_FOOTER || + le64_to_cpu(footer.eos_marker.val) != 0 || + le32_to_cpu(footer.eos_marker.size) != 0 || + le32_to_cpu(footer.eos_marker.type) != MARKER_END_OF_STREAM) + { + return -EINVAL; + } + + header = footer.header; + } + l1_entry_sectors = le32_to_cpu(header.num_gtes_per_gte) * le64_to_cpu(header.granularity); if (l1_entry_sectors == 0) { -- cgit v1.2.1 From 48467328c6dccc9c7be6628ed0ef0810f83be2a9 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 16 Aug 2012 10:56:35 +0200 Subject: Documentation: Warn against qemu-img on active image People have repeatedly expected that you can do things like snapshotting an image with qemu-img while a qemu instance is running. Maybe we need to consider locking the files while they are in use, but having a warning in the qemu-img manpage is doable for 1.2 and can't hurt anyway. Signed-off-by: Kevin Wolf --- qemu-img.texi | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/qemu-img.texi b/qemu-img.texi index 77c6d0b6b0..6b42e35fe7 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -4,6 +4,16 @@ usage: qemu-img command [command options] @c man end @end example +@c man begin DESCRIPTION +qemu-img allows you to create, convert and modify images offline. It can handle +all image formats supported by QEMU. + +@b{Warning:} Never use qemu-img to modify images in use by a running virtual +machine or any other process; this may destroy the image. Also, be aware that +querying an image that is being modified by another process may encounter +inconsistent state. +@c man end + @c man begin OPTIONS The following commands are supported: -- cgit v1.2.1 From eec7f96c2cac88f59fd8c79b78a6e027df4abfb2 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 16 Aug 2012 09:57:49 +0100 Subject: virtio-blk: hide VIRTIO_BLK_F_CONFIG_WCE from old machine types QEMU has a policy of keeping a stable guest device ABI. When new guest device features are introduced they must not change hardware info seen by existing guests. This is important because operating systems or applications may "fingerprint" the hardware and refuse to run when the hardware changes. To always get the latest guest device ABI, run with x86 machine type "pc". This patch hides the new VIRTIO_BLK_F_CONFIG_WCE virtio feature bit from existing machine types. Only pc-1.2 and later will expose this feature by default. For more info on the VIRTIO_BLK_F_CONFIG_WCE feature bit, see: commit 13e3dce068773c971ff2f19d986378c55897c4a3 Author: Paolo Bonzini Date: Thu Aug 9 16:07:19 2012 +0200 virtio-blk: support VIRTIO_BLK_F_CONFIG_WCE Also rename VIRTIO_BLK_F_WCACHE to VIRTIO_BLK_F_WCE for consistency with the spec. Signed-off-by: Paolo Bonzini Signed-off-by: Kevin Wolf Anthony Liguori reported: This broke qemu-test because it changed the pc-1.0 machine type: Setting guest RANDOM seed to 47167 *** Running tests *** Running test /tests/finger-print.sh... OK --- fingerprints/pc-1.0.x86_64 2011-12-18 13:08:40.000000000 -0600 +++ fingerprint.txt 2012-08-12 13:30:48.000000000 -0500 @@ -55,7 +55,7 @@ /sys/bus/pci/devices/0000:00:06.0/subsystem_device=0x0002 /sys/bus/pci/devices/0000:00:06.0/class=0x010000 /sys/bus/pci/devices/0000:00:06.0/revision=0x00 -/sys/bus/pci/devices/0000:00:06.0/virtio/host-features=0x710006d4 +/sys/bus/pci/devices/0000:00:06.0/virtio/host-features=0x71000ed4 /sys/class/dmi/id/bios_vendor=Bochs /sys/class/dmi/id/bios_date=01/01/2007 /sys/class/dmi/id/bios_version=Bochs Guest fingerprint changed for pc-1.0! Reported-by: Anthony Liguori Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- hw/pc_piix.c | 4 ++++ hw/virtio-blk.c | 4 +++- hw/virtio-blk.h | 1 + hw/virtio-pci.c | 1 + 4 files changed, 9 insertions(+), 1 deletion(-) diff --git a/hw/pc_piix.c b/hw/pc_piix.c index 0c0096fd7e..d68dbb2320 100644 --- a/hw/pc_piix.c +++ b/hw/pc_piix.c @@ -375,6 +375,10 @@ static QEMUMachine pc_machine_v1_2 = { .driver = "qxl",\ .property = "vgamem_mb",\ .value = stringify(8),\ + },{\ + .driver = "virtio-blk-pci",\ + .property = "config-wce",\ + .value = "off",\ } static QEMUMachine pc_machine_v1_1 = { diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index fd8fa90792..0bc2b5e7c5 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -533,7 +533,9 @@ static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features) features |= (1 << VIRTIO_BLK_F_BLK_SIZE); features |= (1 << VIRTIO_BLK_F_SCSI); - features |= (1 << VIRTIO_BLK_F_CONFIG_WCE); + if (s->blk->config_wce) { + features |= (1 << VIRTIO_BLK_F_CONFIG_WCE); + } if (bdrv_enable_write_cache(s->bs)) features |= (1 << VIRTIO_BLK_F_WCE); diff --git a/hw/virtio-blk.h b/hw/virtio-blk.h index 35834cf493..454f445d61 100644 --- a/hw/virtio-blk.h +++ b/hw/virtio-blk.h @@ -104,6 +104,7 @@ struct VirtIOBlkConf BlockConf conf; char *serial; uint32_t scsi; + uint32_t config_wce; }; #define DEFINE_VIRTIO_BLK_FEATURES(_state, _field) \ diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c index 5e6e09efb7..2a3d86f176 100644 --- a/hw/virtio-pci.c +++ b/hw/virtio-pci.c @@ -886,6 +886,7 @@ static Property virtio_blk_properties[] = { #ifdef __linux__ DEFINE_PROP_BIT("scsi", VirtIOPCIProxy, blk.scsi, 0, true), #endif + DEFINE_PROP_BIT("config-wce", VirtIOPCIProxy, blk.config_wce, 0, true), DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags, VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true), DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2), DEFINE_VIRTIO_BLK_FEATURES(VirtIOPCIProxy, host_features), -- cgit v1.2.1