qemu-e2k/tests/qemu-iotests/177
Eric Blake b66ff2c298 iotests: Specify explicit backing format where sensible
There are many existing qcow2 images that specify a backing file but
no format.  This has been the source of CVEs in the past, but has
become more prominent of a problem now that libvirt has switched to
-blockdev.  With older -drive, at least the probing was always done by
qemu (so the only risk of a changed format between successive boots of
a guest was if qemu was upgraded and probed differently).  But with
newer -blockdev, libvirt must specify a format; if libvirt guesses raw
where the image was formatted, this results in data corruption visible
to the guest; conversely, if libvirt guesses qcow2 where qemu was
using raw, this can result in potential security holes, so modern
libvirt instead refuses to use images without explicit backing format.

The change in libvirt to reject images without explicit backing format
has pointed out that a number of tools have been far too reliant on
probing in the past.  It's time to set a better example in our own
iotests of properly setting this parameter.

iotest calls to create, rebase, and convert are all impacted to some
degree.  It's a bit annoying that we are inconsistent on command line
- while all of those accept -o backing_file=...,backing_fmt=..., the
shortcuts are different: create and rebase have -b and -F, while
convert has -B but no -F.  (amend has no shortcuts, but the previous
patch just deprecated the use of amend to change backing chains).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-9-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00

118 lines
3.3 KiB
Bash
Executable File

#!/usr/bin/env bash
#
# Test corner cases with unusual block geometries
#
# Copyright (C) 2016-2018 Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# creator
owner=eblake@redhat.com
seq=`basename $0`
echo "QA output created by $seq"
status=1 # failure is the default!
_cleanup()
{
_cleanup_test_img
}
trap "_cleanup; exit \$status" 0 1 2 3 15
# get standard environment, filters and checks
. ./common.rc
. ./common.filter
# This test is runnable under compat=0.10; see test 204 for additional
# tests specific to compat=1.1.
_supported_fmt qcow2
_supported_proto file
CLUSTER_SIZE=1M
size=128M
options=driver=blkdebug,image.driver=qcow2
echo
echo "== setting up files =="
TEST_IMG="$TEST_IMG.base" _make_test_img $size
$QEMU_IO -c "write -P 11 0 $size" "$TEST_IMG.base" | _filter_qemu_io
_make_test_img -b "$TEST_IMG.base" -F $IMGFMT
$QEMU_IO -c "write -P 22 0 $size" "$TEST_IMG" | _filter_qemu_io
# Limited to 64k max-transfer
echo
echo "== constrained alignment and max-transfer =="
limits=align=4k,max-transfer=64k
$QEMU_IO -c "open -o $options,$limits blkdebug::$TEST_IMG" \
-c "write -P 33 1000 128k" -c "read -P 33 1000 128k" | _filter_qemu_io
echo
echo "== write zero with constrained max-transfer =="
limits=align=512,max-transfer=64k,opt-write-zero=$CLUSTER_SIZE
$QEMU_IO -c "open -o $options,$limits blkdebug::$TEST_IMG" \
-c "write -z 8003584 2093056" | _filter_qemu_io
# non-power-of-2 write-zero/discard alignments
echo
echo "== non-power-of-2 write zeroes limits =="
limits=align=512,opt-write-zero=15M,max-write-zero=15M,opt-discard=15M,max-discard=15M
$QEMU_IO -c "open -o $options,$limits blkdebug::$TEST_IMG" \
-c "write -z 32M 32M" | _filter_qemu_io
echo
echo "== non-power-of-2 discard limits =="
limits=align=512,opt-write-zero=15M,max-write-zero=15M,opt-discard=15M,max-discard=15M
$QEMU_IO -c "open -o $options,$limits blkdebug::$TEST_IMG" \
-c "discard 80000001 30M" | _filter_qemu_io
echo
echo "== verify image content =="
verify_io()
{
if ($QEMU_IMG info -f "$IMGFMT" "$TEST_IMG" |
grep "compat: 0.10" > /dev/null); then
# In v2 images clusters are not discarded when there is a backing file
# so the previous value is read
discarded=22
else
# Discarded clusters are zeroed for v3 or later
discarded=0
fi
echo read -P 22 0 1000
echo read -P 33 1000 128k
echo read -P 22 132072 7871512
echo read -P 0 8003584 2093056
echo read -P 22 10096640 23457792
echo read -P 0 32M 32M
echo read -P 22 64M 13M
echo read -P $discarded 77M 29M
echo read -P 22 106M 22M
}
verify_io | $QEMU_IO -r "$TEST_IMG" | _filter_qemu_io
_check_test_img
# success, all done
echo "*** done"
status=0