mirror of https://github.com/xemu-project/xemu.git
![]() The VHD file format is used by both Virtual PC, and Hyper-V. However, how the virtual disk size is calculated varies between the two. Virtual PC uses the CHS drive parameters to determine the drive size. Hyper-V, on the other hand, uses the current_size field in the footer when determining image size. This is problematic for a few reasons: * VHD images from Hyper-V, using CHS calculations, will likely be trunctated. * If we just rely always on current_size, then QEMU may have data compatibility issues with Virtual PC (we may write too much data into a VHD file to be used by Virtual PC, for instance). * Existing VHD images created by QEMU have used the CHS calculations, except for images exceeding the 127GB limit. We want to remain compatible with our own generated images. Luckily, the VHD specification defines a 'Creator App' field, that is used to indicate what software created the VHD file. This patch does two things: 1. Uses the 'Creator App' field to help determine how to calculate size, and 2. Adds a VPC format option 'force_size_calc', so that the user can override the 'Creator App' auto-detection, in case there exist VHD images with unknown or contradictory 'Creator App' entries. N.B.: We currently use the maximum CHS value as an indication to use the current_size field. This patch does not change that, even with the 'force_size_calc' option. Signed-off-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> |
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audio | ||
backends | ||
block | ||
bsd-user | ||
contrib | ||
crypto | ||
default-configs | ||
disas | ||
docs | ||
dtc@65cc4d2748 | ||
fpu | ||
fsdev | ||
gdb-xml | ||
hw | ||
include | ||
io | ||
libdecnumber | ||
linux-headers | ||
linux-user | ||
migration | ||
nbd | ||
net | ||
pc-bios | ||
pixman@87eea99e44 | ||
po | ||
qapi | ||
qga | ||
qobject | ||
qom | ||
replay | ||
roms | ||
scripts | ||
slirp | ||
stubs | ||
target-alpha | ||
target-arm | ||
target-cris | ||
target-i386 | ||
target-lm32 | ||
target-m68k | ||
target-microblaze | ||
target-mips | ||
target-moxie | ||
target-openrisc | ||
target-ppc | ||
target-s390x | ||
target-sh4 | ||
target-sparc | ||
target-tilegx | ||
target-tricore | ||
target-unicore32 | ||
target-xtensa | ||
tcg | ||
tests | ||
trace | ||
ui | ||
util | ||
.dir-locals.el | ||
.exrc | ||
.gitignore | ||
.gitmodules | ||
.mailmap | ||
.travis.yml | ||
CODING_STYLE | ||
COPYING | ||
COPYING.LIB | ||
Changelog | ||
HACKING | ||
LICENSE | ||
MAINTAINERS | ||
Makefile | ||
Makefile.objs | ||
Makefile.target | ||
README | ||
VERSION | ||
accel.c | ||
aio-posix.c | ||
aio-win32.c | ||
arch_init.c | ||
async.c | ||
balloon.c | ||
block.c | ||
blockdev-nbd.c | ||
blockdev.c | ||
blockjob.c | ||
bootdevice.c | ||
bt-host.c | ||
bt-vhci.c | ||
configure | ||
cpu-exec-common.c | ||
cpu-exec.c | ||
cpus.c | ||
cputlb.c | ||
device-hotplug.c | ||
device_tree.c | ||
disas.c | ||
dma-helpers.c | ||
dump.c | ||
exec.c | ||
gdbstub.c | ||
hmp-commands-info.hx | ||
hmp-commands.hx | ||
hmp.c | ||
hmp.h | ||
iohandler.c | ||
ioport.c | ||
iothread.c | ||
kvm-all.c | ||
kvm-stub.c | ||
main-loop.c | ||
memory.c | ||
memory_mapping.c | ||
module-common.c | ||
monitor.c | ||
numa.c | ||
os-posix.c | ||
os-win32.c | ||
page_cache.c | ||
qapi-schema.json | ||
qdev-monitor.c | ||
qdict-test-data.txt | ||
qemu-bridge-helper.c | ||
qemu-char.c | ||
qemu-doc.texi | ||
qemu-ga.texi | ||
qemu-img-cmds.hx | ||
qemu-img.c | ||
qemu-img.texi | ||
qemu-io-cmds.c | ||
qemu-io.c | ||
qemu-nbd.c | ||
qemu-nbd.texi | ||
qemu-options-wrapper.h | ||
qemu-options.h | ||
qemu-options.hx | ||
qemu-seccomp.c | ||
qemu-tech.texi | ||
qemu-timer.c | ||
qemu.nsi | ||
qemu.sasl | ||
qjson.c | ||
qmp-commands.hx | ||
qmp.c | ||
qtest.c | ||
rules.mak | ||
softmmu_template.h | ||
spice-qemu-char.c | ||
tcg-runtime.c | ||
tci.c | ||
thread-pool.c | ||
thunk.c | ||
tpm.c | ||
trace-events | ||
translate-all.c | ||
translate-all.h | ||
translate-common.c | ||
user-exec.c | ||
version.rc | ||
vl.c | ||
xen-common-stub.c | ||
xen-common.c | ||
xen-hvm-stub.c | ||
xen-hvm.c | ||
xen-mapcache.c |
README
QEMU README =========== QEMU is a generic and open source machine & userspace emulator and virtualizer. QEMU is capable of emulating a complete machine in software without any need for hardware virtualization support. By using dynamic translation, it achieves very good performance. QEMU can also integrate with the Xen and KVM hypervisors to provide emulated hardware while allowing the hypervisor to manage the CPU. With hypervisor support, QEMU can achieve near native performance for CPUs. When QEMU emulates CPUs directly it is capable of running operating systems made for one machine (e.g. an ARMv7 board) on a different machine (e.g. an x86_64 PC board). QEMU is also capable of providing userspace API virtualization for Linux and BSD kernel interfaces. This allows binaries compiled against one architecture ABI (e.g. the Linux PPC64 ABI) to be run on a host using a different architecture ABI (e.g. the Linux x86_64 ABI). This does not involve any hardware emulation, simply CPU and syscall emulation. QEMU aims to fit into a variety of use cases. It can be invoked directly by users wishing to have full control over its behaviour and settings. It also aims to facilitate integration into higher level management layers, by providing a stable command line interface and monitor API. It is commonly invoked indirectly via the libvirt library when using open source applications such as oVirt, OpenStack and virt-manager. QEMU as a whole is released under the GNU General Public License, version 2. For full licensing details, consult the LICENSE file. Building ======== QEMU is multi-platform software intended to be buildable on all modern Linux platforms, OS-X, Win32 (via the Mingw64 toolchain) and a variety of other UNIX targets. The simple steps to build QEMU are: mkdir build cd build ../configure make Complete details of the process for building and configuring QEMU for all supported host platforms can be found in the qemu-tech.html file. Additional information can also be found online via the QEMU website: http://qemu-project.org/Hosts/Linux http://qemu-project.org/Hosts/W32 Submitting patches ================== The QEMU source code is maintained under the GIT version control system. git clone git://git.qemu-project.org/qemu.git When submitting patches, the preferred approach is to use 'git format-patch' and/or 'git send-email' to format & send the mail to the qemu-devel@nongnu.org mailing list. All patches submitted must contain a 'Signed-off-by' line from the author. Patches should follow the guidelines set out in the HACKING and CODING_STYLE files. Additional information on submitting patches can be found online via the QEMU website http://qemu-project.org/Contribute/SubmitAPatch http://qemu-project.org/Contribute/TrivialPatches Bug reporting ============= The QEMU project uses Launchpad as its primary upstream bug tracker. Bugs found when running code built from QEMU git or upstream released sources should be reported via: https://bugs.launchpad.net/qemu/ If using QEMU via an operating system vendor pre-built binary package, it is preferable to report bugs to the vendor's own bug tracker first. If the bug is also known to affect latest upstream code, it can also be reported via launchpad. For additional information on bug reporting consult: http://qemu-project.org/Contribute/ReportABug Contact ======= The QEMU community can be contacted in a number of ways, with the two main methods being email and IRC - qemu-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/qemu-devel - #qemu on irc.oftc.net Information on additional methods of contacting the community can be found online via the QEMU website: http://qemu-project.org/Contribute/StartHere -- End