qcow2 writes a cluster reference count on every cluster update. This causes
performance to crater when using anything but cache=writeback. This is most
noticeable when using savevm. Right now, qcow2 isn't a reliable format
regardless of the type of cache your using because metadata is not updated in
the correct order. Considering this, I think it's somewhat reasonable to use
writeback caching by default with qcow2 files.
It at least avoids the massive performance regression for users until we sort
out the issues in qcow2.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5879 c046a42c-6fe2-441c-8c8c-71466251a162
qemu_get_clock() returns a structure containing the time the user wants
to be set (either UTC time, a local time, or a given date). Use mktimegm()
instead of mktime() to convert it into POSIX time without taking the host
timezone into account.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5878 c046a42c-6fe2-441c-8c8c-71466251a162
Windows does not have sys/uio.h and does not have err.h.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5877 c046a42c-6fe2-441c-8c8c-71466251a162
...and fix a bug, the implementation in hw/apic.c was wrong.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5876 c046a42c-6fe2-441c-8c8c-71466251a162
This adds a VirtIO based balloon driver. It uses madvise() to actually balloon
the memory when possible.
Until 2.6.27, KVM forced memory pinning so we must disable ballooning unless the
kernel actually supports it when using KVM. It's always safe when using TCG.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5874 c046a42c-6fe2-441c-8c8c-71466251a162
Balloon devices allow you to ask the guest to allocate memory. This allows you
to release that memory. It's mostly useful for freeing up large chunks of
memory from cooperative guests.
Ballooning is supported by both Xen and VirtIO.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5873 c046a42c-6fe2-441c-8c8c-71466251a162
As suggested by Laurent Desnogues.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5872 c046a42c-6fe2-441c-8c8c-71466251a162
TARGET_PAGE_SIZE should only be used internal to qemu, not in guest/host
interfaces. The virtio frontend code in Linux uses two constants (PFN shift
and vring alignment) for the interface, so update qemu to match.
I've tested this with PowerPC KVM and confirmed that it fixes virtio problems
when using non-TARGET_PAGE_SIZE pages in the guest.
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5871 c046a42c-6fe2-441c-8c8c-71466251a162
Virtio-blk is a paravirtual block device based on VirtIO. It can be used by
specifying the if=virtio parameter to the -drive parameter.
When using -enable-kvm, it can achieve very good performance compared to IDE or
SCSI.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5870 c046a42c-6fe2-441c-8c8c-71466251a162
This patch adds core support for VirtIO. VirtIO is a paravirtualization
framework that has been in Linux since 2.6.21. A PCI transport has been
available since 2.6.25. Network drivers are also available for Windows.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5869 c046a42c-6fe2-441c-8c8c-71466251a162
This is needed for virtio. The implementation is originally from
Marcelo Tosatti.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5868 c046a42c-6fe2-441c-8c8c-71466251a162
This PCI controller can be found on a number of 4xx SoCs, including the 440EP.
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Acked-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5862 c046a42c-6fe2-441c-8c8c-71466251a162
Currently the order is this (during cow since it's the interesting case):
1. Decrement refcount of old clusters
2. Increment refcount for newly allocated clusters
3. Copy content of old sectors that will not be rewritten
4. Update L2 table with pointers to new clusters
5. Write guest data into new clusters (asynchronously)
There are several problems with this order. The first one is that if qemu
crashes (or killed or host reboots) after new clusters are linked into L2
table but before user data is written there, then on the next reboot guest
will find neither old data nor new one in those sectors and this is not
what gust expects even when journaling file system is in use. The other
problem is that if qemu is killed between steps 1 and 4 then refcount
of old cluster will be incorrect and may cause snapshot corruption.
The patch change the order to be like this:
1. Increment refcount for newly allocated clusters
2. Write guest data into new clusters (asynchronously)
3. Copy content of old sectors that were not rewritten
4. Update L2 table with pointers to new clusters
5. Decrement refcount of old clusters
Unexpected crash may cause cluster leakage, but guest data should be safe.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5861 c046a42c-6fe2-441c-8c8c-71466251a162
Otherwise if VM is killed between two writes data may be lost.
But if offset and size fields are at the same disk block one
write should update them both simultaneously.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5859 c046a42c-6fe2-441c-8c8c-71466251a162
Use it to remove code duplications from qcow_aio_read_cb().
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5858 c046a42c-6fe2-441c-8c8c-71466251a162
When using an existing unix socket like:
-vnc unix:/tmp/file1Y2nY2
qemu fails to bind a unix socket because the vnc call to unix_listen includes
the unix: prefix and stores that in the unix.sun_path. The fix is to not pass
in unix: for the filename (same way qemu-char.c does it).
Signed-off-by: Ryan Harper <ryanh@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5856 c046a42c-6fe2-441c-8c8c-71466251a162
VNC should not maintain modifer state upon reconnects With some window
managers/vnc clients it will only see a key down event for a modifier
followed by immediate disconnect(think Alt-F4), with a net effect of
subsequently connected clients operating as if the modifier was never
released.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5851 c046a42c-6fe2-441c-8c8c-71466251a162
This allows among other things to capturing A/V of running
guests. Ad-hoc client that does this (via script that invokes ffmpeg)
can be found at:
http://repo.or.cz/w/qemu/malc.git?a=tree;f=vcap;hb=capture3
Thanks to Anthony Liguori for comments and review.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5850 c046a42c-6fe2-441c-8c8c-71466251a162
According to malc TCG will often genereate an add2/sub2/mul2 with low
half of the output in the same register as high half of one of the
inputs, so account for that.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5847 c046a42c-6fe2-441c-8c8c-71466251a162
Otherwise when tb_exit generates a jump beyond the pc-relative range,
tcg_out_goto() spans two/three instructions and we load the tb return
value from a wrong address. This is #ifdefed out currently because
we take care for the jumps to be local.
Problem spotted by Steffen Liebergeld.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5845 c046a42c-6fe2-441c-8c8c-71466251a162
Unfortunately this range is so narrow that I'm not sure if it makes more
sense to always use memory load to pc kind of branch instead.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5844 c046a42c-6fe2-441c-8c8c-71466251a162
Calling the clear cache syscall directly generates an illegal instruction
on some (armv4) kernels.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5843 c046a42c-6fe2-441c-8c8c-71466251a162
Data integrity is not important in qemu-img, so open the files with
cache=writeback. This fixes the performance regression seen with qemu-img
since revision 5485, and most particularly with the qcow2 format.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5839 c046a42c-6fe2-441c-8c8c-71466251a162
Should not give any performance penality given cpu_mmu_index() is
an inline function returning a value from env.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5837 c046a42c-6fe2-441c-8c8c-71466251a162
Minor fixes of spelling and grammar in comments and documentation
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5835 c046a42c-6fe2-441c-8c8c-71466251a162
Fix data type (this fixes a warning from sparse)
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5834 c046a42c-6fe2-441c-8c8c-71466251a162
Remove unnecessary declaration for errno (this fixes a warning from sparse)
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5833 c046a42c-6fe2-441c-8c8c-71466251a162
