Benefits to blktap2 over the old version of blktap:
* Isolation from xenstore - Blktap devices are now created directly on
the linux dom0 command line, rather than being spawned in response
to XenStore events. This is handy for debugging, makes blktap
generally easier to work with, and is a step toward a generic
user-level block device implementation that is not Xen-specific.
* Improved tapdisk infrastructure: simpler request forwarding, new
request scheduler, request merging, more efficient use of AIO.
* Improved tapdisk error handling and memory management. No
allocations on the block data path, IO retry logic to protect
guests
transient block device failures. This has been tested and is known
to work on weird environments such as NFS soft mounts.
* Pause and snapshot of live virtual disks (see xmsnap script).
* VHD support. The VHD code in this release has been rigorously
tested, and represents a very mature implementation of the VHD
image
format.
* No more duplication of mechanism with blkback. The blktap kernel
module has changed dramatically from the original blktap. Blkback
is now always used to talk to Xen guests, blktap just presents a
Linux gendisk that blkback can export. This is done while
preserving the zero-copy data path from domU to physical device.
These patches deprecate the old blktap code, which can hopefully be
removed from the tree completely at some point in the future.
Signed-off-by: Jake Wires <jake.wires@citrix.com>
Signed-off-by: Dutch Meyer <dmeyer@cs.ubc.ca>
Tmem, when called from a tmem-capable (paravirtualized) guest, makes
use of otherwise unutilized ("fallow") memory to create and manage
pools of pages that can be accessed from the guest either as
"ephemeral" pages or as "persistent" pages. In either case, the pages
are not directly addressible by the guest, only copied to and fro via
the tmem interface. Ephemeral pages are a nice place for a guest to
put recently evicted clean pages that it might need again; these pages
can be reclaimed synchronously by Xen for other guests or other uses.
Persistent pages are a nice place for a guest to put "swap" pages to
avoid sending them to disk. These pages retain data as long as the
guest lives, but count against the guest memory allocation.
Tmem pages may optionally be compressed and, in certain cases, can be
shared between guests. Tmem also handles concurrency nicely and
provides limited QoS settings to combat malicious DoS attempts.
Save/restore and live migration support is not yet provided.
Tmem is primarily targeted for an x86 64-bit hypervisor. On a 32-bit
x86 hypervisor, it has limited functionality and testing due to
limitations of the xen heap. Nearly all of tmem is
architecture-independent; three routines remain to be ported to ia64
and it should work on that architecture too. It is also structured to
be portable to non-Xen environments.
Tmem defaults off (for now) and must be enabled with a "tmem" xen boot
option (and does nothing unless a tmem-capable guest is running). The
"tmem_compress" boot option enables compression which takes about 10x
more CPU but approximately doubles the number of pages that can be
stored.
Tmem can be controlled via several "xm" commands and many interesting
tmem statistics can be obtained. A README and internal specification
will follow, but lots of useful prose about tmem, as well as Linux
patches, can be found at http://oss.oracle.com/projects/tmem .
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
In the case where a device is attached to an inactive domain
and then removed before the domain is activated it won't have
a vslot assigned, but it should still be valid to remove it.
I don't think that there are any other cases where vslot can
be invalid.
Signed-off-by: Simon Horman <horms@verge.net.au>
This patch adds the option "superpages" to the domain configuration
file. If it is set, the domain is populated using 2M pages.
This code does not support fallback to small pages. If the domain can
not be created with 2M pages, the create will fail.
The patch also includes support for saving and restoring domains with
the superpage flag set. However, if a domain has freed small pages
within its physical page array and then extended the array, the
restore will fill in those freed pages. It will then attempt to
allocate more than its memory limit and will fail. This is
significant because apparently Linux does this during boot, thus a
freshly booted Linux image can not be saved and restored successfully.
Signed-off-by: Dave McCracken <dcm@mccr.org>
In the efforts to clarify MiniOS license it came to my attention that
few portions of MiniOS were taken from other GPL projects, one of them
is the mktime implementation. This patch replaces the current GPL
licensed mktime implementation with a different and BSD licensed
version.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Allow 'file' based disks, that are blkback based disks, to be shared
between the guest domain and the stubdom. It does so exploiting the
same exception introduced in the previous patch "stubdoms phy disks
sharing". Now we can remove the hack in stubdom-dm that forces "file"
disks to be opened using blktap instead of blkback.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
The first and last sector as well as the sector number of the request
is expressed in 512 bytes units, independently from the real sector
size.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
This is to properly handle SRAT rev 2 extended proximity domain
values.
Also a first step to eliminate the redundant definitions of
ACPI provided table structures (Linux eliminated all of the duplicates
from include/linux/acpi.h in 2.6.21).
Portions based on a Linux patch from Kurt Garloff <garloff@suse.de>
and Alexey Starikovskiy <astarikovskiy@suse.de>.
IA64 build tested only.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
With the unification of the heaps, the pages freed from the Xen boot
image now can also end up being allocated to a domain, and hence the
respective aliases need handling when such pages get their
cacheability attributes changed.
Rather than establishing multiple mappings with non-WB attributes
(which temporarily still can cause aliasing issues), simply unmap
those pages from the Xen virtual space, and re-map them (to allow re-
establishing of eventual large page mappings) when the cachability
attribute for them gets restored to normal (WB).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
This is to avoid undue virtual address aliases in case the over-mapped
pages happen to get allocated to a domain, and then get their
cacheability attributes changed.
At the same time, use 1Gb mappings if possible and reasonable.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cloning the similar construct from Linux, allowing to detect improper
uses of ARRAY_SIZE() at build time.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Remove *all* hardcoded "/etc/xen" strings in python code.
Additionally, it removes pygrub_path from osdep.py. Its use has been
replaced with auxbin.pathTo("pygrub").
Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>
It currently doesn't even compile; with this patch applied, it
compiles and didn't immediately explode as soon as I started a VM.
I've not given it much testing beyond that, though.
Signed-off-by: Steven Smith <steven.smith@citrix.com>
if they are to be linked with object files created by ocamlc and the minios
kernel.
This is needed to build stubdoms written in ocaml.
Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com>
We could stub them out as unsupported, but we may as well implement
them as they are very simple.
Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com>
These are referenced by the libs that ocamlopt links xenstored to, but
ought not actually get called.
Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com>
To use, set CONFIG_OCAML_XENSTORED=y at build time.
Then the build system will automatically download the remote repo
to tools/ocaml-xenstored.
Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com>
In some configurations, when dom0 is busy with I/O, it may take
several minutes to complete all hotplug scripts required when a new
domain is being created. As device create timeout is set to 100
seconds, users get "hotplug scripts not working" error instead of a
new domain.
This patch makes both DEVICE_CREATE_TIMEOUT and DEVICE_DESTROY_TIMEOUT
configurable in xend-config.sxp to allow users to easily adapt hotplug
timeouts to their environment.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
This can greatly improve ssl relocation performance (to about 1/3
compared with buffersize 1024).
Signed-off-by: Zhigang Wang <zhigang.x.wang@oracle.com>
For now hardcode /etc w/o a prefix as there are hardcoded
config paths in the code which would break otherwise.
Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>
In the case of inactive managed domains:
The following error occurs currently. We cannot change the
configuration of the VBD by using xm block-configure. Of course,
using xm block-detach and xm block-attach instead of xm
block-configure, we can change it. However, I'd like to change it by
using xm block-configure.
In the case of active domains:
Another problem occurs after a domain was rebooted. Even if we
change a configuration of a VBD in the domain by using xm
block-configure, the configuration of the VBD is reverted to previous
configuration after the domain was rebooted.
Signed-off-by: Masaki Kanno <kanno.masaki@jp.fujitsu.com>
APERF/MPERF MSRs provides feedback about actual freq in
eplased time, which could be different from requested freq by
governor. However currently ondemand governor only takes that
feedback at freq down path. We should do that for scale up too.
Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
Current IOAPIC interrupt remapping code assumes there is only one
IOAPIC in system. It brings problem when there are more than one
IOAPIC in system. This patch extends ioapic_pin_to_intremap_index[]
array to handle multiple IOAPICs case.
Signed-off-by: Weidong Han <weidong.han@intel.com>
For timer_deadline == 0 or timer_deadline - now > largest u32
case, the expected_us (in u32 type) may become wrong.
Add a tunable option to ease conditional adjustment.
Signed-off-by: Wei Gang <gang.wei@intel.com>
Linux started to pass around pointers to 'const cpumask_t' a while ago,
and passing such a pointer to set_xen_guest_handle() requires that the
field be a handle for a constant type in order to avoid compiler
warnings.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
When a PCI function is passed-through extra options may be passed
through.
In the case of boot-time PCI pass-through the documented format is:
[dom:]bus:dev.slot[@vslot][[,opt]...]
e.g.
00:01.00.1@7,msitranslate=3D1
In the case of PCI hot-plug the xm pci-attach command take the
following arguments:
[-o opt[,opt]...] [dom:]bus:dev.slot [vslot]
e.g.
-o msitranslate=3D1 00:01.00.1 7
These xm ends up passing these to xem-qemu as:
[dom:]bus:dev.slot[[,opt]...][@vslot]
e.g.
00:01.00.1,msitranslate=3D1@7
Note that the option and the vslot have are transposed when
compared to the format used by boot-time PCI pass-through.
The parser inside qemu-xen can only handle the format used by
boot-time PCI pass-through and because of this ignores
any options passed by hot-plug.
This patch alters format used by hot-plug to match the parser.
Signed-off-by: Simon Horman <horms@verge.net.au>
Keir Fraser