table map track handles".
There is no race since the hypercall takes the
domain-lock. Furthermore removing locking from get_maptrack_handle()
races gnttab_setup_table().
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
This patch support exchange a page for a suspended PV guest from user
space.
The basic idea to offline a page is:
1) mark a page offline pending
2) If the page is owned by a HVM domain, user have to live migrate it.
In future, with stub-domain support, we can also exchange the page
without migration.
3) If the page is owned by a PV domain, we will try to exchange the
offline pending page to a new one and free the old page.
This patch achieves item 3.
The method to exchange the offline pending page for PV domain is:
1) Suspend the guest.
2) If the page is being granted out, return with offline pending.
3) Get a copy for the content
4) Scan all page table page to see if any reference to the offending
page, if yes, make the entry to be non-present to reduce the reference
count.
5) After update all page tables, user space tools will try to exchange
the old page. If the new mfn has no reference anymore (i.e.
count_info & count_mask =3D 1), the exchange will allocate a new page,
update the m2p and return success, otherwise it will return fail.
6) If step 5 is success, user space tools will update the content of
the new page change the p2m table, and change all entries scaned in
step 4 to point to new entry.
if step failed, it will try to undo step 4 to revert page table.
7) Resume the guest.
Please refer to thread in
http://www.mailinglistarchive.com/xen-devel@lists.xensource.com/msg63084.html
for more information.
Signed-off-by: Jiang, Yunhong <yunhong.jiang@intel.com>
This patch firstly change the xc_core_arch_map_p2m() to map the p2m to
be writable, then it export this function.
One notice for this patch is, caller should make sure change the p2m
in flight will not cause trouble.
Signed-off-by: Jiang, Yunhong <yunhong.jiang@intel.com>
When a tmem-enabled domain is destroyed, if the domain was
using a persistent pool, the domain destruction process
to scrubs page races tmem's attempts to gracefully dismantle
data structures. Move tmem_destroy earlier in the domain
destruction process.
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
This fixes the check for a request to detatch a non-existent device
in pci_device_configure. The previous check was bogus because the
format of AUTO_PHP_SLOT_STR is not the same as that of x['vslot'].
However, it works in a slightly non-obvious way, checking that vslot
hasn't been altered from its initial value AUTO_PHP_SLOT_STR. To
make this shceme a little clearer, use an empty string as the inital
value.
Formting issues asside, neither AUTO_PHP_SLOT_STR nor the empty
string are valid values for x['vslot']. In the event
of invalid data (indicating a bug), it should be caught by
self.hvm_destroyPCIDevice.
Signed-off-by: Simon Horman <horms@verge.net.au>
Currently there are two interfaces to pass-through PCI devices:
1. A method driven through per-device xenstore entries that is used at
boot-time
2. An event-based method used for hot-plug.
This seems somewhat redundant and makes extending the code cumbersome
and prone to error - often the change needs to be made twice, in
two different ways.
This patch unifies PCI pass-through by using the existing event-based
method at boot-time.
Signed-off-by: Simon Horman <horms@verge.net.au>
On Python 2.3, xend cannot started:
File
"usr/lib/python2.3/site-packages/xen/xend/server/BlktapController.=
py", line 3, in ?
import subprocess
ImportError: No module named subprocess
This patch uses `popen2' instead of `subprocess' for Python 2.3.
Signed-off-by: KUWAMURA Shin'ya <kuwa@jp.fujitsu.com>
This is another attempt at having pci-list produce consistent output.
Without this change there differences in the output of both vslots
and domain occur for domains that have never been started and domains
that have been started.
In order to address this I have taken the approach of
using integers where possible and explicitly formating them,
rather than relying on string representations that are present in
data structures.
I have also re-used the common part of the format, to try
and mitigate. the possibility of future inconsistencies there.
This patch also:
* Removes trailing whitespace
* Removes unnecessary brackets and whitespace from print invocations
* Prints the header outside of the loop to avoid having
to maintain a state variable
Signed-off-by: Simon Horman <horms@verge.net.au>
These changes lay the ground work for ATS enabling in Xen. It will be
followed by patch which enables PCI MMCFG which is needed for actual
enabling of ATS functionality.
Signed-off-by: Allen Kay <allen.m.kay@intel.com>
iptables cannot correctly handle situations when more than one command
is trying to set netfilter rules. In such situations, iptables may fail
with EAGAIN, which results in iptables: Unknown error
18446744073709551615.
Such situation can easily happen when multiple network devices are
configured for a domain as vif hotplug scripts are called in parallel
for all of the network devices.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
is passed a struct-by-value which is not yet fully defined. Thus
defining a request struct which contains a pointer to a function which
is passed-by-value an instance of that request structure is
impossible. We work around it by defining the function poiinter as
void* and then casting in one place.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
This patch updates info['platform']['pci'] for PCI devices
assignment to domains.
When a domain is started, xend confirms by using xc.test_assign_device
whether PCI devices can be assigned to the domain. For the
confirmation, info['platform']['pci'] must be an appropriate value.
However, info['platform']['pci'] may be not appropriate. Because
info['platform']['pci'] isn't almost always updated even if the PCI
device configuration of the domain was changed by using xm
pci-attach/detach. This patch updates info['platform']['pci'] to the
appropriate value when domains are started.
Signed-off-by: Masaki Kanno <kanno.masaki@jp.fujitsu.com>
This patch fixes the following error.
cc1: warnings being treated as errors
In file included from usr/include/sys/resource.h:25,
from tapdisk-daemon.c:559:
usr/include/bits/resource.h: In function 'main':
usr/include/bits/resource.h:33: warning: ISO C90 forbids mixed
declarations and code
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
- clean up to use SUBDIRS-y
- With parallel make, libvhd might not be created before
link. guarantee it.
- use LDFLAGS for link which is set by upper level makefiles.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
It allows fully virtualized guests to run real mode and unpaged mode
code natively in the VMX mode when EPT is turned on. With the
unrestricted guest there is no need to emulate the guest real mode
code in the vm86 container or in the emulator. Also the guest big real
mode code works like native.
This patch enhances Xen to use the unrestricted guest feature if
available on the processor. It also adds a new xen parameter to
disable the unrestricted guest feature at the boot time.
Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
The first function is compiled only in case minios is compiled without
newlib, since newlib already provides an implementation for ffs.
On the other hand ffsl and ffsll are always compiled because newlib
misses those functions.
This patch also provides an implementation for __ffsti2 and __ffsdi2
because they are needed by gcc in order to successfully link ffsll.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
This patch fixes the following error.
ia64/xc_ia64_linux_restore.c:546: error: conflicting types for
xc_domain_restore
./xenguest.h:49: error: previous declaration of xc_domain_restore was
here
make[4]: *** [ia64/xc_ia64_linux_restore.o] Error 1
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
This patch fixes the following link error.
xen/common/built_in.o: In function `_rw_is_write_locked':
xen/common/spinlock.c:249: undefined reference to
`_raw_rw_is_write_locked'
make[3]: *** [xen/xen-syms] Error 1
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
At present, we're not doing any at all, so if a domain e.g. tries to
do two map operations at the same time from different vcpus then you
could end up with both operations getting back the same maptrack
handle.
Fix this problem by just shoving an enormous lock around grant table
operations. This is unlikely to be heavily contended, because netback
and blkback both restrict themselves to mapping on a single vcpu at a
time (globally for netback, and per-device for blkback), and most of
the interesting bits are already protected by the remote domain's
grant table lock anyway.
The unconteded acquisition cost might be significant for some
workloads. If that were the case, it might be worth only acquiring
the lock only for multi-vcpu domains, since we only manipulate the
maptrack table in the context of one of the domain's vcpus. I've not
done that optimisation here, because I didn't want to think about what
would happen if e.g. a cpu got hot-unplugged from a domain while it
was performing a map operation.
Signed-off-by: Steven Smith <steven.smith@citrix.com>
I've checked the duplicate-check code here and I found that's checked
only in the context of one domain but not cross-domain. The thing is
that we should check tap/vbd device cross-domain not to allow another
guest to use the same disk image in some circumstances to prevent VM's
disk corruption.
The patch included denies disk image addition under those
circumstances:
1. We're adding read-only disk that's already used as write-exclusive
2. We're adding write-shared disk that's already used as
write-exclusive
3. We're adding write-exclusive disk that's already used
4. We're adding read-only disk that's already used as write-shared*
(because of I/O caching issues etc.)
The vif device duplicate check remains the same it was and it's
checked in the context of current domain only so that behaviour has
been preserved.
Signed-off-by: Michal Novotny <minovotn@redhat.com>
New AMD processors will support the Pause Filter Feature.
This feature creates a new field in the VMCB called Pause
Filter Count. If Pause Filter Count is greater than 0 and
ntercepting PAUSEs is enabled, the processor will increment
an internal counter when a PAUSE instruction occurs instead
of intercepting. When the internal counter reaches the
Pause Filter Count value, a PAUSE intercept will occur.
This feature can be used to detect contended spinlocks,
especially when the lock holding VCPU is not scheduled.
Rescheduling another VCPU prevents the VCPU seeking the
lock from wasting its quantum by spinning idly.
Experimental results show that most spinlocks are held
for less than 1000 PAUSE cycles or more than a few
thousand. Default the Pause Filter Counter to 3000 to
detect the contended spinlocks.
Processor support for this feature is indicated by a CPUID
bit.
On a 24 core system running 4 guests each with 16 VCPUs,
this patch improved overall performance of each guest's
32 job kernbench by approximately 1%. Further performance
improvement may be possible with a more sophisticated
yield algorithm.
Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
If boot="ndc", rombios cannot try to boot next device.
Because rombios jump to the boot vector without pushing return
address, gPXE code and so on cannot return if it fail to boot.
Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com>
Remove the unused "retry" parameter of on_selected_cpus(),
on_each_cpu(), smp_call_function(), and smp_call_function_single().
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Rather than passing cpumasks by value in all cases (which is
problematic for large NR_CPUS configurations), pass them 'by
reference' (i.e. through a pointer to a const cpumask).
On x86 this changes send_IPI_mask() to always only send IPIs to remote
CPUs (meaning any caller needing to handle the current CPU as well has
to do so on its own).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
... splitting it into global nr_irqs (determined at boot time) and
per- domain nr_pirqs (derived from nr_irqs and a possibly command line
specified value, which probably should later become a per-domain
config setting).
This has the (desirable imo) side effect of reducing the size of
struct hvm_irq_dpci from requiring an order-3 page to order-2 (on
x86-64), which nevertheless still is too large.
However, there is now a variable size bit array on the stack in
pt_irq_time_out() - while for the moment this probably is okay, it
certainly doesn't look nice. However, replacing this with a static
(pre-)allocation also seems less than ideal, because that would
require at least min(d->nr_pirqs, NR_VECTORS) bit arrays of
d->nr_pirqs bits, since this bit array is used outside of the
serialized code region in that function, and keeping the domain's
event lock acquired across pirq_guest_eoi() doesn't look like a good
idea either.
The IRQ- and vector-indexed arrays hanging off struct hvm_irq_dpci
could in fact be changed further to dynamically use the smaller of the
two ranges for indexing, since there are other assumptions about a
one-to-one relationship between IRQs and vectors here and elsewhere.
Additionally, it seems to me that struct hvm_mirq_dpci_mapping's
digl_list and gmsi fields could really be overlayed, which would yield
significant savings since this structure gets always instanciated in
form of d->nr_pirqs (as per the above could also be the smaller of
this and NR_VECTORS) dimensioned arrays.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
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>
Keir Fraser