Currently mem-sharing can be performed on a page-by-page basis from the control
domain. However, this process is quite wasteful when a range of pages have to
be deduplicated.
This patch introduces a new mem_sharing memop for range sharing where
the user doesn't have to separately nominate each page in both the source and
destination domain, and the looping over all pages happen in the hypervisor.
This significantly reduces the overhead of sharing a range of memory.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
As recommended in http://www.gnu.org/licenses/gpl-howto.en.html.
This is the result of:
$ git grep -El Mass\|Temple\|Franklin | xargs ./fsf.pl
Where fsf.pl is:
#!/usr/bin/perl -w -pi.bak -0777
my $repl = 'If not, see <http://www.gnu.org/licenses/>.';
my $br = qr/(?:\s*\n\s*(?:[\*\#]|\/\/|\.\\" )?\s*|\s+)/;
my $inwt = qr/[Ii]f${br}not,${br}write${br}(?:to${br})?the${br}Free${br}Software${br}Foundation,(?:${br}Inc\.,)?/;
my $mass = qr/675${br}Mass${br}Ave,?${br}Cambridge,?${br}MA${br}02139,?${br}USA,?\.?/;
my $franklin = qr/51${br}Franklin${br}St(?:reet)?(?:,${br}| - )Fifth${br}Floor,?${br}Boston,?${br}MA,?${br}02110-1301,?${br}USA,?\.?/;
my $temple = qr/59${br}Temple${br}Place(?:,${br}| - )Suite${br}330,?${br}Boston,?${br}MA,?${br}021110?-1307,?${br}USA,?\.?/;
s|$inwt$br$mass|$repl|m;
s|$inwt$br$franklin|$repl|m;
s|$inwt$br$temple|$repl|m;
The only remaining mentions of these addresses are in COPYING files which I
haven't touched.
Some of the changed files are imports from elsewhere, however
filtering them out is tricky, I think it is tolerable to have these
files be modified here and then perhaps reverted on the next sync,
since it's only 1-2 lines and obvious what is going on.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Thus far mem_access and mem_sharing memops had been able to signal
to Xen to start pulling responses off the corresponding rings. In this patch
we retire these memops and add them to the option to the vm_event_op domctl.
The vm_event_op domctl suboptions are the same for each ring thus we
consolidate them into XEN_VM_EVENT_ENABLE/DISABLE/RESUME.
As part of this patch in libxc we also rename the mem_access_enable/disable
functions to monitor_enable/disable and move them into xc_monitor.c.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
In this patch we mechanically rename mem_event to vm_event. This patch
introduces no logic changes to the code. Using the name vm_event better
describes the intended use of this subsystem, which is not limited to memory
events. It can be used for off-loading the decision making logic into helper
applications when encountering various events during a VM's execution.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
The name of one of the mem_event rings still implies it is used only
for memory accesses, which is no longer the case. It is also used to
deliver various HVM events, thus the name "monitor" is more appropriate
in this setting.
Couple functions incorrectly labeled as part of mem_event is also renamed
to reflect that they belong to mem_access.
The mem_event subop definitions are also shortened to be more meaningful.
The tool side changes are only mechanical renaming to match these new names.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Remove costly mem_sharing audits from the inline path, and instead make them
callable as a memop.
Have the audit function return the number of errors detected.
Update memshrtool to be able to trigger audits.
Set sharing audits as enabled by default.
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Signed-off-by: Adin Scannell <adin@scannell.ca>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Tim Deegan <tim@xen.org>
Per page operations in the paging, sharing, and access tracking subsystems are
all implemented with domctls (e.g. a domctl to evict one page, or to share one
page).
Under heavy load, the domctl path reveals a lack of scalability. The domctl
lock serializes dom0's vcpus in the hypervisor. When performing thousands of
per-page operations on dozens of domains, these vcpus will spin in the
hypervisor. Beyond the aggressive locking, an added inefficiency of blocking
vcpus in the domctl lock is that dom0 is prevented from re-scheduling any of
its other work-starved processes.
We retain the domctl interface for setting up and tearing down
paging/sharing/mem access for a domain. But we migrate all the per page
operations to use the memory_op hypercalls (e.g XENMEM_*).
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla>
Signed-off-by: Adin Scannell <adin@scannell.ca>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Tim Deegan <tim@xen.org>
This patch is the folded version of API updates, along with the associated tool
changes to ensure that the build is always consistent.
API updates:
- The source domain in the sharing calls is no longer assumed to be dom0.
- Previously, the mem sharing code would return an opaque handle to index
shared pages (and nominees) in its global hash table. By removing the hash
table, the handle becomes a version, to avoid sharing a stale version of a
page. Thus, libxc wrappers and tools need to be updated to recall the share
functions with the information needed to fetch the page (which they readily
have).
Tool updates:
The only (in-tree, that we know of) consumer of the mem sharing API is the
memshr tool. This is updated to use the new API.
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Signed-off-by: Adin Scannell <adin@scannell.ca>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Tim Deegan <tim@xen.org>
Currently the memshr functions use uint32_t for the domid. This actually leads
to a funny domid_t -> uint32_t -> domid_t sequence of casts. This patch
updates the API functions to be domid_t in the first place.
No tools need to be modified with this patch, the casts were implicit.
Signed-off-by: Adin Scannell <adin@scannell.ca>
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Acked-by: Ian Jackson <ian.jackson.citrix.com>
Committed-by: Ian Jackson <ian.jackson.citrix.com>
Up to now a single ring buffer was used for mem_share, xenpaging and
xen-access. Each helper would have to cooperate and pull only its own
requests from the ring. Unfortunately this was not implemented. And
even if it was, it would make the whole concept fragile because a crash
or early exit of one helper would stall the others.
What happend up to now is that active xenpaging + memory_sharing would
push memsharing requests in the buffer. xenpaging is not prepared for
such requests.
This patch creates an independet ring buffer for mem_share, xenpaging
and xen-access and adds also new functions to enable xenpaging and
xen-access. The xc_mem_event_enable/xc_mem_event_disable functions will
be removed. The various XEN_DOMCTL_MEM_EVENT_* macros were cleaned up.
Due to the removal the API changed, so the SONAME will be changed too.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Tim Deegan <tim@xen.org>
# User Ian Campbell <ian.campbell@citrix.com>
# Date 1282671421 -3600
# Node ID d1dd29a470ef1b9d2c77478a123326036dfe90bb
# Parent d7a4adad9c328decbd384d87b23001aea8951b86
tools/libxc, tools/libelf: Relicense under LGPL v2.1
Relicense these two libraries under LGPL v2.1 only except where
individual files already included the "or later" provision.
Copyright holders have been contacted by Stephen Spector and have all
agreed this change.
Removed tools/libxc/ia64/aclinux.h since it appeared to be
unused. There is a separate, more up to date, copy in
xen/include/acpi/platform/aclinux.h which does appear to be used.
Clarify the license of MiniOS privcmd.h under the same terms as other
tools/include/xen-sys headers.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Stephen Spector <stephen.spector@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
This patch eliminate the global variables in libxenctrl (used for
logging and error reporting).
Instead the information which was in the global variables is now in a
new xc_interface* opaque structure, which xc_interface open returns
instead of the raw file descriptor; furthermore, logging is done via
xentoollog.
There are three new parameters to xc_interface_open to control the
logging, but existing callers can just pass "0" for all three to get
the old behaviour.
All libxc callers have been adjusted accordingly.
Also update QEMU_TAG for corresponding qemu change.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Tamas K Lengyel
Ian Campbell
Andres Lagar-Cavilla
Tim Deegan
Olaf Hering
Keir Fraser