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* Fix emacs local variable block to use correct C style variable.David Vrabel2013-02-211-1/+1
| | | | | | | The emacs variable to set the C style from a local variable block is c-file-style, not c-set-style. Signed-off-by: David Vrabel <david.vrabel@citrix.com
* Use a reserved pfn in the guest address space to store mem event ringsTim Deegan2012-03-081-3/+3
| | | | | | | | | | | | | | | | | | This solves a long-standing issue in which the pages backing these rings were pages belonging to dom0 user-space processes. Thus, if the process would die unexpectedly, Xen would keep posting events to a page now belonging to some other process. We update all API-consumers in tree (xenpaging and xen-access). This is an API/ABI change, so please speak up if it breaks your accumptions. The patch touches tools, hypervisor x86/hvm bits, and hypervisor x86/mm bits. Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org> Acked-by: Tim Deegan <tim@xen.org> Acked-by: Ian Campbell <ian.campbell@citrix.com> Committed-by: Tim Deegan <tim@xen.org>
* Tools: Remove shared page from mem_event/access/paging interfacesTim Deegan2012-03-081-2/+8
| | | | | | | | | | | | | | | | | | | | | | Don't use the superfluous shared page, return the event channel directly as part of the domctl struct, instead. In-tree consumers (xenpaging, xen-access) updated. This is an ABI/API change, so please voice any concerns. Known pending issues: - pager could die and its ring page could be used by some other process, yet Xen retains the mapping to it. - use a saner interface for the paging_load buffer. This change also affects the x86/mm bits in the hypervisor that process the mem_event setup domctl. Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org> Acked-by: Tim Deegan <tim@xen.org> Acked-by: Olaf Hering <olaf@aepfle.de> Acked-by: Ian Campbell <ian.campbell@citrix.com> Committed-by: Tim Deegan <tim@xen.org>
* Use memops for mem paging, sharing, and access, instead of domctlsAndres Lagar-Cavilla2012-02-101-6/+6
| | | | | | | | | | | | | | | | | | | | | | | 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>
* mem_event: use different ringbuffers for share, paging and accessOlaf Hering2011-09-161-2/+19
| | | | | | | | | | | | | | | | | | | | | | | 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>
* mem_access: HVMOPs for setting mem accessJoe Epstein2011-01-071-0/+42
* Creates HVMOPs for setting and getting memory access. The hypercalls can set individual pages or the default access for new/refreshed pages. * Added functions to libxc to access these hypercalls. Signed-off-by: Joe Epstein <jepstein98@gmail.com> Reviewed-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Keir Fraser <keir@xen.org> Acked-by: Tim Deegan <Tim.Deegan@citrix.com>