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* xen/balloon: Fix declared-but-not-defined warningRoss Lagerwall2016-06-231-15/+13
| | | | | | | | | | | Fix a declared-but-not-defined warning when building with XEN_BALLOON_MEMORY_HOTPLUG=n. This fixes a regression introduced by commit dfd74a1edfab ("xen/balloon: Fix crash when ballooning on x86 32 bit PAE"). Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Acked-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen/balloon: Fix crash when ballooning on x86 32 bit PAERoss Lagerwall2016-04-061-0/+16
| | | | | | | | | | | | | | | | | Commit 55b3da98a40dbb3776f7454daf0d95dde25c33d2 (xen/balloon: find non-conflicting regions to place hotplugged memory) caused a regression in 4.4. When ballooning on an x86 32 bit PAE system with close to 64 GiB of memory, the address returned by allocate_resource may be above 64 GiB. When using CONFIG_SPARSEMEM, this setup is limited to using physical addresses < 64 GiB. When adding memory at this address, it runs off the end of the mem_section array and causes a crash. Instead, fail the ballooning request. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Cc: <stable@vger.kernel.org> # 4.4+ Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* Merge tag 'for-linus-4.6-rc0-tag' of ↵Linus Torvalds2016-03-221-4/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from David Vrabel: "Features and fixes for 4.6: - Make earlyprintk=xen work for HVM guests - Remove module support for things never built as modules" * tag 'for-linus-4.6-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: drivers/xen: make platform-pci.c explicitly non-modular drivers/xen: make sys-hypervisor.c explicitly non-modular drivers/xen: make xenbus_dev_[front/back]end explicitly non-modular drivers/xen: make [xen-]ballon explicitly non-modular xen: audit usages of module.h ; remove unnecessary instances xen/x86: Drop mode-selecting ifdefs in startup_xen() xen/x86: Zero out .bss for PV guests hvc_xen: make early_printk work with HVM guests hvc_xen: fix xenboot for DomUs hvc_xen: add earlycon support
| * drivers/xen: make [xen-]ballon explicitly non-modularPaul Gortmaker2016-03-211-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Makefile / Kconfig currently controlling compilation here is: obj-y += grant-table.o features.o balloon.o manage.o preempt.o time.o [...] obj-$(CONFIG_XEN_BALLOON) += xen-balloon.o ...with: drivers/xen/Kconfig:config XEN_BALLOON drivers/xen/Kconfig: bool "Xen memory balloon driver" ...meaning that they currently are not being built as modules by anyone. Lets remove the modular code that is essentially orphaned, so that when reading the driver there is no doubt it is builtin-only. In doing so we uncover two implict includes that were obtained by module.h having such a wide include scope itself: In file included from drivers/xen/xen-balloon.c:41:0: include/xen/balloon.h:26:51: warning: ‘struct page’ declared inside parameter list [enabled by default] int alloc_xenballooned_pages(int nr_pages, struct page **pages); ^ include/xen/balloon.h: In function ‘register_xen_selfballooning’: include/xen/balloon.h:35:10: error: ‘ENOSYS’ undeclared (first use in this function) return -ENOSYS; ^ This is fixed by adding mm-types.h and errno.h to the list. We also delete the MODULE_LICENSE tags since all that information is already contained at the top of the file in the comments. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* | xen_balloon: support memory auto onlining policyVitaly Kuznetsov2016-03-161-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for the newly added kernel memory auto onlining policy to Xen ballon driver. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Suggested-by: Daniel Kiper <daniel.kiper@oracle.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Acked-by: David Vrabel <david.vrabel@citrix.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memory-hotplug: add automatic onlining policy for the newly added memoryVitaly Kuznetsov2016-03-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, all newly added memory blocks remain in 'offline' state unless someone onlines them, some linux distributions carry special udev rules like: SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online" to make this happen automatically. This is not a great solution for virtual machines where memory hotplug is being used to address high memory pressure situations as such onlining is slow and a userspace process doing this (udev) has a chance of being killed by the OOM killer as it will probably require to allocate some memory. Introduce default policy for the newly added memory blocks in /sys/devices/system/memory/auto_online_blocks file with two possible values: "offline" which preserves the current behavior and "online" which causes all newly added memory blocks to go online as soon as they're added. The default is "offline". Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | xen, mm: Set IORESOURCE_SYSTEM_RAM to System RAMToshi Kani2016-01-301-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Set IORESOURCE_SYSTEM_RAM in struct resource.flags of "System RAM" entries. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: David Vrabel <david.vrabel@citrix.com> # xen Cc: Andrew Banman <abanman@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-arch@vger.kernel.org Cc: linux-mm <linux-mm@kvack.org> Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1453841853-11383-9-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* xen/balloon: Use the correct sizeof when declaring frame_listJulien Grall2015-10-231-1/+1
| | | | | | | | | | | | | | | The type of the item in frame_list is xen_pfn_t which is not an unsigned long on ARM but an uint64_t. With the current computation, the size of frame_list will be 2 * PAGE_SIZE rather than PAGE_SIZE. I bet it's just mistake when the type has been switched from "unsigned long" to "xen_pfn_t" in commit 965c0aaafe3e75d4e65cd4ec862915869bde3abd "xen: balloon: use correct type for frame_list". Signed-off-by: Julien Grall <julien.grall@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen/balloon: Don't rely on the page granularity is the same for Xen and LinuxJulien Grall2015-10-231-15/+55
| | | | | | | | | | | | | | | | | | | | | For ARM64 guests, Linux is able to support either 64K or 4K page granularity. Although, the hypercall interface is always based on 4K page granularity. With 64K page granularity, a single page will be spread over multiple Xen frame. To avoid splitting the page into 4K frame, take advantage of the extent_order field to directly allocate/free chunk of the Linux page size. Note that PVMMU is only used for PV guest (which is x86) and the page granularity is always 4KB. Some BUILD_BUG_ON has been added to ensure that because the code has not been modified. Signed-off-by: Julien Grall <julien.grall@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen/balloon: pre-allocate p2m entries for ballooned pagesDavid Vrabel2015-10-231-0/+5
| | | | | | | | | | | | | | | Pages returned by alloc_xenballooned_pages() will be used for grant mapping which will call set_phys_to_machine() (in PV guests). Ballooned pages are set as INVALID_P2M_ENTRY in the p2m and thus may be using the (shared) missing tables and a subsequent set_phys_to_machine() will need to allocate new tables. Since the grant mapping may be done from a context that cannot sleep, the p2m entries must already be allocated. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
* xen/balloon: use hotplugged pages for foreign mappings etc.David Vrabel2015-10-231-10/+80
| | | | | | | | | | | | | | | | | | | | alloc_xenballooned_pages() is used to get ballooned pages to back foreign mappings etc. Instead of having to balloon out real pages, use (if supported) hotplugged memory. This makes more memory available to the guest and reduces fragmentation in the p2m. This is only enabled if the xen.balloon.hotplug_unpopulated sysctl is set to 1. This sysctl defaults to 0 in case the udev rules to automatically online hotplugged memory do not exist. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> --- v3: - Add xen.balloon.hotplug_unpopulated sysctl to enable use of hotplug for unpopulated pages.
* xen/balloon: make alloc_xenballoon_pages() always allocate low pagesDavid Vrabel2015-10-231-13/+8
| | | | | | | | All users of alloc_xenballoon_pages() wanted low memory pages, so remove the option for high memory. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
* xen/balloon: only hotplug additional memory if requiredDavid Vrabel2015-10-231-4/+19
| | | | | | | | | | | | | | | | | | | Now that we track the total number of pages (included hotplugged regions), it is easy to determine if more memory needs to be hotplugged. Add a new BP_WAIT state to signal that the balloon process needs to wait until kicked by the memory add notifier (when the new section is onlined by userspace). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> --- v3: - Return BP_WAIT if enough sections are already hotplugged. v2: - New BP_WAIT status after adding new memory sections.
* xen/balloon: rationalize memory hotplug statsDavid Vrabel2015-10-231-63/+12
| | | | | | | | | | | | | | The stats used for memory hotplug make no sense and are fiddled with in odd ways. Remove them and introduce total_pages to track the total number of pages (both populated and unpopulated) including those within hotplugged regions (note that this includes not yet onlined pages). This will be used in a subsequent commit (xen/balloon: only hotplug additional memory if required) when deciding whether additional memory needs to be hotplugged. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
* xen/balloon: find non-conflicting regions to place hotplugged memoryDavid Vrabel2015-10-231-20/+53
| | | | | | | | | | | | Instead of placing hotplugged memory at the end of RAM (which may conflict with PCI devices or reserved regions) use allocate_resource() to get a new, suitably aligned resource that does not conflict. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> --- v3: - Remove stale comment.
* xen: Use correctly the Xen memory terminologiesJulien Grall2015-09-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN is meant, I suspect this is because the first support for Xen was for PV. This resulted in some misimplementation of helpers on ARM and confused developers about the expected behavior. For instance, with pfn_to_mfn, we expect to get an MFN based on the name. Although, if we look at the implementation on x86, it's returning a GFN. For clarity and avoid new confusion, replace any reference to mfn with gfn in any helpers used by PV drivers. The x86 code will still keep some reference of pfn_to_mfn which may be used by all kind of guests No changes as been made in the hypercall field, even though they may be invalid, in order to keep the same as the defintion in xen repo. Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a name to close to the KVM function gfn_to_page. Take also the opportunity to simplify simple construction such as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up will come in follow-up patches. [1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cb Signed-off-by: Julien Grall <julien.grall@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen: switch extra memory accounting to use pfnsJuergen Gross2015-09-081-3/+3
| | | | | | | | | | | Instead of using physical addresses for accounting of extra memory areas available for ballooning switch to pfns as this is much less error prone regarding partial pages. Reported-by: Roger Pau Monné <roger.pau@citrix.com> Tested-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen: release lock occasionally during ballooningJuergen Gross2015-07-201-8/+7
| | | | | | | | | | | | | | | | When dom0 is being ballooned balloon_process() will hold the balloon mutex until it is finished. This will block e.g. creation of new domains as the device backends for the new domain need some autoballooned pages for the ring buffers. Avoid this by releasing the balloon mutex from time to time during ballooning. Adjust the comment above balloon_process() regarding multiple instances of balloon_process(). Instead of open coding it, just use cond_resched(). Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen/balloon: before adding hotplugged memory, set frames to invalidJuergen Gross2015-03-231-0/+23
| | | | | | | | | | | | | | | Commit 25b884a83d487fd62c3de7ac1ab5549979188482 ("x86/xen: set regions above the end of RAM as 1:1") introduced a regression. To be able to add memory pages which were added via memory hotplug to a pv domain, the pages must be "invalid" instead of "identity" in the p2m list before they can be added. Suggested-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Juergen Gross <jgross@suse.com> Cc: <stable@vger.kernel.org> # 3.16+ Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen: remove scratch frames for ballooned pages and m2p overrideDavid Vrabel2015-01-281-84/+2
| | | | | | | | | | | | | | | | | | | | | | The scratch frame mappings for ballooned pages and the m2p override are broken. Remove them in preparation for replacing them with simpler mechanisms that works. The scratch pages did not ensure that the page was not in use. In particular, the foreign page could still be in use by hardware. If the guest reused the frame the hardware could read or write that frame. The m2p override did not handle the same frame being granted by two different grant references. Trying an M2P override lookup in this case is impossible. With the m2p override removed, the grant map/unmap for the kernel mappings (for x86 PV) can be easily batched in set_foreign_p2m_mapping() and clear_foreign_p2m_mapping(). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
* xen/balloon: Don't continue ballooning when BP_ECANCELED is encounteredBoris Ostrovsky2014-10-231-0/+3
| | | | | | | | | | | | | | | | Commit 3dcf63677d4e ("xen/balloon: cancel ballooning if adding new memory failed") makes reserve_additional_memory() return BP_ECANCELED when an error is encountered. This error, however, is ignored by the caller (balloon_process()) since it is overwritten by subsequent call to update_schedule(). This results in continuous attempts to add more memory, all of which are likely to fail again. We should stop trying to schedule next iteration of ballooning when the current one has failed. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen/balloon: cancel ballooning if adding new memory failedDavid Vrabel2014-09-021-2/+2
| | | | | | | | | If the balloon driver is adding additional memory regions to the balloon and add_memory() fails it will likely continuously fail so cancel the balloon operation. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
* xen/balloon: set ballooned out pages as invalid in p2mDavid Vrabel2014-07-041-7/+5
| | | | | | | | | | | | | | | | | | | | | | | Since cd9151e26d31048b2b5e00fd02e110e07d2200c9 (xen/balloon: set a mapping for ballooned out pages), a ballooned out page had its entry in the p2m set to the MFN of one of the scratch pages. This means that the p2m will contain many entries pointing to the same MFN. During a domain save, these many-to-one entries are not identified as such and the scratch page is saved multiple times. On restore the ballooned pages are populated with new frames and the domain may use up its allocation before all pages can be restored. Since the original fix only needed to keep a mapping for the ballooned page it is safe to set ballooned out pages as INVALID_P2M_ENTRY in the p2m (as they were before). Thus preventing them from being saved and re-populated on restore. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reported-by: Marek Marczykowski <marmarek@invisiblethingslab.com> Tested-by: Marek Marczykowski <marmarek@invisiblethingslab.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: <stable@vger.kernel.org>
* Merge tag 'cpu-hotplug-3.15-rc1' of ↵Linus Torvalds2014-04-071-12/+24
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull CPU hotplug notifiers registration fixes from Rafael Wysocki: "The purpose of this single series of commits from Srivatsa S Bhat (with a small piece from Gautham R Shenoy) touching multiple subsystems that use CPU hotplug notifiers is to provide a way to register them that will not lead to deadlocks with CPU online/offline operations as described in the changelog of commit 93ae4f978ca7f ("CPU hotplug: Provide lockless versions of callback registration functions"). The first three commits in the series introduce the API and document it and the rest simply goes through the users of CPU hotplug notifiers and converts them to using the new method" * tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits) net/iucv/iucv.c: Fix CPU hotplug callback registration net/core/flow.c: Fix CPU hotplug callback registration mm, zswap: Fix CPU hotplug callback registration mm, vmstat: Fix CPU hotplug callback registration profile: Fix CPU hotplug callback registration trace, ring-buffer: Fix CPU hotplug callback registration xen, balloon: Fix CPU hotplug callback registration hwmon, via-cputemp: Fix CPU hotplug callback registration hwmon, coretemp: Fix CPU hotplug callback registration thermal, x86-pkg-temp: Fix CPU hotplug callback registration octeon, watchdog: Fix CPU hotplug callback registration oprofile, nmi-timer: Fix CPU hotplug callback registration intel-idle: Fix CPU hotplug callback registration clocksource, dummy-timer: Fix CPU hotplug callback registration drivers/base/topology.c: Fix CPU hotplug callback registration acpi-cpufreq: Fix CPU hotplug callback registration zsmalloc: Fix CPU hotplug callback registration scsi, fcoe: Fix CPU hotplug callback registration scsi, bnx2fc: Fix CPU hotplug callback registration scsi, bnx2i: Fix CPU hotplug callback registration ...
| * xen, balloon: Fix CPU hotplug callback registrationSrivatsa S. Bhat2014-03-201-12/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). The xen balloon driver doesn't take get/put_online_cpus() around this code, but that is also buggy, since it can miss CPU hotplug events in between the initialization and callback registration: for_each_online_cpu(cpu) init_cpu(cpu); ^ | Race window; Can miss CPU hotplug events here. v register_cpu_notifier(&foobar_cpu_notifier); Interestingly, the balloon code in xen can simply be reorganized as shown below, to have a race-free method to register hotplug callbacks, without even taking get/put_online_cpus(). This is because the initialization performed for already online CPUs is exactly the same as that performed for CPUs that come online later. Moreover, the code has checks in place to avoid double initialization. register_cpu_notifier(&foobar_cpu_notifier); get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); put_online_cpus(); A hotplug operation that occurs between registering the notifier and calling get_online_cpus(), won't disrupt anything, because the code takes care to perform the memory allocations only once. So reorganize the balloon code in xen this way to fix the issues with CPU hotplug callback registration. Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ingo Molnar <mingo@kernel.org> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | xen/balloon: flush persistent kmaps in correct positionWei Liu2014-03-251-6/+18
|/ | | | | | | | | | | | | | | | | | | | | | | Xen balloon driver will update ballooned out pages' P2M entries to point to scratch page for PV guests. In 24f69373e2 ("xen/balloon: don't alloc page while non-preemptible", kmap_flush_unused was moved after updating P2M table. In that case for 32 bit PV guest we might end up with P2M X -----> S (S is mfn of balloon scratch page) M2P Y -----> X (Y is mfn in persistent kmap entry) kmap_flush_unused() iterates through all the PTEs in the kmap address space, using pte_to_page() to obtain the page. If the p2m and the m2p are inconsistent the incorrect page is returned. This will clear page->address on the wrong page which may cause subsequent oopses if that page is currently kmap'ed. Move the flush back between get_page and __set_phys_to_machine to fix this. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: stable@vger.kernel.org # 3.12+
* xen: simplify balloon_first_page() with list_first_entry_or_null()Jie Liu2014-01-061-8/+1
| | | | | | | | | | Replace the code logic at balloon_first_page() by calling list_first_entry_or_null() directly. since here is only one user of that routine, therefore we can just remove it. Signed-off-by: Jie Liu <jeff.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com>
* xen/balloon: Seperate the auto-translate logic properly (v2)Stefano Stabellini2013-12-131-29/+34
| | | | | | | | | | | | | | | | | | | | | | The auto-xlat logic vs the non-xlat means that we don't need to for auto-xlat guests (like PVH, HVM or ARM): - use P2M - use scratch page. However the code in increase_reservation does modify the p2m for auto_translate guests, but not in decrease_reservation. Fix that by avoiding any p2m modifications in both increase_reservation and decrease_reservation for auto_translated guests. And also avoid allocating or using scratch pages for auto_translated guests. Lastly, since !auto-xlat is really another way of saying 'xen_pv' remove the redundant 'xen_pv_domain' check. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> [v2: Updated the description] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: delete new instances of added __cpuinitPaul Gortmaker2013-11-081-2/+2
| | | | | | | | | | | | | | | | | | commit 6efa20e49b9cb1db1ab66870cc37323474a75a13 ("xen: Support 64-bit PV guest receiving NMIs") and commit cd9151e26d31048b2b5e00fd02e110e07d2200c9 ( "xen/balloon: set a mapping for ballooned out pages") added new instances of __cpuinit usage. We removed this a couple versions ago; we now want to remove the compat no-op stubs. Introducing new users is not what we want to see at this point in time, as it will break once the stubs are gone. Cc: Konrad Rzeszutek Wilk <konrad@kernel.org> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/balloon: Set balloon's initial state to number of existing RAM pagesBoris Ostrovsky2013-11-081-1/+1
| | | | | | | | | | | | Currently balloon's initial value is set to max_pfn which includes non-RAM ranges such as MMIO hole. As result, initial memory target (specified by guest's configuration file) will appear smaller than what balloon driver perceives to be the current number of available pages. Thus it will balloon down "extra" pages, decreasing amount of available memory for no good reason. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/balloon: don't alloc page while non-preemptibleDavid Vrabel2013-09-241-12/+11
| | | | | | | | | get_balloon_scratch_page() disables preemption so we cannot call alloc_page() in between get/put_balloon_scratch_page(). Shuffle bits around in decrease_reservation() to avoid this. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/balloon: remove BUG_ON in increase_reservationWei Liu2013-09-111-2/+0
| | | | | | | | | The BUG_ON in increase_reservation is wrong as we have P2M entry ballooned out page set to balloon scratch page, so it might have a valid P2M entry at that point. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
* xen/balloon: ensure preemption is disabled when using a scratch pageDavid Vrabel2013-09-111-4/+7
| | | | | | | | | | | | | In decrease_reservation(), if the kernel is preempted between updating the mapping and updating the p2m then they may end up using different scratch pages. Use get_balloon_scratch_page() and put_balloon_scratch_page() which use get_cpu_var() and put_cpu_var() to correctly disable preemption. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Tested-by: Sander Eikelenboom <linux@eikelenboom.it>
* xen/balloon: don't set P2M entry for auto translated guestWei Liu2013-08-301-2/+7
| | | | | | | | | | | | | | | | | | In commit cd9151e2: xen/balloon: set a mapping for ballooned out pages we have the ballooned out page's mapping set to a scratch page. That commit also sets the P2M entry of ballooned out page to the scratch page's MFN. This is necessary for PV guest but not for HVM guest. On the other hand, setting the P2M entry would trigger BUG_ON in __set_phys_to_machine. The correct thing to do here is to avoid calling __set_phys_to_machine for auto translated guest. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
* xen/balloon: set a mapping for ballooned out pagesStefano Stabellini2013-08-091-3/+66
| | | | | | | | | | | | | | | | | Currently ballooned out pages are mapped to 0 and have INVALID_P2M_ENTRY in the p2m. These ballooned out pages are used to map foreign grants by gntdev and blkback (see alloc_xenballooned_pages). Allocate a page per cpu and map all the ballooned out pages to the corresponding mfn. Set the p2m accordingly. This way reading from a ballooned out page won't cause a kernel crash (see http://lists.xen.org/archives/html/xen-devel/2012-12/msg01154.html). Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> CC: alex@alex.org.uk CC: dcrisan@flexiant.com Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* Merge branch 'akpm' (updates from Andrew Morton)Linus Torvalds2013-07-041-18/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge first patch-bomb from Andrew Morton: - various misc bits - I'm been patchmonkeying ocfs2 for a while, as Joel and Mark have been distracted. There has been quite a bit of activity. - About half the MM queue - Some backlight bits - Various lib/ updates - checkpatch updates - zillions more little rtc patches - ptrace - signals - exec - procfs - rapidio - nbd - aoe - pps - memstick - tools/testing/selftests updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (445 commits) tools/testing/selftests: don't assume the x bit is set on scripts selftests: add .gitignore for kcmp selftests: fix clean target in kcmp Makefile selftests: add .gitignore for vm selftests: add hugetlbfstest self-test: fix make clean selftests: exit 1 on failure kernel/resource.c: remove the unneeded assignment in function __find_resource aio: fix wrong comment in aio_complete() drivers/w1/slaves/w1_ds2408.c: add magic sequence to disable P0 test mode drivers/memstick/host/r592.c: convert to module_pci_driver drivers/memstick/host/jmb38x_ms: convert to module_pci_driver pps-gpio: add device-tree binding and support drivers/pps/clients/pps-gpio.c: convert to module_platform_driver drivers/pps/clients/pps-gpio.c: convert to devm_* helpers drivers/parport/share.c: use kzalloc Documentation/accounting/getdelays.c: avoid strncpy in accounting tool aoe: update internal version number to v83 aoe: update copyright date aoe: perform I/O completions in parallel ...
| * mm: correctly update zone->managed_pagesJiang Liu2013-07-041-18/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enhance adjust_managed_page_count() to adjust totalhigh_pages for highmem pages. And change code which directly adjusts totalram_pages to use adjust_managed_page_count() because it adjusts totalram_pages, totalhigh_pages and zone->managed_pages altogether in a safe way. Remove inc_totalhigh_pages() and dec_totalhigh_pages() from xen/balloon driver bacause adjust_managed_page_count() has already adjusted totalhigh_pages. This patch also fixes two bugs: 1) enhances virtio_balloon driver to adjust totalhigh_pages when reserve/unreserve pages. 2) enhance memory_hotplug.c to adjust totalhigh_pages when hot-removing memory. We still need to deal with modifications of totalram_pages in file arch/powerpc/platforms/pseries/cmm.c, but need help from PPC experts. [akpm@linux-foundation.org: remove ifdef, per Wanpeng Li, virtio_balloon.c cleanup, per Sergei] [akpm@linux-foundation.org: export adjust_managed_page_count() to modules, for drivers/virtio/virtio_balloon.c] Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Minchan Kim <minchan@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <sworddragon2@aol.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | xen: Convert printks to pr_<level>Joe Perches2013-06-281-2/+4
|/ | | | | | | | | | | | | | | | | Convert printks to pr_<level> (excludes printk(KERN_DEBUG...) to be more consistent throughout the xen subsystem. Add pr_fmt with KBUILD_MODNAME or "xen:" KBUILD_MODNAME Coalesce formats and add missing word spaces Add missing newlines Align arguments and reflow to 80 columns Remove DRV_NAME from formats as pr_fmt adds the same content This does change some of the prefixes of these messages but it also does make them more consistent. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: Fixed assignment error in if statementLisa Nguyen2013-05-201-1/+2
| | | | | | | Fixed assignment error in if statement in balloon.c Signed-off-by: Lisa Nguyen <lisa@xenapiadmin.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: balloon: allow PVMMU interfaces to be compiled outIan Campbell2012-11-291-1/+4
| | | | | | | | | | | | | The ARM platform has no concept of PVMMU and therefor no HYPERVISOR_update_va_mapping et al. Allow this code to be compiled out when not required. In some similar situations (e.g. P2M) we have defined dummy functions to avoid this, however I think we can/should draw the line at dummying out actual hypercalls. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: balloon: use correct type for frame_listIan Campbell2012-10-191-1/+1
| | | | | | | This is now a xen_pfn_t. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: balloon: don't include e820.hIan Campbell2012-10-191-1/+0
| | | | | | | | This breaks on !X86 and AFAICT is not required on X86 either. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/balloon: Avoid OOM when requesting highmemDaniel De Graaf2011-11-161-2/+2
| | | | | | | | | | | If highmem pages are requested from the balloon on a system without highmem, the implementation of alloc_xenballooned_pages will allocate all available memory trying to find highmem pages to return. Allow low memory to be returned when highmem pages are requested to avoid this loop. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* Merge branch 'stable/cleanups-3.2' of ↵Linus Torvalds2011-11-071-7/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * 'stable/cleanups-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: use static initializers in xen-balloon.c Xen: fix braces and tabs coding style issue in xenbus_probe.c Xen: fix braces coding style issue in xenbus_probe.h Xen: fix whitespaces,tabs coding style issue in drivers/xen/pci.c Xen: fix braces coding style issue in gntdev.c and grant-table.c Xen: fix whitespaces,tabs coding style issue in drivers/xen/events.c Xen: fix whitespaces,tabs coding style issue in drivers/xen/balloon.c Fix up trivial whitespace-conflicts in drivers/xen/{balloon.c,pci.c,xenbus/xenbus_probe.c}
| * Xen: fix whitespaces,tabs coding style issue in drivers/xen/balloon.cRuslan Pisarev2011-07-261-8/+7
| | | | | | | | | | | | | | | | This is a patch to the balloon.c file that fixed up whitespaces, tabs errors found by the checkpatch.pl tools. Signed-off-by: Ruslan Pisarev <ruslan@rpisarev.org.ua> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen: Add module.h to modular drivers/xen users.Paul Gortmaker2011-11-011-0/+1
| | | | | | | | | | | | | | | | Previously these drivers just got module.h implicitly, but we are cleaning that up and it will be no longer. Call out the real users of it. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
| |
| \
*-. \ Merge branches 'stable/bug.fixes-3.2' and 'stable/mmu.fixes' of ↵Linus Torvalds2011-10-251-4/+8
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen * 'stable/bug.fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/p2m/debugfs: Make type_name more obvious. xen/p2m/debugfs: Fix potential pointer exception. xen/enlighten: Fix compile warnings and set cx to known value. xen/xenbus: Remove the unnecessary check. xen/irq: If we fail during msi_capability_init return proper error code. xen/events: Don't check the info for NULL as it is already done. xen/events: BUG() when we can't allocate our event->irq array. * 'stable/mmu.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: Fix selfballooning and ensure it doesn't go too far xen/gntdev: Fix sleep-inside-spinlock xen: modify kernel mappings corresponding to granted pages xen: add an "highmem" parameter to alloc_xenballooned_pages xen/p2m: Use SetPagePrivate and its friends for M2P overrides. xen/p2m: Make debug/xen/mmu/p2m visible again. Revert "xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set."
| | * | xen: add an "highmem" parameter to alloc_xenballooned_pagesStefano Stabellini2011-09-291-4/+8
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an highmem parameter to alloc_xenballooned_pages, to allow callers to request lowmem or highmem pages. Fix the code style of free_xenballooned_pages' prototype. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | | xen: allow balloon driver to use more than one memory regionDavid Vrabel2011-09-291-17/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow the xen balloon driver to populate its list of extra pages from more than one region of memory. This will allow platforms to provide (for example) a region of low memory and a region of high memory. The maximum possible number of extra regions is 128 (== E820MAX) which is quite large so xen_extra_mem is placed in __initdata. This is safe as both xen_memory_setup() and balloon_init() are in __init. The balloon regions themselves are not altered (i.e., there is still only the one region). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | | xen/balloon: simplify test for the end of usable RAMDavid Vrabel2011-09-291-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | When initializing the balloon only max_pfn needs to be checked (max_pfn will always be <= e820_end_of_ram_pfn()) and improve the confusing comment. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>