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2019-07-19Merge tag 'for-linus-5.3a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds1-3/+13
Pull xen updates from Juergen Gross: "Fixes and features: - A series to introduce a common command line parameter for disabling paravirtual extensions when running as a guest in virtualized environment - A fix for int3 handling in Xen pv guests - Removal of the Xen-specific tmem driver as support of tmem in Xen has been dropped (and it was experimental only) - A security fix for running as Xen dom0 (XSA-300) - A fix for IRQ handling when offlining cpus in Xen guests - Some small cleanups" * tag 'for-linus-5.3a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: let alloc_xenballooned_pages() fail if not enough memory free xen/pv: Fix a boot up hang revealed by int3 self test x86/xen: Add "nopv" support for HVM guest x86/paravirt: Remove const mark from x86_hyper_xen_hvm variable xen: Map "xen_nopv" parameter to "nopv" and mark it obsolete x86: Add "nopv" parameter to disable PV extensions x86/xen: Mark xen_hvm_need_lapic() and xen_x2apic_para_available() as __init xen: remove tmem driver Revert "x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized" xen/events: fix binding user event channels to cpus
2019-07-18proc/sysctl: add shared variables for range checkMatteo Croce1-5/+2
In the sysctl code the proc_dointvec_minmax() function is often used to validate the user supplied value between an allowed range. This function uses the extra1 and extra2 members from struct ctl_table as minimum and maximum allowed value. On sysctl handler declaration, in every source file there are some readonly variables containing just an integer which address is assigned to the extra1 and extra2 members, so the sysctl range is enforced. The special values 0, 1 and INT_MAX are very often used as range boundary, leading duplication of variables like zero=0, one=1, int_max=INT_MAX in different source files: $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l 248 Add a const int array containing the most commonly used values, some macros to refer more easily to the correct array member, and use them instead of creating a local one for every object file. This is the bloat-o-meter output comparing the old and new binary compiled with the default Fedora config: # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164) Data old new delta sysctl_vals - 12 +12 __kstrtab_sysctl_vals - 12 +12 max 14 10 -4 int_max 16 - -16 one 68 - -68 zero 128 28 -100 Total: Before=20583249, After=20583085, chg -0.00% [mcroce@redhat.com: tipc: remove two unused variables] Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com [akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c] [arnd@arndb.de: proc/sysctl: make firmware loader table conditional] Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de [akpm@linux-foundation.org: fix fs/eventpoll.c] Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18xen: let alloc_xenballooned_pages() fail if not enough memory freeJuergen Gross1-3/+13
Instead of trying to allocate pages with GFP_USER in add_ballooned_pages() check the available free memory via si_mem_available(). GFP_USER is far less limiting memory exhaustion than the test via si_mem_available(). This will avoid dom0 running out of memory due to excessive foreign page mappings especially on ARM and on x86 in PVH mode, as those don't have a pre-ballooned area which can be used for foreign mappings. As the normal ballooning suffers from the same problem don't balloon down more than si_mem_available() pages in one iteration. At the same time limit the default maximum number of retries. This is part of XSA-300. Signed-off-by: Juergen Gross <jgross@suse.com>
2019-03-15xen/balloon: Fix mapping PG_offline pages to user spaceDavid Hildenbrand1-1/+4
The XEN balloon driver - in contrast to other balloon drivers - allows to map some inflated pages to user space. Such pages are allocated via alloc_xenballooned_pages() and freed via free_xenballooned_pages(). The pfn space of these allocated pages is used to map other things by the hypervisor using hypercalls. Pages marked with PG_offline must never be mapped to user space (as this page type uses the mapcount field of struct pages). So what we can do is, clear/set PG_offline when allocating/freeing an inflated pages. This way, most inflated pages can be excluded by dumping tools and the "reused for other purpose" balloon pages are correctly not marked as PG_offline. Fixes: 77c4adf6a6df (xen/balloon: mark inflated pages PG_offline) Reported-by: Julien Grall <julien.grall@arm.com> Tested-by: Julien Grall <julien.grall@arm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-03-05xen/balloon: mark inflated pages PG_offlineDavid Hildenbrand1-0/+3
Mark inflated and never onlined pages PG_offline, to tell the world that the content is stale and should not be dumped. Link: http://lkml.kernel.org/r/20181119101616.8901-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian Hansen <chansen3@cisco.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Julien Freche <jfreche@vmware.com> Cc: Kairui Song <kasong@redhat.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Len Brown <len.brown@intel.com> Cc: Lianbo Jiang <lijiang@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Miles Chen <miles.chen@mediatek.com> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Pankaj gupta <pagupta@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xavier Deguillard <xdeguillard@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05mm/page_alloc.c: memory hotplug: free pages as higher orderArun KS1-5/+10
When freeing pages are done with higher order, time spent on coalescing pages by buddy allocator can be reduced. With section size of 256MB, hot add latency of a single section shows improvement from 50-60 ms to less than 1 ms, hence improving the hot add latency by 60 times. Modify external providers of online callback to align with the change. [arunks@codeaurora.org: v11] Link: http://lkml.kernel.org/r/1547792588-18032-1-git-send-email-arunks@codeaurora.org [akpm@linux-foundation.org: remove unused local, per Arun] [akpm@linux-foundation.org: avoid return of void-returning __free_pages_core(), per Oscar] [akpm@linux-foundation.org: fix it for mm-convert-totalram_pages-and-totalhigh_pages-variables-to-atomic.patch] [arunks@codeaurora.org: v8] Link: http://lkml.kernel.org/r/1547032395-24582-1-git-send-email-arunks@codeaurora.org [arunks@codeaurora.org: v9] Link: http://lkml.kernel.org/r/1547098543-26452-1-git-send-email-arunks@codeaurora.org Link: http://lkml.kernel.org/r/1538727006-5727-1-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mathieu Malaterre <malat@debian.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Srivatsa Vaddagiri <vatsa@codeaurora.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28mm/memory_hotplug: drop "online" parameter from add_memory_resource()David Hildenbrand1-1/+1
Userspace should always be in charge of how to online memory and if memory should be onlined automatically in the kernel. Let's drop the parameter to overwrite this - XEN passes memhp_auto_online, just like add_memory(), so we can directly use that instead internally. Link: http://lkml.kernel.org/r/20181123123740.27652-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Juergen Gross <jgross@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: David Hildenbrand <david@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Mathieu Malaterre <malat@debian.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-02Merge tag 'for-linus-4.20a-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds1-56/+9
Pull xen fixes from Juergen Gross: - A revert of a previous commit as it is no longer necessary and has shown to cause problems in some memory hotplug cases. - Some small fixes and a minor cleanup. - A patch for adding better diagnostic data in a very rare failure case. * tag 'for-linus-4.20a-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: pvcalls-front: fixes incorrect error handling Revert "xen/balloon: Mark unallocated host memory as UNUSABLE" xen: xlate_mmu: add missing header to fix 'W=1' warning xen/x86: add diagnostic printout to xen_mc_flush() in case of error x86/xen: cleanup includes in arch/x86/xen/spinlock.c
2018-11-29Revert "xen/balloon: Mark unallocated host memory as UNUSABLE"Igor Druzhinin1-56/+9
This reverts commit b3cf8528bb21febb650a7ecbf080d0647be40b9f. That commit unintentionally broke Xen balloon memory hotplug with "hotplug_unpopulated" set to 1. As long as "System RAM" resource got assigned under a new "Unusable memory" resource in IO/Mem tree any attempt to online this memory would fail due to general kernel restrictions on having "System RAM" resources as 1st level only. The original issue that commit has tried to workaround fa564ad96366 ("x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 00-1f, 30-3f, 60-7f)") also got amended by the following 03a551734 ("x86/PCI: Move and shrink AMD 64-bit window to avoid conflict") which made the original fix to Xen ballooning unnecessary. Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2018-10-31mm/memory_hotplug: make add_memory() take the device_hotplug_lockDavid Hildenbrand1-0/+3
add_memory() currently does not take the device_hotplug_lock, however is aleady called under the lock from arch/powerpc/platforms/pseries/hotplug-memory.c drivers/acpi/acpi_memhotplug.c to synchronize against CPU hot-remove and similar. In general, we should hold the device_hotplug_lock when adding memory to synchronize against online/offline request (e.g. from user space) - which already resulted in lock inversions due to device_lock() and mem_hotplug_lock - see 30467e0b3be ("mm, hotplug: fix concurrent memory hot-add deadlock"). add_memory()/add_memory_resource() will create memory block devices, so this really feels like the right thing to do. Holding the device_hotplug_lock makes sure that a memory block device can really only be accessed (e.g. via .online/.state) from user space, once the memory has been fully added to the system. The lock is not held yet in drivers/xen/balloon.c arch/powerpc/platforms/powernv/memtrace.c drivers/s390/char/sclp_cmd.c drivers/hv/hv_balloon.c So, let's either use the locked variants or take the lock. Don't export add_memory_resource(), as it once was exported to be used by XEN, which is never built as a module. If somebody requires it, we also have to export a locked variant (as device_hotplug_lock is never exported). Link: http://lkml.kernel.org/r/20180925091457.28651-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mathieu Malaterre <malat@debian.org> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-31mm: remove include/linux/bootmem.hMike Rapoport1-1/+1
Move remaining definitions and declarations from include/linux/bootmem.h into include/linux/memblock.h and remove the redundant header. The includes were replaced with the semantic patch below and then semi-automated removal of duplicated '#include <linux/memblock.h> @@ @@ - #include <linux/bootmem.h> + #include <linux/memblock.h> [sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au [sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au [sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal] Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26xen/balloon: Share common memory reservation routinesOleksandr Andrushchenko1-69/+6
Memory {increase|decrease}_reservation and VA mappings update/reset code used in balloon driver can be made common, so other drivers can also re-use the same functionality without open-coding. Create a dedicated file for the shared code and export corresponding symbols for other kernel modules. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-12-20xen/balloon: Mark unallocated host memory as UNUSABLEBoris Ostrovsky1-9/+56
Commit f5775e0b6116 ("x86/xen: discard RAM regions above the maximum reservation") left host memory not assigned to dom0 as available for memory hotplug. Unfortunately this also meant that those regions could be used by others. Specifically, commit fa564ad96366 ("x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 00-1f, 30-3f, 60-7f)") may try to map those addresses as MMIO. To prevent this mark unallocated host memory as E820_TYPE_UNUSABLE (thus effectively reverting f5775e0b6116) and keep track of that region as a hostmem resource that can be used for the hotplug. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com>
2017-08-31xen: Don't try to call xen_alloc_p2m_entry() on autotranslating guestsBoris Ostrovsky1-3/+5
Commit aba831a69632 ("xen: remove tests for pvh mode in pure pv paths") removed XENFEAT_auto_translated_physmap test in xen_alloc_p2m_entry() since it is assumed that the routine is never called by non-PV guests. However, alloc_xenballooned_pages() may make this call on a PVH guest. Prevent this from happening by adding XENFEAT_auto_translated_physmap check there. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Fixes: aba831a69632 ("xen: remove tests for pvh mode in pure pv paths")
2017-07-23xen/balloon: don't online new memory initiallyJuergen Gross1-0/+3
When setting up the Xenstore watch for the memory target size the new watch will fire at once. Don't try to reach the configured target size by onlining new memory in this case, as the current memory size will be smaller in almost all cases due to e.g. BIOS reserved pages. Onlining new memory will lead to more problems e.g. undesired conflicts with NVMe devices meant to be operated as block devices. Instead remember the difference between target size and current size when the watch fires for the first time and apply it to any further size changes, too. In order to avoid races between balloon.c and xen-balloon.c init calls do the xen-balloon.c initialization from balloon.c. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02xen/balloon: decorate PV-only parts with #ifdef CONFIG_XEN_PVVitaly Kuznetsov1-10/+20
Balloon driver uses several PV-only concepts (xen_start_info, xen_extra_mem,..) and it seems the simpliest solution to make HVM-only build happy is to decorate these parts with #ifdefs. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-03-02sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>Ingo Molnar1-0/+1
Add #include <linux/cred.h> dependencies to all .c files rely on sched.h doing that for them. Note that even if the count where we need to add extra headers seems high, it's still a net win, because <linux/sched.h> is included in over 2,200 files ... Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-12xen/balloon: Only mark a page as managed when it is releasedRoss Lagerwall1-4/+2
Only mark a page as managed when it is released back to the allocator. This ensures that the managed page count does not get falsely increased when a VM is running. Correspondingly change it so that pages are marked as unmanaged after getting them from the allocator. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2016-06-23xen/balloon: Fix declared-but-not-defined warningRoss Lagerwall1-15/+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>
2016-04-06xen/balloon: Fix crash when ballooning on x86 32 bit PAERoss Lagerwall1-0/+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>
2016-03-22Merge tag 'for-linus-4.6-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds1-4/+0
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
2016-03-21drivers/xen: make [xen-]ballon explicitly non-modularPaul Gortmaker1-4/+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>
2016-03-15xen_balloon: support memory auto onlining policyVitaly Kuznetsov1-1/+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>
2016-03-15memory-hotplug: add automatic onlining policy for the newly added memoryVitaly Kuznetsov1-1/+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>
2016-01-30xen, mm: Set IORESOURCE_SYSTEM_RAM to System RAMToshi Kani1-1/+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>
2015-10-23xen/balloon: Use the correct sizeof when declaring frame_listJulien Grall1-1/+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>
2015-10-23xen/balloon: Don't rely on the page granularity is the same for Xen and LinuxJulien Grall1-15/+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>
2015-10-23xen/balloon: pre-allocate p2m entries for ballooned pagesDavid Vrabel1-0/+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>
2015-10-23xen/balloon: use hotplugged pages for foreign mappings etc.David Vrabel1-10/+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.
2015-10-23xen/balloon: make alloc_xenballoon_pages() always allocate low pagesDavid Vrabel1-13/+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>
2015-10-23xen/balloon: only hotplug additional memory if requiredDavid Vrabel1-4/+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.
2015-10-23xen/balloon: rationalize memory hotplug statsDavid Vrabel1-63/+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>
2015-10-23xen/balloon: find non-conflicting regions to place hotplugged memoryDavid Vrabel1-20/+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.
2015-09-08xen: Use correctly the Xen memory terminologiesJulien Grall1-1/+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>
2015-09-08xen: switch extra memory accounting to use pfnsJuergen Gross1-3/+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>
2015-07-20xen: release lock occasionally during ballooningJuergen Gross1-8/+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>
2015-03-23xen/balloon: before adding hotplugged memory, set frames to invalidJuergen Gross1-0/+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>
2015-01-28xen: remove scratch frames for ballooned pages and m2p overrideDavid Vrabel1-84/+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>
2014-10-23xen/balloon: Don't continue ballooning when BP_ECANCELED is encounteredBoris Ostrovsky1-0/+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>
2014-09-02xen/balloon: cancel ballooning if adding new memory failedDavid Vrabel1-2/+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>
2014-07-04xen/balloon: set ballooned out pages as invalid in p2mDavid Vrabel1-7/+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>
2014-04-07Merge tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds1-12/+24
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 ...
2014-03-25xen/balloon: flush persistent kmaps in correct positionWei Liu1-6/+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+
2014-03-20xen, balloon: Fix CPU hotplug callback registrationSrivatsa S. Bhat1-12/+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>
2014-01-06xen: simplify balloon_first_page() with list_first_entry_or_null()Jie Liu1-8/+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>
2013-12-13xen/balloon: Seperate the auto-translate logic properly (v2)Stefano Stabellini1-29/+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>
2013-11-08xen: delete new instances of added __cpuinitPaul Gortmaker1-2/+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>
2013-11-08xen/balloon: Set balloon's initial state to number of existing RAM pagesBoris Ostrovsky1-1/+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>
2013-09-24xen/balloon: don't alloc page while non-preemptibleDavid Vrabel1-12/+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>
2013-09-11xen/balloon: remove BUG_ON in increase_reservationWei Liu1-2/+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>
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