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* Revert "xen PVonHVM: use E820_Reserved area for shared_info"Konrad Rzeszutek Wilk2013-02-141-1/+1
| | | | | | | | | | | | | This reverts commit 9d02b43dee0d7fb18dfb13a00915550b1a3daa9f. We are doing this b/c on 32-bit PVonHVM with older hypervisors (Xen 4.1) it ends up bothing up the start_info. This is bad b/c we use it for the time keeping, and the timekeeping code loops forever - as the version field never changes. Olaf says to revert it, so lets do that. Acked-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen PVonHVM: use E820_Reserved area for shared_infoOlaf Hering2012-11-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a respin of 00e37bdb0113a98408de42db85be002f21dbffd3 ("xen PVonHVM: move shared_info to MMIO before kexec"). Currently kexec in a PVonHVM guest fails with a triple fault because the new kernel overwrites the shared info page. The exact failure depends on the size of the kernel image. This patch moves the pfn from RAM into an E820 reserved memory area. The pfn containing the shared_info is located somewhere in RAM. This will cause trouble if the current kernel is doing a kexec boot into a new kernel. The new kernel (and its startup code) can not know where the pfn is, so it can not reserve the page. The hypervisor will continue to update the pfn, and as a result memory corruption occours in the new kernel. The toolstack marks the memory area FC000000-FFFFFFFF as reserved in the E820 map. Within that range newer toolstacks (4.3+) will keep 1MB starting from FE700000 as reserved for guest use. Older Xen4 toolstacks will usually not allocate areas up to FE700000, so FE700000 is expected to work also with older toolstacks. In Xen3 there is no reserved area at a fixed location. If the guest is started on such old hosts the shared_info page will be placed in RAM. As a result kexec can not be used. Signed-off-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/arm: receive Xen events on ARMStefano Stabellini2012-09-141-1/+0
| | | | | | | | | | Compile events.c on ARM. Parse, map and enable the IRQ to get event notifications from the device tree (node "/xen"). Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/p2m: Add logic to revector a P2M tree to use __va leafs.Konrad Rzeszutek Wilk2012-08-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During bootup Xen supplies us with a P2M array. It sticks it right after the ramdisk, as can be seen with a 128GB PV guest: (certain parts removed for clarity): xc_dom_build_image: called xc_dom_alloc_segment: kernel : 0xffffffff81000000 -> 0xffffffff81e43000 (pfn 0x1000 + 0xe43 pages) xc_dom_pfn_to_ptr: domU mapping: pfn 0x1000+0xe43 at 0x7f097d8bf000 xc_dom_alloc_segment: ramdisk : 0xffffffff81e43000 -> 0xffffffff925c7000 (pfn 0x1e43 + 0x10784 pages) xc_dom_pfn_to_ptr: domU mapping: pfn 0x1e43+0x10784 at 0x7f0952dd2000 xc_dom_alloc_segment: phys2mach : 0xffffffff925c7000 -> 0xffffffffa25c7000 (pfn 0x125c7 + 0x10000 pages) xc_dom_pfn_to_ptr: domU mapping: pfn 0x125c7+0x10000 at 0x7f0942dd2000 xc_dom_alloc_page : start info : 0xffffffffa25c7000 (pfn 0x225c7) xc_dom_alloc_page : xenstore : 0xffffffffa25c8000 (pfn 0x225c8) xc_dom_alloc_page : console : 0xffffffffa25c9000 (pfn 0x225c9) nr_page_tables: 0x0000ffffffffffff/48: 0xffff000000000000 -> 0xffffffffffffffff, 1 table(s) nr_page_tables: 0x0000007fffffffff/39: 0xffffff8000000000 -> 0xffffffffffffffff, 1 table(s) nr_page_tables: 0x000000003fffffff/30: 0xffffffff80000000 -> 0xffffffffbfffffff, 1 table(s) nr_page_tables: 0x00000000001fffff/21: 0xffffffff80000000 -> 0xffffffffa27fffff, 276 table(s) xc_dom_alloc_segment: page tables : 0xffffffffa25ca000 -> 0xffffffffa26e1000 (pfn 0x225ca + 0x117 pages) xc_dom_pfn_to_ptr: domU mapping: pfn 0x225ca+0x117 at 0x7f097d7a8000 xc_dom_alloc_page : boot stack : 0xffffffffa26e1000 (pfn 0x226e1) xc_dom_build_image : virt_alloc_end : 0xffffffffa26e2000 xc_dom_build_image : virt_pgtab_end : 0xffffffffa2800000 So the physical memory and virtual (using __START_KERNEL_map addresses) layout looks as so: phys __ka /------------\ /-------------------\ | 0 | empty | 0xffffffff80000000| | .. | | .. | | 16MB | <= kernel starts | 0xffffffff81000000| | .. | | | | 30MB | <= kernel ends => | 0xffffffff81e43000| | .. | & ramdisk starts | .. | | 293MB | <= ramdisk ends=> | 0xffffffff925c7000| | .. | & P2M starts | .. | | .. | | .. | | 549MB | <= P2M ends => | 0xffffffffa25c7000| | .. | start_info | 0xffffffffa25c7000| | .. | xenstore | 0xffffffffa25c8000| | .. | cosole | 0xffffffffa25c9000| | 549MB | <= page tables => | 0xffffffffa25ca000| | .. | | | | 550MB | <= PGT end => | 0xffffffffa26e1000| | .. | boot stack | | \------------/ \-------------------/ As can be seen, the ramdisk, P2M and pagetables are taking a bit of __ka addresses space. Which is a problem since the MODULES_VADDR starts at 0xffffffffa0000000 - and P2M sits right in there! This results during bootup with the inability to load modules, with this error: ------------[ cut here ]------------ WARNING: at /home/konrad/ssd/linux/mm/vmalloc.c:106 vmap_page_range_noflush+0x2d9/0x370() Call Trace: [<ffffffff810719fa>] warn_slowpath_common+0x7a/0xb0 [<ffffffff81030279>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e [<ffffffff81071a45>] warn_slowpath_null+0x15/0x20 [<ffffffff81130b89>] vmap_page_range_noflush+0x2d9/0x370 [<ffffffff81130c4d>] map_vm_area+0x2d/0x50 [<ffffffff811326d0>] __vmalloc_node_range+0x160/0x250 [<ffffffff810c5369>] ? module_alloc_update_bounds+0x19/0x80 [<ffffffff810c6186>] ? load_module+0x66/0x19c0 [<ffffffff8105cadc>] module_alloc+0x5c/0x60 [<ffffffff810c5369>] ? module_alloc_update_bounds+0x19/0x80 [<ffffffff810c5369>] module_alloc_update_bounds+0x19/0x80 [<ffffffff810c70c3>] load_module+0xfa3/0x19c0 [<ffffffff812491f6>] ? security_file_permission+0x86/0x90 [<ffffffff810c7b3a>] sys_init_module+0x5a/0x220 [<ffffffff815ce339>] system_call_fastpath+0x16/0x1b ---[ end trace fd8f7704fdea0291 ]--- vmalloc: allocation failure, allocated 16384 of 20480 bytes modprobe: page allocation failure: order:0, mode:0xd2 Since the __va and __ka are 1:1 up to MODULES_VADDR and cleanup_highmap rids __ka of the ramdisk mapping, what we want to do is similar - get rid of the P2M in the __ka address space. There are two ways of fixing this: 1) All P2M lookups instead of using the __ka address would use the __va address. This means we can safely erase from __ka space the PMD pointers that point to the PFNs for P2M array and be OK. 2). Allocate a new array, copy the existing P2M into it, revector the P2M tree to use that, and return the old P2M to the memory allocate. This has the advantage that it sets the stage for using XEN_ELF_NOTE_INIT_P2M feature. That feature allows us to set the exact virtual address space we want for the P2M - and allows us to boot as initial domain on large machines. So we pick option 2). This patch only lays the groundwork in the P2M code. The patch that modifies the MMU is called "xen/mmu: Copy and revector the P2M tree." Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/mmu: The xen_setup_kernel_pagetable doesn't need to return anything.Konrad Rzeszutek Wilk2012-08-231-1/+1
| | | | | | | We don't need to return the new PGD - as we do not use it. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* Merge tag 'stable/for-linus-3.5-rc0-tag' of ↵Linus Torvalds2012-05-241-1/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen Pull Xen updates from Konrad Rzeszutek Wilk: "Features: * Extend the APIC ops implementation and add IRQ_WORKER vector support so that 'perf' can work properly. * Fix self-ballooning code, and balloon logic when booting as initial domain. * Move array printing code to generic debugfs * Support XenBus domains. * Lazily free grants when a domain is dead/non-existent. * In M2P code use batching calls Bug-fixes: * Fix NULL dereference in allocation failure path (hvc_xen) * Fix unbinding of IRQ_WORKER vector during vCPU hot-unplug * Fix HVM guest resume - we would leak an PIRQ value instead of reusing the existing one." Fix up add-add onflicts in arch/x86/xen/enlighten.c due to addition of apic ipi interface next to the new apic_id functions. * tag 'stable/for-linus-3.5-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: do not map the same GSI twice in PVHVM guests. hvc_xen: NULL dereference on allocation failure xen: Add selfballoning memory reservation tunable. xenbus: Add support for xenbus backend in stub domain xen/smp: unbind irqworkX when unplugging vCPUs. xen: enter/exit lazy_mmu_mode around m2p_override calls xen/acpi/sleep: Enable ACPI sleep via the __acpi_os_prepare_sleep xen: implement IRQ_WORK_VECTOR handler xen: implement apic ipi interface xen/setup: update VA mapping when releasing memory during setup xen/setup: Combine the two hypercall functions - since they are quite similar. xen/setup: Populate freed MFNs from non-RAM E820 entries and gaps to E820 RAM xen/setup: Only print "Freeing XXX-YYY pfn range: Z pages freed" if Z > 0 xen/gnttab: add deferred freeing logic debugfs: Add support to print u32 array in debugfs xen/p2m: An early bootup variant of set_phys_to_machine xen/p2m: Collapse early_alloc_p2m_middle redundant checks. xen/p2m: Allow alloc_p2m_middle to call reserve_brk depending on argument xen/p2m: Move code around to allow for better re-usage.
| * xen/setup: update VA mapping when releasing memory during setupDavid Vrabel2012-05-071-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In xen_memory_setup(), if a page that is being released has a VA mapping this must also be updated. Otherwise, the page will be not released completely -- it will still be referenced in Xen and won't be freed util the mapping is removed and this prevents it from being reallocated at a different PFN. This was already being done for the ISA memory region in xen_ident_map_ISA() but on many systems this was omitting a few pages as many systems marked a few pages below the ISA memory region as reserved in the e820 map. This fixes errors such as: (XEN) page_alloc.c:1148:d0 Over-allocation for domain 0: 2097153 > 2097152 (XEN) memory.c:133:d0 Could not allocate order=0 extent: id=0 memflags=0 (0 of 17) Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen/x86: Implement x86_apic_opsKonrad Rzeszutek Wilk2012-05-011-0/+4
|/ | | | | | | | | | | | Or rather just implement one different function as opposed to the native one : the read function. We synthesize the values. Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> [v1: Rebased on top of tip/x86/urgent] [v2: Return 0xfd instead of 0xff in the default case] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* Merge branch 'stable/vga.support' into stable/driversKonrad Rzeszutek Wilk2011-06-211-0/+11
|\ | | | | | | | | * stable/vga.support: xen: allow enable use of VGA console on dom0
| * xen: allow enable use of VGA console on dom0Jeremy Fitzhardinge2011-06-061-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | Get the information about the VGA console hardware from Xen, and put it into the form the bootloader normally generates, so that the rest of the kernel can deal with VGA as usual. [ Impact: make VGA console work in dom0 ] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> [v1: Rebased on 2.6.39] [v2: Removed incorrect comments and fixed compile warnings] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | arch/x86/xen/xen-ops: Cleanup code/data sections definitionsDaniel Kiper2011-05-191-1/+1
|/ | | | | | | | Cleanup code/data sections definitions accordingly to include/linux/init.h. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: PV on HVM: support PV spinlocks and IPIsStefano Stabellini2011-02-251-0/+2
| | | | | | | | | | | Initialize PV spinlocks on boot CPU right after native_smp_prepare_cpus (that switch to APIC mode and initialize APIC routing); on secondary CPUs on CPU_UP_PREPARE. Enable the usage of event channels to send and receive IPIs when running as a PV on HVM guest. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
* xen: unplug the emulated devices at resume timeStefano Stabellini2010-12-021-1/+1
| | | | | | Early after being resumed we need to unplug again the emulated devices. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
* xen: add support for PATJeremy Fitzhardinge2010-10-221-0/+2
| | | | | | | | | | | | | | | | | | | | | Convert Linux PAT entries into Xen ones when constructing ptes. Linux doesn't use _PAGE_PAT for ptes, so the only difference in the first 4 entries is that Linux uses _PAGE_PWT for WC, whereas Xen (and default) use it for WT. xen_pte_val does the inverse conversion. We hard-code assumptions about Linux's current PAT layout, but a warning on the wrmsr to MSR_IA32_CR_PAT should point out any problems. If necessary we could go to a more general table-based conversion between Linux and Xen PAT entries. hugetlbfs poses a problem at the moment, the x86 architecture uses the same flag for _PAGE_PAT and _PAGE_PSE, which changes meaning depending on which pagetable level we're using. At the moment this should be OK so long as nobody tries to do a pte_val on a hugetlbfs pte. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* xen: make sure xen_max_p2m_pfn is up to dateJeremy Fitzhardinge2010-10-221-0/+1
| | | | | | | | | Keep xen_max_p2m_pfn up to date with the end of the extra memory we're adding. It is possible that it will be too high since memory may be truncated by a "mem=" option on the kernel command line, but that won't matter. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* Merge branch 'upstream/pvhvm' into upstream/xenJeremy Fitzhardinge2010-08-041-5/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * upstream/pvhvm: Introduce CONFIG_XEN_PVHVM compile option blkfront: do not create a PV cdrom device if xen_hvm_guest support multiple .discard.* sections to avoid section type conflicts xen/pvhvm: fix build problem when !CONFIG_XEN xenfs: enable for HVM domains too x86: Call HVMOP_pagetable_dying on exit_mmap. x86: Unplug emulated disks and nics. x86: Use xen_vcpuop_clockevent, xen_clocksource and xen wallclock. xen: Fix find_unbound_irq in presence of ioapic irqs. xen: Add suspend/resume support for PV on HVM guests. xen: Xen PCI platform device driver. x86/xen: event channels delivery on HVM. x86: early PV on HVM features initialization. xen: Add support for HVM hypercalls. Conflicts: arch/x86/xen/enlighten.c arch/x86/xen/time.c
| * x86: Unplug emulated disks and nics.Stefano Stabellini2010-07-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a xen_emul_unplug command line option to the kernel to unplug xen emulated disks and nics. Set the default value of xen_emul_unplug depending on whether or not the Xen PV frontends and the Xen platform PCI driver have been compiled for this kernel (modules or built-in are both OK). The user can specify xen_emul_unplug=ignore to enable PV drivers on HVM even if the host platform doesn't support unplug. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * x86: Use xen_vcpuop_clockevent, xen_clocksource and xen wallclock.Stefano Stabellini2010-07-261-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use xen_vcpuop_clockevent instead of hpet and APIC timers as main clockevent device on all vcpus, use the xen wallclock time as wallclock instead of rtc and use xen_clocksource as clocksource. The pv clock algorithm needs to work correctly for the xen_clocksource and xen wallclock to be usable, only modern Xen versions offer a reliable pv clock in HVM guests (XENFEAT_hvm_safe_pvclock). Using the hpet as clocksource means a VMEXIT every time we read/write to the hpet mmio addresses, pvclock give us a better rating without VMEXITs. Same goes for the xen wallclock and xen_vcpuop_clockevent Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Don Dutile <ddutile@redhat.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * xen: Add suspend/resume support for PV on HVM guests.Stefano Stabellini2010-07-221-0/+1
| | | | | | | | | | | | | | | | | | Suspend/resume requires few different things on HVM: the suspend hypercall is different; we don't need to save/restore memory related settings; except the shared info page and the callback mechanism. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * x86/xen: event channels delivery on HVM.Sheng Yang2010-07-221-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Set the callback to receive evtchns from Xen, using the callback vector delivery mechanism. The traditional way for receiving event channel notifications from Xen is via the interrupts from the platform PCI device. The callback vector is a newer alternative that allow us to receive notifications on any vcpu and doesn't need any PCI support: we allocate a vector exclusively to receive events, in the vector handler we don't need to interact with the vlapic, therefore we avoid a VMEXIT. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* | Xen: register panic notifier to take crashes of xen guests on panicDonald Dutile2010-08-041-0/+2
|/ | | | | | | | Register a panic notifier so that when the guest crashes it can shut down the domain and indicate it was a crash to the host. Signed-off-by: Donald Dutile <ddutile@redhat.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* xen: correctly restore pfn_to_mfn_list_list after resumeIan Campbell2009-12-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pvops kernels >= 2.6.30 can currently only be saved and restored once. The second attempt to save results in: ERROR Internal error: Frame# in pfn-to-mfn frame list is not in pseudophys ERROR Internal error: entry 0: p2m_frame_list[0] is 0xf2c2c2c2, max 0x120000 ERROR Internal error: Failed to map/save the p2m frame list I finally narrowed it down to: commit cdaead6b4e657f960d6d6f9f380e7dfeedc6a09b Author: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Date: Fri Feb 27 15:34:59 2009 -0800 xen: split construction of p2m mfn tables from registration Build the p2m_mfn_list_list early with the rest of the p2m table, but register it later when the real shared_info structure is in place. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> The unforeseen side-effect of this change was to cause the mfn list list to not be rebuilt on resume. Prior to this change it would have been rebuilt via xen_post_suspend() -> xen_setup_shared_info() -> xen_setup_mfn_list_list(). Fix by explicitly calling xen_build_mfn_list_list() from xen_post_suspend(). Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stable Kernel <stable@kernel.org>
* xen: re-register runstate area earlier on resume.Ian Campbell2009-12-031-0/+1
| | | | | | | | | | | | | | This is necessary to ensure the runstate area is available to xen_sched_clock before any calls to printk which will require it in order to provide a timestamp. I chose to pull the xen_setup_runstate_info out of xen_time_init into the caller in order to maintain parity with calling xen_setup_runstate_info separately from calling xen_time_resume. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stable Kernel <stable@kernel.org>
* x86: Move xen_post_allocator_init into xen_pagetable_setup_doneThomas Gleixner2009-08-311-2/+0
| | | | | | | | | We really do not need two paravirt/x86_init_ops functions which are called in two consecutive source lines. Move the only user of post_allocator_init into the already existing pagetable_setup_done function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'x86-xen-for-linus' of ↵Linus Torvalds2009-06-101-1/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (42 commits) xen: cache cr0 value to avoid trap'n'emulate for read_cr0 xen/x86-64: clean up warnings about IST-using traps xen/x86-64: fix breakpoints and hardware watchpoints xen: reserve Xen start_info rather than e820 reserving xen: add FIX_TEXT_POKE to fixmap lguest: update lazy mmu changes to match lguest's use of kvm hypercalls xen: honour VCPU availability on boot xen: add "capabilities" file xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet xen/sys/hypervisor: change writable_pt to features xen: add /sys/hypervisor support xen/xenbus: export xenbus_dev_changed xen: use device model for suspending xenbus devices xen: remove suspend_cancel hook xen/dev-evtchn: clean up locking in evtchn xen: export ioctl headers to userspace xen: add /dev/xen/evtchn driver xen: add irq_from_evtchn xen: clean up gate trap/interrupt constants xen: set _PAGE_NX in __supported_pte_mask before pagetable construction ...
| * xen/mmu: some early pagetable cleanupsJeremy Fitzhardinge2009-03-301-2/+0
| | | | | | | | | | | | | | | | | | 1. make sure early-allocated ptes are pinned, so they can be later unpinned 2. don't pin pmd+pud, just make them RO 3. scatter some __inits around Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| * x86/paravirt: flush pending mmu updates on context switchJeremy Fitzhardinge2009-03-291-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: allow preemption during lazy mmu updates If we're in lazy mmu mode when context switching, leave lazy mmu mode, but remember the task's state in TIF_LAZY_MMU_UPDATES. When we resume the task, check this flag and re-enter lazy mmu mode if its set. This sets things up for allowing lazy mmu mode while preemptible, though that won't actually be active until the next change. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
* | x86: Fix performance regression caused by paravirt_ops on native kernelsJeremy Fitzhardinge2009-05-151-4/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Xiaohui Xin and some other folks at Intel have been looking into what's behind the performance hit of paravirt_ops when running native. It appears that the hit is entirely due to the paravirtualized spinlocks introduced by: | commit 8efcbab674de2bee45a2e4cdf97de16b8e609ac8 | Date: Mon Jul 7 12:07:51 2008 -0700 | | paravirt: introduce a "lock-byte" spinlock implementation The extra call/return in the spinlock path is somehow causing an increase in the cycles/instruction of somewhere around 2-7% (seems to vary quite a lot from test to test). The working theory is that the CPU's pipeline is getting upset about the call->call->locked-op->return->return, and seems to be failing to speculate (though I haven't seen anything definitive about the precise reasons). This doesn't entirely make sense, because the performance hit is also visible on unlock and other operations which don't involve locked instructions. But spinlock operations clearly swamp all the other pvops operations, even though I can't imagine that they're nearly as common (there's only a .05% increase in instructions executed). If I disable just the pv-spinlock calls, my tests show that pvops is identical to non-pvops performance on native (my measurements show that it is actually about .1% faster, but Xiaohui shows a .05% slowdown). Summary of results, averaging 10 runs of the "mmperf" test, using a no-pvops build as baseline: nopv Pv-nospin Pv-spin CPU cycles 100.00% 99.89% 102.18% instructions 100.00% 100.10% 100.15% CPI 100.00% 99.79% 102.03% cache ref 100.00% 100.84% 100.28% cache miss 100.00% 90.47% 88.56% cache miss rate 100.00% 89.72% 88.31% branches 100.00% 99.93% 100.04% branch miss 100.00% 103.66% 107.72% branch miss rt 100.00% 103.73% 107.67% wallclock 100.00% 99.90% 102.20% The clear effect here is that the 2% increase in CPI is directly reflected in the final wallclock time. (The other interesting effect is that the more ops are out of line calls via pvops, the lower the cache access and miss rates. Not too surprising, but it suggests that the non-pvops kernel is over-inlined. On the flipside, the branch misses go up correspondingly...) So, what's the fix? Paravirt patching turns all the pvops calls into direct calls, so _spin_lock etc do end up having direct calls. For example, the compiler generated code for paravirtualized _spin_lock is: <_spin_lock+0>: mov %gs:0xb4c8,%rax <_spin_lock+9>: incl 0xffffffffffffe044(%rax) <_spin_lock+15>: callq *0xffffffff805a5b30 <_spin_lock+22>: retq The indirect call will get patched to: <_spin_lock+0>: mov %gs:0xb4c8,%rax <_spin_lock+9>: incl 0xffffffffffffe044(%rax) <_spin_lock+15>: callq <__ticket_spin_lock> <_spin_lock+20>: nop; nop /* or whatever 2-byte nop */ <_spin_lock+22>: retq One possibility is to inline _spin_lock, etc, when building an optimised kernel (ie, when there's no spinlock/preempt instrumentation/debugging enabled). That will remove the outer call/return pair, returning the instruction stream to a single call/return, which will presumably execute the same as the non-pvops case. The downsides arel 1) it will replicate the preempt_disable/enable code at eack lock/unlock callsite; this code is fairly small, but not nothing; and 2) the spinlock definitions are already a very heavily tangled mass of #ifdefs and other preprocessor magic, and making any changes will be non-trivial. The other obvious answer is to disable pv-spinlocks. Making them a separate config option is fairly easy, and it would be trivial to enable them only when Xen is enabled (as the only non-default user). But it doesn't really address the common case of a distro build which is going to have Xen support enabled, and leaves the open question of whether the native performance cost of pv-spinlocks is worth the performance improvement on a loaded Xen system (10% saving of overall system CPU when guests block rather than spin). Still it is a reasonable short-term workaround. [ Impact: fix pvops performance regression when running native ] Analysed-by: "Xin Xiaohui" <xiaohui.xin@intel.com> Analysed-by: "Li Xin" <xin.li@intel.com> Analysed-by: "Nakajima Jun" <jun.nakajima@intel.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Xen-devel <xen-devel@lists.xensource.com> LKML-Reference: <4A0B62F7.5030802@goop.org> [ fixed the help text ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen/mmu: some early pagetable cleanupsJeremy Fitzhardinge2009-04-081-2/+0
|/ | | | | | | | | 1. make sure early-allocated ptes are pinned, so they can be later unpinned 2. don't pin pmd+pud, just make them RO 3. scatter some __inits around Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* xen: setup percpu data pointersJeremy Fitzhardinge2009-02-041-0/+2
| | | | | | | | | | | | | | We need to access percpu data fairly early, so set up the percpu registers as soon as possible. We only need to load the appropriate segment register. We already have a GDT, but its hard to change it early because we need to manipulate the pagetable to do so, and that hasn't been set up yet. Also, set the kernel stack when bringing up secondary CPUs. If we don't they all end up sharing the same stack... Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* xen: move remaining mmu-related stuff into mmu.cJeremy Fitzhardinge2009-01-301-0/+8
| | | | | | | | | | Impact: Cleanup Move remaining mmu-related stuff into mmu.c. A general cleanup, and lay the groundwork for later patches. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* xen: convert to cpumask_var_t and new cpumask primitives.Mike Travis2008-12-161-1/+1
| | | | | | | | Simple change, and eventual space saving when NR_CPUS >> nr_cpu_ids. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
* xen_setup_vcpu_info_placement() is not init on x86Al Viro2008-11-301-1/+1
| | | | | | | ... so get xen-ops.h in agreement with xen/smp.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* xen: make CPU hotplug functions staticAlex Nixon2008-09-081-4/+0
| | | | | | | | There's no need for these functions to be accessed from outside of xen/smp.c Signed-off-by: Alex Nixon <alex.nixon@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: implement CPU hotpluggingAlex Nixon2008-08-251-0/+6
| | | | | | | | | | | | | | | | | Note the changes from 2.6.18-xen CPU hotplugging: A vcpu_down request from the remote admin via Xenbus both hotunplugs the CPU, and disables it by removing it from the cpu_present map, and removing its entry in /sys. A vcpu_up request from the remote admin only re-enables the CPU, and does not immediately bring the CPU up. A udev event is emitted, which can be caught by the user if he wishes to automatically re-up CPUs when available, or implement a more complex policy. Signed-off-by: Alex Nixon <alex.nixon@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: build fix in "xen spinlock updates and performance measurements"Jeremy Fitzhardinge2008-08-221-0/+2
| | | | | | | | | | | | | | | | Ingo Molnar wrote: > -tip testing found this build failure: > > arch/x86/xen/spinlock.c: In function ‘spin_time_start’: > arch/x86/xen/spinlock.c:60: error: implicit declaration of function ‘xen_clocksource_read’ > > i've excluded these new commits for now from tip/master - could you > please send a delta fix against tip/x86/xen? Make xen_clocksource_read non-static. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: compile irq functions without -pg for ftraceJeremy Fitzhardinge2008-07-311-0/+1
| | | | | | | | | | | | | For some reason I managed to miss a bunch of irq-related functions which also need to be compiled without -pg when using ftrace. This patch moves them into their own file, and starts a cleanup process I've been meaning to do anyway. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: "Alex Nixon (Intern)" <Alex.Nixon@eu.citrix.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: split spinlock implementations out into their own filesJeremy Fitzhardinge2008-07-241-0/+3
| | | | | | | | | | | | | ftrace requires certain low-level code, like spinlocks and timestamps, to be compiled without -pg in order to avoid infinite recursion. This patch splits out the core paravirt spinlocks and the Xen spinlocks into separate files which can be compiled without -pg. Also do xen/time.c while we're about it. As a result, we can now use ftrace within a Xen domain. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen64: set up syscall and sysenter entrypoints for 64-bitJeremy Fitzhardinge2008-07-161-0/+3
| | | | | | | | | | | | We set up entrypoints for syscall and sysenter. sysenter is only used for 32-bit compat processes, whereas syscall can be used in by both 32 and 64-bit processes. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen64: deal with extra words Xen pushes onto exception framesJeremy Fitzhardinge2008-07-161-0/+2
| | | | | | | | | | | | | Xen pushes two extra words containing the values of rcx and r11. This pvop hook copies the words back into their appropriate registers, and cleans them off the stack. This leaves the stack in native form, so the normal handler can run unchanged. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen64: smp.c compile hackingJeremy Fitzhardinge2008-07-161-2/+0
| | | | | | | | | | A number of random changes to make xen/smp.c compile in 64-bit mode. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>a Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: move smp setup into smp.cJeremy Fitzhardinge2008-07-161-8/+5
| | | | | | | | | | | Move all the smp_ops setup into smp.c, allowing a lot of things to become static. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: add xen_arch_resume()/xen_timer_resume hook for ia64 supportIsaku Yamahata2008-07-161-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | add xen_timer_resume() hook. Timer resume should be done after event channel is resumed. add xen_arch_resume() hook when ipi becomes usable after resume. After resume, some cpu specific resource must be reinitialized on ia64 that can't be set by another cpu. However available hooks is run once on only one cpu so that ipi has to be used. During stop_machine_run() ipi can't be used because interrupt is masked. So add another hook after stop_machine_run(). Another approach might be use resume hook which is run by device_resume(). However device_resume() may be executed on suspend error recovery path. So it is necessary to determine whether it is executed on real resume path or error recovery path. Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'generic-ipi' into generic-ipi-for-linusIngo Molnar2008-07-151-7/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/powerpc/Kconfig arch/s390/kernel/time.c arch/x86/kernel/apic_32.c arch/x86/kernel/cpu/perfctr-watchdog.c arch/x86/kernel/i8259_64.c arch/x86/kernel/ldt.c arch/x86/kernel/nmi_64.c arch/x86/kernel/smpboot.c arch/x86/xen/smp.c include/asm-x86/hw_irq_32.h include/asm-x86/hw_irq_64.h include/asm-x86/mach-default/irq_vectors.h include/asm-x86/mach-voyager/irq_vectors.h include/asm-x86/smp.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * x86: convert to generic helpers for IPI function callsJens Axboe2008-06-261-7/+2
| | | | | | | | | | | | | | | | | | | | This converts x86, x86-64, and xen to use the new helpers for smp_call_function() and friends, and adds support for smp_call_function_single(). Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | x86: rename paravirtualized TSC functionsAlok Kataria2008-07-091-1/+1
| | | | | | | | | | | | | | | | | | | | Rename the paravirtualized calculate_cpu_khz to calibrate_tsc. In all cases, we actually calibrate_tsc and use that as the cpu_khz value. Signed-off-by: Alok N Kataria <akataria@vmware.com> Signed-off-by: Dan Hecht <dhecht@vmware.com> Cc: Dan Hecht <dhecht@vmware.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: resume timers on all vcpusJeremy Fitzhardinge2008-06-021-0/+1
| | | | | | | | | | | | | | | | | | | | On resume, the vcpu timer modes will not be restored. The timer infrastructure doesn't do this for us, since it assumes the cpus are offline. We can just poke the other vcpus into the right mode directly though. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: restore vcpu_info mappingJeremy Fitzhardinge2008-06-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we're using vcpu_info mapping, then make sure its restored on all processors before relasing them from stop_machine. The only complication is that if this fails, we can't continue because we've already made assumptions that the mapping is available (baked in calls to the _direct versions of the functions, for example). Fortunately this can only happen with a 32-bit hypervisor, which may possibly run out of mapping space. On a 64-bit hypervisor, this is a non-issue. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | xen: implement save/restoreJeremy Fitzhardinge2008-05-271-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements Xen save/restore and migration. Saving is triggered via xenbus, which is polled in drivers/xen/manage.c. When a suspend request comes in, the kernel prepares itself for saving by: 1 - Freeze all processes. This is primarily to prevent any partially-completed pagetable updates from confusing the suspend process. If CONFIG_PREEMPT isn't defined, then this isn't necessary. 2 - Suspend xenbus and other devices 3 - Stop_machine, to make sure all the other vcpus are quiescent. The Xen tools require the domain to run its save off vcpu0. 4 - Within the stop_machine state, it pins any unpinned pgds (under construction or destruction), performs canonicalizes various other pieces of state (mostly converting mfns to pfns), and finally 5 - Suspend the domain Restore reverses the steps used to save the domain, ending when all the frozen processes are thawed. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | xen: add p2m mfn_list_listJeremy Fitzhardinge2008-05-271-0/+2
| | | | | | | | | | | | | | | | | | | | When saving a domain, the Xen tools need to remap all our mfns to portable pfns. In order to remap our p2m table, it needs to know where all its pages are, so maintain the references to the p2m table for it to use. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>