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* xen: Fix possible user space selector corruptionFrediano Ziglio2013-10-101-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Due to the way kernel is initialized under Xen is possible that the ring1 selector used by the kernel for the boot cpu end up to be copied to userspace leading to segmentation fault in the userspace. Xen code in the kernel initialize no-boot cpus with correct selectors (ds and es set to __USER_DS) but the boot one keep the ring1 (passed by Xen). On task context switch (switch_to) we assume that ds, es and cs already point to __USER_DS and __KERNEL_CSso these selector are not changed. If processor is an Intel that support sysenter instruction sysenter/sysexit is used so ds and es are not restored switching back from kernel to userspace. In the case the selectors point to a ring1 instead of __USER_DS the userspace code will crash on first memory access attempt (to be precise Xen on the emulated iret used to do sysexit will detect and set ds and es to zero which lead to GPF anyway). Now if an userspace process call kernel using sysenter and get rescheduled (for me it happen on a specific init calling wait4) could happen that the ring1 selector is set to ds and es. This is quite hard to detect cause after a while these selectors are fixed (__USER_DS seems sticky). Bisecting the code commit 7076aada1040de4ed79a5977dbabdb5e5ea5e249 appears to be the first one that have this issue. Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
* xen/smp: Update pv_lock_ops functions before alternative code starts under PVHVMKonrad Rzeszutek Wilk2013-09-091-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before this patch we would patch all of the pv_lock_ops sites using alternative assembler. Then later in the bootup cycle change the unlock_kick and lock_spinning to the Xen specific - without re patching. That meant that for the core of the kernel we would be running with the baremetal version of unlock_kick and lock_spinning while for modules we would have the proper Xen specific slowpaths. As most of the module uses some API from the core kernel that ended up with slowpath lockers waiting forever to be kicked (b/c they would be using the Xen specific slowpath logic). And the kick never came b/c the unlock path that was taken was the baremetal one. On PV we do not have the problem as we initialise before the alternative code kicks in. The fix is to make the updating of the pv_lock_ops function be done before the alternative code starts patching. Note that this patch fixes issues discovered by commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23. ("xen: disable PV spinlocks on HVM") wherein it mentioned PV spinlocks cannot possibly work with the current code because they are enabled after pvops patching has already been done, and because PV spinlocks use a different data structure than native spinlocks so we cannot switch between them dynamically. The first problem is solved by this patch. The second problem has been solved by commit 816434ec4a674fcdb3c2221a6dffdc8f34020550 (Merge branch 'x86-spinlocks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip) P.S. There is still the commit 70dd4998cb85f0ecd6ac892cc7232abefa432efb (xen/spinlock: Disable IRQ spinlock (PV) allocation on PVHVM) to revert but that can be done later after all other bugs have been fixed. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com>
* xen/spinlock: Fix locking path engaging too soon under PVHVM.Konrad Rzeszutek Wilk2013-09-091-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The xen_lock_spinning has a check for the kicker interrupts and if it is not initialized it will spin normally (not enter the slowpath). But for PVHVM case we would initialize the kicker interrupt before the CPU came online. This meant that if the booting CPU used a spinlock and went in the slowpath - it would enter the slowpath and block forever. The forever part because during bootup: the spinlock would be taken _before_ the CPU sets itself to be online (more on this further), and we enter to poll on the event channel forever. The bootup CPU (see commit fc78d343fa74514f6fd117b5ef4cd27e4ac30236 "xen/smp: initialize IPI vectors before marking CPU online" for details) and the CPU that started the bootup consult the cpu_online_mask to determine whether the booting CPU should get an IPI. The booting CPU has to set itself in this mask via: set_cpu_online(smp_processor_id(), true); However, if the spinlock is taken before this (and it is) and it polls on an event channel - it will never be woken up as the kernel will never send an IPI to an offline CPU. Note that the PVHVM logic in sending IPIs is using the HVM path which has numerous checks using the cpu_online_mask and cpu_active_mask. See above mention git commit for details. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com>
* Merge tag 'v3.11-rc7' into stable/for-linus-3.12Konrad Rzeszutek Wilk2013-09-091-2/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux 3.11-rc7 As we need the git commit 28817e9de4f039a1a8c1fe1df2fa2df524626b9e Author: Chuck Anderson <chuck.anderson@oracle.com> Date: Tue Aug 6 15:12:19 2013 -0700 xen/smp: initialize IPI vectors before marking CPU online * tag 'v3.11-rc7': (443 commits) Linux 3.11-rc7 ARC: [lib] strchr breakage in Big-endian configuration VFS: collect_mounts() should return an ERR_PTR bfs: iget_locked() doesn't return an ERR_PTR efs: iget_locked() doesn't return an ERR_PTR() proc: kill the extra proc_readfd_common()->dir_emit_dots() cope with potentially long ->d_dname() output for shmem/hugetlb usb: phy: fix build breakage USB: OHCI: add missing PCI PM callbacks to ohci-pci.c staging: comedi: bug-fix NULL pointer dereference on failed attach lib/lz4: correct the LZ4 license memcg: get rid of swapaccount leftovers nilfs2: fix issue with counting number of bio requests for BIO_EOPNOTSUPP error detection nilfs2: remove double bio_put() in nilfs_end_bio_write() for BIO_EOPNOTSUPP error drivers/platform/olpc/olpc-ec.c: initialise earlier ipv4: expose IPV4_DEVCONF ipv6: handle Redirect ICMP Message with no Redirected Header option be2net: fix disabling TX in be_close() Revert "ACPI / video: Always call acpi_video_init_brightness() on init" Revert "genetlink: fix family dump race" ... Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * Merge tag 'stable/for-linus-3.11-rc6-tag' of ↵Linus Torvalds2013-08-211-2/+9
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen bug-fixes from Konrad Rzeszutek Wilk: - On ARM did not have balanced calls to get/put_cpu. - Fix to make tboot + Xen + Linux correctly. - Fix events VCPU binding issues. - Fix a vCPU online race where IPIs are sent to not-yet-online vCPU. * tag 'stable/for-linus-3.11-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/smp: initialize IPI vectors before marking CPU online xen/events: mask events when changing their VCPU binding xen/events: initialize local per-cpu mask for all possible events x86/xen: do not identity map UNUSABLE regions in the machine E820 xen/arm: missing put_cpu in xen_percpu_init
| | * xen/smp: initialize IPI vectors before marking CPU onlineChuck Anderson2013-08-201-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An older PVHVM guest (v3.0 based) crashed during vCPU hot-plug with: kernel BUG at drivers/xen/events.c:1328! RCU has detected that a CPU has not entered a quiescent state within the grace period. It needs to send the CPU a reschedule IPI if it is not offline. rcu_implicit_offline_qs() does this check: /* * If the CPU is offline, it is in a quiescent state. We can * trust its state not to change because interrupts are disabled. */ if (cpu_is_offline(rdp->cpu)) { rdp->offline_fqs++; return 1; } Else the CPU is online. Send it a reschedule IPI. The CPU is in the middle of being hot-plugged and has been marked online (!cpu_is_offline()). See start_secondary(): set_cpu_online(smp_processor_id(), true); ... per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE; start_secondary() then waits for the CPU bringing up the hot-plugged CPU to mark it as active: /* * Wait until the cpu which brought this one up marked it * online before enabling interrupts. If we don't do that then * we can end up waking up the softirq thread before this cpu * reached the active state, which makes the scheduler unhappy * and schedule the softirq thread on the wrong cpu. This is * only observable with forced threaded interrupts, but in * theory it could also happen w/o them. It's just way harder * to achieve. */ while (!cpumask_test_cpu(smp_processor_id(), cpu_active_mask)) cpu_relax(); /* enable local interrupts */ local_irq_enable(); The CPU being hot-plugged will be marked active after it has been fully initialized by the CPU managing the hot-plug. In the Xen PVHVM case xen_smp_intr_init() is called to set up the hot-plugged vCPU's XEN_RESCHEDULE_VECTOR. The hot-plugging CPU is marked online, not marked active and does not have its IPI vectors set up. rcu_implicit_offline_qs() sees the hot-plugging cpu is !cpu_is_offline() and tries to send it a reschedule IPI: This will lead to: kernel BUG at drivers/xen/events.c:1328! xen_send_IPI_one() xen_smp_send_reschedule() rcu_implicit_offline_qs() rcu_implicit_dynticks_qs() force_qs_rnp() force_quiescent_state() __rcu_process_callbacks() rcu_process_callbacks() __do_softirq() call_softirq() do_softirq() irq_exit() xen_evtchn_do_upcall() because xen_send_IPI_one() will attempt to use an uninitialized IRQ for the XEN_RESCHEDULE_VECTOR. There is at least one other place that has caused the same crash: xen_smp_send_reschedule() wake_up_idle_cpu() add_timer_on() clocksource_watchdog() call_timer_fn() run_timer_softirq() __do_softirq() call_softirq() do_softirq() irq_exit() xen_evtchn_do_upcall() xen_hvm_callback_vector() clocksource_watchdog() uses cpu_online_mask to pick the next CPU to handle a watchdog timer: /* * Cycle through CPUs to check if the CPUs stay synchronized * to each other. */ next_cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask); if (next_cpu >= nr_cpu_ids) next_cpu = cpumask_first(cpu_online_mask); watchdog_timer.expires += WATCHDOG_INTERVAL; add_timer_on(&watchdog_timer, next_cpu); This resulted in an attempt to send an IPI to a hot-plugging CPU that had not initialized its reschedule vector. One option would be to make the RCU code check to not check for CPU offline but for CPU active. As becoming active is done after a CPU is online (in older kernels). But Srivatsa pointed out that "the cpu_active vs cpu_online ordering has been completely reworked - in the online path, cpu_active is set *before* cpu_online, and also, in the cpu offline path, the cpu_active bit is reset in the CPU_DYING notification instead of CPU_DOWN_PREPARE." Drilling in this the bring-up path: "[brought up CPU].. send out a CPU_STARTING notification, and in response to that, the scheduler sets the CPU in the cpu_active_mask. Again, this mask is better left to the scheduler alone, since it has the intelligence to use it judiciously." The conclusion was that: " 1. At the IPI sender side: It is incorrect to send an IPI to an offline CPU (cpu not present in the cpu_online_mask). There are numerous places where we check this and warn/complain. 2. At the IPI receiver side: It is incorrect to let the world know of our presence (by setting ourselves in global bitmasks) until our initialization steps are complete to such an extent that we can handle the consequences (such as receiving interrupts without crashing the sender etc.) " (from Srivatsa) As the native code enables the interrupts at some point we need to be able to service them. In other words a CPU must have valid IPI vectors if it has been marked online. It doesn't need to handle the IPI (interrupts may be disabled) but needs to have valid IPI vectors because another CPU may find it in cpu_online_mask and attempt to send it an IPI. This patch will change the order of the Xen vCPU bring-up functions so that Xen vectors have been set up before start_secondary() is called. It also will not continue to bring up a Xen vCPU if xen_smp_intr_init() fails to initialize it. Orabug 13823853 Signed-off-by Chuck Anderson <chuck.anderson@oracle.com> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | | Merge branch 'x86/spinlocks' of ↵Konrad Rzeszutek Wilk2013-09-091-1/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into stable/for-linus-3.12 * 'x86/spinlocks' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kvm/guest: Fix sparse warning: "symbol 'klock_waiting' was not declared as static" kvm: Paravirtual ticketlocks support for linux guests running on KVM hypervisor kvm guest: Add configuration support to enable debug information for KVM Guests kvm uapi: Add KICK_CPU and PV_UNHALT definition to uapi xen, pvticketlock: Allow interrupts to be enabled while blocking x86, ticketlock: Add slowpath logic jump_label: Split jumplabel ratelimit x86, pvticketlock: When paravirtualizing ticket locks, increment by 2 x86, pvticketlock: Use callee-save for lock_spinning xen, pvticketlocks: Add xen_nopvspin parameter to disable xen pv ticketlocks xen, pvticketlock: Xen implementation for PV ticket locks xen: Defer spinlock setup until boot CPU setup x86, ticketlock: Collapse a layer of functions x86, ticketlock: Don't inline _spin_unlock when using paravirt spinlocks x86, spinlock: Replace pv spinlocks with pv ticketlocks
| * | | xen: Defer spinlock setup until boot CPU setupJeremy Fitzhardinge2013-08-091-1/+1
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no need to do it at very early init, and doing it there makes it impossible to use the jump_label machinery. Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Link: http://lkml.kernel.org/r/1376058122-8248-5-git-send-email-raghavendra.kt@linux.vnet.ibm.com Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* | | xen: Support 64-bit PV guest receiving NMIsKonrad Rzeszutek Wilk2013-08-091-0/+6
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is based on a patch that Zhenzhong Duan had sent - which was missing some of the remaining pieces. The kernel has the logic to handle Xen-type-exceptions using the paravirt interface in the assembler code (see PARAVIRT_ADJUST_EXCEPTION_FRAME - pv_irq_ops.adjust_exception_frame and and INTERRUPT_RETURN - pv_cpu_ops.iret). That means the nmi handler (and other exception handlers) use the hypervisor iret. The other changes that would be neccessary for this would be to translate the NMI_VECTOR to one of the entries on the ipi_vector and make xen_send_IPI_mask_allbutself use different events. Fortunately for us commit 1db01b4903639fcfaec213701a494fe3fb2c490b (xen: Clean up apic ipi interface) implemented this and we piggyback on the cleanup such that the apic IPI interface will pass the right vector value for NMI. With this patch we can trigger NMIs within a PV guest (only tested x86_64). For this to work with normal PV guests (not initial domain) we need the domain to be able to use the APIC ops - they are already implemented to use the Xen event channels. For that to be turned on in a PV domU we need to remove the masking of X86_FEATURE_APIC. Incidentally that means kgdb will also now work within a PV guest without using the 'nokgdbroundup' workaround. Note that the 32-bit version is different and this patch does not enable that. CC: Lisa Nguyen <lisa@xenapiadmin.com> CC: Ben Guthro <benjamin.guthro@citrix.com> CC: Zhenzhong Duan <zhenzhong.duan@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [v1: Fixed up per David Vrabel comments] Reviewed-by: Ben Guthro <benjamin.guthro@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com>
* | x86: delete __cpuinit usage from all x86 filesPaul Gortmaker2013-07-141-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) are flagged as __cpuinit -- so if we remove the __cpuinit from arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the arch/x86 uses of the __cpuinit macros from all C files. x86 only had the one __CPUINIT used in assembly files, and it wasn't paired off with a .previous or a __FINIT, so we can delete it directly w/o any corresponding additional change there. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | Merge tag 'stable/for-linus-3.11-rc0-tag-two' of ↵Linus Torvalds2013-07-031-32/+59
|\ \ | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen Pull Xen bugfixes from Konrad Rzeszutek Wilk: - Fix memory leak when CPU hotplugging. - Compile bugs with various #ifdefs - Fix state changes in Xen PCI front not dealing well with new toolstack. - Cleanups in code (use pr_*, fix 80 characters splits, etc) - Long standing bug in double-reporting the steal time * tag 'stable/for-linus-3.11-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/time: remove blocked time accounting from xen "clockchip" xen: Convert printks to pr_<level> xen: ifdef CONFIG_HIBERNATE_CALLBACKS xen_*_suspend xen/pcifront: Deal with toolstack missing 'XenbusStateClosing' state. xen/time: Free onlined per-cpu data structure if we want to online it again. xen/time: Check that the per_cpu data structure has data before freeing. xen/time: Don't leak interrupt name when offlining. xen/time: Encapsulate the struct clock_event_device in another structure. xen/spinlock: Don't leak interrupt name when offlining. xen/smp: Don't leak interrupt name when offlining. xen/smp: Set the per-cpu IRQ number to a valid default. xen/smp: Introduce a common structure to contain the IRQ name and interrupt line. xen/smp: Coalesce the free_irq calls in one function. xen-pciback: fix error return code in pcistub_irq_handler_switch()
| * xen/smp: Don't leak interrupt name when offlining.Konrad Rzeszutek Wilk2013-06-101-1/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the user does: echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online kmemleak reports: kmemleak: 7 new suspected memory leaks (see /sys/kernel/debug/kmemleak) unreferenced object 0xffff88003fa51240 (size 32): comm "swapper/0", pid 1, jiffies 4294667339 (age 1027.789s) hex dump (first 32 bytes): 72 65 73 63 68 65 64 31 00 00 00 00 00 00 00 00 resched1........ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff81660721>] kmemleak_alloc+0x21/0x50 [<ffffffff81190aac>] __kmalloc_track_caller+0xec/0x2a0 [<ffffffff812fe1bb>] kvasprintf+0x5b/0x90 [<ffffffff812fe228>] kasprintf+0x38/0x40 [<ffffffff81047ed1>] xen_smp_intr_init+0x41/0x2c0 [<ffffffff816636d3>] xen_cpu_up+0x393/0x3e8 [<ffffffff8166bbf5>] _cpu_up+0xd1/0x14b [<ffffffff8166bd48>] cpu_up+0xd9/0xec [<ffffffff81ae6e4a>] smp_init+0x4b/0xa3 [<ffffffff81ac4981>] kernel_init_freeable+0xdb/0x1e6 [<ffffffff8165ce39>] kernel_init+0x9/0xf0 [<ffffffff8167edfc>] ret_from_fork+0x7c/0xb0 [<ffffffffffffffff>] 0xffffffffffffffff This patch fixes some of it by using the 'struct xen_common_irq->name' field to stash away the char so that it can be freed when the interrupt line is destroyed. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * xen/smp: Set the per-cpu IRQ number to a valid default.Konrad Rzeszutek Wilk2013-06-101-9/+19
| | | | | | | | | | | | | | | | When we free it we want to make sure to set it to a default value of -1 so that we don't double-free it (in case somebody calls us twice). Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * xen/smp: Introduce a common structure to contain the IRQ name and interrupt ↵Konrad Rzeszutek Wilk2013-06-101-20/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | line. This patch adds a new structure to contain the common two things that each of the per-cpu interrupts need: - an interrupt number, - and the name of the interrupt (to be added in 'xen/smp: Don't leak interrupt name when offlining'). This allows us to carry the tuple of the per-cpu interrupt data structure and expand it as we need in the future. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * xen/smp: Coalesce the free_irq calls in one function.Konrad Rzeszutek Wilk2013-06-101-21/+19
| | | | | | | | | | | | | | | | | | | | There are two functions that do a bunch of 'free_irq' on the per_cpu IRQ. Instead of having duplicate code just move it to one function. This is just code movement. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen/smp: Fixup NOHZ per cpu data when onlining an offline CPU.Konrad Rzeszutek Wilk2013-06-041-0/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The xen_play_dead is an undead function. When the vCPU is told to offline it ends up calling xen_play_dead wherin it calls the VCPUOP_down hypercall which offlines the vCPU. However, when the vCPU is onlined back, it resumes execution right after VCPUOP_down hypercall. That was OK (albeit the API for play_dead assumes that the CPU stays dead and never returns) but with commit 4b0c0f294 (tick: Cleanup NOHZ per cpu data on cpu down) that is no longer safe as said commit resets the ts->inidle which at the start of the cpu_idle loop was set. The net effect is that we get this warn: Broke affinity for irq 16 installing Xen timer for CPU 1 cpu 1 spinlock event irq 48 ------------[ cut here ]------------ WARNING: at /home/konrad/linux-linus/kernel/time/tick-sched.c:935 tick_nohz_idle_exit+0x195/0x1b0() Modules linked in: dm_multipath dm_mod xen_evtchn iscsi_boot_sysfs CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.10.0-rc3upstream-00068-gdcdbe33 #1 Hardware name: BIOSTAR Group N61PB-M2S/N61PB-M2S, BIOS 6.00 PG 09/03/2009 ffffffff8193b448 ffff880039da5e60 ffffffff816707c8 ffff880039da5ea0 ffffffff8108ce8b ffff880039da4010 ffff88003fa8e500 ffff880039da4010 0000000000000001 ffff880039da4000 ffff880039da4010 ffff880039da5eb0 Call Trace: [<ffffffff816707c8>] dump_stack+0x19/0x1b [<ffffffff8108ce8b>] warn_slowpath_common+0x6b/0xa0 [<ffffffff8108ced5>] warn_slowpath_null+0x15/0x20 [<ffffffff810e4745>] tick_nohz_idle_exit+0x195/0x1b0 [<ffffffff810da755>] cpu_startup_entry+0x205/0x250 [<ffffffff81661070>] cpu_bringup_and_idle+0x13/0x15 ---[ end trace 915c8c486004dda1 ]--- b/c ts_inidle is set to zero. Thomas suggested that we just add a workaround to call tick_nohz_idle_enter before returning from xen_play_dead() - and that is what this patch does and fixes the issue. We also add the stable part b/c git commit 4b0c0f294 is on the stable tree. CC: stable@vger.kernel.org Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: Clean up apic ipi interfaceStefan Bader2013-05-291-6/+4
| | | | | | | | | | | | | | | | | Commit f447d56d36af18c5104ff29dcb1327c0c0ac3634 introduced the implementation of the PV apic ipi interface. But there were some odd things (it seems none of which cause really any issue but maybe they should be cleaned up anyway): - xen_send_IPI_mask_allbutself (and by that xen_send_IPI_allbutself) ignore the passed in vector and only use the CALL_FUNCTION_SINGLE vector. While xen_send_IPI_all and xen_send_IPI_mask use the vector. - physflat_send_IPI_allbutself is declared unnecessarily. It is never used. This patch tries to clean up those things. Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds2013-04-301-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull SMP/hotplug changes from Ingo Molnar: "This is a pretty large, multi-arch series unifying and generalizing the various disjunct pieces of idle routines that architectures have historically copied from each other and have grown in random, wildly inconsistent and sometimes buggy directions: 101 files changed, 455 insertions(+), 1328 deletions(-) this went through a number of review and test iterations before it was committed, it was tested on various architectures, was exposed to linux-next for quite some time - nevertheless it might cause problems on architectures that don't read the mailing lists and don't regularly test linux-next. This cat herding excercise was motivated by the -rt kernel, and was brought to you by Thomas "the Whip" Gleixner." * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) idle: Remove GENERIC_IDLE_LOOP config switch um: Use generic idle loop ia64: Make sure interrupts enabled when we "safe_halt()" sparc: Use generic idle loop idle: Remove unused ARCH_HAS_DEFAULT_IDLE bfin: Fix typo in arch_cpu_idle() xtensa: Use generic idle loop x86: Use generic idle loop unicore: Use generic idle loop tile: Use generic idle loop tile: Enter idle with preemption disabled sh: Use generic idle loop score: Use generic idle loop s390: Use generic idle loop powerpc: Use generic idle loop parisc: Use generic idle loop openrisc: Use generic idle loop mn10300: Use generic idle loop mips: Use generic idle loop microblaze: Use generic idle loop ...
| * x86: Use generic idle loopThomas Gleixner2013-04-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130321215235.486594473@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: x86@kernel.org
* | xen/smp: Unifiy some of the PVs and PVHVM offline CPU pathKonrad Rzeszutek Wilk2013-04-161-10/+4
| | | | | | | | | | | | | | The "xen_cpu_die" and "xen_hvm_cpu_die" are very similar. Lets coalesce them. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen/smp/pvhvm: Don't initialize IRQ_WORKER as we are using the native one.Konrad Rzeszutek Wilk2013-04-161-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | There is no need to use the PV version of the IRQ_WORKER mechanism as under PVHVM we are using the native version. The native version is using the SMP API. They just sit around unused: 69: 0 0 xen-percpu-ipi irqwork0 83: 0 0 xen-percpu-ipi irqwork1 Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen/smp/spinlock: Fix leakage of the spinlock interrupt line for every CPU ↵Konrad Rzeszutek Wilk2013-04-161-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | online/offline While we don't use the spinlock interrupt line (see for details commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23 - xen: disable PV spinlocks on HVM) - we should still do the proper init / deinit sequence. We did not do that correctly and for the CPU init for PVHVM guest we would allocate an interrupt line - but failed to deallocate the old interrupt line. This resulted in leakage of an irq_desc but more importantly this splat as we online an offlined CPU: genirq: Flags mismatch irq 71. 0002cc20 (spinlock1) vs. 0002cc20 (spinlock1) Pid: 2542, comm: init.late Not tainted 3.9.0-rc6upstream #1 Call Trace: [<ffffffff811156de>] __setup_irq+0x23e/0x4a0 [<ffffffff81194191>] ? kmem_cache_alloc_trace+0x221/0x250 [<ffffffff811161bb>] request_threaded_irq+0xfb/0x160 [<ffffffff8104c6f0>] ? xen_spin_trylock+0x20/0x20 [<ffffffff813a8423>] bind_ipi_to_irqhandler+0xa3/0x160 [<ffffffff81303758>] ? kasprintf+0x38/0x40 [<ffffffff8104c6f0>] ? xen_spin_trylock+0x20/0x20 [<ffffffff810cad35>] ? update_max_interval+0x15/0x40 [<ffffffff816605db>] xen_init_lock_cpu+0x3c/0x78 [<ffffffff81660029>] xen_hvm_cpu_notify+0x29/0x33 [<ffffffff81676bdd>] notifier_call_chain+0x4d/0x70 [<ffffffff810bb2a9>] __raw_notifier_call_chain+0x9/0x10 [<ffffffff8109402b>] __cpu_notify+0x1b/0x30 [<ffffffff8166834a>] _cpu_up+0xa0/0x14b [<ffffffff816684ce>] cpu_up+0xd9/0xec [<ffffffff8165f754>] store_online+0x94/0xd0 [<ffffffff8141d15b>] dev_attr_store+0x1b/0x20 [<ffffffff81218f44>] sysfs_write_file+0xf4/0x170 [<ffffffff811a2864>] vfs_write+0xb4/0x130 [<ffffffff811a302a>] sys_write+0x5a/0xa0 [<ffffffff8167ada9>] system_call_fastpath+0x16/0x1b cpu 1 spinlock event irq -16 smpboot: Booting Node 0 Processor 1 APIC 0x2 And if one looks at the /proc/interrupts right after offlining (CPU1): 70: 0 0 xen-percpu-ipi spinlock0 71: 0 0 xen-percpu-ipi spinlock1 77: 0 0 xen-percpu-ipi spinlock2 There is the oddity of the 'spinlock1' still being present. CC: stable@vger.kernel.org Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen/smp: Fix leakage of timer interrupt line for every CPU online/offline.Konrad Rzeszutek Wilk2013-04-161-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the PVHVM path when we do CPU online/offline path we would leak the timer%d IRQ line everytime we do a offline event. The online path (xen_hvm_setup_cpu_clockevents via x86_cpuinit.setup_percpu_clockev) would allocate a new interrupt line for the timer%d. But we would still use the old interrupt line leading to: kernel BUG at /home/konrad/ssd/konrad/linux/kernel/hrtimer.c:1261! invalid opcode: 0000 [#1] SMP RIP: 0010:[<ffffffff810b9e21>] [<ffffffff810b9e21>] hrtimer_interrupt+0x261/0x270 .. snip.. <IRQ> [<ffffffff810445ef>] xen_timer_interrupt+0x2f/0x1b0 [<ffffffff81104825>] ? stop_machine_cpu_stop+0xb5/0xf0 [<ffffffff8111434c>] handle_irq_event_percpu+0x7c/0x240 [<ffffffff811175b9>] handle_percpu_irq+0x49/0x70 [<ffffffff813a74a3>] __xen_evtchn_do_upcall+0x1c3/0x2f0 [<ffffffff813a760a>] xen_evtchn_do_upcall+0x2a/0x40 [<ffffffff8167c26d>] xen_hvm_callback_vector+0x6d/0x80 <EOI> [<ffffffff81666d01>] ? start_secondary+0x193/0x1a8 [<ffffffff81666cfd>] ? start_secondary+0x18f/0x1a8 There is also the oddity (timer1) in the /proc/interrupts after offlining CPU1: 64: 1121 0 xen-percpu-virq timer0 78: 0 0 xen-percpu-virq timer1 84: 0 2483 xen-percpu-virq timer2 This patch fixes it. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> CC: stable@vger.kernel.org
* xen/smp: Move the common CPU init code a bit to prep for PVH patch.Konrad Rzeszutek Wilk2013-02-191-19/+23
| | | | | | | | | | | | | The PV and PVH code CPU init code share some functionality. The PVH code ("xen/pvh: Extend vcpu_guest_context, p2m, event, and XenBus") sets some of these up, but not all. To make it easier to read, this patch removes the PV specific out of the generic way. No functional change - just code movement. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> [v2: Fixed compile errors noticed by Fengguang Wu build system] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* Revert "xen/smp: Fix CPU online/offline bug triggering a BUG: scheduling ↵Konrad Rzeszutek Wilk2013-01-151-7/+0
| | | | | | | | | | | | | while atomic." This reverts commit 41bd956de3dfdc3a43708fe2e0c8096c69064a1e. The fix is incorrect and not appropiate for the latest kernels. In fact it _causes_ the BUG: scheduling while atomic while doing vCPU hotplug. Suggested-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/smp: Use smp_store_boot_cpu_info() to store cpu info for BSP during boot ↵Konrad Rzeszutek Wilk2012-12-171-1/+1
| | | | | | | | | | | | | | time. Git commit 30106c174311b8cfaaa3186c7f6f9c36c62d17da ("x86, hotplug: Support functions for CPU0 online/offline") alters what the call to smp_store_cpu_info() does. For BSP we should use the smp_store_boot_cpu_info() and for secondary CPU's the old variant of smp_store_cpu_info() should be used. This fixes the regression introduced by said commit. Reported-and-Tested-by: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* x86/smp: Don't ever patch back to UP if we unplug cpusRusty Russell2012-08-231-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We still patch SMP instructions to UP variants if we boot with a single CPU, but not at any other time. In particular, not if we unplug CPUs to return to a single cpu. Paul McKenney points out: mean offline overhead is 6251/48=130.2 milliseconds. If I remove the alternatives_smp_switch() from the offline path [...] the mean offline overhead is 550/42=13.1 milliseconds Basically, we're never going to get those 120ms back, and the code is pretty messy. We get rid of: 1) The "smp-alt-once" boot option. It's actually "smp-alt-boot", the documentation is wrong. It's now the default. 2) The skip_smp_alternatives flag used by suspend. 3) arch_disable_nonboot_cpus_begin() and arch_disable_nonboot_cpus_end() which were only used to set this one flag. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paul.mckenney@us.ibm.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/87vcgwwive.fsf@rustcorp.com.au Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86-smp-remove-call-to-ipi_call_lock-ipi_call_unlockYong Zhang2012-06-051-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | ipi_call_lock/unlock() lock resp. unlock call_function.lock. This lock protects only the call_function data structure itself, but it's completely unrelated to cpu_online_mask. The mask to which the IPIs are sent is calculated before call_function.lock is taken in smp_call_function_many(), so the locking around set_cpu_online() is pointless and can be removed. [ tglx: Massaged changelog ] Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: ralf@linux-mips.org Cc: sshtylyov@mvista.com Cc: david.daney@cavium.com Cc: nikunj@linux.vnet.ibm.com Cc: paulmck@linux.vnet.ibm.com Cc: axboe@kernel.dk Cc: peterz@infradead.org Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: http://lkml.kernel.org/r/1338275765-3217-7-git-send-email-yong.zhang0@gmail.com Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge tag 'stable/for-linus-3.5-rc0-tag' of ↵Linus Torvalds2012-05-241-4/+108
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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/smp: unbind irqworkX when unplugging vCPUs.Konrad Rzeszutek Wilk2012-05-211-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The git commit 1ff2b0c303698e486f1e0886b4d9876200ef8ca5 "xen: implement IRQ_WORK_VECTOR handler" added the functionality to have a per-cpu "irqworkX" for the IPI APIC functionality. However it missed the unbind when a vCPU is unplugged resulting in an orphaned per-cpu interrupt line for unplugged vCPU: 30: 216 0 xen-dyn-event hvc_console 31: 810 4 xen-dyn-event eth0 32: 29 0 xen-dyn-event blkif - 36: 0 0 xen-percpu-ipi irqwork2 - 37: 287 0 xen-dyn-event xenbus + 36: 287 0 xen-dyn-event xenbus NMI: 0 0 Non-maskable interrupts LOC: 0 0 Local timer interrupts SPU: 0 0 Spurious interrupts Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * xen: implement IRQ_WORK_VECTOR handlerLin Ming2012-05-071-0/+30
| | | | | | | | | | Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * xen: implement apic ipi interfaceBen Guthro2012-05-071-4/+77
| | | | | | | | | | | | | | | | | | | | Map native ipi vector to xen vector. Implement apic ipi interface with xen_send_IPI_one. Tested-by: Steven Noonan <steven@uplinklabs.net> Signed-off-by: Ben Guthro <ben@guthro.net> Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | Merge branch 'smp/threadalloc' into smp/hotplugThomas Gleixner2012-05-081-0/+15
|\ \ | | | | | | | | | | | | | | | | | | Reason: Pull in the separate branch which was created so arch/tile can base further work on it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | xen/smp: Fix crash when booting with ACPI hotplug CPUs.Konrad Rzeszutek Wilk2012-04-261-0/+15
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we boot on a machine that can hotplug CPUs and we are using 'dom0_max_vcpus=X' on the Xen hypervisor line to clip the amount of CPUs available to the initial domain, we get this: (XEN) Command line: com1=115200,8n1 dom0_mem=8G noreboot dom0_max_vcpus=8 sync_console mce_verbosity=verbose console=com1,vga loglvl=all guest_loglvl=all .. snip.. DMI: Intel Corporation S2600CP/S2600CP, BIOS SE5C600.86B.99.99.x032.072520111118 07/25/2011 .. snip. SMP: Allowing 64 CPUs, 32 hotplug CPUs installing Xen timer for CPU 7 cpu 7 spinlock event irq 361 NMI watchdog: disabled (cpu7): hardware events not enabled Brought up 8 CPUs .. snip.. [acpi processor finds the CPUs are not initialized and starts calling arch_register_cpu, which creates /sys/devices/system/cpu/cpu8/online] CPU 8 got hotplugged CPU 9 got hotplugged CPU 10 got hotplugged .. snip.. initcall 1_acpi_battery_init_async+0x0/0x1b returned 0 after 406 usecs calling erst_init+0x0/0x2bb @ 1 [and the scheduler sticks newly started tasks on the new CPUs, but said CPUs cannot be initialized b/c the hypervisor has limited the amount of vCPUS to 8 - as per the dom0_max_vcpus=8 flag. The spinlock tries to kick the other CPU, but the structure for that is not initialized and we crash.] BUG: unable to handle kernel paging request at fffffffffffffed8 IP: [<ffffffff81035289>] xen_spin_lock+0x29/0x60 PGD 180d067 PUD 180e067 PMD 0 Oops: 0002 [#1] SMP CPU 7 Modules linked in: Pid: 1, comm: swapper/0 Not tainted 3.4.0-rc2upstream-00001-gf5154e8 #1 Intel Corporation S2600CP/S2600CP RIP: e030:[<ffffffff81035289>] [<ffffffff81035289>] xen_spin_lock+0x29/0x60 RSP: e02b:ffff8801fb9b3a70 EFLAGS: 00010282 With this patch, we cap the amount of vCPUS that the initial domain can run, to exactly what dom0_max_vcpus=X has specified. In the future, if there is a hypercall that will allow a running domain to expand past its initial set of vCPUS, this patch should be re-evaluated. CC: stable@kernel.org Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | x86: Use generic idle thread allocationThomas Gleixner2012-04-261-13/+2
| | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20120420124557.246929343@linutronix.de
* | x86: Add task_struct argument to smp_ops.cpu_upThomas Gleixner2012-04-261-3/+3
|/ | | | | | | | | | | | | Preparatory patch to use the generic idle thread allocation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20120420124557.176604405@linutronix.de
* Merge tag 'stable/for-linus-3.4-rc1-tag' of ↵Linus Torvalds2012-04-061-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen Pull xen fixes from Konrad Rzeszutek Wilk: "Two fixes for regressions: * one is a workaround that will be removed in v3.5 with proper fix in the tip/x86 tree, * the other is to fix drivers to load on PV (a previous patch made them only load in PVonHVM mode). The rest are just minor fixes in the various drivers and some cleanup in the core code." * tag 'stable/for-linus-3.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/pcifront: avoid pci_frontend_enable_msix() falsely returning success xen/pciback: fix XEN_PCI_OP_enable_msix result xen/smp: Remove unnecessary call to smp_processor_id() xen/x86: Workaround 'x86/ioapic: Add register level checks to detect bogus io-apic entries' xen: only check xen_platform_pci_unplug if hvm
| * xen/smp: Remove unnecessary call to smp_processor_id()Srivatsa S. Bhat2012-04-061-1/+1
| | | | | | | | | | | | | | | | There is an extra and unnecessary call to smp_processor_id() in cpu_bringup(). Remove it. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | Merge tag 'stable/for-linus-3.4-tag-two' of ↵Linus Torvalds2012-03-241-0/+6
|\ \ | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen Pull more xen updates from Konrad Rzeszutek Wilk: "One tiny feature that accidentally got lost in the initial git pull: * Add fast-EOI acking of interrupts (clear a bit instead of hypercall) And bug-fixes: * Fix CPU bring-up code missing a call to notify other subsystems. * Fix reading /sys/hypervisor even if PVonHVM drivers are not loaded. * In Xen ACPI processor driver: remove too verbose WARN messages, fix up the Kconfig dependency to be a module by default, and add dependency on CPU_FREQ. * Disable CPU frequency drivers from loading when booting under Xen (as we want the Xen ACPI processor to be used instead). * Cleanups in tmem code." * tag 'stable/for-linus-3.4-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/acpi: Fix Kconfig dependency on CPU_FREQ xen: initialize platform-pci even if xen_emul_unplug=never xen/smp: Fix bringup bug in AP code. xen/acpi: Remove the WARN's as they just create noise. xen/tmem: cleanup xen: support pirq_eoi_map xen/acpi-processor: Do not depend on CPU frequency scaling drivers. xen/cpufreq: Disable the cpu frequency scaling drivers from loading. provide disable_cpufreq() function to disable the API.
| * xen/smp: Fix bringup bug in AP code.Konrad Rzeszutek Wilk2012-03-221-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The CPU hotplug code has now a callback to help bring up the CPU. Without the call we end up getting: BUG: soft lockup - CPU#0 stuck for 29s! [migration/0:6] Modules linked in: CPU ] Pid: 6, comm: migration/0 Not tainted 3.3.0upstream-01180-ged378a5 #1 Dell Inc. PowerEdge T105 /0RR825 RIP: e030:[<ffffffff810d3b8b>] [<ffffffff810d3b8b>] stop_machine_cpu_stop+0x7b/0xf0 RSP: e02b:ffff8800ceaabdb0 EFLAGS: 00000293 .. snip.. Call Trace: [<ffffffff810d3b10>] ? stop_one_cpu_nowait+0x50/0x50 [<ffffffff810d3841>] cpu_stopper_thread+0xf1/0x1c0 [<ffffffff815a9776>] ? __schedule+0x3c6/0x760 [<ffffffff815aa749>] ? _raw_spin_unlock_irqrestore+0x19/0x30 [<ffffffff810d3750>] ? res_counter_charge+0x150/0x150 [<ffffffff8108dc76>] kthread+0x96/0xa0 [<ffffffff815b27e4>] kernel_thread_helper+0x4/0x10 [<ffffffff815aacbc>] ? retint_restore_ar Thix fixes it. Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | Merge tag 'stable/for-linus-3.4-tag' of ↵Linus Torvalds2012-03-221-1/+1
|\ \ | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen Pull xen updates from Konrad Rzeszutek Wilk: "which has three neat features: - PV multiconsole support, so that there can be hvc1, hvc2, etc; This can be used in HVM and in PV mode. - P-state and C-state power management driver that uploads said power management data to the hypervisor. It also inhibits cpufreq scaling drivers to load so that only the hypervisor can make power management decisions - fixing a weird perf bug. There is one thing in the Kconfig that you won't like: "default y if (X86_ACPI_CPUFREQ = y || X86_POWERNOW_K8 = y)" (note, that it all depends on CONFIG_XEN which depends on CONFIG_PARAVIRT which by default is off). I've a fix to convert that boolean expression into "default m" which I am going to post after the cpufreq git pull - as the two patches to make this work depend on a fix in Dave Jones's tree. - Function Level Reset (FLR) support in the Xen PCI backend. Fixes: - Kconfig dependencies for Xen PV keyboard and video - Compile warnings and constify fixes - Change over to use percpu_xxx instead of this_cpu_xxx" Fix up trivial conflicts in drivers/tty/hvc/hvc_xen.c due to changes to a removed commit. * tag 'stable/for-linus-3.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen kconfig: relax INPUT_XEN_KBDDEV_FRONTEND deps xen/acpi-processor: C and P-state driver that uploads said data to hypervisor. xen: constify all instances of "struct attribute_group" xen/xenbus: ignore console/0 hvc_xen: introduce HVC_XEN_FRONTEND hvc_xen: implement multiconsole support hvc_xen: support PV on HVM consoles xenbus: don't free other end details too early xen/enlighten: Expose MWAIT and MWAIT_LEAF if hypervisor OKs it. xen/setup/pm/acpi: Remove the call to boot_option_idle_override. xenbus: address compiler warnings xen: use this_cpu_xxx replace percpu_xxx funcs xen/pciback: Support pci_reset_function, aka FLR or D3 support. pci: Introduce __pci_reset_function_locked to be used when holding device_lock. xen: Utilize the restore_msi_irqs hook.
| * xen: use this_cpu_xxx replace percpu_xxx funcsAlex Shi2012-01-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | percpu_xxx funcs are duplicated with this_cpu_xxx funcs, so replace them for further code clean up. I don't know much of xen code. But, since the code is in x86 architecture, the percpu_xxx is exactly same as this_cpu_xxx serials functions. So, the change is safe. Signed-off-by: Alex Shi <alex.shi@intel.com> Acked-by: Christoph Lameter <cl@gentwo.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen/smp: Fix CPU online/offline bug triggering a BUG: scheduling while atomic.Konrad Rzeszutek Wilk2012-02-031-0/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a user offlines a VCPU and then onlines it, we get: NMI watchdog disabled (cpu2): hardware events not enabled BUG: scheduling while atomic: swapper/2/0/0x00000002 Modules linked in: dm_multipath dm_mod xen_evtchn iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi scsi_mod libcrc32c crc32c radeon fbco ttm bitblit softcursor drm_kms_helper xen_blkfront xen_netfront xen_fbfront fb_sys_fops sysimgblt sysfillrect syscopyarea xen_kbdfront xenfs [last unloaded: Pid: 0, comm: swapper/2 Tainted: G O 3.2.0phase15.1-00003-gd6f7f5b-dirty #4 Call Trace: [<ffffffff81070571>] __schedule_bug+0x61/0x70 [<ffffffff8158eb78>] __schedule+0x798/0x850 [<ffffffff8158ed6a>] schedule+0x3a/0x50 [<ffffffff810349be>] cpu_idle+0xbe/0xe0 [<ffffffff81583599>] cpu_bringup_and_idle+0xe/0x10 The reason for this should be obvious from this call-chain: cpu_bringup_and_idle: \- cpu_bringup | \-[preempt_disable] | |- cpu_idle \- play_dead [assuming the user offlined the VCPU] | \ | +- (xen_play_dead) | \- HYPERVISOR_VCPU_off [so VCPU is dead, once user | | onlines it starts from here] | \- cpu_bringup [preempt_disable] | +- preempt_enable_no_reschedule() +- schedule() \- preempt_enable() So we have two preempt_disble() and one preempt_enable(). Calling preempt_enable() after the cpu_bringup() in the xen_play_dead fixes the imbalance. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: disable PV spinlocks on HVMStefano Stabellini2011-09-081-1/+0
| | | | | | | | | | | | | PV spinlocks cannot possibly work with the current code because they are enabled after pvops patching has already been done, and because PV spinlocks use a different data structure than native spinlocks so we cannot switch between them dynamically. A spinlock that has been taken once by the native code (__ticket_spin_lock) cannot be taken by __xen_spin_lock even after it has been released. Reported-and-Tested-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/smp: Warn user why they keel over - nosmp or noapic and what to use instead.Konrad Rzeszutek Wilk2011-09-011-0/+10
| | | | | | | | | | | | | | | We have hit a couple of customer bugs where they would like to use those parameters to run an UP kernel - but both of those options turn of important sources of interrupt information so we end up not being able to boot. The correct way is to pass in 'dom0_max_vcpus=1' on the Xen hypervisor line and the kernel will patch itself to be a UP kernel. Fixes bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=637308 CC: stable@kernel.org Acked-by: Ian Campbell <Ian.Campbell@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: Do not enable PV IPIs when vector callback not presentStefano Stabellini2011-08-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | Fix regression for HVM case on older (<4.1.1) hypervisors caused by commit 99bbb3a84a99cd04ab16b998b20f01a72cfa9f4f Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Date: Thu Dec 2 17:55:10 2010 +0000 xen: PV on HVM: support PV spinlocks and IPIs This change replaced the SMP operations with event based handlers without taking into account that this only works when the hypervisor supports callback vectors. This causes unexplainable hangs early on boot for HVM guests with more than one CPU. BugLink: http://bugs.launchpad.net/bugs/791850 CC: stable@kernel.org Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Tested-and-Reported-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: support CONFIG_MAXSMPAndrew Jones2011-06-151-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | The MAXSMP config option requires CPUMASK_OFFSTACK, which in turn requires we init the memory for the maps while we bring up the cpus. MAXSMP also increases NR_CPUS to 4096. This increase in size exposed an issue in the argument construction for multicalls from xen_flush_tlb_others. The args should only need space for the actual number of cpus. Also in 2.6.39 it exposes a bootup problem. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8157a1d3>] set_cpu_sibling_map+0x123/0x30d ... Call Trace: [<ffffffff81039a3f>] ? xen_restore_fl_direct_reloc+0x4/0x4 [<ffffffff819dc4db>] xen_smp_prepare_cpus+0x36/0x135 .. CC: stable@kernel.org Signed-off-by: Andrew Jones <drjones@redhat.com> [v2: Updated to compile on 3.0] [v3: Updated to compile when CONFIG_SMP is not defined] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
*-. Merge branches 'sched-core-for-linus' and 'sched-urgent-for-linus' of ↵Linus Torvalds2011-05-191-3/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (60 commits) sched: Fix and optimise calculation of the weight-inverse sched: Avoid going ahead if ->cpus_allowed is not changed sched, rt: Update rq clock when unthrottling of an otherwise idle CPU sched: Remove unused parameters from sched_fork() and wake_up_new_task() sched: Shorten the construction of the span cpu mask of sched domain sched: Wrap the 'cfs_rq->nr_spread_over' field with CONFIG_SCHED_DEBUG sched: Remove unused 'this_best_prio arg' from balance_tasks() sched: Remove noop in alloc_rt_sched_group() sched: Get rid of lock_depth sched: Remove obsolete comment from scheduler_tick() sched: Fix sched_domain iterations vs. RCU sched: Next buddy hint on sleep and preempt path sched: Make set_*_buddy() work on non-task entities sched: Remove need_migrate_task() sched: Move the second half of ttwu() to the remote cpu sched: Restructure ttwu() some more sched: Rename ttwu_post_activation() to ttwu_do_wakeup() sched: Remove rq argument from ttwu_stat() sched: Remove rq->lock from the first half of ttwu() sched: Drop rq->lock from sched_exec() ... * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Fix rt_rq runtime leakage bug
| * | sched: Provide scheduler_ipi() callback in response to smp_send_reschedule()Peter Zijlstra2011-04-141-3/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For future rework of try_to_wake_up() we'd like to push part of that function onto the CPU the task is actually going to run on. In order to do so we need a generic callback from the existing scheduler IPI. This patch introduces such a generic callback: scheduler_ipi() and implements it as a NOP. BenH notes: PowerPC might use this IPI on offline CPUs under rare conditions! Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.744338123@chello.nl
* | arch/x86/xen/smp: Cleanup code/data sections definitionsDaniel Kiper2011-05-191-4/+4
|/ | | | | | | | 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>
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