- 09 Sep, 2013 4 commits
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Konrad Rzeszutek Wilk authored
Merge branch 'x86/spinlocks' of 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
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Julien Grall authored
When linux is running as dom0, Xen doesn't show the physical cpu but a virtual CPU. On some ARM SOC (for instance the exynos 5250), linux registers callbacks for cpuidle and cpufreq. When these callbacks are called, they will modify directly the physical cpu not the virtual one. It can impact the whole board instead of only dom0. Signed-off-by:
Julien Grall <julien.grall@linaro.org> Signed-off-by:
Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Boris Ostrovsky authored
m2p_remove_override() calls get_balloon_scratch_page() in MULTI_update_va_mapping() even though it already has pointer to this page from the earlier call (in scratch_page). This second call doesn't have a matching put_balloon_scratch_page() thus not restoring preempt count back. (Also, there is no put_balloon_scratch_page() in the error path.) In addition, the second multicall uses __xen_mc_entry() which does not disable interrupts. Rearrange xen_mc_* calls to keep interrupts off while performing multicalls. This commit fixes a regression introduced by: commit ee072640 Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Date: Tue Jul 23 17:23:54 2013 +0000 xen/m2p: use GNTTABOP_unmap_and_replace to reinstate the original mapping Signed-off-by:
Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by:
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Rob Herring authored
xen_pm_init was unconditionally setting pm_power_off and arm_pm_restart function pointers. This breaks multi-platform kernels. Make this conditional on running as a Xen guest and make it a late_initcall to ensure it is setup after platform code for Dom0. Signed-off-by:
Rob Herring <rob.herring@calxeda.com> Signed-off-by:
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- 30 Aug, 2013 5 commits
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Joe Perches authored
kzalloc already adds this __GFP_ZERO. Signed-off-by:
Joe Perches <joe@perches.com> Signed-off-by:
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Konrad Rzeszutek Wilk authored
Randy reports: x86_64: drivers/built-in.o: In function `xen_tpmfront_init': xen-tpmfront.c:(.init.text+0x257c): undefined reference to `xenbus_register_frontend' This is nicely fixed by selecting the XenBus frontend module. Reported-by:
Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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Wei Liu authored
In commit cd9151e2: xen/balloon: set a mapping for ballooned out pages we have the ballooned out page's mapping set to a scratch page. That commit also sets the P2M entry of ballooned out page to the scratch page's MFN. This is necessary for PV guest but not for HVM guest. On the other hand, setting the P2M entry would trigger BUG_ON in __set_phys_to_machine. The correct thing to do here is to avoid calling __set_phys_to_machine for auto translated guest. Signed-off-by:
Wei Liu <wei.liu2@citrix.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by:
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Dan Carpenter authored
The call to del_evtchn() frees "evtchn". Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Andres Lagar-Cavilla authored
When a foreign mapper attempts to map guest frames that are paged out, the mapper receives an ENOENT response and will have to try again while a helper process pages the target frame back in. Gating checks on PRIVCMD_MMAPBATCH* ioctl args were preventing retries of mapping calls. Permit subsequent calls to update a sub-range of the VMA, iff nothing is yet mapped in that range. Since it is now valid to call PRIVCMD_MMAPBATCH* multiple times, only set vma->vm_private_data if the parameters are valid and (if necessary) the pages for the auto_translated_physmap case have been allocated. This prevents subsequent calls from incorrectly entering the 'retry' path when there are no pages allocated etc. Signed-off-by:
Andres Lagar-Cavilla <andres@lagarcavilla.org> Signed-off-by:
David Vrabel <david.vrabel@citrix.com> Signed-off-by:
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- 20 Aug, 2013 7 commits
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Vaughan Cao authored
kernel use callback linked in panic_notifier_list to notice others when panic happens. NORET_TYPE void panic(const char * fmt, ...){ ... atomic_notifier_call_chain(&panic_notifier_list, 0, buf); } When Xen becomes aware of this, it will call xen_reboot(SHUTDOWN_crash) to send out an event with reason code - SHUTDOWN_crash. xen_panic_handler_init() is defined to register on panic_notifier_list but we only call it in xen_arch_setup which only be called by PV, this patch is necessary for PVHVM. Without this patch, setting 'on_crash=coredump-restart' in PVHVM guest config file won't lead a vmcore to be generate when the guest panics. It can be reproduced with 'echo c > /proc/sysrq-trigger'. Signed-off-by:Vaughan Cao <vaughan.cao@oracle.com> Signed-off-by:
Joe Jin <joe.jin@oracle.com>
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Stefano Stabellini authored
GNTTABOP_unmap_grant_ref unmaps a grant and replaces it with a 0 mapping instead of reinstating the original mapping. Doing so separately would be racy. To unmap a grant and reinstate the original mapping atomically we use GNTTABOP_unmap_and_replace. GNTTABOP_unmap_and_replace doesn't work with GNTMAP_contains_pte, so don't use it for kmaps. GNTTABOP_unmap_and_replace zeroes the mapping passed in new_addr so we have to reinstate it, however that is a per-cpu mapping only used for balloon scratch pages, so we can be sure that it's not going to be accessed while the mapping is not valid. Signed-off-by:
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Stefano Stabellini authored
The following commit: commit 6efa20e4 Author: Konrad Rzeszutek Wilk <konrad@kernel.org> Date: Fri Jul 19 11:51:31 2013 -0400 xen: Support 64-bit PV guest receiving NMIs breaks the Xen ARM build: CC drivers/xen/events.o drivers/xen/events.c: In function 'xen_send_IPI_one': drivers/xen/events.c:1218:6: error: 'XEN_NMI_VECTOR' undeclared (first use in this function) Simply ifdef the undeclared symbol in the code. Signed-off-by:
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Konrad Rzeszutek Wilk authored
Jeremy has been a key person in making Linux work with Xen. He has been enjoying the last year working on something different so reflect that in the maintainers file. CC: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by:
Jeremy Fitzhardinge <jeremy@goop.org>
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David Vrabel authored
The original comment on the scanning of the start word on the 2nd pass did not reflect the actual behaviour (the code was incorrectly masking bit_idx instead of the pending word itself). The documented behaviour is not actually required since if event were pending in the MSBs, they would be immediately scanned anyway as we go through the loop again. Update the documentation to reflect this (instead of trying to change the behaviour). Signed-off-by:
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David Vrabel authored
During early setup, when the reserved regions and MMIO holes are being setup as 1:1 in the p2m, clear any mappings instead of making them 1:1 (execept for the ISA region which is expected to be mapped). This fixes a regression introduced in 3.5 by 83d51ab4 (xen/setup: update VA mapping when releasing memory during setup) which caused hosts with tboot to fail to boot. tboot marks a region in the e820 map as unusable and the dom0 kernel would attempt to map this region and Xen does not permit unusable regions to be mapped by guests. (XEN) 0000000000000000 - 0000000000060000 (usable) (XEN) 0000000000060000 - 0000000000068000 (reserved) (XEN) 0000000000068000 - 000000000009e000 (usable) (XEN) 0000000000100000 - 0000000000800000 (usable) (XEN) 0000000000800000 - 0000000000972000 (unusable) tboot marked this region as unusable. (XEN) 0000000000972000 - 00000000cf200000 (usable) (XEN) 00000000cf200000 - 00000000cf38f000 (reserved) (XEN) 00000000cf38f000 - 00000000cf3ce000 (ACPI data) (XEN) 00000000cf3ce000 - 00000000d0000000 (reserved) (XEN) 00000000e0000000 - 00000000f0000000 (reserved) (XEN) 00000000fe000000 - 0000000100000000 (reserved) (XEN) 0000000100000000 - 0000000630000000 (usable) Signed-off-by:
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David Vrabel authored
If CONFIG_PREEMPT is enabled then xen_enable_irq() (and xen_restore_fl()) could be preempted and rescheduled on a different VCPU in between the clear of the mask and the check for pending events. This may result in events being lost as the upcall will check for pending events on the wrong VCPU. Fix this by disabling preemption around the unmask and check for events. Signed-off-by:
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- 19 Aug, 2013 1 commit
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Raghavendra K T authored
It was not declared as static since it was thought to be used by pv-flushtlb earlier. Signed-off-by:
Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: <gleb@redhat.com> Cc: <pbonzini@redhat.com> Cc: Jiri Kosina <trivial@kernel.org> Link: http://lkml.kernel.org/r/1376645921-8056-1-git-send-email-raghavendra.kt@linux.vnet.ibm.comSigned-off-by:
Ingo Molnar <mingo@kernel.org>
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- 14 Aug, 2013 1 commit
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Srivatsa Vaddagiri authored
During smp_boot_cpus paravirtualied KVM guest detects if the hypervisor has required feature (KVM_FEATURE_PV_UNHALT) to support pv-ticketlocks. If so, support for pv-ticketlocks is registered via pv_lock_ops. Use KVM_HC_KICK_CPU hypercall to wakeup waiting/halted vcpu. Signed-off-by:
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20130810193849.GA25260@linux.vnet.ibm.comSigned-off-by:
Suzuki Poulose <suzuki@in.ibm.com> [Raghu: check_zero race fix, enum for kvm_contention_stat, jumplabel related changes, addition of safe_halt for irq enabled case, bailout spinning in nmi case(Gleb)] Signed-off-by:
Gleb Natapov <gleb@redhat.com> Acked-by:
H. Peter Anvin <hpa@linux.intel.com>
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- 09 Aug, 2013 22 commits
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Stefano Stabellini authored
swiotlb-xen has an implicit dependency on CONFIG_NEED_SG_DMA_LENGTH. Remove it by replacing dma_length with sg_dma_len. Signed-off-by:
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EunBong Song authored
This patch replace dma_length in "lib/swiotlb.c" to sg_dma_len() macro, because the build error can occur if CONFIG_NEED_SG_DMA_LENGTH is not set, and CONFIG_SWIOTLB is set. Singed-off-by:
EunBong Song <eunb.song@samsung.com> Signed-off-by:
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Stefano Stabellini authored
Currently ballooned out pages are mapped to 0 and have INVALID_P2M_ENTRY in the p2m. These ballooned out pages are used to map foreign grants by gntdev and blkback (see alloc_xenballooned_pages). Allocate a page per cpu and map all the ballooned out pages to the corresponding mfn. Set the p2m accordingly. This way reading from a ballooned out page won't cause a kernel crash (see http://lists.xen.org/archives/html/xen-devel/2012-12/msg01154.html). Signed-off-by:
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David Vrabel authored
The global array of port users and the port_user_lock limits scalability of the evtchn device. Instead of the global array lookup, use a per-use (per-fd) tree of event channels bound by that user and protect the tree with a per-user lock. This is also a prerequiste for extended the number of supported event channels, by removing the fixed size, per-event channel array. Signed-off-by:
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David Vrabel authored
In m2p_remove_override() when removing the grant map from the kernel mapping and replacing with a mapping to the original page, the grant unmap will already have flushed the TLB and it is not necessary to do it again after updating the mapping. Signed-off-by:
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Konrad Rzeszutek Wilk authored
Both Boris and David have graciously volunteered to help in maintaining the Xen subsystem tree. Cementing this in the MAINTAINERS file so they are copied on Xen related patches. Signed-off-by:
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Konrad Rzeszutek Wilk authored
And also drop the virtualization one since we don't really use it. Signed-off-by:
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Jingoo Han authored
The usage of strict_strtoul() is not preferred, because strict_strtoul() is obsolete. Thus, kstrtoul() should be used. Signed-off-by:
Jingoo Han <jg1.han@samsung.com> Signed-off-by:
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Roger Pau Monne authored
With the current implementation, the callback in the tail of the list can be added twice, because the check done in gnttab_request_free_callback is bogus, callback->next can be NULL if it is the last callback in the list. If we add the same callback twice we end up with an infinite loop, were callback == callback->next. Replace this check with a proper one that iterates over the list to see if the callback has already been added. Signed-off-by:
Roger Pau Monné <roger.pau@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by:
Matt Wilson <msw@amazon.com> Reviewed-by:
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Daniel De Graaf authored
This is a complete rewrite of the Xen TPM frontend driver, taking advantage of a simplified frontend/backend interface and adding support for cancellation and timeouts. The backend for this driver is provided by a vTPM stub domain using the interface in Xen 4.3. Signed-off-by:
Daniel De Graaf <dgdegra@tycho.nsa.gov> Acked-by:
Matthew Fioravante <matthew.fioravante@jhuapl.edu> Reviewed-by:
Peter Huewe <peterhuewe@gmx.de> Reviewed-by:
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Konrad Rzeszutek Wilk authored
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 1db01b49 (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:
Ben Guthro <benjamin.guthro@citrix.com> Reviewed-by:
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Srivatsa Vaddagiri authored
Signed-off-by:
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Raghavendra K T authored
These are needed by both guest and host. Originally-from: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by:
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Jeremy Fitzhardinge authored
If interrupts were enabled when taking the spinlock, we can leave them enabled while blocking to get the lock. If we can enable interrupts while waiting for the lock to become available, and we take an interrupt before entering the poll, and the handler takes a spinlock which ends up going into the slow state (invalidating the per-cpu "lock" and "want" values), then when the interrupt handler returns the event channel will remain pending so the poll will return immediately, causing it to return out to the main spinlock loop. Signed-off-by:
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Jeremy Fitzhardinge authored
Maintain a flag in the LSB of the ticket lock tail which indicates whether anyone is in the lock slowpath and may need kicking when the current holder unlocks. The flags are set when the first locker enters the slowpath, and cleared when unlocking to an empty queue (ie, no contention). In the specific implementation of lock_spinning(), make sure to set the slowpath flags on the lock just before blocking. We must do this before the last-chance pickup test to prevent a deadlock with the unlocker: Unlocker Locker test for lock pickup -> fail unlock test slowpath -> false set slowpath flags block Whereas this works in any ordering: Unlocker Locker set slowpath flags test for lock pickup -> fail block unlock test slowpath -> true, kick If the unlocker finds that the lock has the slowpath flag set but it is actually uncontended (ie, head == tail, so nobody is waiting), then it clears the slowpath flag. The unlock code uses a locked add to update the head counter. This also acts as a full memory barrier so that its safe to subsequently read back the slowflag state, knowing that the updated lock is visible to the other CPUs. If it were an unlocked add, then the flag read may just be forwarded from the store buffer before it was visible to the other CPUs, which could result in a deadlock. Unfortunately this means we need to do a locked instruction when unlocking with PV ticketlocks. However, if PV ticketlocks are not enabled, then the old non-locked "add" is the only unlocking code. Note: this code relies on gcc making sure that unlikely() code is out of line of the fastpath, which only happens when OPTIMIZE_SIZE=n. If it doesn't the generated code isn't too bad, but its definitely suboptimal. Thanks to Srivatsa Vaddagiri for providing a bugfix to the original version of this change, which has been folded in. Thanks to Stephan Diestelhorst for commenting on some code which relied on an inaccurate reading of the x86 memory ordering rules. Signed-off-by:
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Andrew Jones authored
Commit b2029520 ("perf, core: Rate limit perf_sched_events jump_label patching") introduced rate limiting for jump label disabling. The changes were made in the jump label code in order to be more widely available and to keep things tidier. This is all fine, except now jump_label.h includes linux/workqueue.h, which makes it impossible to include jump_label.h from anything that workqueue.h needs. For example, it's now impossible to include jump_label.h from asm/spinlock.h, which is done in proposed pv-ticketlock patches. This patch splits out the rate limiting related changes from jump_label.h into a new file, jump_label_ratelimit.h, to resolve the issue. Signed-off-by:
Andrew Jones <drjones@redhat.com> Link: http://lkml.kernel.org/r/1376058122-8248-10-git-send-email-raghavendra.kt@linux.vnet.ibm.comReviewed-by:
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Jeremy Fitzhardinge authored
Increment ticket head/tails by 2 rather than 1 to leave the LSB free to store a "is in slowpath state" bit. This halves the number of possible CPUs for a given ticket size, but this shouldn't matter in practice - kernels built for 32k+ CPU systems are probably specially built for the hardware rather than a generic distro kernel. Signed-off-by:
Attilio Rao <attilio.rao@citrix.com> Signed-off-by:
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Jeremy Fitzhardinge authored
Although the lock_spinning calls in the spinlock code are on the uncommon path, their presence can cause the compiler to generate many more register save/restores in the function pre/postamble, which is in the fast path. To avoid this, convert it to using the pvops callee-save calling convention, which defers all the save/restores until the actual function is called, keeping the fastpath clean. Signed-off-by:
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Jeremy Fitzhardinge authored
Signed-off-by:
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Jeremy Fitzhardinge authored
Replace the old Xen implementation of PV spinlocks with and implementation of xen_lock_spinning and xen_unlock_kick. xen_lock_spinning simply registers the cpu in its entry in lock_waiting, adds itself to the waiting_cpus set, and blocks on an event channel until the channel becomes pending. xen_unlock_kick searches the cpus in waiting_cpus looking for the one which next wants this lock with the next ticket, if any. If found, it kicks it by making its event channel pending, which wakes it up. We need to make sure interrupts are disabled while we're relying on the contents of the per-cpu lock_waiting values, otherwise an interrupt handler could come in, try to take some other lock, block, and overwrite our values. Signed-off-by:
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Jeremy Fitzhardinge authored
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:
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Jeremy Fitzhardinge authored
Now that the paravirtualization layer doesn't exist at the spinlock level any more, we can collapse the __ticket_ functions into the arch_ functions. Signed-off-by:
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