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2011-05-22KVM: Fix kvm mmu_notifier initialization orderOGAWA Hirofumi
Like the following, mmu_notifier can be called after registering immediately. So, kvm have to initialize kvm->mmu_lock before it. BUG: spinlock bad magic on CPU#0, kswapd0/342 lock: ffff8800af8c4000, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 Pid: 342, comm: kswapd0 Not tainted 2.6.39-rc5+ #1 Call Trace: [<ffffffff8118ce61>] spin_bug+0x9c/0xa3 [<ffffffff8118ce91>] do_raw_spin_lock+0x29/0x13c [<ffffffff81024923>] ? flush_tlb_others_ipi+0xaf/0xfd [<ffffffff812e22f3>] _raw_spin_lock+0x9/0xb [<ffffffffa0582325>] kvm_mmu_notifier_clear_flush_young+0x2c/0x66 [kvm] [<ffffffff810d3ff3>] __mmu_notifier_clear_flush_young+0x2b/0x57 [<ffffffff810c8761>] page_referenced_one+0x88/0xea [<ffffffff810c89bf>] page_referenced+0x1fc/0x256 [<ffffffff810b2771>] shrink_page_list+0x187/0x53a [<ffffffff810b2ed7>] shrink_inactive_list+0x1e0/0x33d [<ffffffff810acf95>] ? determine_dirtyable_memory+0x15/0x27 [<ffffffff812e90ee>] ? call_function_single_interrupt+0xe/0x20 [<ffffffff810b3356>] shrink_zone+0x322/0x3de [<ffffffff810a9587>] ? zone_watermark_ok_safe+0xe2/0xf1 [<ffffffff810b3928>] kswapd+0x516/0x818 [<ffffffff810b3412>] ? shrink_zone+0x3de/0x3de [<ffffffff81053d17>] kthread+0x7d/0x85 [<ffffffff812e9394>] kernel_thread_helper+0x4/0x10 [<ffffffff81053c9a>] ? __init_kthread_worker+0x37/0x37 [<ffffffff812e9390>] ? gs_change+0xb/0xb Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22KVM: Validate userspace_addr of memslot when registeredTakuya Yoshikawa
This way, we can avoid checking the user space address many times when we read the guest memory. Although we can do the same for write if we check which slots are writable, we do not care write now: reading the guest memory happens more often than writing. [avi: change VERIFY_READ to VERIFY_WRITE] Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11KVM: cleanup memslot_id functionXiao Guangrong
We can get memslot id from memslot->id directly Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-04-06KVM: Enable async page fault processingGleb Natapov
If asynchronous hva_to_pfn() is requested call GUP with FOLL_NOWAIT to avoid sleeping on IO. Check for hwpoison is done at the same time, otherwise check_user_page_hwpoison() will call GUP again and will put vcpu to sleep. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-25Merge branch 'syscore' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 * 'syscore' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: Introduce ARCH_NO_SYSDEV_OPS config option (v2) cpufreq: Use syscore_ops for boot CPU suspend/resume (v2) KVM: Use syscore_ops instead of sysdev class and sysdev PCI / Intel IOMMU: Use syscore_ops instead of sysdev class and sysdev timekeeping: Use syscore_ops instead of sysdev class and sysdev x86: Use syscore_ops instead of sysdev classes and sysdevs
2011-03-23kvm: use little-endian bitopsAkinobu Mita
As a preparation for removing ext2 non-atomic bit operations from asm/bitops.h. This converts ext2 non-atomic bit operations to little-endian bit operations. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23kvm: stop including asm-generic/bitops/le.h directlyAkinobu Mita
asm-generic/bitops/le.h is only intended to be included directly from asm-generic/bitops/ext2-non-atomic.h or asm-generic/bitops/minix-le.h which implements generic ext2 or minix bit operations. This stops including asm-generic/bitops/le.h directly and use ext2 non-atomic bit operations instead. It seems odd to use ext2_set_bit() on kvm, but it will replaced with __set_bit_le() after introducing little endian bit operations for all architectures. This indirect step is necessary to maintain bisectability for some architectures which have their own little-endian bit operations. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23KVM: Use syscore_ops instead of sysdev class and sysdevRafael J. Wysocki
KVM uses a sysdev class and a sysdev for executing kvm_suspend() after interrupts have been turned off on the boot CPU (during system suspend) and for executing kvm_resume() before turning on interrupts on the boot CPU (during system resume). However, since both of these functions ignore their arguments, the entire mechanism may be replaced with a struct syscore_ops object which is simpler. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Avi Kivity <avi@redhat.com>
2011-03-17KVM: Convert kvm_lock to raw_spinlockJan Kiszka
Code under this lock requires non-preemptibility. Ensure this also over -rt by converting it to raw spinlock. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17KVM: use yield_to instead of sleep in kvm_vcpu_on_spinRik van Riel
Instead of sleeping in kvm_vcpu_on_spin, which can cause gigantic slowdowns of certain workloads, we instead use yield_to to get another VCPU in the same KVM guest to run sooner. This seems to give a 10-15% speedup in certain workloads. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17KVM: keep track of which task is running a KVM vcpuRik van Riel
Keep track of which task is running a KVM vcpu. This helps us figure out later what task to wake up if we want to boost a vcpu that got preempted. Unfortunately there are no guarantees that the same task always keeps the same vcpu, so we can only track the task across a single "run" of the vcpu. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17KVM: Replace is_hwpoison_address with __get_user_pagesHuang Ying
is_hwpoison_address only checks whether the page table entry is hwpoisoned, regardless the memory page mapped. While __get_user_pages will check both. QEMU will clear the poisoned page table entry (via unmap/map) to make it possible to allocate a new memory page for the virtual address across guest rebooting. But it is also possible that the underlying memory page is kept poisoned even after the corresponding page table entry is cleared, that is, a new memory page can not be allocated. __get_user_pages can catch these situations. Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17KVM: make make_all_cpus_request() locklessXiao Guangrong
Now, we have 'vcpu->mode' to judge whether need to send ipi to other cpus, this way is very exact, so checking request bit is needless, then we can drop the spinlock let it's collateral Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17KVM: Add "exiting guest mode" stateXiao Guangrong
Currently we keep track of only two states: guest mode and host mode. This patch adds an "exiting guest mode" state that tells us that an IPI will happen soon, so unless we need to wait for the IPI, we can avoid it completely. Also 1: No need atomically to read/write ->mode in vcpu's thread 2: reorganize struct kvm_vcpu to make ->mode and ->requests in the same cache line explicitly Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17KVM: fix build warning within __kvm_set_memory_region() on s390Heiko Carstens
Get rid of this warning: CC arch/s390/kvm/../../../virt/kvm/kvm_main.o arch/s390/kvm/../../../virt/kvm/kvm_main.c:596:12: warning: 'kvm_create_dirty_bitmap' defined but not used The only caller of the function is within a !CONFIG_S390 section, so add the same ifdef around kvm_create_dirty_bitmap() as well. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17KVM: MMU: Don't flush shadow when enabling dirty trackingAvi Kivity
Instead, drop large mappings, which were the reason we dropped shadow. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-13thp: add compound_trans_head() helperAndrea Arcangeli
Cleanup some code with common compound_trans_head helper. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Avi Kivity <avi@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13thp: mmu_notifier_test_youngAndrea Arcangeli
For GRU and EPT, we need gup-fast to set referenced bit too (this is why it's correct to return 0 when shadow_access_mask is zero, it requires gup-fast to set the referenced bit). qemu-kvm access already sets the young bit in the pte if it isn't zero-copy, if it's zero copy or a shadow paging EPT minor fault we relay on gup-fast to signal the page is in use... We also need to check the young bits on the secondary pagetables for NPT and not nested shadow mmu as the data may never get accessed again by the primary pte. Without this closer accuracy, we'd have to remove the heuristic that avoids collapsing hugepages in hugepage virtual regions that have not even a single subpage in use. ->test_young is full backwards compatible with GRU and other usages that don't have young bits in pagetables set by the hardware and that should nuke the secondary mmu mappings when ->clear_flush_young runs just like EPT does. Removing the heuristic that checks the young bit in khugepaged/collapse_huge_page completely isn't so bad either probably but I thought it was worth it and this makes it reliable. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13thp: kvm mmu transparent hugepage supportAndrea Arcangeli
This should work for both hugetlbfs and transparent hugepages. [akpm@linux-foundation.org: bring forward PageTransCompound() addition for bisectability] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-12KVM: Don't spin on virt instruction faults during rebootAvi Kivity
Since vmx blocks INIT signals, we disable virtualization extensions during reboot. This leads to virtualization instructions faulting; we trap these faults and spin while the reboot continues. Unfortunately spinning on a non-preemptible kernel may block a task that reboot depends on; this causes the reboot to hang. Fix by skipping over the instruction and hoping for the best. Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: MMU: delay flush all tlbs on sync_page pathXiao Guangrong
Quote from Avi: | I don't think we need to flush immediately; set a "tlb dirty" bit somewhere | that is cleareded when we flush the tlb. kvm_mmu_notifier_invalidate_page() | can consult the bit and force a flush if set. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: rename hardware_[dis|en]able() to *_nolock() and add locking wrappersTakuya Yoshikawa
The naming convension of hardware_[dis|en]able family is little bit confusing because only hardware_[dis|en]able_all are using _nolock suffix. Renaming current hardware_[dis|en]able() to *_nolock() and using hardware_[dis|en]able() as wrapper functions which take kvm_lock for them reduces extra confusion. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: take kvm_lock for hardware_disable() during cpu hotplugTakuya Yoshikawa
In kvm_cpu_hotplug(), only CPU_STARTING case is protected by kvm_lock. This patch adds missing protection for CPU_DYING case. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Clean up vm creation and releaseJan Kiszka
IA64 support forces us to abstract the allocation of the kvm structure. But instead of mixing this up with arch-specific initialization and doing the same on destruction, split both steps. This allows to move generic destruction calls into generic code. It also fixes error clean-up on failures of kvm_create_vm for IA64. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: Refactor srcu struct release on early errorsJan Kiszka
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: replace vmalloc and memset with vzallocTakuya Yoshikawa
Let's use newly introduced vzalloc(). Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: get rid of warning within kvm_dev_ioctl_create_vmHeiko Carstens
Fixes this: CC arch/s390/kvm/../../../virt/kvm/kvm_main.o arch/s390/kvm/../../../virt/kvm/kvm_main.c: In function 'kvm_dev_ioctl_create_vm': arch/s390/kvm/../../../virt/kvm/kvm_main.c:1828:10: warning: unused variable 'r' Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: add cast within kvm_clear_guest_page to fix warningHeiko Carstens
Fixes this: CC arch/s390/kvm/../../../virt/kvm/kvm_main.o arch/s390/kvm/../../../virt/kvm/kvm_main.c: In function 'kvm_clear_guest_page': arch/s390/kvm/../../../virt/kvm/kvm_main.c:1224:2: warning: passing argument 3 of 'kvm_write_guest_page' makes pointer from integer without a cast arch/s390/kvm/../../../virt/kvm/kvm_main.c:1185:5: note: expected 'const void *' but argument is of type 'long unsigned int' Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: use kmalloc() for small dirty bitmapsTakuya Yoshikawa
Currently we are using vmalloc() for all dirty bitmaps even if they are small enough, say less than K bytes. We use kmalloc() if dirty bitmap size is less than or equal to PAGE_SIZE so that we can avoid vmalloc area usage for VGA. This will also make the logging start/stop faster. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: pre-allocate one more dirty bitmap to avoid vmalloc()Takuya Yoshikawa
Currently x86's kvm_vm_ioctl_get_dirty_log() needs to allocate a bitmap by vmalloc() which will be used in the next logging and this has been causing bad effect to VGA and live-migration: vmalloc() consumes extra systime, triggers tlb flush, etc. This patch resolves this issue by pre-allocating one more bitmap and switching between two bitmaps during dirty logging. Performance improvement: I measured performance for the case of VGA update by trace-cmd. The result was 1.5 times faster than the original one. In the case of live migration, the improvement ratio depends on the workload and the guest memory size. In general, the larger the memory size is the more benefits we get. Note: This does not change other architectures's logic but the allocation size becomes twice. This will increase the actual memory consumption only when the new size changes the number of pages allocated by vmalloc(). Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: introduce wrapper functions for creating/destroying dirty bitmapsTakuya Yoshikawa
This makes it easy to change the way of allocating/freeing dirty bitmaps. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: x86: trace "exit to userspace" eventGleb Natapov
Add tracepoint for userspace exit. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: propagate fault r/w information to gup(), allow read-only memoryMarcelo Tosatti
As suggested by Andrea, pass r/w error code to gup(), upgrading read fault to writable if host pte allows it. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12KVM: improve hva_to_pfn() readabilityGleb Natapov
Improve vma handling code readability in hva_to_pfn() and fix async pf handling code to properly check vma returned by find_vma(). Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Add memory slot versioning and use it to provide fast guest write interfaceGleb Natapov
Keep track of memslots changes by keeping generation number in memslots structure. Provide kvm_write_guest_cached() function that skips gfn_to_hva() translation if memslots was not changed since previous invocation. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12KVM: Halt vcpu if page it tries to access is swapped outGleb Natapov
If a guest accesses swapped out memory do not swap it in from vcpu thread context. Schedule work to do swapping and put vcpu into halted state instead. Interrupts will still be delivered to the guest and if interrupt will cause reschedule guest will continue to run another task. [avi: remove call to get_user_pages_noio(), nacked by Linus; this makes everything synchrnous again] Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24Merge branch 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (321 commits) KVM: Drop CONFIG_DMAR dependency around kvm_iommu_map_pages KVM: Fix signature of kvm_iommu_map_pages stub KVM: MCE: Send SRAR SIGBUS directly KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTED KVM: fix typo in copyright notice KVM: Disable interrupts around get_kernel_ns() KVM: MMU: Avoid sign extension in mmu_alloc_direct_roots() pae root address KVM: MMU: move access code parsing to FNAME(walk_addr) function KVM: MMU: audit: check whether have unsync sps after root sync KVM: MMU: audit: introduce audit_printk to cleanup audit code KVM: MMU: audit: unregister audit tracepoints before module unloaded KVM: MMU: audit: fix vcpu's spte walking KVM: MMU: set access bit for direct mapping KVM: MMU: cleanup for error mask set while walk guest page table KVM: MMU: update 'root_hpa' out of loop in PAE shadow path KVM: x86 emulator: Eliminate compilation warning in x86_decode_insn() KVM: x86: Fix constant type in kvm_get_time_scale KVM: VMX: Add AX to list of registers clobbered by guest switch KVM guest: Move a printk that's using the clock before it's ready KVM: x86: TSC catchup mode ...
2010-10-24KVM: Drop CONFIG_DMAR dependency around kvm_iommu_map_pagesJan Kiszka
We also have to call kvm_iommu_map_pages for CONFIG_AMD_IOMMU. So drop the dependency on Intel IOMMU, kvm_iommu_map_pages will be a nop anyway if CONFIG_IOMMU_API is not defined. KVM-Stable-Tag. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: fix typo in copyright noticeNicolas Kaiser
Fix typo in copyright notice. Signed-off-by: Nicolas Kaiser <nikai@nikai.net> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: cpu_relax() during spin waiting for rebootAvi Kivity
It doesn't really matter, but if we spin, we should spin in a more relaxed manner. This way, if something goes wrong at least it won't contribute to global warming. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: MMU: rewrite audit_mappings_page() functionXiao Guangrong
There is a bugs in this function, we call gfn_to_pfn() and kvm_mmu_gva_to_gpa_read() in atomic context(kvm_mmu_audit() is called under the spinlock(mmu_lock)'s protection). This patch fix it by: - introduce gfn_to_pfn_atomic instead of gfn_to_pfn - get the mapping gfn from kvm_mmu_page_get_gfn() And it adds 'notrap' ptes check in unsync/direct sps Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24KVM: MMU: introduce gfn_to_page_many_atomic() functionXiao Guangrong
Introduce this function to get consecutive gfn's pages, it can reduce gup's overload, used by later patch Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: MMU: introduce hva_to_pfn_atomic functionXiao Guangrong
Introduce hva_to_pfn_atomic(), it's the fast path and can used in atomic context, the later patch will use it Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM: x86: Add clock sync request to hardware enableZachary Amsden
If there are active VCPUs which are marked as belonging to a particular hardware CPU, request a clock sync for them when enabling hardware; the TSC could be desynchronized on a newly arriving CPU, and we need to recompute guests system time relative to boot after a suspend event. This covers both cases. Note that it is acceptable to take the spinlock, as either no other tasks will be running and no locks held (BSP after resume), or other tasks will be guaranteed to drop the lock relatively quickly (AP on CPU_STARTING). Noting we now get clock synchronization requests for VCPUs which are starting up (or restarting), it is tempting to attempt to remove the arch/x86/kvm/x86.c CPU hot-notifiers at this time, however it is not correct to do so; they are required for systems with non-constant TSC as the frequency may not be known immediately after the processor has started until the cpufreq driver has had a chance to run and query the chipset. Updated: implement better locking semantics for hardware_enable Removed the hack of dropping and retaking the lock by adding the semantic that we always hold kvm_lock when hardware_enable is called. The one place that doesn't need to worry about it is resume, as resuming a frozen CPU, the spinlock won't be taken. Signed-off-by: Zachary Amsden <zamsden@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-22Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: vfs: make no_llseek the default vfs: don't use BKL in default_llseek llseek: automatically add .llseek fop libfs: use generic_file_llseek for simple_attr mac80211: disallow seeks in minstrel debug code lirc: make chardev nonseekable viotape: use noop_llseek raw: use explicit llseek file operations ibmasmfs: use generic_file_llseek spufs: use llseek in all file operations arm/omap: use generic_file_llseek in iommu_debug lkdtm: use generic_file_llseek in debugfs net/wireless: use generic_file_llseek in debugfs drm: use noop_llseek
2010-10-15llseek: automatically add .llseek fopArnd Bergmann
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-09-23KVM: Fix reboot on Intel hostsAvi Kivity
When we reboot, we disable vmx extensions or otherwise INIT gets blocked. If a task on another cpu hits a vmx instruction, it will fault if vmx is disabled. We trap that to avoid a nasty oops and spin until the reboot completes. Problem is, we sleep with interrupts disabled. This blocks smp_send_stop() from running, and the reboot process halts. Fix by enabling interrupts before spinning. KVM-Stable-Tag. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-09-09KVM: x86: Perform hardware_enable in CPU_STARTING callbackZachary Amsden
The CPU_STARTING callback was added upstream with the intention of being used for KVM, specifically for the hardware enablement that must be done before we can run in hardware virt. It had bugs on the x86_64 architecture at the time, where it was called after CPU_ONLINE. The arches have since merged and the bug is gone. It might be noted other features should probably start making use of this callback; microcode updates in particular which might be fixing important erratums would be best applied before beginning to run user tasks. Signed-off-by: Zachary Amsden <zamsden@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-02KVM: Return EFAULT from kvm ioctl when guest accesses bad areaGleb Natapov
Currently if guest access address that belongs to memory slot but is not backed up by page or page is read only KVM treats it like MMIO access. Remove that capability. It was never part of the interface and should not be relied upon. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-02KVM: define hwpoison variables staticGleb Natapov
They are not used outside of the file. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>