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path: root/virt/kvm/kvm_main.c
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2012-04-12KVM: unmap pages from the iommu when slots are removedAlex Williamson1-2/+3
We've been adding new mappings, but not destroying old mappings. This can lead to a page leak as pages are pinned using get_user_pages, but only unpinned with put_page if they still exist in the memslots list on vm shutdown. A memslot that is destroyed while an iommu domain is enabled for the guest will therefore result in an elevated page reference count that is never cleared. Additionally, without this fix, the iommu is only programmed with the first translation for a gpa. This can result in peer-to-peer errors if a mapping is destroyed and replaced by a new mapping at the same gpa as the iommu will still be pointing to the original, pinned memory address. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-03-08KVM: use correct tlbs dirty type in cmpxchgAlex Shi1-1/+1
Using 'int' type is not suitable for a 'long' object. So, correct it. Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08KVM: Ensure all vcpus are consistent with in-kernel irqchip settingsAvi Kivity1-0/+4
If some vcpus are created before KVM_CREATE_IRQCHIP, then irqchip_in_kernel() and vcpu->arch.apic will be inconsistent, leading to potential NULL pointer dereferences. Fix by: - ensuring that no vcpus are installed when KVM_CREATE_IRQCHIP is called - ensuring that a vcpu has an apic if it is installed after KVM_CREATE_IRQCHIP This is somewhat long winded because vcpu->arch.apic is created without kvm->lock held. Based on earlier patch by Michael Ellerman. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08KVM: mmu_notifier: Flush TLBs before releasing mmu_lockTakuya Yoshikawa1-9/+10
Other threads may process the same page in that small window and skip TLB flush and then return before these functions do flush. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08KVM: Introduce kvm_memory_slot::arch and move lpage_info into itTakuya Yoshikawa1-61/+9
Some members of kvm_memory_slot are not used by every architecture. This patch is the first step to make this difference clear by introducing kvm_memory_slot::arch; lpage_info is moved into it. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08KVM: Simplify ifndef conditional usage in __kvm_set_memory_region()Takuya Yoshikawa1-21/+8
Narrow down the controlled text inside the conditional so that it will include lpage_info and rmap stuff only. For this we change the way we check whether the slot is being created from "if (npages && !new.rmap)" to "if (npages && !old.npages)". We also stop checking if lpage_info is NULL when we create lpage_info because we do it from inside the slot creation code block. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08KVM: Split lpage_info creation out from __kvm_set_memory_region()Takuya Yoshikawa1-31/+52
This makes it easy to make lpage_info architecture specific. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08KVM: Introduce gfn_to_index() which returns the index for a given levelTakuya Yoshikawa1-6/+1
This patch cleans up the code and removes the "(void)level;" warning suppressor. Note that we can also use this for PT_PAGE_TABLE_LEVEL to treat every level uniformly later. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: Move gfn_to_memslot() to kvm_host.hPaul Mackerras1-20/+1
This moves __gfn_to_memslot() and search_memslots() from kvm_main.c to kvm_host.h to reduce the code duplication caused by the need for non-modular code in arch/powerpc/kvm/book3s_hv_rm_mmu.c to call gfn_to_memslot() in real mode. Rather than putting gfn_to_memslot() itself in a header, which would lead to increased code size, this puts __gfn_to_memslot() in a header. Then, the non-modular uses of gfn_to_memslot() are changed to call __gfn_to_memslot() instead. This way there is only one place in the source code that needs to be changed should the gfn_to_memslot() implementation need to be modified. On powerpc, the Book3S HV style of KVM has code that is called from real mode which needs to call gfn_to_memslot() and thus needs this. (Module code is allocated in the vmalloc region, which can't be accessed in real mode.) With this, we can remove builtin_gfn_to_memslot() from book3s_hv_rm_mmu.c. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Avi Kivity <avi@redhat.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: Add barriers to allow mmu_notifier_retry to be used locklesslyPaul Mackerras1-3/+3
This adds an smp_wmb in kvm_mmu_notifier_invalidate_range_end() and an smp_rmb in mmu_notifier_retry() so that mmu_notifier_retry() will give the correct answer when called without kvm->mmu_lock being held. PowerPC Book3S HV KVM wants to use a bitlock per guest page rather than a single global spinlock in order to improve the scalability of updates to the guest MMU hashed page table, and so needs this. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Avi Kivity <avi@redhat.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: ucontrol: export SIE control block to userCarsten Otte1-1/+1
This patch exports the s390 SIE hardware control block to userspace via the mapping of the vcpu file descriptor. In order to do so, a new arch callback named kvm_arch_vcpu_fault is introduced for all architectures. It allows to map architecture specific pages. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: add parameter for KVM_CREATE_VMCarsten Otte1-8/+5
This patch introduces a new config option for user controlled kernel virtual machines. It introduces a parameter to KVM_CREATE_VM that allows to set bits that alter the capabilities of the newly created virtual machine. The parameter is passed to kvm_arch_init_vm for all architectures. The only valid modifier bit for now is KVM_VM_S390_UCONTROL. This requires CAP_SYS_ADMIN privileges and creates a user controlled virtual machine on s390 architectures. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-02-01KVM: Fix __set_bit() race in mark_page_dirty() during dirty loggingTakuya Yoshikawa1-1/+1
It is possible that the __set_bit() in mark_page_dirty() is called simultaneously on the same region of memory, which may result in only one bit being set, because some callers do not take mmu_lock before mark_page_dirty(). This problem is hard to produce because when we reach mark_page_dirty() beginning from, e.g., tdp_page_fault(), mmu_lock is being held during __direct_map(): making kvm-unit-tests' dirty log api test write to two pages concurrently was not useful for this reason. So we have confirmed that there can actually be race condition by checking if some callers really reach there without holding mmu_lock using spin_is_locked(): probably they were from kvm_write_guest_page(). To fix this race, this patch changes the bit operation to the atomic version: note that nr_dirty_pages also suffers from the race but we do not need exactly correct numbers for now. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-27KVM: ensure that debugfs entries have been createdHamo1-3/+23
by checking the return value from kvm_init_debug, we can ensure that the entries under debugfs for KVM have been created correctly. Signed-off-by: Yang Bai <hamo.by@gmail.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-27KVM: drop bsp_vcpu pointer from kvm structGleb Natapov1-4/+0
Drop bsp_vcpu pointer from kvm struct since its only use is incorrect anyway. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-27KVM: Use memdup_user instead of kmalloc/copy_from_userSasha Levin1-17/+12
Switch to using memdup_user when possible. This makes code more smaller and compact, and prevents errors. Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: Use kmemdup() instead of kmalloc/memcpySasha Levin1-4/+3
Switch to kmemdup() in two places to shorten the code and avoid possible bugs. Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: introduce a table to map slot id to index in memslots arrayXiao Guangrong1-1/+6
The operation of getting dirty log is frequent when framebuffer-based displays are used(for example, Xwindow), so, we introduce a mapping table to speed up id_to_memslot() Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: sort memslots by its size and use line searchXiao Guangrong1-22/+57
Sort memslots base on its size and use line search to find it, so that the larger memslots have better fit The idea is from Avi Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: introduce id_to_memslot functionXiao Guangrong1-4/+9
Introduce id_to_memslot to get memslot by slot id Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: introduce kvm_for_each_memslot macroXiao Guangrong1-8/+6
Introduce kvm_for_each_memslot to walk all valid memslot Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: introduce update_memslots functionXiao Guangrong1-7/+15
Introduce update_memslots to update slot which will be update to kvm->memslots Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: introduce KVM_MEM_SLOTS_NUM macroXiao Guangrong1-1/+1
Introduce KVM_MEM_SLOTS_NUM macro to instead of KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: Count the number of dirty pages for dirty loggingTakuya Yoshikawa1-1/+3
Needed for the next patch which uses this number to decide how to write protect a slot. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: Use kmemdup rather than duplicating its implementationThomas Meyer1-6/+5
Use kmemdup rather than duplicating its implementation The semantic patch that makes this change is available in scripts/coccinelle/api/memdup.cocci. More information about semantic patching is available at http://coccinelle.lip6.fr/ Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-09-25KVM: Intelligent device lookup on I/O busSasha Levin1-12/+100
Currently the method of dealing with an IO operation on a bus (PIO/MMIO) is to call the read or write callback for each device registered on the bus until we find a device which handles it. Since the number of devices on a bus can be significant due to ioeventfds and coalesced MMIO zones, this leads to a lot of overhead on each IO operation. Instead of registering devices, we now register ranges which points to a device. Lookup is done using an efficient bsearch instead of a linear search. Performance test was conducted by comparing exit count per second with 200 ioeventfds created on one byte and the guest is trying to access a different byte continuously (triggering usermode exits). Before the patch the guest has achieved 259k exits per second, after the patch the guest does 274k exits per second. Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-24KVM: MMU: mmio page fault supportXiao Guangrong1-0/+7
The idea is from Avi: | We could cache the result of a miss in an spte by using a reserved bit, and | checking the page fault error code (or seeing if we get an ept violation or | ept misconfiguration), so if we get repeated mmio on a page, we don't need to | search the slot list/tree. | (https://lkml.org/lkml/2011/2/22/221) When the page fault is caused by mmio, we cache the info in the shadow page table, and also set the reserved bits in the shadow page table, so if the mmio is caused again, we can quickly identify it and emulate it directly Searching mmio gfn in memslots is heavy since we need to walk all memeslots, it can be reduced by this feature, and also avoid walking guest page table for soft mmu. [jan: fix operator precedence issue] Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-24KVM: MMU: filter out the mmio pfn from the fault pfnXiao Guangrong1-2/+14
If the page fault is caused by mmio, the gfn can not be found in memslots, and 'bad_pfn' is returned on gfn_to_hva path, so we can use 'bad_pfn' to identify the mmio page fault. And, to clarify the meaning of mmio pfn, we return fault page instead of bad page when the gfn is not allowd to prefetch Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12KVM: introduce kvm_read_guest_cachedGleb Natapov1-0/+20
Introduce kvm_read_guest_cached() function in addition to write one we already have. [ by glauber: export function signature in kvm header ] Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Eric Munson <emunson@mgebm.net> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12KVM: Add compat ioctl for KVM_SET_SIGNAL_MASKAlexander Graf1-1/+51
KVM has an ioctl to define which signal mask should be used while running inside VCPU_RUN. At least for big endian systems, this mask is different on 32-bit and 64-bit systems (though the size is identical). Add a compat wrapper that converts the mask to whatever the kernel accepts, allowing 32-bit kvm user space to set signal masks. This patch fixes qemu with --enable-io-thread on ppc64 hosts when running 32-bit user land. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12KVM: Clean up error handling during VCPU creationJan Kiszka1-5/+6
So far kvm_arch_vcpu_setup is responsible for freeing the vcpu struct if it fails. Move this confusing resonsibility back into the hands of kvm_vm_ioctl_create_vcpu. Only kvm_arch_vcpu_setup of x86 is affected, all other archs cannot fail. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12KVM: use __copy_to_user/__clear_user to write guest pageXiao Guangrong1-2/+2
Simply use __copy_to_user/__clear_user to write guest page since we have already verified the user address when the memslot is set Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-06-06KVM: Initialize kvm before registering the mmu notifierMike Waychison1-5/+6
It doesn't make sense to ever see a half-initialized kvm structure on mmu notifier callbacks. Previously, 85722cda changed the ordering to ensure that the mmu_lock was initialized before mmu notifier registration, but there is still a race where the mmu notifier could come in and try accessing other portions of struct kvm before they are intialized. Solve this by moving the mmu notifier registration to occur after the structure is completely initialized. Google-Bug-Id: 452199 Signed-off-by: Mike Waychison <mikew@google.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-26KVM: add missing void __user * cast to access_ok() callHeiko Carstens1-1/+3
fa3d315a "KVM: Validate userspace_addr of memslot when registered" introduced this new warning onn s390: kvm_main.c: In function '__kvm_set_memory_region': kvm_main.c:654:7: warning: passing argument 1 of '__access_ok' makes pointer from integer without a cast arch/s390/include/asm/uaccess.h:53:19: note: expected 'const void *' but argument is of type '__u64' Add the missing cast to get rid of it again... Cc: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22KVM: Fix kvm mmu_notifier initialization orderOGAWA Hirofumi1-1/+1
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 Yoshikawa1-2/+5
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 Guangrong1-17/+0
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 Natapov1-2/+21
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>
2011-03-26Merge branch 'syscore' of ↵Linus Torvalds1-26/+8
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
2011-03-24kvm: use little-endian bitopsAkinobu Mita1-1/+1
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>
2011-03-24kvm: stop including asm-generic/bitops/le.h directlyAkinobu Mita1-2/+1
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>
2011-03-24KVM: Use syscore_ops instead of sysdev class and sysdevRafael J. Wysocki1-26/+8
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 Kiszka1-18/+18
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 Riel1-10/+47
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 Riel1-0/+10
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 Ying1-1/+10
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 Guangrong1-6/+3
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 Guangrong1-1/+6
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 Carstens1-0/+2
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 Kivity1-6/+1
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>
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