27 Dec, 2011
12 commits
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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
Signed-off-by: Marcelo Tosatti -
Drop bsp_vcpu pointer from kvm struct since its only use is incorrect
anyway.Signed-off-by: Gleb Natapov
Signed-off-by: Marcelo Tosatti -
Switch to using memdup_user when possible. This makes code more
smaller and compact, and prevents errors.Signed-off-by: Sasha Levin
Signed-off-by: Avi Kivity -
Switch to kmemdup() in two places to shorten the code and avoid possible bugs.
Signed-off-by: Sasha Levin
Signed-off-by: Avi Kivity -
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
Signed-off-by: Avi Kivity -
Sort memslots base on its size and use line search to find it, so that the
larger memslots have better fitThe idea is from Avi
Signed-off-by: Xiao Guangrong
Signed-off-by: Avi Kivity -
Introduce id_to_memslot to get memslot by slot id
Signed-off-by: Xiao Guangrong
Signed-off-by: Avi Kivity -
Introduce kvm_for_each_memslot to walk all valid memslot
Signed-off-by: Xiao Guangrong
Signed-off-by: Avi Kivity -
Introduce update_memslots to update slot which will be update to
kvm->memslotsSigned-off-by: Xiao Guangrong
Signed-off-by: Avi Kivity -
Introduce KVM_MEM_SLOTS_NUM macro to instead of
KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTSSigned-off-by: Xiao Guangrong
Signed-off-by: Avi Kivity -
Needed for the next patch which uses this number to decide how to write
protect a slot.Signed-off-by: Takuya Yoshikawa
Signed-off-by: Avi Kivity -
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
Signed-off-by: Marcelo Tosatti
26 Sep, 2011
1 commit
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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
Cc: Marcelo Tosatti
Signed-off-by: Sasha Levin
Signed-off-by: Avi Kivity
24 Jul, 2011
2 commits
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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 directlySearching 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
Signed-off-by: Jan Kiszka
Signed-off-by: Avi Kivity -
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 prefetchSigned-off-by: Xiao Guangrong
Signed-off-by: Avi Kivity
12 Jul, 2011
4 commits
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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
Signed-off-by: Glauber Costa
Acked-by: Rik van Riel
Tested-by: Eric Munson
Signed-off-by: Avi Kivity -
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
Signed-off-by: Avi Kivity -
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
Signed-off-by: Avi Kivity -
Simply use __copy_to_user/__clear_user to write guest page since we have
already verified the user address when the memslot is setSigned-off-by: Xiao Guangrong
Signed-off-by: Marcelo Tosatti
06 Jun, 2011
1 commit
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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
Signed-off-by: Avi Kivity
26 May, 2011
1 commit
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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
Signed-off-by: Heiko Carstens
Signed-off-by: Avi Kivity
22 May, 2011
2 commits
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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: /-1, .owner_cpu: 0
Pid: 342, comm: kswapd0 Not tainted 2.6.39-rc5+ #1
Call Trace:
[] spin_bug+0x9c/0xa3
[] do_raw_spin_lock+0x29/0x13c
[] ? flush_tlb_others_ipi+0xaf/0xfd
[] _raw_spin_lock+0x9/0xb
[] kvm_mmu_notifier_clear_flush_young+0x2c/0x66 [kvm]
[] __mmu_notifier_clear_flush_young+0x2b/0x57
[] page_referenced_one+0x88/0xea
[] page_referenced+0x1fc/0x256
[] shrink_page_list+0x187/0x53a
[] shrink_inactive_list+0x1e0/0x33d
[] ? determine_dirtyable_memory+0x15/0x27
[] ? call_function_single_interrupt+0xe/0x20
[] shrink_zone+0x322/0x3de
[] ? zone_watermark_ok_safe+0xe2/0xf1
[] kswapd+0x516/0x818
[] ? shrink_zone+0x3de/0x3de
[] kthread+0x7d/0x85
[] kernel_thread_helper+0x4/0x10
[] ? __init_kthread_worker+0x37/0x37
[] ? gs_change+0xb/0xbSigned-off-by: OGAWA Hirofumi
Signed-off-by: Avi Kivity -
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
Signed-off-by: Avi Kivity
11 May, 2011
1 commit
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We can get memslot id from memslot->id directly
Signed-off-by: Xiao Guangrong
Signed-off-by: Avi Kivity
06 Apr, 2011
1 commit
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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
Signed-off-by: Avi Kivity
26 Mar, 2011
1 commit
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* '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
24 Mar, 2011
3 commits
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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
Cc: Avi Kivity
Cc: Marcelo Tosatti
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Cc: Avi Kivity
Cc: Marcelo Tosatti
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Avi Kivity
18 Mar, 2011
8 commits
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Code under this lock requires non-preemptibility. Ensure this also over
-rt by converting it to raw spinlock.Signed-off-by: Jan Kiszka
Signed-off-by: Avi Kivity -
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
Signed-off-by: Marcelo Tosatti
Signed-off-by: Avi Kivity -
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
Signed-off-by: Avi Kivity -
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
Signed-off-by: Marcelo Tosatti -
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 collateralSigned-off-by: Xiao Guangrong
Signed-off-by: Avi Kivity -
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 thread2: reorganize struct kvm_vcpu to make ->mode and ->requests
in the same cache line explicitlySigned-off-by: Xiao Guangrong
Signed-off-by: Avi Kivity -
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 usedThe 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
Signed-off-by: Marcelo Tosatti -
Instead, drop large mappings, which were the reason we dropped shadow.
Signed-off-by: Avi Kivity
Signed-off-by: Marcelo Tosatti
14 Jan, 2011
3 commits
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Cleanup some code with common compound_trans_head helper.
Signed-off-by: Andrea Arcangeli
Cc: Hugh Dickins
Cc: Johannes Weiner
Cc: Marcelo Tosatti
Cc: Avi Kivity
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This should work for both hugetlbfs and transparent hugepages.
[akpm@linux-foundation.org: bring forward PageTransCompound() addition for bisectability]
Signed-off-by: Andrea Arcangeli
Cc: Avi Kivity
Cc: Marcelo Tosatti
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
