gfn_to_memslot() can return NULL or invalid slot. We need to check slot
validity before accessing it.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
In commit e935b8372c ("KVM: Convert kvm_lock to raw_spinlock"),
the kvm_lock was made a raw lock. However, the kvm mmu_shrink()
function tries to grab the (non-raw) mmu_lock within the scope of
the raw locked kvm_lock being held. This leads to the following:
BUG: sleeping function called from invalid context at kernel/rtmutex.c:659
in_atomic(): 1, irqs_disabled(): 0, pid: 55, name: kswapd0
Preemption disabled at:[<ffffffffa0376eac>] mmu_shrink+0x5c/0x1b0 [kvm]
Pid: 55, comm: kswapd0 Not tainted 3.4.34_preempt-rt
Call Trace:
[<ffffffff8106f2ad>] __might_sleep+0xfd/0x160
[<ffffffff817d8d64>] rt_spin_lock+0x24/0x50
[<ffffffffa0376f3c>] mmu_shrink+0xec/0x1b0 [kvm]
[<ffffffff8111455d>] shrink_slab+0x17d/0x3a0
[<ffffffff81151f00>] ? mem_cgroup_iter+0x130/0x260
[<ffffffff8111824a>] balance_pgdat+0x54a/0x730
[<ffffffff8111fe47>] ? set_pgdat_percpu_threshold+0xa7/0xd0
[<ffffffff811185bf>] kswapd+0x18f/0x490
[<ffffffff81070961>] ? get_parent_ip+0x11/0x50
[<ffffffff81061970>] ? __init_waitqueue_head+0x50/0x50
[<ffffffff81118430>] ? balance_pgdat+0x730/0x730
[<ffffffff81060d2b>] kthread+0xdb/0xe0
[<ffffffff8106e122>] ? finish_task_switch+0x52/0x100
[<ffffffff817e1e94>] kernel_thread_helper+0x4/0x10
[<ffffffff81060c50>] ? __init_kthread_worker+0x
After the previous patch, kvm_lock need not be a raw spinlock anymore,
so change it back.
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: kvm@vger.kernel.org
Cc: gleb@redhat.com
Cc: jan.kiszka@siemens.com
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Page tables in a read-only memory slot will currently cause a triple
fault because the page walker uses gfn_to_hva and it fails on such a slot.
OVMF uses such a page table; however, real hardware seems to be fine with
that as long as the accessed/dirty bits are set. Save whether the slot
is readonly, and later check it when updating the accessed and dirty bits.
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is the type-safe comparison function, so the double-underscore is
not related.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
The checks on PG_reserved in the page structure on head and tail pages
aren't necessary because split_huge_page wouldn't transfer the
PG_reserved bit from head to tail anyway.
This was a forward-thinking check done in the case PageReserved was
set by a driver-owned page mapped in userland with something like
remap_pfn_range in a VM_PFNMAP region, but using hugepmds (not
possible right now). It was meant to be very safe, but it's overkill
as it's unlikely split_huge_page could ever run without the driver
noticing and tearing down the hugepage itself.
And if a driver in the future will really want to map a reserved
hugepage in userland using an huge pmd it should simply take care of
marking all subpages reserved too to keep KVM safe. This of course
would require such a hypothetical driver to tear down the huge pmd
itself and splitting the hugepage itself, instead of relaying on
split_huge_page, but that sounds very reasonable, especially
considering split_huge_page wouldn't currently transfer the reserved
bit anyway.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
KVM uses anon_inode_get() to allocate file descriptors as part
of some of its ioctls. But those ioctls are lacking a flag argument
allowing userspace to choose options for the newly opened file descriptor.
In such case it's advised to use O_CLOEXEC by default so that
userspace is allowed to choose, without race, if the file descriptor
is going to be inherited across exec().
This patch set O_CLOEXEC flag on all file descriptors created
with anon_inode_getfd() to not leak file descriptors across exec().
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://lkml.kernel.org/r/cover.1377372576.git.ydroneaud@opteya.com
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
kvm_io_bus_sort_cmp is used also directly, not just as a callback for
sort and bsearch. In these cases, it is handy to have a type-safe
variant. This patch introduces such a variant, __kvm_io_bus_sort_cmp,
and uses it throughout kvm_main.c.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is called right after the memslots is updated, i.e. when the result
of update_memslots() gets installed in install_new_memslots(). Since
the memslots needs to be updated twice when we delete or move a memslot,
kvm_arch_commit_memory_region() does not correspond to this exactly.
In the following patch, x86 will use this new API to check if the mmio
generation has reached its maximum value, in which case mmio sptes need
to be flushed out.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Acked-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add new functions kvm_io_bus_{read,write}_cookie() that allows users of
the kvm io infrastructure to use a cookie value to speed up lookup of a
device on an io bus.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
We can easily reach the 1000 limit by start VM with a couple
hundred I/O devices (multifunction=on). The hardcode limit
already been adjusted 3 times (6 ~ 200 ~ 300 ~ 1000).
In userspace, we already have maximum file descriptor to
limit ioeventfd count. But kvm_io_bus devices also are used
for pit, pic, ioapic, coalesced_mmio. They couldn't be limited
by maximum file descriptor.
Currently only ioeventfds take too much kvm_io_bus devices,
so just exclude it from counting kvm_io_range limit.
Also fixed one indent issue in kvm_host.h
Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Add the missing misc_deregister() before return from kvm_init()
in the debugfs init error handling case.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Pull kvm fixes from Gleb Natapov:
"Most of the fixes are in the emulator since now we emulate more than
we did before for correctness sake we see more bugs there, but there
is also an OOPS fixed and corruption of xcr0 register."
* tag 'kvm-3.10-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: emulator: emulate SALC
KVM: emulator: emulate XLAT
KVM: emulator: emulate AAM
KVM: VMX: fix halt emulation while emulating invalid guest sate
KVM: Fix kvm_irqfd_init initialization
KVM: x86: fix maintenance of guest/host xcr0 state
Pull MIPS updates from Ralf Baechle:
- More work on DT support for various platforms
- Various fixes that were to late to make it straight into 3.9
- Improved platform support, in particular the Netlogic XLR and
BCM63xx, and the SEAD3 and Malta eval boards.
- Support for several Ralink SOC families.
- Complete support for the microMIPS ASE which basically reencodes the
existing MIPS32/MIPS64 ISA to use non-constant size instructions.
- Some fallout from LTO work which remove old cruft and will generally
make the MIPS kernel easier to maintain and resistant to compiler
optimization, even in absence of LTO.
- KVM support. While MIPS has announced hardware virtualization
extensions this KVM extension uses trap and emulate mode for
virtualization of MIPS32. More KVM work to add support for VZ
hardware virtualizaiton extensions and MIPS64 will probably already
be merged for 3.11.
Most of this has been sitting in -next for a long time. All defconfigs
have been build or run time tested except three for which fixes are being
sent by other maintainers.
Semantic conflict with kvm updates done as per Ralf
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (118 commits)
MIPS: Add new GIC clockevent driver.
MIPS: Formatting clean-ups for clocksources.
MIPS: Refactor GIC clocksource code.
MIPS: Move 'gic_frequency' to common location.
MIPS: Move 'gic_present' to common location.
MIPS: MIPS16e: Add unaligned access support.
MIPS: MIPS16e: Support handling of delay slots.
MIPS: MIPS16e: Add instruction formats.
MIPS: microMIPS: Optimise 'strnlen' core library function.
MIPS: microMIPS: Optimise 'strlen' core library function.
MIPS: microMIPS: Optimise 'strncpy' core library function.
MIPS: microMIPS: Optimise 'memset' core library function.
MIPS: microMIPS: Add configuration option for microMIPS kernel.
MIPS: microMIPS: Disable LL/SC and fix linker bug.
MIPS: microMIPS: Add vdso support.
MIPS: microMIPS: Add unaligned access support.
MIPS: microMIPS: Support handling of delay slots.
MIPS: microMIPS: Add support for exception handling.
MIPS: microMIPS: Floating point support.
MIPS: microMIPS: Fix macro naming in micro-assembler.
...
Pull kvm updates from Gleb Natapov:
"Highlights of the updates are:
general:
- new emulated device API
- legacy device assignment is now optional
- irqfd interface is more generic and can be shared between arches
x86:
- VMCS shadow support and other nested VMX improvements
- APIC virtualization and Posted Interrupt hardware support
- Optimize mmio spte zapping
ppc:
- BookE: in-kernel MPIC emulation with irqfd support
- Book3S: in-kernel XICS emulation (incomplete)
- Book3S: HV: migration fixes
- BookE: more debug support preparation
- BookE: e6500 support
ARM:
- reworking of Hyp idmaps
s390:
- ioeventfd for virtio-ccw
And many other bug fixes, cleanups and improvements"
* tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits)
kvm: Add compat_ioctl for device control API
KVM: x86: Account for failing enable_irq_window for NMI window request
KVM: PPC: Book3S: Add API for in-kernel XICS emulation
kvm/ppc/mpic: fix missing unlock in set_base_addr()
kvm/ppc: Hold srcu lock when calling kvm_io_bus_read/write
kvm/ppc/mpic: remove users
kvm/ppc/mpic: fix mmio region lists when multiple guests used
kvm/ppc/mpic: remove default routes from documentation
kvm: KVM_CAP_IOMMU only available with device assignment
ARM: KVM: iterate over all CPUs for CPU compatibility check
KVM: ARM: Fix spelling in error message
ARM: KVM: define KVM_ARM_MAX_VCPUS unconditionally
KVM: ARM: Fix API documentation for ONE_REG encoding
ARM: KVM: promote vfp_host pointer to generic host cpu context
ARM: KVM: add architecture specific hook for capabilities
ARM: KVM: perform HYP initilization for hotplugged CPUs
ARM: KVM: switch to a dual-step HYP init code
ARM: KVM: rework HYP page table freeing
ARM: KVM: enforce maximum size for identity mapped code
ARM: KVM: move to a KVM provided HYP idmap
...
This API shouldn't have 32/64-bit issues, but VFS assumes it does
unless told otherwise.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
This adds the API for userspace to instantiate an XICS device in a VM
and connect VCPUs to it. The API consists of a new device type for
the KVM_CREATE_DEVICE ioctl, a new capability KVM_CAP_IRQ_XICS, which
functions similarly to KVM_CAP_IRQ_MPIC, and the KVM_IRQ_LINE ioctl,
which is used to assert and deassert interrupt inputs of the XICS.
The XICS device has one attribute group, KVM_DEV_XICS_GRP_SOURCES.
Each attribute within this group corresponds to the state of one
interrupt source. The attribute number is the same as the interrupt
source number.
This does not support irq routing or irqfd yet.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
The hassle of getting refcounting right was greater than the hassle
of keeping a list of devices to destroy on VM exit.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Hook the MPIC code up to the KVM interfaces, add locking, etc.
Signed-off-by: Scott Wood <scottwood@freescale.com>
[agraf: add stub function for kvmppc_mpic_set_epr, non-booke, 64bit]
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently, devices that are emulated inside KVM are configured in a
hardcoded manner based on an assumption that any given architecture
only has one way to do it. If there's any need to access device state,
it is done through inflexible one-purpose-only IOCTLs (e.g.
KVM_GET/SET_LAPIC). Defining new IOCTLs for every little thing is
cumbersome and depletes a limited numberspace.
This API provides a mechanism to instantiate a device of a certain
type, returning an ID that can be used to set/get attributes of the
device. Attributes may include configuration parameters (e.g.
register base address), device state, operational commands, etc. It
is similar to the ONE_REG API, except that it acts on devices rather
than vcpus.
Both device types and individual attributes can be tested without having
to create the device or get/set the attribute, without the need for
separately managing enumerated capabilities.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Gleb Natapov
Paolo Bonzini
Andrea Arcangeli
Yann Droneaud
Takuya Yoshikawa
Cornelia Huck
Amos Kong
Wei Yongjun
Linus Torvalds
Ralf Baechle
Sanjay Lal
Asias He
Scott Wood
Paul Mackerras