commit 350b8bdd689cd2ab2c67c8a86a0be86cfa0751a7 upstream.
The third parameter of kvm_iommu_put_pages is wrong,
It should be 'gfn - slot->base_gfn'.
By making gfn very large, malicious guest or userspace can cause kvm to
go to this error path, and subsequently to pass a huge value as size.
Alternatively if gfn is small, then pages would be pinned but never
unpinned, causing host memory leak and local DOS.
Passing a reasonable but large value could be the most dangerous case,
because it would unpin a page that should have stayed pinned, and thus
allow the device to DMA into arbitrary memory. However, this cannot
happen because of the condition that can trigger the error:
- out of memory (where you can't allocate even a single page)
should not be possible for the attacker to trigger
- when exceeding the iommu's address space, guest pages after gfn
will also exceed the iommu's address space, and inside
kvm_iommu_put_pages() the iommu_iova_to_phys() will fail. The
page thus would not be unpinned at all.
Reported-by: Jack Morgenstein <jackm@mellanox.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0f6c0a740b7d3e1f3697395922d674000f83d060 upstream.
Currently, the EOI exit bitmap (used for APICv) does not include
interrupts that are masked. However, this can cause a bug that manifests
as an interrupt storm inside the guest. Alex Williamson reported the
bug and is the one who really debugged this; I only wrote the patch. :)
The scenario involves a multi-function PCI device with OHCI and EHCI
USB functions and an audio function, all assigned to the guest, where
both USB functions use legacy INTx interrupts.
As soon as the guest boots, interrupts for these devices turn into an
interrupt storm in the guest; the host does not see the interrupt storm.
Basically the EOI path does not work, and the guest continues to see the
interrupt over and over, even after it attempts to mask it at the APIC.
The bug is only visible with older kernels (RHEL6.5, based on 2.6.32
with not many changes in the area of APIC/IOAPIC handling).
Alex then tried forcing bit 59 (corresponding to the USB functions' IRQ)
on in the eoi_exit_bitmap and TMR, and things then work. What happens
is that VFIO asserts IRQ11, then KVM recomputes the EOI exit bitmap.
It does not have set bit 59 because the RTE was masked, so the IOAPIC
never sees the EOI and the interrupt continues to fire in the guest.
My guess was that the guest is masking the interrupt in the redirection
table in the interrupt routine, i.e. while the interrupt is set in a
LAPIC's ISR, The simplest fix is to ignore the masking state, we would
rather have an unnecessary exit rather than a missed IRQ ACK and anyway
IOAPIC interrupts are not as performance-sensitive as for example MSIs.
Alex tested this patch and it fixed his bug.
[Thanks to Alex for his precise description of the problem
and initial debugging effort. A lot of the text above is
based on emails exchanged with him.]
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5678de3f15010b9022ee45673f33bcfc71d47b60 upstream.
QE reported that they got the BUG_ON in ioapic_service to trigger.
I cannot reproduce it, but there are two reasons why this could happen.
The less likely but also easiest one, is when kvm_irq_delivery_to_apic
does not deliver to any APIC and returns -1.
Because irqe.shorthand == 0, the kvm_for_each_vcpu loop in that
function is never reached. However, you can target the similar loop in
kvm_irq_delivery_to_apic_fast; just program a zero logical destination
address into the IOAPIC, or an out-of-range physical destination address.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 668f9abbd4334e6c29fa8acd71635c4f9101caa7 upstream.
Commit bf6bddf192 ("mm: introduce compaction and migration for
ballooned pages") introduces page_count(page) into memory compaction
which dereferences page->first_page if PageTail(page).
This results in a very rare NULL pointer dereference on the
aforementioned page_count(page). Indeed, anything that does
compound_head(), including page_count() is susceptible to racing with
prep_compound_page() and seeing a NULL or dangling page->first_page
pointer.
This patch uses Andrea's implementation of compound_trans_head() that
deals with such a race and makes it the default compound_head()
implementation. This includes a read memory barrier that ensures that
if PageTail(head) is true that we return a head page that is neither
NULL nor dangling. The patch then adds a store memory barrier to
prep_compound_page() to ensure page->first_page is set.
This is the safest way to ensure we see the head page that we are
expecting, PageTail(page) is already in the unlikely() path and the
memory barriers are unfortunately required.
Hugetlbfs is the exception, we don't enforce a store memory barrier
during init since no race is possible.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Holger Kiehl <Holger.Kiehl@dwd.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit aac5c4226e7136c331ed384c25d5560204da10a0 upstream.
If kvm_io_bus_register_dev() fails then it returns success but it should
return an error code.
I also did a little cleanup like removing an impossible NULL test.
Fixes: 2b3c246a68 ('KVM: Make coalesced mmio use a device per zone')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 338c7dbadd2671189cec7faf64c84d01071b3f96 upstream.
In multiple functions the vcpu_id is used as an offset into a bitfield. Ag
malicious user could specify a vcpu_id greater than 255 in order to set or
clear bits in kernel memory. This could be used to elevate priveges in the
kernel. This patch verifies that the vcpu_id provided is less than 255.
The api documentation already specifies that the vcpu_id must be less than
max_vcpus, but this is currently not checked.
Reported-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 27ef63c7e97d1e5dddd85051c03f8d44cc887f34 upstream.
When determining the page size we could use to map with the IOMMU, the
page size should also be aligned with the hva, not just the gfn. The
gfn may not reflect the real alignment within the hugetlbfs file.
Most of the time, this works fine. However, if the hugetlbfs file is
backed by non-contiguous huge pages, a multi-huge page memslot starts at
an unaligned offset within the hugetlbfs file, and the gfn is aligned
with respect to the huge page size, kvm_host_page_size() will return the
huge page size and we will use that to map with the IOMMU.
When we later unpin that same memslot, the IOMMU returns the unmap size
as the huge page size, and we happily unpin that many pfns in
monotonically increasing order, not realizing we are spanning
non-contiguous huge pages and partially unpin the wrong huge page.
Ensure the IOMMU mapping page size is aligned with the hva corresponding
to the gfn, which does reflect the alignment within the hugetlbfs file.
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Edwards <gedwards@ddn.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Now that we have most irqfd code completely platform agnostic, let's move
irqfd's resample capability return to generic code as well.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Setting up IRQ routes is nothing IOAPIC specific. Extract everything
that really is generic code into irqchip.c and only leave the ioapic
specific bits to irq_comm.c.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
The current irq_comm.c file contains pieces of code that are generic
across different irqchip implementations, as well as code that is
fully IOAPIC specific.
Split the generic bits out into irqchip.c.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
The IRQ routing set ioctl lives in the hacky device assignment code inside
of KVM today. This is definitely the wrong place for it. Move it to the much
more natural kvm_main.c.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Quite a bit of code in KVM has been conditionalized on availability of
IOAPIC emulation. However, most of it is generically applicable to
platforms that don't have an IOPIC, but a different type of irq chip.
Make code that only relies on IRQ routing, not an APIC itself, on
CONFIG_HAVE_KVM_IRQ_ROUTING, so that we can reuse it later.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
The concept of routing interrupt lines to an irqchip is nothing
that is IOAPIC specific. Every irqchip has a maximum number of pins
that can be linked to irq lines.
So let's add a new define that allows us to reuse generic code for
non-IOAPIC platforms.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Only deliver the posted interrupt when target vcpu is running
and there is no previous interrupt pending in pir.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We already know the trigger mode of a given interrupt when programming
the ioapice entry. So it's not necessary to set it in each interrupt
delivery.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Both TMR and EOI exit bitmap need to be updated when ioapic changed
or vcpu's id/ldr/dfr changed. So use common function instead eoi exit
bitmap specific function.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Current interrupt coalescing logci which only used by RTC has conflict
with Posted Interrupt.
This patch introduces a new mechinism to use eoi to track interrupt:
When delivering an interrupt to vcpu, the pending_eoi set to number of
vcpu that received the interrupt. And decrease it when each vcpu writing
eoi. No subsequent RTC interrupt can deliver to vcpu until all vcpus
write eoi.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Userspace may deliver RTC interrupt without query the status. So we
want to track RTC EOI for this case.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Need the EOI to track interrupt deliver status, so force vmexit
on EOI for rtc interrupt when enabling virtual interrupt delivery.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Add a new parameter to know vcpus who received the interrupt.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
rtc_status is used to track RTC interrupt delivery status. The pending_eoi
will be increased by vcpu who received RTC interrupt and will be decreased
when EOI to this interrupt.
Also, we use dest_map to record the destination vcpu to avoid the case that
vcpu who didn't get the RTC interupt, but issued EOI with same vector of RTC
and descreased pending_eoi by mistake.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Add vcpu info to ioapic_update_eoi, so we can know which vcpu
issued this EOI.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The routine kvm_spurious_fault() is an x86 specific routine, so
move it from virt/kvm/kvm_main.c to arch/x86/kvm/x86.c.
Fixes this sparse warning when building on arm64:
virt/kvm/kvm_main.c⚠️ symbol 'kvm_spurious_fault' was not declared. Should it be static?
Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
The routines get_user_page_nowait(), kvm_io_bus_sort_cmp(), kvm_io_bus_insert_dev()
and kvm_io_bus_get_first_dev() are only referenced within kvm_main.c, so give them
static linkage.
Fixes sparse warnings like these:
virt/kvm/kvm_main.c: warning: symbol 'get_user_page_nowait' was not declared. Should it be static?
Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
PIO and MMIO are separate address spaces, but
ioeventfd registration code mistakenly detected
two eventfds as duplicate if they use the same address,
even if one is PIO and another one MMIO.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
For a given vcpu, kvm_apic_match_dest() will tell you whether
the vcpu in the destination list quickly. Drop kvm_calculate_eoi_exitmap()
and use kvm_apic_match_dest() instead.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
This patch adds support for kvm_gfn_to_hva_cache_init functions for
reads and writes that will cross a page. If the range falls within
the same memslot, then this will be a fast operation. If the range
is split between two memslots, then the slower kvm_read_guest and
kvm_write_guest are used.
Tested: Test against kvm_clock unit tests.
Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Merge reason:
From: Alexander Graf <agraf@suse.de>
"Just recently this really important patch got pulled into Linus' tree for 3.9:
commit 1674400aae
Author: Anton Blanchard <anton <at> samba.org>
Date: Tue Mar 12 01:51:51 2013 +0000
Without that commit, I can not boot my G5, thus I can't run automated tests on it against my queue.
Could you please merge kvm/next against linus/master, so that I can base my trees against that?"
* upstream/master: (653 commits)
PCI: Use ROM images from firmware only if no other ROM source available
sparc: remove unused "config BITS"
sparc: delete "if !ULTRA_HAS_POPULATION_COUNT"
KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798)
KVM: x86: Convert MSR_KVM_SYSTEM_TIME to use gfn_to_hva_cache functions (CVE-2013-1797)
KVM: x86: fix for buffer overflow in handling of MSR_KVM_SYSTEM_TIME (CVE-2013-1796)
arm64: Kconfig.debug: Remove unused CONFIG_DEBUG_ERRORS
arm64: Do not select GENERIC_HARDIRQS_NO_DEPRECATED
inet: limit length of fragment queue hash table bucket lists
qeth: Fix scatter-gather regression
qeth: Fix invalid router settings handling
qeth: delay feature trace
sgy-cts1000: Remove __dev* attributes
KVM: x86: fix deadlock in clock-in-progress request handling
KVM: allow host header to be included even for !CONFIG_KVM
hwmon: (lm75) Fix tcn75 prefix
hwmon: (lm75.h) Update header inclusion
MAINTAINERS: Remove Mark M. Hoffman
xfs: ensure we capture IO errors correctly
xfs: fix xfs_iomap_eof_prealloc_initial_size type
...
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If the guest specifies a IOAPIC_REG_SELECT with an invalid value and follows
that with a read of the IOAPIC_REG_WINDOW KVM does not properly validate
that request. ioapic_read_indirect contains an
ASSERT(redir_index < IOAPIC_NUM_PINS), but the ASSERT has no effect in
non-debug builds. In recent kernels this allows a guest to cause a kernel
oops by reading invalid memory. In older kernels (pre-3.3) this allows a
guest to read from large ranges of host memory.
Tested: tested against apic unit tests.
Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This helps in filtering out the eligible candidates further and
thus potentially helps in quickly allowing preempted lockholders to run.
Note that if a vcpu was spinning during preemption we filter them
by checking whether they are preempted due to pause loop exit.
Reviewed-by: Chegu Vinod <chegu_vinod@hp.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Note that we mark as preempted only when vcpu's task state was
Running during preemption.
Thanks Jiannan, Avi for preemption notifier ideas. Thanks Gleb, PeterZ
for their precious suggestions. Thanks Srikar for an idea on avoiding
rcu lock while checking task state that improved overcommit numbers.
Reviewed-by: Chegu Vinod <chegu_vinod@hp.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Enhance KVM_IOEVENTFD with a new flag that allows to attach to virtio-ccw
devices on s390 via the KVM_VIRTIO_CCW_NOTIFY_BUS.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently, eventfd introduces module_init/module_exit functions
to initialize/cleanup the irqfd workqueue. This only works, however,
if no other module_init/module_exit functions are built into the
same module.
Let's just move the initialization and cleanup to kvm_init and kvm_exit.
This way, it is also clearer where kvm startup may fail.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch makes the parameter old a const pointer to the old memory
slot and adds a new parameter named change to know the change being
requested: the former is for removing extra copying and the latter is
for cleaning up the code.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch drops the parameter old, a copy of the old memory slot, and
adds a new parameter named change to know the change being requested.
This not only cleans up the code but also removes extra copying of the
memory slot structure.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This will be used for cleaning up prepare/commit_memory_region() later.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Except ia64's stale code, KVM_SET_MEMORY_REGION support, this is only
used for sanity checks in __kvm_set_memory_region() which can easily
be changed to use slot id instead.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
X86 does not use this any more. The remaining user, s390's !user_alloc
check, can be simply removed since KVM_SET_MEMORY_REGION ioctl is no
longer supported.
Note: fixed powerpc's indentations with spaces to suppress checkpatch
errors.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
