Commits e4d57e1ee1 (KVM: Move irq notifier implementation into
eventfd.c, 2014-06-30) included the irq notifier code unconditionally
in eventfd.c, while it was under CONFIG_HAVE_KVM_IRQCHIP before.
Similarly, commit 297e21053a (KVM: Give IRQFD its own separate enabling
Kconfig option, 2014-06-30) moved code from CONFIG_HAVE_IRQ_ROUTING
to CONFIG_HAVE_KVM_IRQFD but forgot to move the pieces that used to be
under CONFIG_HAVE_KVM_IRQCHIP.
Together, this broke compilation without CONFIG_KVM_XICS. Fix by adding
or changing the #ifdefs so that they point at CONFIG_HAVE_KVM_IRQFD.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently, the IRQFD code is conditional on CONFIG_HAVE_KVM_IRQ_ROUTING.
So that we can have the IRQFD code compiled in without having the
IRQ routing code, this creates a new CONFIG_HAVE_KVM_IRQFD, makes
the IRQFD code conditional on it instead of CONFIG_HAVE_KVM_IRQ_ROUTING,
and makes all the platforms that currently select HAVE_KVM_IRQ_ROUTING
also select HAVE_KVM_IRQFD.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The KVM_CHECK_EXTENSION is only available on the kvm fd today. Unfortunately
on PPC some of the capabilities change depending on the way a VM was created.
So instead we need a way to expose capabilities as VM ioctl, so that we can
see which VM type we're using (HV or PR). To enable this, add the
KVM_CHECK_EXTENSION ioctl to our vm ioctl portfolio.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
In preparation to make the check_extension function available to VM scope
we add a struct kvm * argument to the function header and rename the function
accordingly. It will still be called from the /dev/kvm fd, but with a NULL
argument for struct kvm *.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Pull more scheduler updates from Ingo Molnar:
"Second round of scheduler changes:
- try-to-wakeup and IPI reduction speedups, from Andy Lutomirski
- continued power scheduling cleanups and refactorings, from Nicolas
Pitre
- misc fixes and enhancements"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Delete extraneous extern for to_ratio()
sched/idle: Optimize try-to-wake-up IPI
sched/idle: Simplify wake_up_idle_cpu()
sched/idle: Clear polling before descheduling the idle thread
sched, trace: Add a tracepoint for IPI-less remote wakeups
cpuidle: Set polling in poll_idle
sched: Remove redundant assignment to "rt_rq" in update_curr_rt(...)
sched: Rename capacity related flags
sched: Final power vs. capacity cleanups
sched: Remove remaining dubious usage of "power"
sched: Let 'struct sched_group_power' care about CPU capacity
sched/fair: Disambiguate existing/remaining "capacity" usage
sched/fair: Change "has_capacity" to "has_free_capacity"
sched/fair: Remove "power" from 'struct numa_stats'
sched: Fix signedness bug in yield_to()
sched/fair: Use time_after() in record_wakee()
sched/balancing: Reduce the rate of needless idle load balancing
sched/fair: Fix unlocked reads of some cfs_b->quota/period
When starting lots of dataplane devices the bootup takes very long on
Christian's s390 with irqfd patches. With larger setups he is even
able to trigger some timeouts in some components. Turns out that the
KVM_SET_GSI_ROUTING ioctl takes very long (strace claims up to 0.1 sec)
when having multiple CPUs. This is caused by the synchronize_rcu and
the HZ=100 of s390. By changing the code to use a private srcu we can
speed things up. This patch reduces the boot time till mounting root
from 8 to 2 seconds on my s390 guest with 100 disks.
Uses of hlist_for_each_entry_rcu, hlist_add_head_rcu, hlist_del_init_rcu
are fine because they do not have lockdep checks (hlist_for_each_entry_rcu
uses rcu_dereference_raw rather than rcu_dereference, and write-sides
do not do rcu lockdep at all).
Note that we're hardly relying on the "sleepable" part of srcu. We just
want SRCU's faster detection of grace periods.
Testing was done by Andrew Theurer using netperf tests STREAM, MAERTS
and RR. The difference between results "before" and "after" the patch
has mean -0.2% and standard deviation 0.6%. Using a paired t-test on the
data points says that there is a 2.5% probability that the patch is the
cause of the performance difference (rather than a random fluctuation).
(Restricting the t-test to RR, which is the most likely to be affected,
changes the numbers to respectively -0.3% mean, 0.7% stdev, and 8%
probability that the numbers actually say something about the patch.
The probability increases mostly because there are fewer data points).
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> # s390
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Lazy storage key handling
-------------------------
Linux does not use the ACC and F bits of the storage key. Newer Linux
versions also do not use the storage keys for dirty and reference
tracking. We can optimize the guest handling for those guests for faults
as well as page-in and page-out by simply not caring about the guest
visible storage key. We trap guest storage key instruction to enable
those keys only on demand.
Migration bitmap
Until now s390 never provided a proper dirty bitmap. Let's provide a
proper migration bitmap for s390. We also change the user dirty tracking
to a fault based mechanism. This makes the host completely independent
from the storage keys. Long term this will allow us to back guest memory
with large pages.
per-VM device attributes
------------------------
To avoid the introduction of new ioctls, let's provide the
attribute semanantic also on the VM-"device".
Userspace controlled CMMA
-------------------------
The CMMA assist is changed from "always on" to "on if requested" via
per-VM device attributes. In addition a callback to reset all usage
states is provided.
Proper guest DAT handling for intercepts
----------------------------------------
While instructions handled by SIE take care of all addressing aspects,
KVM/s390 currently does not care about guest address translation of
intercepts. This worked out fine, because
- the s390 Linux kernel has a 1:1 mapping between kernel virtual<->real
for all pages up to memory size
- intercepts happen only for a small amount of cases
- all of these intercepts happen to be in the kernel text for current
distros
Of course we need to be better for other intercepts, kernel modules etc.
We provide the infrastructure and rework all in-kernel intercepts to work
on logical addresses (paging etc) instead of real ones. The code has
been running internally for several months now, so it is time for going
public.
GDB support
-----------
We provide breakpoints, single stepping and watchpoints.
Fixes/Cleanups
--------------
- Improve program check delivery
- Factor out the handling of transactional memory on program checks
- Use the existing define __LC_PGM_TDB
- Several cleanups in the lowcore structure
- Documentation
NOTES
-----
- All patches touching base s390 are either ACKed or written by the s390
maintainers
- One base KVM patch "KVM: add kvm_is_error_gpa() helper"
- One patch introduces the notion of VM device attributes
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Conflicts:
include/uapi/linux/kvm.h
Replace the kvm_s390_sync_dirty_log() stub with code to construct the KVM
dirty_bitmap from S390 memory change bits. Also add code to properly clear
the dirty_bitmap size when clearing the bitmap.
Signed-off-by: Jason J. Herne <jjherne@us.ibm.com>
CC: Dominik Dingel <dingel@linux.vnet.ibm.com>
[Dominik Dingel: use gmap_test_and_clear_dirty, locking fixes]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
With KVM, MMIO is much slower than PIO, due to the need to
do page walk and emulation. But with EPT, it does not have to be: we
know the address from the VMCS so if the address is unique, we can look
up the eventfd directly, bypassing emulation.
Unfortunately, this only works if userspace does not need to match on
access length and data. The implementation adds a separate FAST_MMIO
bus internally. This serves two purposes:
- minimize overhead for old userspace that does not use eventfd with lengtth = 0
- minimize disruption in other code (since we don't know the length,
devices on the MMIO bus only get a valid address in write, this
way we don't need to touch all devices to teach them to handle
an invalid length)
At the moment, this optimization only has effect for EPT on x86.
It will be possible to speed up MMIO for NPT and MMU using the same
idea in the future.
With this patch applied, on VMX MMIO EVENTFD is essentially as fast as PIO.
I was unable to detect any measureable slowdown to non-eventfd MMIO.
Making MMIO faster is important for the upcoming virtio 1.0 which
includes an MMIO signalling capability.
The idea was suggested by Peter Anvin. Lots of thanks to Gleb for
pre-review and suggestions.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Pull kvm updates from Paolo Bonzini:
"PPC and ARM do not have much going on this time. Most of the cool
stuff, instead, is in s390 and (after a few releases) x86.
ARM has some caching fixes and PPC has transactional memory support in
guests. MIPS has some fixes, with more probably coming in 3.16 as
QEMU will soon get support for MIPS KVM.
For x86 there are optimizations for debug registers, which trigger on
some Windows games, and other important fixes for Windows guests. We
now expose to the guest Broadwell instruction set extensions and also
Intel MPX. There's also a fix/workaround for OS X guests, nested
virtualization features (preemption timer), and a couple kvmclock
refinements.
For s390, the main news is asynchronous page faults, together with
improvements to IRQs (floating irqs and adapter irqs) that speed up
virtio devices"
* tag 'kvm-3.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (96 commits)
KVM: PPC: Book3S HV: Save/restore host PMU registers that are new in POWER8
KVM: PPC: Book3S HV: Fix decrementer timeouts with non-zero TB offset
KVM: PPC: Book3S HV: Don't use kvm_memslots() in real mode
KVM: PPC: Book3S HV: Return ENODEV error rather than EIO
KVM: PPC: Book3S: Trim top 4 bits of physical address in RTAS code
KVM: PPC: Book3S HV: Add get/set_one_reg for new TM state
KVM: PPC: Book3S HV: Add transactional memory support
KVM: Specify byte order for KVM_EXIT_MMIO
KVM: vmx: fix MPX detection
KVM: PPC: Book3S HV: Fix KVM hang with CONFIG_KVM_XICS=n
KVM: PPC: Book3S: Introduce hypervisor call H_GET_TCE
KVM: PPC: Book3S HV: Fix incorrect userspace exit on ioeventfd write
KVM: s390: clear local interrupts at cpu initial reset
KVM: s390: Fix possible memory leak in SIGP functions
KVM: s390: fix calculation of idle_mask array size
KVM: s390: randomize sca address
KVM: ioapic: reinject pending interrupts on KVM_SET_IRQCHIP
KVM: Bump KVM_MAX_IRQ_ROUTES for s390
KVM: s390: irq routing for adapter interrupts.
KVM: s390: adapter interrupt sources
...
Use the arch specific function kvm_arch_vcpu_runnable() to add a further
criterium to identify a suitable vcpu to yield to during undirected yield
processing.
Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When this was introduced, kvm_flush_remote_tlbs() could be called
without holding mmu_lock. It is now acknowledged that the function
must be called before releasing mmu_lock, and all callers have already
been changed to do so.
There is no need to use smp_mb() and cmpxchg() any more.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds a floating irq controller as a kvm_device.
It will be necessary for migration of floating interrupts as well
as for hardening the reset code by allowing user space to explicitly
remove all pending floating interrupts.
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Pull KVM updates from Paolo Bonzini:
"First round of KVM updates for 3.14; PPC parts will come next week.
Nothing major here, just bugfixes all over the place. The most
interesting part is the ARM guys' virtualized interrupt controller
overhaul, which lets userspace get/set the state and thus enables
migration of ARM VMs"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (67 commits)
kvm: make KVM_MMU_AUDIT help text more readable
KVM: s390: Fix memory access error detection
KVM: nVMX: Update guest activity state field on L2 exits
KVM: nVMX: Fix nested_run_pending on activity state HLT
KVM: nVMX: Clean up handling of VMX-related MSRs
KVM: nVMX: Add tracepoints for nested_vmexit and nested_vmexit_inject
KVM: nVMX: Pass vmexit parameters to nested_vmx_vmexit
KVM: nVMX: Leave VMX mode on clearing of feature control MSR
KVM: VMX: Fix DR6 update on #DB exception
KVM: SVM: Fix reading of DR6
KVM: x86: Sync DR7 on KVM_SET_DEBUGREGS
add support for Hyper-V reference time counter
KVM: remove useless write to vcpu->hv_clock.tsc_timestamp
KVM: x86: fix tsc catchup issue with tsc scaling
KVM: x86: limit PIT timer frequency
KVM: x86: handle invalid root_hpa everywhere
kvm: Provide kvm_vcpu_eligible_for_directed_yield() stub
kvm: vfio: silence GCC warning
KVM: ARM: Remove duplicate include
arm/arm64: KVM: relax the requirements of VMA alignment for THP
...
Commit 7940876e13 ("kvm: make local
functions static") broke KVM PPC builds due to removing (rather than
moving) the stub version of kvm_vcpu_eligible_for_directed_yield().
This patch reintroduces it.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Alexander Graf <agraf@suse.de>
[Move the #ifdef inside the function. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The function kvm_io_bus_read_cookie is defined but never used
in current in-tree code.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Running 'make namespacecheck' found lots of functions that
should be declared static, since only used in one file.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Support creating the ARM VGIC device through the KVM_CREATE_DEVICE
ioctl, which can then later be leveraged to use the
KVM_{GET/SET}_DEVICE_ATTR, which is useful both for setting addresses in
a more generic API than the ARM-specific one and is useful for
save/restore of VGIC state.
Adds KVM_CAP_DEVICE_CTRL to ARM capabilities.
Note that we change the check for creating a VGIC from bailing out if
any VCPUs were created, to bailing out if any VCPUs were ever run. This
is an important distinction that shouldn't break anything, but allows
creating the VGIC after the VCPUs have been created.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Since the commit 15ad7146 ("KVM: Use the scheduler preemption notifiers
to make kvm preemptible"), the remaining stuff in this function is a
simple cond_resched() call with an extra need_resched() check which was
there to avoid dropping VCPUs unnecessarily. Now it is meaningless.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Using the address of 'empty_zero_page' as source address in order to
clear a page is wrong. On some architectures empty_zero_page is only the
pointer to the struct page of the empty_zero_page. Therefore the clear
page operation would copy the contents of a couple of struct pages instead
of clearing a page. For kvm only arm/arm64 are affected by this bug.
To fix this use the ZERO_PAGE macro instead which will return the struct
page address of the empty_zero_page on all architectures.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Paolo Bonzini
Paul Mackerras
Alexander Graf
Linus Torvalds
Dan Carpenter
Christian Borntraeger
Xiao Guangrong
Marcelo Tosatti
Jason J. Herne
Michael S. Tsirkin
Michael Mueller
Takuya Yoshikawa
Andi Kleen
Jens Freimann
Scott Wood
Stephen Hemminger
Christoffer Dall
Andy Honig
Heiko Carstens