Some wakeups should not be considered a sucessful poll. For example on
s390 I/O interrupts are usually floating, which means that _ALL_ CPUs
would be considered runnable - letting all vCPUs poll all the time for
transactional like workload, even if one vCPU would be enough.
This can result in huge CPU usage for large guests.
This patch lets architectures provide a way to qualify wakeups if they
should be considered a good/bad wakeups in regard to polls.
For s390 the implementation will fence of halt polling for anything but
known good, single vCPU events. The s390 implementation for floating
interrupts does a wakeup for one vCPU, but the interrupt will be delivered
by whatever CPU checks first for a pending interrupt. We prefer the
woken up CPU by marking the poll of this CPU as "good" poll.
This code will also mark several other wakeup reasons like IPI or
expired timers as "good". This will of course also mark some events as
not sucessful. As KVM on z runs always as a 2nd level hypervisor,
we prefer to not poll, unless we are really sure, though.
This patch successfully limits the CPU usage for cases like uperf 1byte
transactional ping pong workload or wakeup heavy workload like OLTP
while still providing a proper speedup.
This also introduced a new vcpu stat "halt_poll_no_tuning" that marks
wakeups that are considered not good for polling.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com> (for an earlier version)
Cc: David Matlack <dmatlack@google.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
[Rename config symbol. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce a FLIC operation for clearing I/O interrupts for a subchannel.
Rationale: According to the platform specification, pending I/O
interruption requests have to be revoked in certain situations. For
instance, according to the Principles of Operation (page 17-27), a
subchannel put into the installed parameters initialized state is in the
same state as after an I/O system reset (just parameters possibly changed).
This implies that any I/O interrupts for that subchannel are no longer
pending (as I/O system resets clear I/O interrupts). Therefore, we need an
interface to clear pending I/O interrupts.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
HAS_ATTR is useful for determining the supported attributes; let's
implement it.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Pull s390 updates from Martin Schwidefsky:
- Add the CPU id for the new z13s machine
- Add a s390 specific XOR template for RAID-5 checksumming based on the
XC instruction. Remove all other alternatives, XC is always faster
- The merge of our four different stack tracers into a single one
- Tidy up the code related to page tables, several large inline
functions are now out-of-line. Bloat-o-meter reports ~11K text size
reduction
- A binary interface for the priviledged CLP instruction to retrieve
the hardware view of the installed PCI functions
- Improvements for the dasd format code
- Bug fixes and cleanups
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (31 commits)
s390/pci: enforce fmb page boundary rule
s390: fix floating pointer register corruption (again)
s390/cpumf: add missing lpp magic initialization
s390: Fix misspellings in comments
s390/mm: split arch/s390/mm/pgtable.c
s390/mm: uninline pmdp_xxx functions from pgtable.h
s390/mm: uninline ptep_xxx functions from pgtable.h
s390/pci: add ioctl interface for CLP
s390: Use pr_warn instead of pr_warning
s390/dasd: remove casts to dasd_*_private
s390/dasd: Refactor dasd format functions
s390/dasd: Simplify code in format logic
s390/dasd: Improve dasd format code
s390/percpu: remove this_cpu_cmpxchg_double_4
s390/cpumf: Improve guest detection heuristics
s390/fault: merge report_user_fault implementations
s390/dis: use correct escape sequence for '%' character
s390/kvm: simplify set_guest_storage_key
s390/oprofile: add z13/z13s model numbers
s390: add z13s model number to z13 elf platform
...
but lots of architecture-specific changes.
* ARM:
- VHE support so that we can run the kernel at EL2 on ARMv8.1 systems
- PMU support for guests
- 32bit world switch rewritten in C
- various optimizations to the vgic save/restore code.
* PPC:
- enabled KVM-VFIO integration ("VFIO device")
- optimizations to speed up IPIs between vcpus
- in-kernel handling of IOMMU hypercalls
- support for dynamic DMA windows (DDW).
* s390:
- provide the floating point registers via sync regs;
- separated instruction vs. data accesses
- dirty log improvements for huge guests
- bugfixes and documentation improvements.
* x86:
- Hyper-V VMBus hypercall userspace exit
- alternative implementation of lowest-priority interrupts using vector
hashing (for better VT-d posted interrupt support)
- fixed guest debugging with nested virtualizations
- improved interrupt tracking in the in-kernel IOAPIC
- generic infrastructure for tracking writes to guest memory---currently
its only use is to speedup the legacy shadow paging (pre-EPT) case, but
in the future it will be used for virtual GPUs as well
- much cleanup (LAPIC, kvmclock, MMU, PIT), including ubsan fixes.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)
iQEcBAABAgAGBQJW5r3BAAoJEL/70l94x66D2pMH/jTSWWwdTUJMctrDjPVzKzG0
yOzHW5vSLFoFlwEOY2VpslnXzn5TUVmCAfrdmFNmQcSw6hGb3K/xA/ZX/KLwWhyb
oZpr123ycahga+3q/ht/dFUBCCyWeIVMdsLSFwpobEBzPL0pMgc9joLgdUC6UpWX
tmN0LoCAeS7spC4TTiTTpw3gZ/L+aB0B6CXhOMjldb9q/2CsgaGyoVvKA199nk9o
Ngu7ImDt7l/x1VJX4/6E/17VHuwqAdUrrnbqerB/2oJ5ixsZsHMGzxQ3sHCmvyJx
WG5L00ubB1oAJAs9fBg58Y/MdiWX99XqFhdEfxq4foZEiQuCyxygVvq3JwZTxII=
=OUZZ
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"One of the largest releases for KVM... Hardly any generic
changes, but lots of architecture-specific updates.
ARM:
- VHE support so that we can run the kernel at EL2 on ARMv8.1 systems
- PMU support for guests
- 32bit world switch rewritten in C
- various optimizations to the vgic save/restore code.
PPC:
- enabled KVM-VFIO integration ("VFIO device")
- optimizations to speed up IPIs between vcpus
- in-kernel handling of IOMMU hypercalls
- support for dynamic DMA windows (DDW).
s390:
- provide the floating point registers via sync regs;
- separated instruction vs. data accesses
- dirty log improvements for huge guests
- bugfixes and documentation improvements.
x86:
- Hyper-V VMBus hypercall userspace exit
- alternative implementation of lowest-priority interrupts using
vector hashing (for better VT-d posted interrupt support)
- fixed guest debugging with nested virtualizations
- improved interrupt tracking in the in-kernel IOAPIC
- generic infrastructure for tracking writes to guest
memory - currently its only use is to speedup the legacy shadow
paging (pre-EPT) case, but in the future it will be used for
virtual GPUs as well
- much cleanup (LAPIC, kvmclock, MMU, PIT), including ubsan fixes"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (217 commits)
KVM: x86: remove eager_fpu field of struct kvm_vcpu_arch
KVM: x86: disable MPX if host did not enable MPX XSAVE features
arm64: KVM: vgic-v3: Only wipe LRs on vcpu exit
arm64: KVM: vgic-v3: Reset LRs at boot time
arm64: KVM: vgic-v3: Do not save an LR known to be empty
arm64: KVM: vgic-v3: Save maintenance interrupt state only if required
arm64: KVM: vgic-v3: Avoid accessing ICH registers
KVM: arm/arm64: vgic-v2: Make GICD_SGIR quicker to hit
KVM: arm/arm64: vgic-v2: Only wipe LRs on vcpu exit
KVM: arm/arm64: vgic-v2: Reset LRs at boot time
KVM: arm/arm64: vgic-v2: Do not save an LR known to be empty
KVM: arm/arm64: vgic-v2: Move GICH_ELRSR saving to its own function
KVM: arm/arm64: vgic-v2: Save maintenance interrupt state only if required
KVM: arm/arm64: vgic-v2: Avoid accessing GICH registers
KVM: s390: allocate only one DMA page per VM
KVM: s390: enable STFLE interpretation only if enabled for the guest
KVM: s390: wake up when the VCPU cpu timer expires
KVM: s390: step the VCPU timer while in enabled wait
KVM: s390: protect VCPU cpu timer with a seqcount
KVM: s390: step VCPU cpu timer during kvm_run ioctl
...
The pgtable.c file is quite big, before it grows any larger split it
into pgtable.c, pgalloc.c and gmap.c. In addition move the gmap related
header definitions into the new gmap.h header and all of the pgste
helpers from pgtable.h to pgtable.c.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When the VCPU cpu timer expires, we have to wake up just like when the ckc
triggers. For now, setting up a cpu timer in the guest and going into
enabled wait will never lead to a wakeup. This patch fixes this problem.
Just as for the ckc, we have to take care of waking up too early. We
have to recalculate the sleep time and go back to sleep.
Please note that the timer callback calls kvm_s390_get_cpu_timer() from
interrupt context. As the timer is canceled when leaving handle_wait(),
and we don't do any VCPU cpu timer writes/updates in that function, we can
be sure that we will never try to read the VCPU cpu timer from the same cpu
that is currentyl updating the timer (deadlock).
Reported-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Tested-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We want to manually step the cpu timer in certain scenarios in the future.
Let's abstract any access to the cpu timer, so we can hide the complexity
internally.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The problem:
On -rt, an emulated LAPIC timer instances has the following path:
1) hard interrupt
2) ksoftirqd is scheduled
3) ksoftirqd wakes up vcpu thread
4) vcpu thread is scheduled
This extra context switch introduces unnecessary latency in the
LAPIC path for a KVM guest.
The solution:
Allow waking up vcpu thread from hardirq context,
thus avoiding the need for ksoftirqd to be scheduled.
Normal waitqueues make use of spinlocks, which on -RT
are sleepable locks. Therefore, waking up a waitqueue
waiter involves locking a sleeping lock, which
is not allowed from hard interrupt context.
cyclictest command line:
This patch reduces the average latency in my tests from 14us to 11us.
Daniel writes:
Paolo asked for numbers from kvm-unit-tests/tscdeadline_latency
benchmark on mainline. The test was run 1000 times on
tip/sched/core 4.4.0-rc8-01134-g0905f04:
./x86-run x86/tscdeadline_latency.flat -cpu host
with idle=poll.
The test seems not to deliver really stable numbers though most of
them are smaller. Paolo write:
"Anything above ~10000 cycles means that the host went to C1 or
lower---the number means more or less nothing in that case.
The mean shows an improvement indeed."
Before:
min max mean std
count 1000.000000 1000.000000 1000.000000 1000.000000
mean 5162.596000 2019270.084000 5824.491541 20681.645558
std 75.431231 622607.723969 89.575700 6492.272062
min 4466.000000 23928.000000 5537.926500 585.864966
25% 5163.000000 1613252.750000 5790.132275 16683.745433
50% 5175.000000 2281919.000000 5834.654000 23151.990026
75% 5190.000000 2382865.750000 5861.412950 24148.206168
max 5228.000000 4175158.000000 6254.827300 46481.048691
After
min max mean std
count 1000.000000 1000.00000 1000.000000 1000.000000
mean 5143.511000 2076886.10300 5813.312474 21207.357565
std 77.668322 610413.09583 86.541500 6331.915127
min 4427.000000 25103.00000 5529.756600 559.187707
25% 5148.000000 1691272.75000 5784.889825 17473.518244
50% 5160.000000 2308328.50000 5832.025000 23464.837068
75% 5172.000000 2393037.75000 5853.177675 24223.969976
max 5222.000000 3922458.00000 6186.720500 42520.379830
[Patch was originaly based on the swait implementation found in the -rt
tree. Daniel ported it to mainline's version and gathered the
benchmark numbers for tscdeadline_latency test.]
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-rt-users@vger.kernel.org
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1455871601-27484-4-git-send-email-wagi@monom.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Program irq injection during program irq intercepts is the last candidates
that injects nullifying irqs and relies on delivery to do the right thing.
As we should not rely on the icptcode during any delivery (because that
value will not be migrated), let's add a flag, telling prog IRQ delivery
to not rewind the PSW in case of nullifying prog IRQs.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We have to migrate the program irq ilc and someday we will have to
specify the ilc without KVM trying to autodetect the value.
Let's reuse one of the spare fields in our program irq that should
always be set to 0 by user space. Because we also want to make use
of 0 ilcs ("not available"), we need a validity indicator.
If no valid ilc is given, we try to autodetect the ilc via the current
icptcode and icptstatus + parameter and store the valid ilc in the
irq structure.
This has a nice effect: QEMU's making use of KVM_S390_IRQ /
KVM_S390_SET_IRQ_STATE / KVM_S390_GET_IRQ_STATE for migration will
directly migrate the ilc without any changes.
Please note that we use bit 0 as validity and bit 1,2 for the ilc, so
by applying the ilc mask we directly get the ilen which is usually what
we work with.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We have some confusion about ilc vs. ilen in our current code. So let's
correctly use the term ilen when dealing with (ilc << 1).
Program irq injection didn't take care of the correct ilc in case of
irqs triggered by EXECUTE functions, let's provide one function
kvm_s390_get_ilen() to take care of all that.
Also, manually specifying in intercept handlers the size of the
instruction (and sometimes overwriting that value for EXECUTE internally)
doesn't make too much sense. So also provide the functions:
- kvm_s390_retry_instr to retry the currently intercepted instruction
- kvm_s390_rewind_psw to rewind the PSW without internal overwrites
- kvm_s390_forward_psw to forward the PSW
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Pull s390 updates from Martin Schwidefsky:
"Among the traditional bug fixes and cleanups are some improvements:
- A tool to generated the facility lists, generating the bit fields
by hand has been a source of bugs in the past
- The spinlock loop is reordered to avoid bursts of hypervisor calls
- Add support for the open-for-business interface to the service
element
- The get_cpu call is added to the vdso
- A set of tracepoints is defined for the common I/O layer
- The deprecated sclp_cpi module is removed
- Update default configuration"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (56 commits)
s390/sclp: fix possible control register corruption
s390: fix normalization bug in exception table sorting
s390/configs: update default configurations
s390/vdso: optimize getcpu system call
s390: drop smp_mb in vdso_init
s390: rename struct _lowcore to struct lowcore
s390/mem_detect: use unsigned longs
s390/ptrace: get rid of long longs in psw_bits
s390/sysinfo: add missing SYSIB 1.2.2 multithreading fields
s390: get rid of CONFIG_SCHED_MC and CONFIG_SCHED_BOOK
s390/Kconfig: remove pointless 64 bit dependencies
s390/dasd: fix failfast for disconnected devices
s390/con3270: testing return kzalloc retval
s390/hmcdrv: constify hmcdrv_ftp_ops structs
s390/cio: add NULL test
s390/cio: Change I/O instructions from inline to normal functions
s390/cio: Introduce common I/O layer tracepoints
s390/cio: Consolidate inline assemblies and related data definitions
s390/cio: Fix incorrect xsch opcode specification
s390/cio: Remove unused inline assemblies
...
Finally get rid of the leading underscore. I tried this already two or
three years ago, however Michael Holzheu objected since this would
break the crash utility (again).
However Michael integrated support for the new name into the crash
utility back then, so it doesn't break if the name will be changed
now. So finally get rid of the ever confusing leading underscore.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If CPUSTAT_ECALL_PEND isn't set, we can't have an external call pending,
so we can directly avoid taking the lock.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch adds code that performs transparent switch to Extended
SCA on addition of 65th VCPU in a VM. Disposal of ESCA is added too.
The entier ESCA functionality, however, is still not enabled.
The enablement will be provided in a separate patch.
This patch also uses read/write lock protection of SCA and its subfields for
possible disposal at the BSCA-to-ESCA transition. While only Basic SCA needs such
a protection (for the swap), any SCA access is now guarded.
Signed-off-by: Eugene (jno) Dvurechenski <jno@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch updates the routines (sca_*) to provide transparent access
to and manipulation on the data for both Basic and Extended SCA in use.
The kvm.arch.sca is generalized to (void *) to handle BSCA/ESCA cases.
Also the kvm.arch.use_esca flag is provided.
The actual functionality is kept the same.
Signed-off-by: Eugene (jno) Dvurechenski <jno@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch adds new structures and updates some existing ones to
provide the base for Extended SCA functionality.
The old sca_* structures were renamed to bsca_* to keep things uniform.
The access to fields of SIGP controls were turned into bitfields instead
of hardcoded bitmasks.
Signed-off-by: Eugene (jno) Dvurechenski <jno@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch generalizes access to the SIGP controls, which is a part of SCA.
This is to prepare for upcoming introduction of Extended SCA support.
Signed-off-by: Eugene (jno) Dvurechenski <jno@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
For now, VCPUs were always created sequentially with incrementing
VCPU ids. Therefore, the index in the VCPUs array matched the id.
As sequential creation might change with cpu hotplug, let's use
the correct lookup function to find a VCPU by id, not array index.
Let's also use kvm_lookup_vcpu() for validation of the sending VCPU
on external call injection.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: stable@vger.kernel.org # db27a7a KVM: Provide function for VCPU lookup by id
Commit 383d0b0501 ("KVM: s390: handle pending local interrupts via
bitmap") introduced a possible memory overwrite from user space.
User space could pass an invalid emergency signal code (sending VCPU)
and therefore exceed the bitmap. Let's take care of this case and
check that the id is in the valid range.
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v3.19+ db27a7a KVM: Provide function for VCPU lookup by id
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's factor this out and always use get_tod_clock_fast() when
reading the guest TOD.
STORE CLOCK FAST does not do serialization and, therefore, might
result in some fuzziness between different processors in a way
that subsequent calls on different CPUs might have time stamps that
are earlier. This semantics is fine though for all KVM use cases.
To make it obvious that the new function has STORE CLOCK FAST
semantics we name it kvm_s390_get_tod_clock_fast.
With this patch, we only have a handful of places were we
have to care about STP sync (using preempt_disable() logic).
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
PER events can always co-exist with other program interrupts.
For now, we always overwrite all program interrupt parameters when
injecting any type of program interrupt.
Let's handle that correctly by only overwriting the relevant portion of
the program interrupt parameters. Therefore we can now inject PER events
and ordinary program interrupts concurrently, resulting in no loss of
program interrupts. This will especially by helpful when manually detecting
PER events later - as both types might be triggered during one SIE exit.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The main reason to keep program injection in kernel separated until now
was that we were able to do some checking, if really only the owning
thread injects program interrupts (via waitqueue_active(li->wq)).
This BUG_ON was never triggered and the chances of really hitting it, if
another thread injected a program irq to another vcpu, were very small.
Let's drop this check and turn kvm_s390_inject_program_int() and
kvm_s390_inject_prog_irq() into simple inline functions that makes use of
kvm_s390_inject_vcpu().
__must_check can be dropped as they are implicitely given by
kvm_s390_inject_vcpu(), to avoid ugly long function prototypes.
Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's get rid of the local variable and exit directly if we found
any pending interrupt. This is not only faster, but also better
readable.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We can remove that double check.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
No need to separate pending and floating irqs when setting interception
requests. Let's do it for all equally.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We don't care about program event recording irqs (synchronous
program irqs) but asynchronous irqs when checking for disabled
wait. Machine checks were missing.
Let's directly switch to the functions we have for that purpose
instead of testing once again for magic bits.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
the float int structure is no longer used in __inject_vm.
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Pull locking and atomic updates from Ingo Molnar:
"Main changes in this cycle are:
- Extend atomic primitives with coherent logic op primitives
(atomic_{or,and,xor}()) and deprecate the old partial APIs
(atomic_{set,clear}_mask())
The old ops were incoherent with incompatible signatures across
architectures and with incomplete support. Now every architecture
supports the primitives consistently (by Peter Zijlstra)
- Generic support for 'relaxed atomics':
- _acquire/release/relaxed() flavours of xchg(), cmpxchg() and {add,sub}_return()
- atomic_read_acquire()
- atomic_set_release()
This came out of porting qwrlock code to arm64 (by Will Deacon)
- Clean up the fragile static_key APIs that were causing repeat bugs,
by introducing a new one:
DEFINE_STATIC_KEY_TRUE(name);
DEFINE_STATIC_KEY_FALSE(name);
which define a key of different types with an initial true/false
value.
Then allow:
static_branch_likely()
static_branch_unlikely()
to take a key of either type and emit the right instruction for the
case. To be able to know the 'type' of the static key we encode it
in the jump entry (by Peter Zijlstra)
- Static key self-tests (by Jason Baron)
- qrwlock optimizations (by Waiman Long)
- small futex enhancements (by Davidlohr Bueso)
- ... and misc other changes"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits)
jump_label/x86: Work around asm build bug on older/backported GCCs
locking, ARM, atomics: Define our SMP atomics in terms of _relaxed() operations
locking, include/llist: Use linux/atomic.h instead of asm/cmpxchg.h
locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics
locking/qrwlock: Implement queue_write_unlock() using smp_store_release()
locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition
locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t'
locking, asm-generic: Rework atomic-long.h to avoid bulk code duplication
locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic operations
locking, compiler.h: Cast away attributes in the WRITE_ONCE() magic
locking/static_keys: Make verify_keys() static
jump label, locking/static_keys: Update docs
locking/static_keys: Provide a selftest
jump_label: Provide a self-test
s390/uaccess, locking/static_keys: employ static_branch_likely()
x86, tsc, locking/static_keys: Employ static_branch_likely()
locking/static_keys: Add selftest
locking/static_keys: Add a new static_key interface
locking/static_keys: Rework update logic
locking/static_keys: Add static_key_{en,dis}able() helpers
...
If the host has STP enabled, the TOD of the host will be changed during
synchronization phases. These are performed during a stop_machine() call.
As the guest TOD is based on the host TOD, we have to make sure that:
- no VCPU is in the SIE (implicitly guaranteed via stop_machine())
- manual guest TOD calculations are not affected
"Epoch" is the guest TOD clock delta to the host TOD clock. We have to
adjust that value during the STP synchronization and make sure that code
that accesses the epoch won't get interrupted in between (via disabling
preemption).
Signed-off-by: Fan Zhang <zhangfan@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch adds names for missing irq types to the trace events.
In order to identify adapter irqs, the define is moved from
interrupt.c to the other basic irq defines in uapi/linux/kvm.h.
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This reworks the debug logging for interrupt related logs.
Several changes:
- unify program int/irq
- improve decoding (e.g. use mcic instead of parm64 for machine
check injection)
- remove useless interrupt type number (the name is enough)
- rename "interrupt:" to "deliver:" as the other side is called "inject"
- use log level 3 for state changing and/or seldom events (like machine
checks, restart..)
- use log level 4 for frequent events
- use 0x prefix for hex numbers
- add pfault done logging
- move some tracing outside spinlock
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
The "from user"/"from kernel" part of the log/trace messages is not
always correct anymore and therefore not really helpful.
Let's remove that part from the log + trace messages. For program
interrupts, we can now move the logging/tracing part into the real
injection function, as already done for the other injection functions.
Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
SPX (SET PREFIX) and SIGP (Set prefix) can change the prefix
register of a CPU. As sigp set prefix may be handled in user
space (KVM_CAP_S390_USER_SIGP), we would not log the changes
triggered via SIGP in that case. Let's have just one VCPU_EVENT
at the central location that tracks prefix changes.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Replace the deprecated atomic_{set,clear}_mask() usage with the now
ubiquous atomic_{or,andnot}() functions.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
for silicon that no one owns: these are really new features for
everyone.
* ARM: several features are in progress but missed the 4.2 deadline.
So here is just a smattering of bug fixes, plus enabling the VFIO
integration.
* s390: Some fixes/refactorings/optimizations, plus support for
2GB pages.
* x86: 1) host and guest support for marking kvmclock as a stable
scheduler clock. 2) support for write combining. 3) support for
system management mode, needed for secure boot in guests. 4) a bunch
of cleanups required for 2+3. 5) support for virtualized performance
counters on AMD; 6) legacy PCI device assignment is deprecated and
defaults to "n" in Kconfig; VFIO replaces it. On top of this there are
also bug fixes and eager FPU context loading for FPU-heavy guests.
* Common code: Support for multiple address spaces; for now it is
used only for x86 SMM but the s390 folks also have plans.
There are some x86 conflicts, one with the rc8 pull request and
the rest with Ingo's FPU rework.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)
iQEcBAABAgAGBQJViYzhAAoJEL/70l94x66Dda0H/1IepMbfEy+o849d5G71fNTs
F8Y8qUP2GZuL7T53FyFUGSBw+AX7kimu9ia4gR/PmDK+QYsdosYeEjwlsolZfTBf
sHuzNtPoJhi5o1o/ur4NGameo0WjGK8f1xyzr+U8z74QDQyQv/QYCdK/4isp4BJL
ugHNHkuROX6Zng4i7jc9rfaSRg29I3GBxQUYpMkEnD3eMYMUBWGm6Rs8pHgGAMvL
vqzntgW00WNxehTqcAkmD/Wv+txxhkvIadZnjgaxH49e9JeXeBKTIR5vtb7Hns3s
SuapZUyw+c95DIipXq4EznxxaOrjbebOeFgLCJo8+XMXZum8RZf/ob24KroYad0=
=YsAR
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull first batch of KVM updates from Paolo Bonzini:
"The bulk of the changes here is for x86. And for once it's not for
silicon that no one owns: these are really new features for everyone.
Details:
- ARM:
several features are in progress but missed the 4.2 deadline.
So here is just a smattering of bug fixes, plus enabling the
VFIO integration.
- s390:
Some fixes/refactorings/optimizations, plus support for 2GB
pages.
- x86:
* host and guest support for marking kvmclock as a stable
scheduler clock.
* support for write combining.
* support for system management mode, needed for secure boot in
guests.
* a bunch of cleanups required for the above
* support for virtualized performance counters on AMD
* legacy PCI device assignment is deprecated and defaults to "n"
in Kconfig; VFIO replaces it
On top of this there are also bug fixes and eager FPU context
loading for FPU-heavy guests.
- Common code:
Support for multiple address spaces; for now it is used only for
x86 SMM but the s390 folks also have plans"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (124 commits)
KVM: s390: clear floating interrupt bitmap and parameters
KVM: x86/vPMU: Enable PMU handling for AMD PERFCTRn and EVNTSELn MSRs
KVM: x86/vPMU: Implement AMD vPMU code for KVM
KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch
KVM: x86/vPMU: introduce kvm_pmu_msr_idx_to_pmc
KVM: x86/vPMU: reorder PMU functions
KVM: x86/vPMU: whitespace and stylistic adjustments in PMU code
KVM: x86/vPMU: use the new macros to go between PMC, PMU and VCPU
KVM: x86/vPMU: introduce pmu.h header
KVM: x86/vPMU: rename a few PMU functions
KVM: MTRR: do not map huge page for non-consistent range
KVM: MTRR: simplify kvm_mtrr_get_guest_memory_type
KVM: MTRR: introduce mtrr_for_each_mem_type
KVM: MTRR: introduce fixed_mtrr_addr_* functions
KVM: MTRR: sort variable MTRRs
KVM: MTRR: introduce var_mtrr_range
KVM: MTRR: introduce fixed_mtrr_segment table
KVM: MTRR: improve kvm_mtrr_get_guest_memory_type
KVM: MTRR: do not split 64 bits MSR content
KVM: MTRR: clean up mtrr default type
...
commit 6d3da24141 ("KVM: s390: deliver floating interrupts in order
of priority") introduced a regression for the reset handling.
We don't clear the bitmap of pending floating interrupts
and interrupt parameters. This could result in stale interrupts
even after a reset. Let's fix this by clearing the pending bitmap
and the parameters for service and machine check interrupts.
Cc: stable@vger.kernel.org # 4.1
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Let's unify basic access to sclp fields by storing the data in an external
struct in asm/sclp.h.
The values can now directly be accessed by other components, so there is
no need for most accessor functions and external variables anymore.
The mtid, mtid_max and facility part will be cleaned up separately.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch factors out the search for a floating irq destination
VCPU as well as the kicking of the found VCPU. The search is optimized
in the following ways:
1. stopped VCPUs can't take any floating interrupts, so try to find an
operating one. We have to take care of the special case where all
VCPUs are stopped and we don't have any valid destination.
2. use online_vcpus, not KVM_MAX_VCPU. This speeds up the search
especially if KVM_MAX_VCPU is increased one day. As these VCPU
objects are initialized prior to increasing online_vcpus, we can be
sure that they exist.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We can avoid checking guest control registers and guest PSW as well
as all the masking and calculations on the interrupt masks when
no interrupts are pending.
Also, the check for IRQ_PEND_COUNT can be removed, because we won't
enter the while loop if no interrupts are pending and invalid interrupt
types can't be injected.
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Commit ea5f496925 ("KVM: s390: only one external call may be pending
at a time") introduced a bug on machines that don't have SIGP
interpretation facility installed.
The injection of an external call will now always fail with -EBUSY
(if none is already pending).
This leads to the following symptoms:
- An external call will be injected but with the wrong "src cpu id",
as this id will not be remembered.
- The target vcpu will not be woken up, therefore the guest will hang if
it cannot deal with unexpected failures of the SIGP EXTERNAL CALL
instruction.
- If an external call is already pending, -EBUSY will not be reported.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.0
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch adds support to migrate vcpu interrupts. Two new vcpu ioctls
are added which get/set the complete status of pending interrupts in one
go. The ioctls are marked as available with the new capability
KVM_CAP_S390_IRQ_STATE.
We can not use a ONEREG, as the number of pending local interrupts is not
constant and depends on the number of CPUs.
To retrieve the interrupt state we add an ioctl KVM_S390_GET_IRQ_STATE.
Its input parameter is a pointer to a struct kvm_s390_irq_state which
has a buffer and length. For all currently pending interrupts, we copy
a struct kvm_s390_irq into the buffer and pass it to userspace.
To store interrupt state into a buffer provided by userspace, we add an
ioctl KVM_S390_SET_IRQ_STATE. It passes a struct kvm_s390_irq_state into
the kernel and injects all interrupts contained in the buffer.
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Let's provide a version of kvm_s390_inject_vcpu() that
does not acquire the local-interrupt lock and skips
waking up the vcpu.
To be used in a later patch for vcpu-local interrupt migration,
where we are already holding the lock.
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
We now have a mechanism for delivering interrupts according to their priority.
Let's inject them using our new infrastructure (instead of letting only hardware
handle them), so we can be sure that the irq priorities are satisfied.
For s390, the cpu timer and the clock comparator are to be checked for common
code kvm_cpu_has_pending_timer(), although the cpu timer is only stepped when
the guest is being executed.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This patch makes interrupt handling compliant to the z/Architecture
Principles of Operation with regard to interrupt priorities.
Add a bitmap for pending floating interrupts. Each bit relates to a
interrupt type and its list. A turned on bit indicates that a list
contains items (interrupts) which need to be delivered. When delivering
interrupts on a cpu we can merge the existing bitmap for cpu-local
interrupts and floating interrupts and have a single mechanism for
delivery.
Currently we have one list for all kinds of floating interrupts and a
corresponding spin lock. This patch adds a separate list per
interrupt type. An exception to this are service signal and machine check
interrupts, as there can be only one pending interrupt at a time.
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This fixes a bug introduced with commit c05c4186bb ("KVM: s390:
add floating irq controller").
get_all_floating_irqs() does copy_to_user() while holding
a spin lock. Let's fix this by filling a temporary buffer
first and copy it to userspace after giving up the lock.
Cc: <stable@vger.kernel.org> # 3.18+: 69a8d45626 KVM: s390: no need to hold...
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
If the PER-3 facility is installed, the breaking-event address is to be
stored in the low core.
There is no facility bit for PER-3 in stfl(e) and Linux always uses the
value at address 272 no matter if PER-3 is available or not.
We can't hide its existence from the guest. All program interrupts
injected via the SIE automatically store this information if the PER-3
facility is available in the hypervisor. Also the itdb contains the
address automatically.
As there is no switch to turn this mechanism off, let's simply make it
consistent and also store the breaking event address in case of manual
program interrupt injection.
Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Store additional status in the machine check handler, in order to
collect status (such as vector registers) that is not defined by
store status.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
A new exception type for vector instructions is introduced with
the new processor, but is handled exactly like a Data Exception
which is already handled by the system.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Christian Borntraeger