KVM: add missing misc_deregister() on error in kvm_init()

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>
KVM: MMU: Use kvm_mmu_sync_roots() in kvm_mmu_load()

No need to open-code this function.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
KVM: x86: Remove support for reporting coalesced APIC IRQs

Since the arrival of posted interrupt support we can no longer guarantee
that coalesced IRQs are always reported to the IRQ source. Moreover,
accumulated APIC timer events could cause a busy loop when a VCPU should
rather be halted. The consensus is to remove coalesced tracking from the
LAPIC.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
KVM: x86: limit difference between kvmclock updates

kvmclock updates which are isolated to a given vcpu, such as vcpu->cpu
migration, should not allow system_timestamp from the rest of the vcpus
to remain static. Otherwise ntp frequency correction applies to one
vcpu's system_timestamp but not the others.

So in those cases, request a kvmclock update for all vcpus. The worst
case for a remote vcpu to update its kvmclock is then bounded by maximum
nohz sleep latency.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
KVM: MMU: clenaup locking in mmu_free_roots()

Do locking around each case separately instead of having one lock and two
unlocks. Move root_hpa assignment out of the lock.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
ARM: KVM: move GIC/timer code to a common location

As KVM/arm64 is looming on the horizon, it makes sense to move some
of the common code to a single location in order to reduce duplication.

The code could live anywhere. Actually, most of KVM is already built
with a bunch of ugly ../../.. hacks in the various Makefiles, so we're
not exactly talking about style here. But maybe it is time to start
moving into a less ugly direction.

The include files must be in a "public" location, as they are accessed
from non-KVM files (arch/arm/kernel/asm-offsets.c).

For this purpose, introduce two new locations:
- virt/kvm/arm/ : x86 and ia64 already share the ioapic code in
  virt/kvm, so this could be seen as a (very ugly) precedent.
- include/kvm/  : there is already an include/xen, and while the
  intent is slightly different, this seems as good a location as
  any

Eventually, we should probably have independant Makefiles at every
levels (just like everywhere else in the kernel), but this is just
the first step.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
KVM: get rid of $(addprefix ../../../virt/kvm/, ...) in Makefiles

As requested by the KVM maintainers, remove the addprefix used to
refer to the main KVM code from the arch code, and replace it with
a KVM variable that does the same thing.

Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Christoffer Dall <cdall@cs.columbia.edu>
Acked-by: Xiantao Zhang <xiantao.zhang@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
s390/pgtable: fix ipte notify bit

Dont use the same bit as user referenced.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
s390/kvm: fix psw rewinding in handle_skey

The PSW can wrap if the guest has been running in the 24 bit or 31 bit
addressing mode. Use __rewind_psw to find the correct address.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
s390/kvm: rename RCP_xxx defines to PGSTE_xxx

The RCP byte is a part of the PGSTE value, the existing RCP_xxx names
are inaccurate. As the defines describe bits and pieces of the PGSTE,
the names should start with PGSTE_. The KVM_UR_BIT and KVM_UC_BIT are
part of the PGSTE as well, give them better names as well.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
s390/kvm: Mark if a cpu is in SIE

Lets track in a private bit if the sie control block is active.
We want to track this as closely as possible, so we also have to
instrument the interrupt and program check handler. Lets use the
existing HANDLE_SIE_INTERCEPT macro.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
s390/kvm: Provide a way to prevent reentering SIE

Lets provide functions to prevent KVM from reentering SIE and
to kick cpus out of SIE. We cannot use the common kvm_vcpu_kick code,
since we need to kick out guests in places that hold architecture
specific locks (e.g. pgste lock) which might be necessary on the
other cpus - so no waiting possible.

So lets provide a bit in a private field of the sie control block
that acts as a gate keeper, after we claimed we are in SIE.
Please note that we do not reuse prog0c, since we want to access
that bit without atomic ops.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
s390/kvm: Kick guests out of sie if prefix page host pte is touched

The guest prefix pages must be mapped writeable all the time
while SIE is running, otherwise the guest might see random
behaviour. (pinned at the pte level) Turns out that mlocking is
not enough, the page table entry (not the page) might change or
become r/o. This patch uses the gmap notifiers to kick guest
cpus out of SIE.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
s390/kvm: avoid automatic sie reentry

Do not automatically restart the sie instruction in entry64.S after an
interrupt, return to the caller with a reason code instead. That allows
to deal with RCU and other conditions in C code.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
s390: fix gmap_ipte_notifier vs. software dirty pages

On heavy paging load some guest cpus started to loop in gmap_ipte_notify.
This was visible as stalled cpus inside the guest. The gmap_ipte_notifier
tries to map a user page and then made sure that the pte is valid and
writable. Turns out that with the software change bit tracking the pte
can become read-only (and only software writable) if the page is clean.
Since we loop in this code, the page would stay clean and, therefore,
be never writable again.
Let us just use fixup_user_fault, that guarantees to call handle_mm_fault.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
KVM: x86 emulator: add support for writing back the source operand

Some instructions write back the source operand, not just the destination.
Add support for doing this via the decode flags.

Gleb: add BUG_ON() to prevent source to be memory operand.

Signed-off-by: Avi Kivity <avi.kivity@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
KVM: x86 emulator: decode extended accumulator explicity

Single-operand MUL and DIV access an extended accumulator: AX for byte
instructions, and DX:AX, EDX:EAX, or RDX:RAX for larger-sized instructions.
Add support for fetching the extended accumulator.

In order not to change things too much, RDX is loaded into Src2, which is
already loaded by fastop().  This avoids increasing register pressure on
i386.

Gleb: disable src writeback for ByteOp div/mul.

Signed-off-by: Avi Kivity <avi.kivity@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
KVM: x86 emulator: switch MUL/DIV to DstXacc

Signed-off-by: Avi Kivity <avi.kivity@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
KVM: x86 emulator: Switch fastop src operand to RDX

This makes OpAccHi useful.

Signed-off-by: Avi Kivity <avi.kivity@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
KVM: x86 emulator: convert single-operand MUL/IMUL to fastop

Signed-off-by: Avi Kivity <avi.kivity@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>