We don't need to do anything when mode is EXITING_GUEST_MODE, because
we essentially are outside of guest mode and did everything it asked
us to do by the time we check it.
Signed-off-by: NAlexander Graf <agraf@suse.de>

We need to call kvm_guest_enter in booke and book3s, so move its
call to generic code.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Today, we disable preemption while inside guest context, because we need
to expose to the world that we are not in a preemptible context. However,
during that time we already have interrupts disabled, which would indicate
that we are in a non-preemptible context.

The reason the checks for irqs_disabled() fail for us though is that we
manually control hard IRQs and ignore all the lazy EE framework. Let's
stop doing that. Instead, let's always use lazy EE to indicate when we
want to disable IRQs, but do a special final switch that gets us into
EE disabled, but soft enabled state. That way when we get back out of
guest state, we are immediately ready to process interrupts.

This simplifies the code drastically and reduces the time that we appear
as preempt disabled.
Signed-off-by: NAlexander Graf <agraf@suse.de>

When getting out of __vcpu_run, let's be consistent about the state we
return in. We want to always

  * have IRQs enabled
  * have called kvm_guest_exit before
Signed-off-by: NAlexander Graf <agraf@suse.de>

When going out of guest mode, indicate that we are in vcpu->mode. That way
requests from other CPUs don't needlessly need to kick us to process them,
because it'll just happen next time we enter the guest.
Signed-off-by: NAlexander Graf <agraf@suse.de>

The x86 implementation of KVM accounts for host time while processing
guest exits. Do the same for us.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Now that we use our generic exit helper, we can safely drop our previous
kvm_resched that we used to trigger at the beginning of the exit handler
function.
Signed-off-by: NAlexander Graf <agraf@suse.de>

We only need to set vcpu->mode to outside once.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Now that we have very simple MMU Notifier support for e500 in place,
also add the same simple support to book3s. It gets us one step closer
to actual fast support.
Signed-off-by: NAlexander Graf <agraf@suse.de>

We need to do the same things when preparing to enter a guest for booke and
book3s_pr cores. Fold the generic code into a generic function that both call.
Signed-off-by: NAlexander Graf <agraf@suse.de>

We only call kvmppc_check_requests() when vcpu->requests != 0, so drop
the redundant check in the function itself
Signed-off-by: NAlexander Graf <agraf@suse.de>

Without trace points, debugging what exactly is going on inside guest
code can be very tricky. Add a few more trace points at places that
hopefully tell us more when things go wrong.
Signed-off-by: NAlexander Graf <agraf@suse.de>

The e500 target has lived without mmu notifiers ever since it got
introduced, but fails for the user space check on them with hugetlbfs.

So in order to get that one working, implement mmu notifiers in a
reasonably dumb fashion and be happy. On embedded hardware, we almost
never end up with mmu notifier calls, since most people don't overcommit.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Generic KVM code might want to know whether we are inside guest context
or outside. It also wants to be able to push us out of guest context.

Add support to the BookE code for the generic vcpu->mode field that describes
the above states.
Signed-off-by: NAlexander Graf <agraf@suse.de>

We need a central place to check for pending requests in. Add one that
only does the timer check we already do in a different place.

Later, this central function can be extended by more checks.
Signed-off-by: NAlexander Graf <agraf@suse.de>

This fixes breakage introduced by the following commit:

  commit 6d2d82627f4f1e96a33664ace494fa363e0495cb
  Author: Liu Yu-B13201 <Yu.Liu@freescale.com>
  Date:   Tue Jul 3 05:48:56 2012 +0000

    PPC: Don't use hardcoded opcode for ePAPR hcall invocation

when a driver that uses ePAPR hypercalls is built as a module.
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

This is printed once for every RMA or HPT region that get
preallocated.  If one preallocates hundreds of such regions
(in order to run hundreds of KVM guests), that gets rather
painful, so make it a bit quieter.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Our mapping code assumes that TLB0 entries are always mapped. However, after
calling clear_tlb_refs() this is no longer the case.

Map them dynamically if we find an entry unmapped in TLB0.
Signed-off-by: NAlexander Graf <agraf@suse.de>

We're already counting remote TLB flushes in a variable, but don't export
it to user space yet. Do so, so we know what's going on.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Semantically, the "SYNC" cap means that we have mmu notifiers available.
Express this in our #ifdef'ery around the feature, so that we can be sure
we don't miss out on ppc targets when they get their implementation.
Signed-off-by: NAlexander Graf <agraf@suse.de>

We want to have tracing information on guest exits for booke as well
as book3s. Since most information is identical, use a common trace point.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Signed-off-by: NLiu Yu <yu.liu@freescale.com>
Signed-off-by: NStuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NStuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Signed-off-by: NStuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Signed-off-by: NLiu Yu <yu.liu@freescale.com>
[varun: 64-bit changes]
Signed-off-by: NVarun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: NStuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

And add a new flag definition in kvm_ppc_pvinfo to indicate
whether the host supports the EV_IDLE hcall.
Signed-off-by: NLiu Yu <yu.liu@freescale.com>
[stuart.yoder@freescale.com: cleanup,fixes for conditions allowing idle]
Signed-off-by: NStuart Yoder <stuart.yoder@freescale.com>
[agraf: fix typo]
Signed-off-by: NAlexander Graf <agraf@suse.de>

Signed-off-by: NLiu Yu <yu.liu@freescale.com>
[stuart: factored this out from idle hcall support in host patch]
Signed-off-by: NStuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Signed-off-by: NStuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Signed-off-by: NStuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Recent changes (KVM: make processes waiting on vcpu mutex killable)
now requires to check the return value of vcpu_load. This triggered
a warning in s390 specific kvm code. Turns out that we can actually
remove the put/load, since schedule will do the right thing via
the preempt notifiers.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

If we reset a vcpu on INIT, we so far overwrote dr7 as provided by
KVM_SET_GUEST_DEBUG, and we also cleared switch_db_regs unconditionally.

Fix this by saving the dr7 used for guest debugging and calculating the
effective register value as well as switch_db_regs on any potential
change. This will change to focus of the set_guest_debug vendor op to
update_dp_bp_intercept.

Found while trying to stop on start_secondary.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

To emulate level triggered interrupts, add a resample option to
KVM_IRQFD.  When specified, a new resamplefd is provided that notifies
the user when the irqchip has been resampled by the VM.  This may, for
instance, indicate an EOI.  Also in this mode, posting of an interrupt
through an irqfd only asserts the interrupt.  On resampling, the
interrupt is automatically de-asserted prior to user notification.
This enables level triggered interrupts to be posted and re-enabled
from vfio with no userspace intervention.

All resampling irqfds can make use of a single irq source ID, so we
reserve a new one for this interface.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Most interrupt are delivered to only one vcpu. Use pre-build tables to
find interrupt destination instead of looping through all vcpus. In case
of logical mode loop only through vcpus in a logical cluster irq is sent
to.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

'ac' essentially reconstructs the 'access' variable we already
have, except for the PFERR_PRESENT_MASK and PFERR_RSVD_MASK.  As
these are not used by callees, just use 'access' directly.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Keep track of accessed/dirty bits; if they are all set, do not
enter the accessed/dirty update loop.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

'eperm' is no longer used in the walker loop, so we can eliminate it.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Instead of branchy code depending on level, gpte.ps, and mmu configuration,
prepare everything in a bitmap during mode changes and look it up during
runtime.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The page table walk is coded as an infinite loop, with a special
case on the last pte.

Code it as an ordinary loop with a termination condition on the last
pte (large page or walk length exhausted), and put the last pte handling
code after the loop where it belongs.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

walk_addr_generic() permission checks are a maze of branchy code, which is
performed four times per lookup.  It depends on the type of access, efer.nxe,
cr0.wp, cr4.smep, and in the near future, cr4.smap.

Optimize this away by precalculating all variants and storing them in a
bitmap.  The bitmap is recalculated when rarely-changing variables change
(cr0, cr4) and is indexed by the often-changing variables (page fault error
code, pte access permissions).

The permission check is moved to the end of the loop, otherwise an SMEP
fault could be reported as a false positive, when PDE.U=1 but PTE.U=0.
Noted by Xiao Guangrong.

The result is short, branch-free code.
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

While unspecified, the behaviour of Intel processors is to first
perform the page table walk, then, if the walk was successful, to
atomically update the accessed and dirty bits of walked paging elements.

While we are not required to follow this exactly, doing so will allow us
to perform the access permissions check after the walk is complete, rather
than after each walk step.

(the tricky case is SMEP: a zero in any pte's U bit makes the referenced
page a supervisor page, so we can't fault on a one bit during the walk
itself).
Reviewed-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>