This adds code to measure "stolen" time per virtual core in units of
timebase ticks, and to report the stolen time to the guest using the
dispatch trace log (DTL).  The guest can register an area of memory
for the DTL for a given vcpu.  The DTL is a ring buffer where KVM
fills in one entry every time it enters the guest for that vcpu.

Stolen time is measured as time when the virtual core is not running,
either because the vcore is not runnable (e.g. some of its vcpus are
executing elsewhere in the kernel or in userspace), or when the vcpu
thread that is running the vcore is preempted.  This includes time
when all the vcpus are idle (i.e. have executed the H_CEDE hypercall),
which is OK because the guest accounts stolen time while idle as idle
time.

Each vcpu keeps a record of how much stolen time has been reported to
the guest for that vcpu so far.  When we are about to enter the guest,
we create a new DTL entry (if the guest vcpu has a DTL) and report the
difference between total stolen time for the vcore and stolen time
reported so far for the vcpu as the "enqueue to dispatch" time in the
DTL entry.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The PAPR API allows three sorts of per-virtual-processor areas to be
registered (VPA, SLB shadow buffer, and dispatch trace log), and
furthermore, these can be registered and unregistered for another
virtual CPU.  Currently we just update the vcpu fields pointing to
these areas at the time of registration or unregistration.  If this
is done on another vcpu, there is the possibility that the target vcpu
is using those fields at the time and could end up using a bogus
pointer and corrupting memory.

This fixes the race by making the target cpu itself do the update, so
we can be sure that the update happens at a time when the fields
aren't being used.  Each area now has a struct kvmppc_vpa which is
used to manage these updates.  There is also a spinlock which protects
access to all of the kvmppc_vpa structs, other than to the pinned_addr
fields.  (We could have just taken the spinlock when using the vpa,
slb_shadow or dtl fields, but that would mean taking the spinlock on
every guest entry and exit.)

This also changes 'struct dtl' (which was undefined) to 'struct dtl_entry',
which is what the rest of the kernel uses.

Thanks to Michael Ellerman <michael@ellerman.id.au> for pointing out
the need to initialize vcpu->arch.vpa_update_lock.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Currently on POWER7, if we are running the guest on a core and we don't
need all the hardware threads, we do nothing to ensure that the unused
threads aren't executing in the kernel (other than checking that they
are offline).  We just assume they're napping and we don't do anything
to stop them trying to enter the kernel while the guest is running.
This means that a stray IPI can wake up the hardware thread and it will
then try to enter the kernel, but since the core is in guest context,
it will execute code from the guest in hypervisor mode once it turns the
MMU on, which tends to lead to crashes or hangs in the host.

This fixes the problem by adding two new one-byte flags in the
kvmppc_host_state structure in the PACA which are used to interlock
between the primary thread and the unused secondary threads when entering
the guest.  With these flags, the primary thread can ensure that the
unused secondaries are not already in kernel mode (i.e. handling a stray
IPI) and then indicate that they should not try to enter the kernel
if they do get woken for any reason.  Instead they will go into KVM code,
find that there is no vcpu to run, acknowledge and clear the IPI and go
back to nap mode.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

On PPC, CR2-CR4 are nonvolatile, thus have to be saved across function calls.
We didn't respect that for any architecture until Paul spotted it in his
patch for Book3S-HV. This patch saves/restores CR for all KVM capable PPC hosts.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

SPAPR support includes various in-kernel hypercalls, improving performance
by cutting out the exit to userspace.  H_BULK_REMOVE is implemented in this
patch.
Signed-off-by: NMatt Evans <matt@ozlabs.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

So far, we've always called prepare_to_enter even when all we did was return
to the host. This patch changes that semantic to only call prepare_to_enter
when we actually want to get back into the guest.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When we get a performance monitor interrupt, we need to make sure that
the host receives it. So reinject it like we reinject the other host
destined interrupts.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When reinjecting an interrupt into the host interrupt handler after we're
back in host kernel land, we need to tell the kernel where the interrupt
happened. We can't tell it that we were in guest state, because that might
lead to random code walking host addresses. So instead, we tell it that
we came from the interrupt reinject code.

This helps getting reasonable numbers out of perf.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When during guest context we get a performance monitor interrupt, we
currently bail out and oops. Let's route it to its correct handler
instead.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The tlbncfg registers should be populated with their respective TLB's
values. Fix the obvious typo.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

There was some unused code in the exit code path that must have been
a leftover from earlier iterations. While it did no harm, it's superfluous
and thus should be removed.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The comment for program interrupts triggered when using bookehv was
misleading. Update it to mention why MSR_GS indicates that we have
to inject an interrupt into the guest again, not emulate it.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When during guest execution we get a machine check interrupt, we don't
know how to handle it yet. So let's add the error printing code back
again that we dropped accidently earlier and tell user space that something
went really wrong.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

For BookE HV the guest visible MSR is shared->msr and is identical to
the MSR that is in use while the guest is running, because we can't trap
reads from/to MSR.

So shadow_msr is unused there. Indicate that with a comment.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We need to make sure that no MAS updates happen automatically while we
have the guest MAS registers loaded. So move the disabling code a bit
higher up so that it covers the full time we have guest values in MAS
registers.

The race this patch fixes should never occur, but it makes the code a
bit more logical to do it this way around.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The SET_VCPU macro is a leftover from times when the vcpu struct wasn't
stored in the thread on vcpu_load/put. It's not needed anymore. Remove it.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Instead if doing

  #ifndef CONFIG_64BIT
  ...
  #else
  ...
  #endif

we should rather do

  #ifdef CONFIG_64BIT
  ...
  #else
  ...
  #endif

which is a lot easier to read. Change the bookehv implementation to
stick with this rule.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When using exit timing stats, we clobber r9 in the NEED_EMU case,
so better move that part down a few lines and fix it that way.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The semantics of BOOKE_IRQPRIO_MAX changed to denote the highest available
irqprio + 1, so let's reflect that in the code too.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Instead of checking whether we should reschedule only when we exited
due to an interrupt, let's always check before entering the guest back
again. This gets the target more in line with the other archs.

Also while at it, generalize the whole thing so that eventually we could
have a single kvmppc_prepare_to_enter function for all ppc targets that
does signal and reschedule checking for us.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When we fail to emulate an instruction for the guest, we better go in and
tell it that we failed to emulate it, by throwing an illegal instruction
exception.

Please beware that we basically never get around to telling the guest that
we failed thanks to the debugging code right above it. If user space however
decides that it wants to ignore the debug, we would at least do "the right
thing" afterwards.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The e500mc patches left some debug code in that we don't need. Remove it.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We can't run e500v2 kvm on e500mc kernels, so indicate that by
making the 2 options mutually exclusive in kconfig.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The CONFIG_KVM_E500 option really indicates that we're running on a V2 machine,
not on a machine of the generic E500 class. So indicate that properly and
change the config name accordingly.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

There's always a chance we're unable to read a guest instruction. The guest
could have its TLB mapped execute-, but not readable, something odd happens
and our TLB gets flushed. So it's a good idea to be prepared for that case
and have a fallback that allows us to fix things up in that case.

Add fixup code that keeps guest code from potentially crashing our host kernel.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

If we hit any exception whatsoever in the restore path and r1/r2 aren't the
host registers, we don't get a working oops. So it's always a good idea to
restore them as early as possible.

This time, it actually has practical reasons to do so too, since we need to
have the host page fault handler fix up our guest instruction read code. And
for that to work we need r1/r2 restored.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When setting MSR for an e500mc guest, we implicitly always set MSR_GS
to make sure the guest is in guest state. Since we have this implicit
rule there, we don't need to explicitly pass MSR_GS to set_msr().

Remove all explicit setters of MSR_GS.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When one vcpu wants to kick another, it can issue a special IPI instruction
called msgsnd. This patch emulates this instruction, its clearing counterpart
and the infrastructure required to actually trigger that interrupt inside
a guest vcpu.

With this patch, SMP guests on e500mc work.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Add processor support for e500mc, using hardware virtualization support
(GS-mode).

Current issues include:
 - No support for external proxy (coreint) interrupt mode in the guest.

Includes work by Ashish Kalra <Ashish.Kalra@freescale.com>,
Varun Sethi <Varun.Sethi@freescale.com>, and
Liu Yu <yu.liu@freescale.com>.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

e500mc has a normal PPC FPU, rather than SPE which is found
on e500v1/v2.

Based on code from Liu Yu <yu.liu@freescale.com>.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Chips such as e500mc that implement category E.HV in Power ISA 2.06
provide hardware virtualization features, including a new MSR mode for
guest state.  The guest OS can perform many operations without trapping
into the hypervisor, including transitions to and from guest userspace.

Since we can use SRR1[GS] to reliably tell whether an exception came from
guest state, instead of messing around with IVPR, we use DO_KVM similarly
to book3s.

Current issues include:
 - Machine checks from guest state are not routed to the host handler.
 - The guest can cause a host oops by executing an emulated instruction
   in a page that lacks read permission.  Existing e500/4xx support has
   the same problem.

Includes work by Ashish Kalra <Ashish.Kalra@freescale.com>,
Varun Sethi <Varun.Sethi@freescale.com>, and
Liu Yu <yu.liu@freescale.com>.
Signed-off-by: NScott Wood <scottwood@freescale.com>
[agraf: remove pt_regs usage]
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

DO_KVM will need to identify the particular exception type.

There is an existing set of arbitrary numbers that Linux passes,
but it's an undocumented mess that sort of corresponds to server/classic
exception vectors but not really.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

tlbilx is the new, preferred invalidation instruction.  It is not
found on e500 prior to e500mc, but there should be no harm in
supporting it on all e500.

Based on code from Ashish Kalra <Ashish.Kalra@freescale.com>.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Rather than invalidate everything when a TLB1 entry needs to be
taken down, keep track of which host TLB1 entries are used for
a given guest TLB1 entry, and invalidate just those entries.

Based on code from Ashish Kalra <Ashish.Kalra@freescale.com>
and Liu Yu <yu.liu@freescale.com>.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The PID handling is e500v1/v2-specific, and is moved to e500.c.

The MMU sregs code and kvmppc_core_vcpu_translate will be shared with
e500mc, and is moved from e500.c to e500_tlb.c.

Partially based on patches from Liu Yu <yu.liu@freescale.com>.
Signed-off-by: NScott Wood <scottwood@freescale.com>
[agraf: fix bisectability]
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Move vcpu to the beginning of vcpu_e500 to give it appropriate
prominence, especially if more fields end up getting added to the
end of vcpu_e500 (and vcpu ends up in the middle).

Remove gratuitous "extern" and add parameter names to prototypes.
Signed-off-by: NScott Wood <scottwood@freescale.com>
[agraf: fix bisectability]
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Keeping two separate headers for e500-specific things was a
pain, and wasn't even organized along any logical boundary.

There was TLB stuff in <asm/kvm_e500.h> despite the existence of
arch/powerpc/kvm/e500_tlb.h, and nothing in <asm/kvm_e500.h> needed
to be referenced from outside arch/powerpc/kvm.
Signed-off-by: NScott Wood <scottwood@freescale.com>
[agraf: fix bisectability]
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This is in preparation for merging in the contents of
arch/powerpc/include/asm/kvm_e500.h.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

e500mc will want to do lpid allocation/deallocation here.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This gives us a place to put load/put actions that correspond to
code that is booke-specific but not specific to a particular core.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>