Fastsleep is one of the idle state which cpuidle subsystem currently
uses on power8 machines. In this state L2 cache is brought down to a
threshold voltage. Therefore when the core is in fastsleep, the
communication between L2 and L3 needs to be fenced. But there is a bug
in the current power8 chips surrounding this fencing.

OPAL provides a workaround which precludes the possibility of hitting
this bug. But running with this workaround applied causes checkstop
if any correctable error in L2 cache directory is detected. Hence OPAL
also provides a way to undo the workaround.

In the existing implementation, workaround is applied by the last thread
of the core entering fastsleep and undone by the first thread waking up.
But this has a performance cost. These OPAL calls account for roughly
4000 cycles everytime the core has to enter or wakeup from fastsleep.

This patch introduces a sysfs attribute (fastsleep_workaround_applyonce)
to choose the behavior of this workaround.

By default, fastsleep_workaround_applyonce = 0. In this case, workaround
is applied/undone everytime the core enters/exits fastsleep.

fastsleep_workaround_applyonce = 1. In this case the workaround is
applied once on all the cores and never undone. This can be triggered by
echo 1 > /sys/devices/system/cpu/fastsleep_workaround_applyonce

For simplicity this attribute can be modified only once. Implying, once
fastsleep_workaround_applyonce is changed to 1, it cannot be reverted
to the default state.
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This is a cleanup patch; doesn't change any functionality. Moves
all cpuidle related code from setup.c to a new file.
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
[mpe: Fix the SMP=n build by including asm/smp.h in idle.c]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Currently, cpu_online_cores_map returns a mask, which for every core with
at least one online thread, has the bit for thread 0 of the core set to 1,
and the bits for all other threads of the core set to 0. But thread 0 of
the core itself may not be online always. In such cases, if the returned
mask is used for IPI, then it'll cause IPIs to be skipped on cores where
the first thread is offline, because the IPI code refuses to send IPIs to
offline threads.

Fix this by setting the bit of the first online thread in the core.
This is done by fixing this in the underlying function
cpu_thread_mask_to_cores.

The result has the property that for all cores with online threads, there
is one bit set in the returned map. And further, all bits that are set in
the returned map correspond to online threads.
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
[ Changelog from Michael Ellerman <mpe@ellerman.id.au> ]
Reviewed-by: NGautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The commit 8170a83f ("powerpc: Wireup the kcmp syscall to sys_ni") has
disabled the kcmp syscall for powerpc.  This has been done due to the use
of unsigned long parameters which may require a dedicated wrapper to handle
32bit process on top of 64bit kernel.  However in the kcmp() case, the 2
unsigned long parameters are currently only used to carry file descriptors
from user space to the kernel.  Since such a parameter is passed through
register, and file descriptor doesn't need to get extended, there is,
today, no need for a wrapper.

In the case there will be a need to pass address in or out of this system
call, then a wrapper could be required, it will then be to care of it.

As today this is not the case, it is safe to enable kcmp() on powerpc.

Tested (by Laurent) on 64-bit, 32-bit, and 32-bit userspace on 64-bit
kernel using tools/testing/selftests/kcmp [mpe].
Signed-off-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The only little endian configuration we support is ppc64le, all other
configurations are big endian.

So we should only offer a choice of endian if we're building for 64-bit
Book3S, ie. PPC_BOOK3S_64.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Currently, the macro IS_BRIDGE is not used any where.
This patch just removes it.
Signed-off-by: NWei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

As the comment indicates, powernv_eeh_get_state() will inform EEH core to
delay 1 second. This means the delay doesn't happen when
powernv_eeh_get_state() returns.

This patch moves the delay subtraction just before msleep(), which is the
same logic in pseries_eeh_wait_state().
Signed-off-by: NWei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

To retrieve the PCI slot state, EEH driver would set a timeout for that.
While current comment is not aligned to what the code does.

This patch fixes those comments according to the code.
Signed-off-by: NWei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

struct pci_io_addr_range{} stores the information of pci resources. It
would be better to keep these related fields have the same type as in
struct resource{}.

This patch fixes the start/end/flags type in struct pci_io_addr_range{} to
have the same type as in struct resource{}.
Signed-off-by: NWei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The patch defines PCI error types and functions in uapi/asm/eeh.h
and exports function eeh_pe_inject_err(), which will be called by
VFIO driver to inject the specified PCI error to the indicated
PE for testing purpose.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

There are two equivalent sets of PE state constants, defined in
arch/powerpc/include/asm/eeh.h and include/uapi/linux/vfio.h.
Though the names are different, their corresponding values are
exactly same. The former is used by EEH core and the latter is
used by userspace.

The patch moves those constants from arch/powerpc/include/asm/eeh.h
to arch/powerpc/include/uapi/asm/eeh.h, which are expected to be
used by userspace from now on. We can't delete those constants in
vfio.h as it's uncertain that those constants have been or will be
used by userspace.
Suggested-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

OpenPower BMC machines do not place any sysparams in the device tree, so
at every boot we get a warning:

 [    0.437176] SYSPARAM: Opal sysparam node not found

Remove the warning, and reorder the init so we don't peform allocations
when there is no sysparam node in the device tree.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Acked-by: NNeelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The only little endian configuration we support is ppc64le. As such if
we're building little endian we don't need a 32-bit VDSO, because there
is no 32-bit userspace.

This patch is a fairly ugly mess of #ifdefs, but is the minimal logic
required to disable the 32-bit VDSO. We can hopefully clean up the
result in future with some further refactoring.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

In vdso_fixup_features() we have start64/start32 and size64/size32, but
they have the same types, ie. void * and unsigned long.

They're only used to save the return value from find_sectionXX() for the
subsequent call to do_feature_fixups(), so there's no overlap in their
usage either.

So we can just consolidate them into start/size and avoid the
duplication.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

It's in the git history if we ever need it back.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

There is a bug in binutils 2.24 which causes miscompilation if we're
building little endian and using weak symbols (which the kernel does).

It is fixed in binutils commit 57fa7b8c7e59 "Correct elf_merge_st_other
arguments for weak symbols", which is in binutils 2.25 and has been
backported to the binutils 2.24 branch and has been picked up by most
distros it seems.

However if we're running stock 2.24 (no extra version) then the bug is
present, so check for that and bail.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

We have several checks for bad gcc versions in our Makefile. These don't
apply if we're building with clang, so skip them in that case.

The obvious check would be for ${COMPILER} = "gcc", but because of the
way the logic in the top level Makefile conditionally sets COMPILER,
it's possible that we're building with gcc but COMPILER was not set.

So instead check for ${COMPILER} != "clang", which we know is currently
the only other possibility.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Currently we print "Starting Linux PPC64" at boot. But we don't mention
anywhere whether the kernel is big or little endian.

If we print the utsname->machine value instead we get either "ppc64" or
"ppc64le" which is much more informative, eg:

  Starting Linux ppc64le #1 SMP Wed Apr 15 12:12:20 AEST 2015
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The pasemi MSI code is currently always built when MPIC=y && PCI_MSI=y.
It should not have any effect on other platforms, because it immediately
checks the MPIC's compatible property for "pasemi,pwrficient-openpic".

However it's odd that it's still built even when PASEMI=n. It also
needn't be in sysdev, as it's only used by pasemi. So move it into
platforms/pasemi, whereby it will only be built for PASEMI=y.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The STRICT_MM_TYPECHECKS code has bit-rotted over the years. To make it
possible to easily build test it, make it a CONFIG option.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Failure return from dlpar_configure_connector when dlpar adding cpus
results in leaking references to the cpus parent device node. Move the
call to of_node_put() prior to checking the result of
dlpar_configure_connector.

Fixes: 8d5ff320 ("powerpc/pseries: Make dlpar_configure_connector parent node aware")
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The irq_domain_ops are not modified by the driver and the irqdomain core
code accepts pointer to a const data.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Patches 7cba160a "powernv/cpuidle: Redesign idle states management"
and 77b54e9f "powernv/powerpc: Add winkle support for offline cpus"
use non-volatile condition registers (cr2, cr3 and cr4) early in the system
reset interrupt handler (system_reset_pSeries()) before it has been determined
if state loss has occurred. If state loss has not occurred, control returns via
the power7_wakeup_noloss() path which does not restore those condition
registers, leaving them corrupted.

Fix this by restoring the condition registers in the power7_wakeup_noloss()
case.

This is apparent when running a KVM guest on hardware that does not
support winkle or sleep and the guest makes use of secondary threads. In
practice this means Power7 machines, though some early unreleased Power8
machines may also be susceptible.

The secondary CPUs are taken off line before the guest is started and
they call pnv_smp_cpu_kill_self(). This checks support for sleep
states (in this case there is no support) and power7_nap() is called.

When the CPU is woken, power7_nap() returns and because the CPU is
still off line, the main while loop executes again. The sleep states
support test is executed again, but because the tested values cannot
have changed, the compiler has optimized the test away and instead we
rely on the result of the first test, which has been left in cr3
and/or cr4. With the result overwritten, the wrong branch is taken and
power7_winkle() is called on a CPU that does not support it, leading
to it stalling.

Fixes: 7cba160a ("powernv/cpuidle: Redesign idle states management")
Fixes: 77b54e9f ("powernv/powerpc: Add winkle support for offline cpus")
[mpe: Massage change log a bit more]
Signed-off-by: NSam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Commit 1c509148b ("powerpc/eeh: Do probe on pci_dn") probes EEH
devices in early stage, which is reasonable to pSeries platform.
However, it's wrong for PowerNV platform because the PE# isn't
determined until the resources (IO and MMIO) are assigned to
PE in hotplug case. So we have to delay probing EEH devices
for PowerNV platform until the PE# is assigned.

Fixes: ff57b454 ("powerpc/eeh: Do probe on pci_dn")
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

When asserting reset in pcibios_set_pcie_reset_state(), the PE
is enforced to (hardware) frozen state in order to drop unexpected
PCI transactions (except PCI config read/write) automatically by
hardware during reset, which would cause recursive EEH error.
However, the (software) frozen state EEH_PE_ISOLATED is missed.
When users get 0xFF from PCI config or MMIO read, EEH_PE_ISOLATED
is set in PE state retrival backend. Unfortunately, nobody (the
reset handler or the EEH recovery functinality in host) will clear
EEH_PE_ISOLATED when the PE has been passed through to guest.

The patch sets and clears EEH_PE_ISOLATED properly during reset
in function pcibios_set_pcie_reset_state() to fix the issue.

Fixes: 28158cd1 ("Enhance pcibios_set_pcie_reset_state()")
Reported-by: NCarol L. Soto <clsoto@us.ibm.com>
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Tested-by: NCarol L. Soto <clsoto@us.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The incorrect ordering of operations during cpu dlpar add results in invalid
affinity for the cpu being added. The ibm,associativity property in the
device tree is populated with all zeroes for the added cpu which results in
invalid affinity mappings and all cpus appear to belong to node 0.

This occurs because rtas configure-connector is called prior to making the
rtas set-indicator calls. Phyp does not assign affinity information
for a cpu until the rtas set-indicator calls are made to set the isolation
and allocation state.

Correct the order of operations to make the rtas set-indicator
calls (done in dlpar_acquire_drc) before calling rtas configure-connector.

Fixes: 1a8061c4 ("powerpc/pseries: Add kernel based CPU DLPAR handling")
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This reverts commit feba4036.

Although the principle of this change is good, the implementation has a
few issues.

Firstly we can sometimes fail to abort a syscall because r12 may have
been clobbered by C code if we went down the virtual CPU accounting
path, or if syscall tracing was enabled.

Secondly we have decided that it is safer to abort the syscall even
earlier in the syscall entry path, so that we avoid the syscall tracing
path when we are transactional.

So that we have time to thoroughly test those changes we have decided to
revert this for this merge window and will merge the fixed version in
the next window.

NB. Rather than reverting the selftest we just drop tm-syscall from
TEST_PROGS so that it's not run by default.

Fixes: feba4036 ("powerpc/tm: Abort syscalls in active transactions")
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Load the PowerNV platform pci controller ops into pci controllers
after all the operations are loaded into the platform ops struct, not
before.

Otherwise we aren't actually setting the ops properly which can break
IO for some devices.

Fixes: 65ebf4b6 ("powerpc/powernv: Move controller ops from ppc_md to controller_ops")
Reported-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Commit 34cb7954 "Convert ICS mutex lock to spin lock" added an
include of asm/spinlock.h, which does not work in the SMP=n case.

It should instead include linux/spinlock.h

Fixes: 34cb7954 ("KVM: PPC: Book3S HV: Convert ICS mutex lock to spin lock")
Acked-by: NPaul Mackerras <paulus@samba.org>
Reviewed-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This fix the below build error

arch/powerpc/mm/hash_utils_64.c: In function ‘flush_hash_hugepage’:
arch/powerpc/mm/hash_utils_64.c:1381:1: error: label at end of compound statement
 tm_abort:
 ^
make[1]: *** [arch/powerpc/mm/hash_utils_64.o] Error 1
Reported-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This uses msgsnd where possible for signalling other threads within
the same core on POWER8 systems, rather than IPIs through the XICS
interrupt controller.  This includes waking secondary threads to run
the guest, the interrupts generated by the virtual XICS, and the
interrupts to bring the other threads out of the guest when exiting.

Aggregated statistics from debugfs across vcpus for a guest with 32
vcpus, 8 threads/vcore, running on a POWER8, show this before the
change:

 rm_entry:     3387.6ns (228 - 86600, 1008969 samples)
  rm_exit:     4561.5ns (12 - 3477452, 1009402 samples)
  rm_intr:     1660.0ns (12 - 553050, 3600051 samples)

and this after the change:

 rm_entry:     3060.1ns (212 - 65138, 953873 samples)
  rm_exit:     4244.1ns (12 - 9693408, 954331 samples)
  rm_intr:     1342.3ns (12 - 1104718, 3405326 samples)

for a test of booting Fedora 20 big-endian to the login prompt.

The time taken for a H_PROD hcall (which is handled in the host
kernel) went down from about 35 microseconds to about 16 microseconds
with this change.

The noinline added to kvmppc_run_core turned out to be necessary for
good performance, at least with gcc 4.9.2 as packaged with Fedora 21
and a little-endian POWER8 host.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

This replaces the assembler code for kvmhv_commence_exit() with C code
in book3s_hv_builtin.c.  It also moves the IPI sending code that was
in book3s_hv_rm_xics.c into a new kvmhv_rm_send_ipi() function so it
can be used by kvmhv_commence_exit() as well as icp_rm_set_vcpu_irq().
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

On entry to the guest, secondary threads now wait for the primary to
switch the MMU after loading up most of their state, rather than before.
This means that the secondary threads get into the guest sooner, in the
common case where the secondary threads get to kvmppc_hv_entry before
the primary thread.

On exit, the first thread out increments the exit count and interrupts
the other threads (to get them out of the guest) before saving most
of its state, rather than after.  That means that the other threads
exit sooner and means that the first thread doesn't spend so much
time waiting for the other threads at the point where the MMU gets
switched back to the host.

This pulls out the code that increments the exit count and interrupts
other threads into a separate function, kvmhv_commence_exit().
This also makes sure that r12 and vcpu->arch.trap are set correctly
in some corner cases.

Statistics from /sys/kernel/debug/kvm/vm*/vcpu*/timings show the
improvement.  Aggregating across vcpus for a guest with 32 vcpus,
8 threads/vcore, running on a POWER8, gives this before the change:

 rm_entry:     avg 4537.3ns (222 - 48444, 1068878 samples)
  rm_exit:     avg 4787.6ns (152 - 165490, 1010717 samples)
  rm_intr:     avg 1673.6ns (12 - 341304, 3818691 samples)

and this after the change:

 rm_entry:     avg 3427.7ns (232 - 68150, 1118921 samples)
  rm_exit:     avg 4716.0ns (12 - 150720, 1119477 samples)
  rm_intr:     avg 1614.8ns (12 - 522436, 3850432 samples)

showing a substantial reduction in the time spent per guest entry in
the real-mode guest entry code, and smaller reductions in the real
mode guest exit and interrupt handling times.  (The test was to start
the guest and boot Fedora 20 big-endian to the login prompt.)
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Currently, the entry_exit_count field in the kvmppc_vcore struct
contains two 8-bit counts, one of the threads that have started entering
the guest, and one of the threads that have started exiting the guest.
This changes it to an entry_exit_map field which contains two bitmaps
of 8 bits each.  The advantage of doing this is that it gives us a
bitmap of which threads need to be signalled when exiting the guest.
That means that we no longer need to use the trick of setting the
HDEC to 0 to pull the other threads out of the guest, which led in
some cases to a spurious HDEC interrupt on the next guest entry.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

This arranges for threads that are napping due to their vcpu having
ceded or due to not having a vcpu to wake up at the end of the guest's
timeslice without having to be poked with an IPI.  We do that by
arranging for the decrementer to contain a value no greater than the
number of timebase ticks remaining until the end of the timeslice.
In the case of a thread with no vcpu, this number is in the hypervisor
decrementer already.  In the case of a ceded vcpu, we use the smaller
of the HDEC value and the DEC value.

Using the DEC like this when ceded means we need to save and restore
the guest decrementer value around the nap.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

When running a multi-threaded guest and vcpu 0 in a virtual core
is not running in the guest (i.e. it is busy elsewhere in the host),
thread 0 of the physical core will switch the MMU to the guest and
then go to nap mode in the code at kvm_do_nap.  If the guest sends
an IPI to thread 0 using the msgsndp instruction, that will wake
up thread 0 and cause all the threads in the guest to exit to the
host unnecessarily.  To avoid the unnecessary exit, this arranges
for the PECEDP bit to be cleared in this situation.  When napping
due to a H_CEDE from the guest, we still set PECEDP so that the
thread will wake up on an IPI sent using msgsndp.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

We can tell when a secondary thread has finished running a guest by
the fact that it clears its kvm_hstate.kvm_vcpu pointer, so there
is no real need for the nap_count field in the kvmppc_vcore struct.
This changes kvmppc_wait_for_nap to poll the kvm_hstate.kvm_vcpu
pointers of the secondary threads rather than polling vc->nap_count.
Besides reducing the size of the kvmppc_vcore struct by 8 bytes,
this also means that we can tell which secondary threads have got
stuck and thus print a more informative error message.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Rather than calling cond_resched() in kvmppc_run_core() before doing
the post-processing for the vcpus that we have just run (that is,
calling kvmppc_handle_exit_hv(), kvmppc_set_timer(), etc.), we now do
that post-processing before calling cond_resched(), and that post-
processing is moved out into its own function, post_guest_process().

The reschedule point is now in kvmppc_run_vcpu() and we define a new
vcore state, VCORE_PREEMPT, to indicate that that the vcore's runner
task is runnable but not running.  (Doing the reschedule with the
vcore in VCORE_INACTIVE state would be bad because there are potentially
other vcpus waiting for the runner in kvmppc_wait_for_exec() which
then wouldn't get woken up.)

Also, we make use of the handy cond_resched_lock() function, which
unlocks and relocks vc->lock for us around the reschedule.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

* Remove unused kvmppc_vcore::n_busy field.
* Remove setting of RMOR, since it was only used on PPC970 and the
  PPC970 KVM support has been removed.
* Don't use r1 or r2 in setting the runlatch since they are
  conventionally reserved for other things; use r0 instead.
* Streamline the code a little and remove the ext_interrupt_to_host
  label.
* Add some comments about register usage.
* hcall_try_real_mode doesn't need to be global, and can't be
  called from C code anyway.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Previously, if kvmppc_run_core() was running a VCPU that needed a VPA
update (i.e. one of its 3 virtual processor areas needed to be pinned
in memory so the host real mode code can update it on guest entry and
exit), we would drop the vcore lock and do the update there and then.
Future changes will make it inconvenient to drop the lock, so instead
we now remove it from the list of runnable VCPUs and wake up its
VCPU task.  This will have the effect that the VCPU task will exit
kvmppc_run_vcpu(), go around the do loop in kvmppc_vcpu_run_hv(), and
re-enter kvmppc_run_vcpu(), whereupon it will do the necessary call
to kvmppc_update_vpas() and then rejoin the vcore.

The one complication is that the runner VCPU (whose VCPU task is the
current task) might be one of the ones that gets removed from the
runnable list.  In that case we just return from kvmppc_run_core()
and let the code in kvmppc_run_vcpu() wake up another VCPU task to be
the runner if necessary.

This all means that the VCORE_STARTING state is no longer used, so we
remove it.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>