Commit graph

108 commits

Author SHA1 Message Date
Mihai Caraman
352df1deb2 KVM: PPC: booke: Get/set guest EPCR register using ONE_REG interface
Implement ONE_REG interface for EPCR register adding KVM_REG_PPC_EPCR to
the list of ONE_REG PPC supported registers.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[agraf: remove HV dependency, use get/put_user]
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-12-06 01:34:20 +01:00
Mihai Caraman
38f988240c KVM: PPC: bookehv: Add EPCR support in mtspr/mfspr emulation
Add EPCR support in booke mtspr/mfspr emulation. EPCR register is defined only
for 64-bit and HV categories, we will expose it at this point only to 64-bit
virtual processors running on 64-bit HV hosts.
Define a reusable setter function for vcpu's EPCR.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[agraf: move HV dependency in the code]
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-12-06 01:34:19 +01:00
Mihai Caraman
95e90b43c9 KVM: PPC: bookehv: Add guest computation mode for irq delivery
When delivering guest IRQs, update MSR computation mode according to guest
interrupt computation mode found in EPCR.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[agraf: remove HV dependency in the code]
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-12-06 01:34:18 +01:00
Mihai Caraman
b50df19ccc KVM: PPC: booke: Fix get_tb() compile error on 64-bit
Include header file for get_tb() declaration.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-12-06 01:34:09 +01:00
Scott Wood
5bd1cf1185 KVM: PPC: set IN_GUEST_MODE before checking requests
Avoid a race as described in the code comment.

Also remove a related smp_wmb() from booke's kvmppc_prepare_to_enter().
I can't see any reason for it, and the book3s_pr version doesn't have it.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:54 +02:00
Paul Mackerras
a47d72f361 KVM: PPC: Book3S HV: Fix updates of vcpu->cpu
This removes the powerpc "generic" updates of vcpu->cpu in load and
put, and moves them to the various backends.

The reason is that "HV" KVM does its own sauce with that field
and the generic updates might corrupt it. The field contains the
CPU# of the -first- HW CPU of the core always for all the VCPU
threads of a core (the one that's online from a host Linux
perspective).

However, the preempt notifiers are going to be called on the
threads VCPUs when they are running (due to them sleeping on our
private waitqueue) causing unload to be called, potentially
clobbering the value.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:52 +02:00
Paul Mackerras
dfe49dbd1f KVM: PPC: Book3S HV: Handle memory slot deletion and modification correctly
This adds an implementation of kvm_arch_flush_shadow_memslot for
Book3S HV, and arranges for kvmppc_core_commit_memory_region to
flush the dirty log when modifying an existing slot.  With this,
we can handle deletion and modification of memory slots.

kvm_arch_flush_shadow_memslot calls kvmppc_core_flush_memslot, which
on Book3S HV now traverses the reverse map chains to remove any HPT
(hashed page table) entries referring to pages in the memslot.  This
gets called by generic code whenever deleting a memslot or changing
the guest physical address for a memslot.

We flush the dirty log in kvmppc_core_commit_memory_region for
consistency with what x86 does.  We only need to flush when an
existing memslot is being modified, because for a new memslot the
rmap array (which stores the dirty bits) is all zero, meaning that
every page is considered clean already, and when deleting a memslot
we obviously don't care about the dirty bits any more.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:51 +02:00
Paul Mackerras
a66b48c3a3 KVM: PPC: Move kvm->arch.slot_phys into memslot.arch
Now that we have an architecture-specific field in the kvm_memory_slot
structure, we can use it to store the array of page physical addresses
that we need for Book3S HV KVM on PPC970 processors.  This reduces the
size of struct kvm_arch for Book3S HV, and also reduces the size of
struct kvm_arch_memory_slot for other PPC KVM variants since the fields
in it are now only compiled in for Book3S HV.

This necessitates making the kvm_arch_create_memslot and
kvm_arch_free_memslot operations specific to each PPC KVM variant.
That in turn means that we now don't allocate the rmap arrays on
Book3S PR and Book E.

Since we now unpin pages and free the slot_phys array in
kvmppc_core_free_memslot, we no longer need to do it in
kvmppc_core_destroy_vm, since the generic code takes care to free
all the memslots when destroying a VM.

We now need the new memslot to be passed in to
kvmppc_core_prepare_memory_region, since we need to initialize its
arch.slot_phys member on Book3S HV.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:51 +02:00
Alexander Graf
7a08c2740f KVM: PPC: BookE: Support FPU on non-hv systems
When running on HV aware hosts, we can not trap when the guest sets the FP
bit, so we just let it do so when it wants to, because it has full access to
MSR.

For non-HV aware hosts with an FPU (like 440), we need to also adjust the
shadow MSR though. Otherwise the guest gets an FP unavailable trap even when
it really enabled the FP bit in MSR.

Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:50 +02:00
Bharat Bhushan
6df8d3fc58 booke: Added ONE_REG interface for IAC/DAC debug registers
IAC/DAC are defined as 32 bit while they are 64 bit wide. So ONE_REG
interface is added to set/get them.

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:47 +02:00
Bharat Bhushan
f61c94bb99 KVM: PPC: booke: Add watchdog emulation
This patch adds the watchdog emulation in KVM. The watchdog
emulation is enabled by KVM_ENABLE_CAP(KVM_CAP_PPC_BOOKE_WATCHDOG) ioctl.
The kernel timer are used for watchdog emulation and emulates
h/w watchdog state machine. On watchdog timer expiry, it exit to QEMU
if TCR.WRC is non ZERO. QEMU can reset/shutdown etc depending upon how
it is configured.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
[bharat.bhushan@freescale.com: reworked patch]
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
[agraf: adjust to new request framework]
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:47 +02:00
Alexander Graf
7c973a2ebb KVM: PPC: Add return value to core_check_requests
Requests may want to tell us that we need to go back into host state,
so add a return value for the checks.

Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:46 +02:00
Alexander Graf
7ee788556b KVM: PPC: Add return value in prepare_to_enter
Our prepare_to_enter helper wants to be able to return in more circumstances
to the host than only when an interrupt is pending. Broaden the interface a
bit and move even more generic code to the generic helper.

Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:46 +02:00
Alexander Graf
3766a4c693 KVM: PPC: Move kvm_guest_enter call into generic code
We need to call kvm_guest_enter in booke and book3s, so move its
call to generic code.

Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:45 +02:00
Alexander Graf
bd2be6836e KVM: PPC: Book3S: PR: Rework irq disabling
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: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:45 +02:00
Alexander Graf
24afa37b9c KVM: PPC: Consistentify vcpu exit path
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: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:45 +02:00
Alexander Graf
706fb730cb KVM: PPC: Exit guest context while handling exit
The x86 implementation of KVM accounts for host time while processing
guest exits. Do the same for us.

Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:43 +02:00
Alexander Graf
e85ad380c6 KVM: PPC: BookE: Drop redundant vcpu->mode set
We only need to set vcpu->mode to outside once.

Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:43 +02:00
Alexander Graf
03d25c5bd5 KVM: PPC: Use same kvmppc_prepare_to_enter code for booke and book3s_pr
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: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:42 +02:00
Alexander Graf
2d8185d4ee KVM: PPC: BookE: No duplicate request != 0 check
We only call kvmppc_check_requests() when vcpu->requests != 0, so drop
the redundant check in the function itself

Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:42 +02:00
Alexander Graf
6346046c3a KVM: PPC: BookE: Add some more trace points
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: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:42 +02:00
Alexander Graf
862d31f788 KVM: PPC: E500: Implement MMU notifiers
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: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:41 +02:00
Alexander Graf
d69c643644 KVM: PPC: BookE: Add support for vcpu->mode
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: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:41 +02:00
Alexander Graf
4ffc6356ec KVM: PPC: BookE: Add check_requests helper function
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: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:41 +02:00
Alexander Graf
cf1c5ca473 KVM: PPC: BookE: Expose remote TLB flushes in debugfs
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: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:39 +02:00
Alexander Graf
97c9505984 KVM: PPC: PR: Use generic tracepoint for guest exit
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: Alexander Graf <agraf@suse.de>
2012-10-05 23:38:39 +02:00
Bharat Bhushan
6328e593c3 booke/bookehv: Add host crit-watchdog exception support
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-07-11 17:39:36 +02:00
Bharat Bhushan
21bd000abf KVM: PPC: booke: Added DECAR support
Added the decrementer auto-reload support. DECAR is readable
on e500v2/e500mc and later cpus.

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-30 11:43:11 +02:00
Alexander Graf
966cd0f3bd KVM: PPC: Ignore unhalt request from kvm_vcpu_block
When running kvm_vcpu_block and it realizes that the CPU is actually good
to run, we get a request bit set for KVM_REQ_UNHALT. Right now, there's
nothing we can do with that bit, so let's unset it right after the call
again so we don't get confused in our later checks for pending work.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 14:02:38 +03:00
Alexander Graf
6020c0f6e7 KVM: PPC: Pass EA to updating emulation ops
When emulating updating load/store instructions (lwzu, stwu, ...) we need to
write the effective address of the load/store into a register.

Currently, we write the physical address in there, which is very wrong. So
instead let's save off where the virtual fault was on MMIO and use that
information as value to put into the register.

While at it, also move the XOP variants of the above instructions to the new
scheme of using the already known vaddr instead of calculating it themselves.

Reported-by: Jörg Sommer <joerg@alea.gnuu.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 14:01:37 +03:00
Alexander Graf
03660ba270 KVM: PPC: Booke: only prepare to enter when we enter
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:55:29 +03:00
Alexander Graf
7cc1e8ee78 KVM: PPC: booke: Reinject performance monitor interrupts
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:55:28 +03:00
Alexander Graf
4e642ccbd6 KVM: PPC: booke: expose good state on irq reinject
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:55:26 +03:00
Alexander Graf
95f2e92144 KVM: PPC: booke: Support perfmon interrupts
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:55:24 +03:00
Alexander Graf
0268597c81 KVM: PPC: booke: add GS documentation for program interrupt
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:55:19 +03:00
Alexander Graf
c35c9d84cf KVM: PPC: booke: Readd debug abort code for machine check
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:55:17 +03:00
Alexander Graf
8b3a00fcd3 KVM: PPC: booke: BOOKE_IRQPRIO_MAX is n+1
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:55:06 +03:00
Alexander Graf
a8e4ef8414 KVM: PPC: booke: rework rescheduling checks
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:55:05 +03:00
Alexander Graf
d1ff54992d KVM: PPC: booke: deliver program int on emulation failure
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:55:03 +03:00
Alexander Graf
acab052906 KVM: PPC: booke: remove leftover debugging
The e500mc patches left some debug code in that we don't need. Remove it.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:55:01 +03:00
Alexander Graf
bf7ca4bdcb KVM: PPC: rename CONFIG_KVM_E500 -> CONFIG_KVM_E500V2
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:54:57 +03:00
Alexander Graf
79300f8cb9 KVM: PPC: e500mc: implicitly set MSR_GS
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:54:52 +03:00
Alexander Graf
4ab969199e KVM: PPC: e500mc: Add doorbell emulation support
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: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:54:50 +03:00
Scott Wood
8fae845f49 KVM: PPC: booke: standard PPC floating point support
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: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:54:15 +03:00
Scott Wood
d30f6e4800 KVM: PPC: booke: category E.HV (GS-mode) support
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: Scott Wood <scottwood@freescale.com>
[agraf: remove pt_regs usage]
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:51:19 +03:00
Scott Wood
fafd683278 KVM: PPC: booke: Move vm core init/destroy out of booke.c
e500mc will want to do lpid allocation/deallocation here.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:51:05 +03:00
Scott Wood
94fa9d9927 KVM: PPC: booke: add booke-level vcpu load/put
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: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:51:04 +03:00
Paul Mackerras
31f3438eca KVM: PPC: Move kvm_vcpu_ioctl_[gs]et_one_reg down to platform-specific code
This moves the get/set_one_reg implementation down from powerpc.c into
booke.c, book3s_pr.c and book3s_hv.c.  This avoids #ifdefs in C code,
but more importantly, it fixes a bug on Book3s HV where we were
accessing beyond the end of the kvm_vcpu struct (via the to_book3s()
macro) and corrupting memory, causing random crashes and file corruption.

On Book3s HV we only accept setting the HIOR to zero, since the guest
runs in supervisor mode and its vectors are never offset from zero.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
[agraf update to apply on top of changed ONE_REG patches]
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:41 +02:00
Scott Wood
dfd4d47e9a KVM: PPC: booke: Improve timer register emulation
Decrementers are now properly driven by TCR/TSR, and the guest
has full read/write access to these registers.

The decrementer keeps ticking (and setting the TSR bit) regardless of
whether the interrupts are enabled with TCR.

The decrementer stops at zero, rather than going negative.

Decrementers (and FITs, once implemented) are delivered as
level-triggered interrupts -- dequeued when the TSR bit is cleared, not
on delivery.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
[scottwood@freescale.com: significant changes]
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:27 +02:00
Scott Wood
b59049720d KVM: PPC: Paravirtualize SPRG4-7, ESR, PIR, MASn
This allows additional registers to be accessed by the guest
in PR-mode KVM without trapping.

SPRG4-7 are readable from userspace.  On booke, KVM will sync
these registers when it enters the guest, so that accesses from
guest userspace will work.  The guest kernel, OTOH, must consistently
use either the real registers or the shared area between exits.  This
also applies to the already-paravirted SPRG3.

On non-booke, it's not clear to what extent SPRG4-7 are supported
(they're not architected for book3s, but exist on at least some classic
chips).  They are copied in the get/set regs ioctls, but I do not see any
non-booke emulation.  I also do not see any syncing with real registers
(in PR-mode) including the user-readable SPRG3.  This patch should not
make that situation any worse.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:26 +02:00