While bolted handlers (including e6500) do not need to deal with a TLB
miss recursively causing another TLB miss, nested TLB misses can still
happen with crit/mc/debug exceptions -- so we still need to honor
SPRG_TLB_EXFRAME.

We don't need to spend time modifying it in the TLB miss fastpath,
though -- the special level exception will handle that.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Cc: kvm-ppc@vger.kernel.org

Previously SPRG3 was marked for use by both VDSO and critical
interrupts (though critical interrupts were not fully implemented).

In commit 8b64a9df ("powerpc/booke64:
Use SPRG0/3 scratch for bolted TLB miss & crit int"), Mihai Caraman
made an attempt to resolve this conflict by restoring the VDSO value
early in the critical interrupt, but this has some issues:

 - It's incompatible with EXCEPTION_COMMON which restores r13 from the
   by-then-overwritten scratch (this cost me some debugging time).
 - It forces critical exceptions to be a special case handled
   differently from even machine check and debug level exceptions.
 - It didn't occur to me that it was possible to make this work at all
   (by doing a final "ld r13, PACA_EXCRIT+EX_R13(r13)") until after
   I made (most of) this patch. :-)

It might be worth investigating using a load rather than SPRG on return
from all exceptions (except TLB misses where the scratch never leaves
the SPRG) -- it could save a few cycles.  Until then, let's stick with
SPRG for all exceptions.

Since we cannot use SPRG4-7 for scratch without corrupting the state of
a KVM guest, move VDSO to SPRG7 on book3e.  Since neither SPRG4-7 nor
critical interrupts exist on book3s, SPRG3 is still used for VDSO
there.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: kvm-ppc@vger.kernel.org

Rather than calling hard_irq_disable() when we're back in C code
we can just call RECONCILE_IRQ_STATE to soft disable IRQs while
we're already in hard disabled state.

This should be functionally equivalent to the code before, but
cleaner and faster.
Signed-off-by: NTiejun Chen <tiejun.chen@windriver.com>
[agraf: fix comment, commit message]
Signed-off-by: NAlexander Graf <agraf@suse.de>

LRAT (Logical to Real Address Translation) present in MMU v2 provides hardware
translation from a logical page number (LPN) to a real page number (RPN) when
tlbwe is executed by a guest or when a page table translation occurs from a
guest virtual address.

Add LRAT error exception handler to Booke3E 64-bit kernel and the basic KVM
handler to avoid build breakage. This is a prerequisite for KVM LRAT support
that will follow.
Signed-off-by: NMihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

Add interrupt handling support for 64-bit bookehv hosts. Unify 32 and 64 bit
implementations using a common stack layout and a common execution flow starting
from kvm_handler_common macro. Update documentation for 64-bit input register
values. This patch only address the bolted TLB miss exception handlers version.
Signed-off-by: NMihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

GET_VCPU define will not be implemented for 64-bit for performance reasons
so get rid of it also on 32-bit.
Signed-off-by: NMihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

After merging the register type check patches from Ben's tree, the
hv enabled booke implementation ceased to compile.

This patch fixes things up so everyone's happy again.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

ESR register is required by Data Storage Interrupt handling code.
Add the specific flag to the interrupt handler.
Signed-off-by: NMihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Signed-off-by: NStuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Merge the defines of VCPU_GPR from different places.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Anything that uses a constructed instruction (ie. from ppc-opcode.h),
need to use the new R0 macro, as %r0 is not going to work.

Also convert usages of macros where we are just determining an offset
(usually for a load/store), like:
	std	r14,STK_REG(r14)(r1)
Can't use STK_REG(r14) as %r14 doesn't work in the STK_REG macro since
it's just calculating an offset.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Guest r8 register is held in the scratch register and stored correctly,
so remove the instruction that clobbers it. Guest r13 was missing from vcpu,
store it there.
Signed-off-by: NMihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Interrupt code used PPC_LL/PPC_STL macros to load/store some of u32 fields
which led to memory overflow on 64-bit. Use lwz/stw instead.
Signed-off-by: NMihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

For Guest accessible SPRGs 4-7, save/restore must be handled differently for 64bit and
non-64 bit case. Use the PPC_STD/PPC_LD macros for saving/restoring to/from these registers.
Signed-off-by: NVarun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Introduced PPC_STD/PPC_LD macros for saving/restoring guest registers to/from their 64 bit copies.
Signed-off-by: NVarun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

No instruction which can change Condition Register (CR) should be executed after
Guest CR is loaded. So the guest CR is restored after the Exit Timing in
lightweight_exit executes cmpw, which can clobber CR.
Signed-off-by: NBharat Bhushan <bharat.bhushan@freescale.com>
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>

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>

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>

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>

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>