linux.git/arch/mips/kvm, branch v3.15

MIPS: KVM: Remove dead code in CP0 emulation

2014-03-19T16:01:50+00:00

The code to check whether rd > MIPS_CP0_DESAVE is dead code, since
MIPS_CP0_DESAVE = 31 and rd is already masked with 0x1f. Remove it.

Signed-off-by: James Hogan 
Cc: Ralf Baechle 
Cc: Gleb Natapov 
Cc: Paolo Bonzini 
Cc: Sanjay Lal 
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini

MIPS: KVM: Consult HWREna before emulating RDHWR

2014-03-19T16:01:43+00:00

The ability to read hardware registers from userland with the RDHWR
instruction should depend upon the corresponding bit of the HWREna
register being set, otherwise a reserved instruction exception should be
generated.

However KVM's current emulation ignores the guest's HWREna and always
emulates RDHWR instructions even if the guest OS has disallowed them.

Therefore rework the RDHWR emulation code to check for privilege or the
corresponding bit in the guest HWREna bit. Also remove the #if 0 case
for the UserLocal register. I presume it was there for debug purposes
but it seems unnecessary now that the guest can control whether it
causes a guest exception.

Signed-off-by: James Hogan 
Cc: Ralf Baechle 
Cc: Gleb Natapov 
Cc: Paolo Bonzini 
Cc: Sanjay Lal 
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini

MIPS: KVM: Pass reserved instruction exceptions to guest

2014-03-19T16:01:34+00:00

Previously a reserved instruction exception while in guest code would
cause a KVM internal error if kvm_mips_handle_ri() didn't recognise the
instruction (including a RDHWR from an unrecognised hardware register).

However the guest OS should really have the opportunity to catch the
exception so that it can take the appropriate actions such as sending a
SIGILL to the guest user process or emulating the instruction itself.

Therefore in these cases emulate a guest RI exception and only return
EMULATE_FAIL if that fails, being careful to revert the PC first in case
the exception occurred in a branch delay slot in which case the PC will
already point to the branch target.

Also turn the printk messages relating to these cases into kvm_debug
messages so that they aren't usually visible.

This allows crashme to run in the guest without killing the entire VM.

Signed-off-by: James Hogan 
Cc: Ralf Baechle 
Cc: Gleb Natapov 
Cc: Paolo Bonzini 
Cc: Sanjay Lal 
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini

mips: delete non-required instances of include

2014-01-24T21:39:56+00:00

None of these files are actually using any __init type directives
and hence don't need to include .  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Signed-off-by: Paul Gortmaker 
Signed-off-by: John Crispin 
Patchwork: http://patchwork.linux-mips.org/patch/6320/

MIPS: KVM: remove shadow_tlb code

2014-01-24T21:39:56+00:00

The kvm_mips_init_shadow_tlb() function is called from
kvm_arch_vcpu_init() and initialises entries 0 to
current_cpu_data.tlbsize-1 of the virtual cpu's shadow_tlb[64] array.

However newer cores with FTLBs can have a tlbsize > 64, for example the
ProAptiv I'm testing on has a total tlbsize of 576. This causes
kvm_mips_init_shadow_tlb() to overflow the shadow_tlb[64] array and
overwrite the comparecount_timer among other things, causing a lock up
when starting a KVM guest.

Aside from kvm_mips_init_shadow_tlb() which only initialises it, the
shadow_tlb[64] array is only actually used by the following functions:
 - kvm_shadow_tlb_put() & kvm_shadow_tlb_load()
     These are never called. The only call sites are #if 0'd out.
 - kvm_mips_dump_shadow_tlbs()
     This is never called.

It was originally added for trap & emulate, but turned out to be
unnecessary so it was disabled.

So instead of fixing the shadow_tlb initialisation code, lets just
remove the shadow_tlb[64] array and the above functions entirely. The
only functional change here is the removal of broken shadow_tlb
initialisation. The rest just deletes dead code.

Signed-off-by: James Hogan 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Cc: Gleb Natapov 
Cc: kvm@vger.kernel.org
Cc: Sanjay Lal 
Acked-by: Paolo Bonzini 
Signed-off-by: John Crispin 
Patchwork: http://patchwork.linux-mips.org/patch/6384/

MIPS: KVM: use common EHINV aware UNIQUE_ENTRYHI

2014-01-24T21:39:56+00:00

When KVM is enabled and TLB invalidation is supported,
kvm_mips_flush_host_tlb() can cause a machine check exception due to
multiple matching TLB entries. This can occur on shutdown even when KVM
hasn't been actively used.

Commit adb78de9eae8 (MIPS: mm: Move UNIQUE_ENTRYHI macro to a header
file) created a common UNIQUE_ENTRYHI in asm/tlb.h but it didn't update
the copy of UNIQUE_ENTRYHI in kvm_tlb.c to use it.

Commit 36b175451399 (MIPS: tlb: Set the EHINV bit for TLBINVF cores when
invalidating the TLB) later added TLB invalidation (EHINV) support to
the common UNIQUE_ENTRYHI.

Therefore make kvm_tlb.c use the EHINV aware UNIQUE_ENTRYHI
implementation in asm/tlb.h too.

Signed-off-by: James Hogan 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Cc: Gleb Natapov 
Cc: kvm@vger.kernel.org
Cc: Sanjay Lal 
Reviewed-by: Markos Chandras 
Acked-by: Paolo Bonzini 
Signed-off-by: John Crispin 
Patchwork: http://patchwork.linux-mips.org/patch/6383/

kvm: Add struct kvm arg to memslot APIs

2013-10-17T13:49:23+00:00

We will use that in the later patch to find the kvm ops handler

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Alexander Graf

Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2013-09-05T01:15:06+00:00

Pull KVM updates from Gleb Natapov:
 "The highlights of the release are nested EPT and pv-ticketlocks
  support (hypervisor part, guest part, which is most of the code, goes
  through tip tree).  Apart of that there are many fixes for all arches"

Fix up semantic conflicts as discussed in the pull request thread..

* 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (88 commits)
  ARM: KVM: Add newlines to panic strings
  ARM: KVM: Work around older compiler bug
  ARM: KVM: Simplify tracepoint text
  ARM: KVM: Fix kvm_set_pte assignment
  ARM: KVM: vgic: Bump VGIC_NR_IRQS to 256
  ARM: KVM: Bugfix: vgic_bytemap_get_reg per cpu regs
  ARM: KVM: vgic: fix GICD_ICFGRn access
  ARM: KVM: vgic: simplify vgic_get_target_reg
  KVM: MMU: remove unused parameter
  KVM: PPC: Book3S PR: Rework kvmppc_mmu_book3s_64_xlate()
  KVM: PPC: Book3S PR: Make instruction fetch fallback work for system calls
  KVM: PPC: Book3S PR: Don't corrupt guest state when kernel uses VMX
  KVM: x86: update masterclock when kvmclock_offset is calculated (v2)
  KVM: PPC: Book3S: Fix compile error in XICS emulation
  KVM: PPC: Book3S PR: return appropriate error when allocation fails
  arch: powerpc: kvm: add signed type cast for comparation
  KVM: x86: add comments where MMIO does not return to the emulator
  KVM: vmx: count exits to userspace during invalid guest emulation
  KVM: rename __kvm_io_bus_sort_cmp to kvm_io_bus_cmp
  kvm: optimize away THP checks in kvm_is_mmio_pfn()
  ...

mips/kvm: Make kvm_locore.S 64-bit buildable/safe.

2013-08-26T09:30:49+00:00

We need to use more of the Macros in asm.h to allow kvm_locore.S to
build in a 64-bit kernel.

For 32-bit there is no change in the generated object code.

Signed-off-by: David Daney 
Acked-by: Ralf Baechle 
Acked-by: Paolo Bonzini 
Signed-off-by: Gleb Natapov

mips/kvm: Cleanup .push/.pop directives in kvm_locore.S

2013-08-26T09:30:39+00:00

There are:
	.set	push
	.set	noreorder
	.set	noat
	 .
	 .
	 .
	.set	pop

Sequences all over the place in this file, but in some places the
final ".set pop" is erroneously converted to ".set push", so none of
these really do what they appear to.

Clean up the whole mess by moving ".set noreorder", ".set noat" to the
top, and get rid of everything else.

Generated object code is unchanged.

Signed-off-by: David Daney 
Acked-by: Paolo Bonzini 
Signed-off-by: Gleb Natapov