Commit Graph

8 Commits

Author SHA1 Message Date
James Hogan 26f4f3b578 MIPS: KVM: Consult HWREna before emulating RDHWR
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 <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-03-19 17:01:43 +01:00
James Hogan 2202794548 MIPS: KVM: asm/kvm_host.h: Clean up whitespace
The whitespace in asm/kvm_host.h is quite inconsistent in places. Clean
up the whole file to use tabs more consistently.

When you use the --ignore-space-change argument to git diff this patch
only changes line wrapping in TLB_IS_GLOBAL and TLB_IS_VALID macros.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-03-19 17:01:15 +01:00
James Hogan 08596b0a75 MIPS: KVM: remove shadow_tlb code
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 <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Gleb Natapov <gleb@redhat.com>
Cc: kvm@vger.kernel.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6384/
2014-01-24 22:39:56 +01:00
Christoffer Dall 015e0513a0 KVM: mips: Get rid of KVM_HPAGE defines
Now when the main kvm code relying on these defines has been moved to
the x86 specific part of the world, we can get rid of these.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-10-14 10:12:08 +03:00
David Daney 4c73fb2b05 mips/kvm: Fix ABI by moving manipulation of CP0 registers to KVM_{G,S}ET_ONE_REG
Because not all 256 CP0 registers are ever implemented, we need a
different method of manipulating them.  Use the
KVM_SET_ONE_REG/KVM_GET_ONE_REG mechanism.

Now unused code and definitions are removed.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-06-03 10:58:54 +03:00
David Daney 48c4ac976a Revert "MIPS: Allow ASID size to be determined at boot time."
This reverts commit d532f3d267.

The original commit has several problems:

1) Doesn't work with 64-bit kernels.

2) Calls TLBMISS_HANDLER_SETUP() before the code is generated.

3) Calls TLBMISS_HANDLER_SETUP() twice in per_cpu_trap_init() when
   only one call is needed.

[ralf@linux-mips.org: Also revert the bits of the ASID patch which were
hidden in the KVM merge.]

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: "Steven J. Hill" <Steven.Hill@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/5242/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-16 20:35:42 +02:00
Ralf Baechle b22d1b6a91 Merge branch 'mti-next' of git://git.linux-mips.org/pub/scm/sjhill/linux-sjhill into mips-for-linux-next 2013-05-09 17:57:30 +02:00
Sanjay Lal 740765ce45 KVM/MIPS32: Arch specific KVM data structures.
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:34 +02:00