linux-toradex.git/arch/mips/kvm/mips.c, branch v4.2.7

MIPS: KVM: Uninit VCPU in vcpu_create error path

2015-12-09T19:31:10+00:00

commit 585bb8f9a5e592f2ce7abbe5ed3112d5438d2754 upstream.

If either of the memory allocations in kvm_arch_vcpu_create() fail, the
vcpu which has been allocated and kvm_vcpu_init'd doesn't get uninit'd
in the error handling path. Add a call to kvm_vcpu_uninit() to fix this.

Fixes: 669e846e6c4e ("KVM/MIPS32: MIPS arch specific APIs for KVM")
Signed-off-by: James Hogan 
Cc: Ralf Baechle 
Cc: Paolo Bonzini 
Cc: Gleb Natapov 
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: add "new" argument to kvm_arch_commit_memory_region

2015-05-28T08:42:58+00:00

This lets the function access the new memory slot without going through
kvm_memslots and id_to_memslot.  It will simplify the code when more
than one address space will be supported.

Unfortunately, the "const"ness of the new argument must be casted
away in two places.  Fixing KVM to accept const struct kvm_memory_slot
pointers would require modifications in pretty much all architectures,
and is left for later.

Reviewed-by: Radim Krcmar 
Signed-off-by: Paolo Bonzini

KVM: const-ify uses of struct kvm_userspace_memory_region

2015-05-26T10:40:13+00:00

Architecture-specific helpers are not supposed to muck with
struct kvm_userspace_memory_region contents.  Add const to
enforce this.

In order to eliminate the only write in __kvm_set_memory_region,
the cleaning of deleted slots is pulled up from update_memslots
to __kvm_set_memory_region.

Reviewed-by: Takuya Yoshikawa 
Reviewed-by: Radim Krcmar 
Signed-off-by: Paolo Bonzini

KVM: use kvm_memslots whenever possible

2015-05-26T10:40:08+00:00

kvm_memslots provides lockdep checking.  Use it consistently instead of
explicit dereferencing of kvm->memslots.

Reviewed-by: Radim Krcmar 
Signed-off-by: Paolo Bonzini

KVM: mips: use id_to_memslot correctly

2015-05-19T18:52:44+00:00

The argument to KVM_GET_DIRTY_LOG is a memslot id; it may not match the
position in the memslots array, which is sorted by gfn.

Cc: stable@vger.kernel.org
Reviewed-by: James Hogan 
Signed-off-by: Paolo Bonzini

KVM: arm/mips/x86/power use __kvm_guest_{enter|exit}

2015-05-07T09:28:22+00:00

Use __kvm_guest_{enter|exit} instead of kvm_guest_{enter|exit}
where interrupts are disabled.

Signed-off-by: Christian Borntraeger 
Signed-off-by: Paolo Bonzini

MIPS: KVM: Wire up MSA capability

2015-03-27T21:25:22+00:00

Now that the code is in place for KVM to support MIPS SIMD Architecutre
(MSA) in MIPS guests, wire up the new KVM_CAP_MIPS_MSA capability.

For backwards compatibility, the capability must be explicitly enabled
in order to detect or make use of MSA from the guest.

The capability is not supported if the hardware supports MSA vector
partitioning, since the extra support cannot be tested yet and it
extends the state that the userland program would have to save.

Signed-off-by: James Hogan 
Acked-by: Paolo Bonzini 
Cc: Ralf Baechle 
Cc: Gleb Natapov 
Cc: Jonathan Corbet 
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: linux-api@vger.kernel.org
Cc: linux-doc@vger.kernel.org

MIPS: KVM: Expose MSA registers

2015-03-27T21:25:21+00:00

Add KVM register numbers for the MIPS SIMD Architecture (MSA) registers,
and implement access to them with the KVM_GET_ONE_REG / KVM_SET_ONE_REG
ioctls when the MSA capability is enabled (exposed in a later patch) and
present in the guest according to its Config3.MSAP bit.

The MSA vector registers use the same register numbers as the FPU
registers except with a different size (128bits). Since MSA depends on
Status.FR=1, these registers are inaccessible when Status.FR=0. These
registers are returned as a single native endian 128bit value, rather
than least significant half first with each 64-bit half native endian as
the kernel uses internally.

Signed-off-by: James Hogan 
Cc: Paolo Bonzini 
Cc: Paul Burton 
Cc: Ralf Baechle 
Cc: Gleb Natapov 
Cc: Jonathan Corbet 
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: linux-api@vger.kernel.org
Cc: linux-doc@vger.kernel.org

MIPS: KVM: Add MSA exception handling

2015-03-27T21:25:20+00:00

Add guest exception handling for MIPS SIMD Architecture (MSA) floating
point exceptions and MSA disabled exceptions.

MSA floating point exceptions from the guest need passing to the guest
kernel, so for these a guest MSAFPE is emulated.

MSA disabled exceptions are normally handled by passing a reserved
instruction exception to the guest (because no guest MSA was supported),
but the hypervisor can now handle them if the guest has MSA by passing
an MSA disabled exception to the guest, or if the guest has MSA enabled
by transparently restoring the guest MSA context and enabling MSA and
the FPU.

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

MIPS: KVM: Add base guest MSA support

2015-03-27T21:25:19+00:00

Add base code for supporting the MIPS SIMD Architecture (MSA) in MIPS
KVM guests. MSA cannot yet be enabled in the guest, we're just laying
the groundwork.

As with the FPU, whether the guest's MSA context is loaded is stored in
another bit in the fpu_inuse vcpu member. This allows MSA to be disabled
when the guest disables it, but keeping the MSA context loaded so it
doesn't have to be reloaded if the guest re-enables it.

New assembly code is added for saving and restoring the MSA context,
restoring only the upper half of the MSA context (for if the FPU context
is already loaded) and for saving/clearing and restoring MSACSR (which
can itself cause an MSA FP exception depending on the value). The MSACSR
is restored before returning to the guest if MSA is already enabled, and
the existing FP exception die notifier is extended to catch the possible
MSA FP exception and step over the ctcmsa instruction.

The helper function kvm_own_msa() is added to enable MSA and restore
the MSA context if it isn't already loaded, which will be used in a
later patch when the guest attempts to use MSA for the first time and
triggers an MSA disabled exception.

The existing FPU helpers are extended to handle MSA. kvm_lose_fpu()
saves the full MSA context if it is loaded (which includes the FPU
context) and both kvm_lose_fpu() and kvm_drop_fpu() disable MSA.

kvm_own_fpu() also needs to lose any MSA context if FR=0, since there
would be a risk of getting reserved instruction exceptions if CU1 is
enabled and we later try and save the MSA context. We shouldn't usually
hit this case since it will be handled when emulating CU1 changes,
however there's nothing to stop the guest modifying the Status register
directly via the comm page, which will cause this case to get hit.

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