arm: KVM: Allow unaligned accesses at HYP

commit 33b5c38852b29736f3b472dd095c9a18ec22746f upstream.

We currently have the HSCTLR.A bit set, trapping unaligned accesses
at HYP, but we're not really prepared to deal with it.

Since the rest of the kernel is pretty happy about that, let's follow
its example and set HSCTLR.A to zero. Modern CPUs don't really care.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S
index ee4f7447a1d35c320b0f03280114f0876c4a1805..622a30a3563abdb78fed36e3f23923fec5ad6bb1 100644 (file)
--- a/arch/arm/kvm/init.S
+++ b/arch/arm/kvm/init.S
@@ -109,7 +109,6 @@ __do_hyp_init:
        @  - Write permission implies XN: disabled
        @  - Instruction cache: enabled
        @  - Data/Unified cache: enabled
-       @  - Memory alignment checks: enabled
        @  - MMU: enabled (this code must be run from an identity mapping)
        mrc     p15, 4, r0, c1, c0, 0   @ HSCR
        ldr     r2, =HSCTLR_MASK
@@ -117,8 +116,8 @@ __do_hyp_init:
        mrc     p15, 0, r1, c1, c0, 0   @ SCTLR
        ldr     r2, =(HSCTLR_EE | HSCTLR_FI | HSCTLR_I | HSCTLR_C)
        and     r1, r1, r2
- ARM(  ldr     r2, =(HSCTLR_M | HSCTLR_A)                      )
- THUMB(        ldr     r2, =(HSCTLR_M | HSCTLR_A | HSCTLR_TE)          )
+ ARM(  ldr     r2, =(HSCTLR_M)                                 )
+ THUMB(        ldr     r2, =(HSCTLR_M | HSCTLR_TE)                     )
        orr     r1, r1, r2
        orr     r0, r0, r1
        isb