Commit 1c953ba5 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by David Gibson
Browse files

ppc: Fix hreg_store_msr() so that non-HV mode cannot alter MSR:HV 



This helper is only used by the various instructions that can alter
MSR and not interrupts. Add a comment to that effect to the interrupt
code as well in case somebody wants to change this

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
parent 932ccbdd

target-ppc/excp_helper.c

+6 −2
Original line number Diff line number Diff line
@@ -709,8 +709,12 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp) 
        }

    }

#endif

    /* XXX: we don't use hreg_store_msr here as already have treated

    /* We don't use hreg_store_msr here as already have treated

     * any special case that could occur. Just store MSR and update hflags

     *

     * Note: We *MUST* not use hreg_store_msr() as-is anyway because it

     * will prevent setting of the HV bit which some exceptions might need

     * to do.

     */

    env->msr = new_msr & env->msr_mask;

    hreg_compute_hflags(env);

target-ppc/helper_regs.h

+2 −2
Original line number Diff line number Diff line
@@ -114,8 +114,8 @@ static inline int hreg_store_msr(CPUPPCState *env, target_ulong value, 
    excp = 0;

    value &= env->msr_mask;

#if !defined(CONFIG_USER_ONLY)

    if (!alter_hv) {

        /* mtmsr cannot alter the hypervisor state */

    /* Neither mtmsr nor guest state can alter HV */

    if (!alter_hv || !(env->msr & MSR_HVB)) {

        value &= ~MSR_HVB;

        value |= env->msr & MSR_HVB;

    }