Re: [Qemu-devel] [PATCH v2 2/4] kvm: ppc: booke206: use MMU API

[Alexander Graf]

On 18.08.2011, at 22:38, Scott Wood wrote:

> Share the TLB array with KVM.  This allows us to set the initial TLB
> both on initial boot and reset, is useful for debugging, and could
> eventually be used to support migration.
> 
> Signed-off-by: Scott Wood <address@hidden>
> ---
> v2 (was 1/3 in v1):
> updated for kernel API change, removed kernel header ifdefs,
> minor changes as requested
> 
> hw/ppce500_mpc8544ds.c |    2 +
> target-ppc/cpu.h       |    2 +
> target-ppc/kvm.c       |   87 ++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 91 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/ppce500_mpc8544ds.c b/hw/ppce500_mpc8544ds.c
> index b739ce2..3626e26 100644
> --- a/hw/ppce500_mpc8544ds.c
> +++ b/hw/ppce500_mpc8544ds.c
> @@ -202,6 +202,8 @@ static void mmubooke_create_initial_mapping(CPUState *env,
>     tlb->mas2 = va & TARGET_PAGE_MASK;
>     tlb->mas7_3 = pa & TARGET_PAGE_MASK;
>     tlb->mas7_3 |= MAS3_UR | MAS3_UW | MAS3_UX | MAS3_SR | MAS3_SW | MAS3_SX;
> +
> +    env->tlb_dirty = true;
> }
> 
> static void mpc8544ds_cpu_reset(void *opaque)
> diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
> index 024eb6f..0e38d4f 100644
> --- a/target-ppc/cpu.h
> +++ b/target-ppc/cpu.h
> @@ -919,6 +919,8 @@ struct CPUPPCState {
>     ppc_tlb_t tlb;   /* TLB is optional. Allocate them only if needed        
> */
>     /* 403 dedicated access protection registers */
>     target_ulong pb[4];
> +    bool tlb_dirty;   /* Set to non-zero when modifying TLB                  
> */
> +    bool kvm_sw_tlb;  /* non-zero if KVM SW TLB API is active                
> */
> #endif
> 
>     /* Other registers */
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index 21f35af7..1e1e5db 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -105,6 +105,54 @@ static int kvm_arch_sync_sregs(CPUState *cenv)
>     return kvm_vcpu_ioctl(cenv, KVM_SET_SREGS, &sregs);
> }
> 
> +/* Set up a shared TLB array with KVM */
> +static int kvm_booke206_tlb_init(CPUState *env)
> +{
> +    struct kvm_book3e_206_tlb_params params = {};
> +    struct kvm_config_tlb cfg = {};
> +    struct kvm_enable_cap encap = {};
> +    size_t array_len;
> +    unsigned int entries = 0;
> +    int ret, i;
> +
> +    if (!kvm_enabled() ||
> +        !kvm_check_extension(env->kvm_state, KVM_CAP_SW_TLB)) {
> +        return 0;
> +    }
> +
> +    assert(ARRAY_SIZE(params.tlb_sizes) == BOOKE206_MAX_TLBN);
> +
> +    for (i = 0; i < BOOKE206_MAX_TLBN; i++) {
> +        params.tlb_sizes[i] = booke206_tlb_size(env, i);
> +        params.tlb_ways[i] = booke206_tlb_ways(env, i);
> +        entries += params.tlb_sizes[i];
> +    }
> +
> +    assert(entries == env->nb_tlb);
> +    assert(sizeof(struct kvm_book3e_206_tlb_entry) == sizeof(ppcmas_tlb_t));
> +
> +    array_len = sizeof(ppcmas_tlb_t) * entries;

/dev/shm/qemu/target-ppc/kvm.c: In function 'kvm_booke206_tlb_init':
/dev/shm/qemu/target-ppc/kvm.c:121:12: warning: variable 'array_len' set but 
not used [-Wunused-but-set-variable]


Alex