Re: [Qemu-devel] [PATCH v1 05/10] target-arm: Add VTTBR_EL2

["Edgar E. Iglesias" <edgar.iglesias@xilinx.com>]

On Tue, Sep 08, 2015 at 03:27:05PM +0100, Peter Maydell wrote:
> On 3 September 2015 at 21:14, Edgar E. Iglesias
> <edgar.iglesias@gmail.com> wrote:
> > From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>
> >
> > Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
> > ---
> >  target-arm/cpu.h    |  1 +
> >  target-arm/helper.c | 34 ++++++++++++++++++++++++++++++++--
> >  2 files changed, 33 insertions(+), 2 deletions(-)
> >
> > diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> > index ba22e12..0ebdaf7 100644
> > --- a/target-arm/cpu.h
> > +++ b/target-arm/cpu.h
> > @@ -221,6 +221,7 @@ typedef struct CPUARMState {
> >              };
> >              uint64_t ttbr1_el[4];
> >          };
> > +        uint64_t vttbr_el2; /* Virtualization Translation Table Base.  */
> >          /* MMU translation table base control. */
> >          TCR tcr_el[4];
> >          TCR vtcr_el2; /* Virtualization Translation Control.  */
> > diff --git a/target-arm/helper.c b/target-arm/helper.c
> > index c82aa1d..ec19e68 100644
> > --- a/target-arm/helper.c
> > +++ b/target-arm/helper.c
> > @@ -2200,6 +2200,19 @@ static void vmsa_ttbr_write(CPUARMState *env, const ARMCPRegInfo *ri,
> >      raw_write(env, ri, value);
> >  }
> >
> > +static void vttbr_write(CPUARMState *env, const ARMCPRegInfo *ri,
> > +                        uint64_t value)
> > +{
> > +    ARMCPU *cpu = arm_env_get_cpu(env);
> > +    CPUState *cs = CPU(cpu);
> > +
> > +    if (raw_read(env, ri) != value) {
> > +        tlb_flush_by_mmuidx(cs, ARMMMUIdx_S12NSE1, ARMMMUIdx_S12NSE0,
> > +                            ARMMMUIdx_S2NS, -1);
> 
> We only need the TLB flush because this could change the VMID and
> our TLB doesn't handle VMIDs, right? That could use a comment
> (compare the remark about ASIDs in vmsa_ttbr_write()).

Yes, will add a comment.


> 
> > +        raw_write(env, ri, value);
> > +    }
> > +}
> > +
> >  static const ARMCPRegInfo vmsa_pmsa_cp_reginfo[] = {
> >      { .name = "DFSR", .cp = 15, .crn = 5, .crm = 0, .opc1 = 0, .opc2 = 0,
> >        .access = PL1_RW, .type = ARM_CP_ALIAS,
> > @@ -3131,6 +3144,14 @@ static const ARMCPRegInfo el3_no_el2_cp_reginfo[] = {
> >        .opc0 = 3, .opc1 = 4, .crn = 2, .crm = 1, .opc2 = 2,
> >        .access = PL2_RW, .accessfn = access_el3_aa32ns_aa64any,
> >        .readfn = arm_cp_read_zero, .writefn = arm_cp_write_ignore },
> > +    { .name = "VTTBR", .state = ARM_CP_STATE_AA32, .type = ARM_CP_64BIT,
> > +      .cp = 15, .opc1 = 6, .crm = 2,
> > +      .access = PL2_RW, .accessfn = access_el3_aa32ns_aa64any,
> > +      .readfn = arm_cp_read_zero, .writefn = arm_cp_write_ignore },
> > +    { .name = "VTTBR_EL2", .state = ARM_CP_STATE_AA64,
> > +      .opc0 = 3, .opc1 = 4, .crn = 2, .crm = 1, .opc2 = 0,
> > +      .access = PL2_RW, .accessfn = access_el3_aa32ns_aa64any,
> > +      .readfn = arm_cp_read_zero, .writefn = arm_cp_write_ignore },
> 
> RAZ/WI registers not using ARM_CP_CONST again...

Thanks, will fix!

Cheers,
Edgar




> 
> >      { .name = "SCTLR_EL2", .state = ARM_CP_STATE_BOTH,
> >        .opc0 = 3, .opc1 = 4, .crn = 1, .crm = 0, .opc2 = 0,
> >        .access = PL2_RW, .type = ARM_CP_CONST, .resetvalue = 0 },
> > @@ -3271,6 +3292,16 @@ static const ARMCPRegInfo el2_cp_reginfo[] = {
> >        .writefn = vmsa_tcr_el1_write,
> >        .resetfn = vmsa_ttbcr_reset, .raw_writefn = raw_write,
> >        .fieldoffset = offsetof(CPUARMState, cp15.vtcr_el2) },
> > +    { .name = "VTTBR", .state = ARM_CP_STATE_AA32, .type = ARM_CP_64BIT,
> > +      .cp = 15, .opc1 = 6, .crm = 2,
> > +      .access = PL2_RW, .accessfn = access_el3_aa32ns_aa64any,
> > +      .fieldoffset = offsetof(CPUARMState, cp15.vttbr_el2),
> > +      .writefn = vttbr_write },
> > +    { .name = "VTTBR_EL2", .state = ARM_CP_STATE_AA64,
> > +      .opc0 = 3, .opc1 = 4, .crn = 2, .crm = 1, .opc2 = 0,
> > +      .access = PL2_RW, .accessfn = access_el3_aa32ns_aa64any,
> > +      .fieldoffset = offsetof(CPUARMState, cp15.vttbr_el2),
> > +      .writefn = vttbr_write },
> >      { .name = "SCTLR_EL2", .state = ARM_CP_STATE_BOTH,
> >        .opc0 = 3, .opc1 = 4, .crn = 1, .crm = 0, .opc2 = 0,
> >        .access = PL2_RW, .raw_writefn = raw_write, .writefn = sctlr_write,
> > @@ -5770,8 +5801,7 @@ static inline uint64_t regime_ttbr(CPUARMState *env, ARMMMUIdx mmu_idx,
> >                                     int ttbrn)
> >  {
> >      if (mmu_idx == ARMMMUIdx_S2NS) {
> > -        /* TODO: return VTTBR_EL2 */
> > -        g_assert_not_reached();
> > +        return env->cp15.vttbr_el2;
> >      }
> >      if (ttbrn == 0) {
> >          return env->cp15.ttbr0_el[regime_el(env, mmu_idx)];
> > --
> > 1.9.1
> >
> 
> thanks
> -- PMM