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Re: [PATCH v1 15/36] target/riscv: Convert mstatus to pointers
From: |
Alistair Francis |
Subject: |
Re: [PATCH v1 15/36] target/riscv: Convert mstatus to pointers |
Date: |
Fri, 31 Jan 2020 09:31:30 -0800 |
On Thu, Jan 30, 2020 at 6:48 AM Palmer Dabbelt <address@hidden> wrote:
>
> On Tue, 21 Jan 2020 11:02:01 GMT (+0000), address@hidden wrote:
> > On Wed, Jan 8, 2020 at 11:30 AM Palmer Dabbelt <address@hidden> wrote:
> >>
> >> On Mon, 09 Dec 2019 10:11:19 PST (-0800), Alistair Francis wrote:
> >> > To handle the new Hypervisor CSR register aliasing let's use pointers.
> >>
> >> For some reason I thought we were making this explicit? In other words,
> >> requiring that all callers provide which privilege mode they're using when
> >> accessing these CSRs, as opposed to swapping around pointers. I don't
> >> actually
> >> care that much, but IIRC when we were talking with the ARM guys at Plumbers
> >> they were pretty adament that would end up being a much cleaner
> >> implementation
> >> as they'd tried this way and later changed over.
> >
> > I think their implementation is different so it doesn't apply the same here.
> >
> > My main concern is that due to the modularity of RISC-V I don't expect
> > all future developers to keep track of the Hypervisor extensions. This
> > way we always have the correct state in the registers.
> >
> > There is only one pointer variable left, so we could drop the pointer
> > swapping part, but for now it's still here.
>
> OK, so in the interest of moving things forwards let's just
>
> Reviewed-by: Palmer Dabbelt <address@hidden>
Thanks
>
> so we can merge this -- it's too big of a patch set to wait around on
> something
> so small for. I think that was the last one missing a review, right?
I have made one small change and dismissed your review from a patch,
it also looks like one patch hasn't been reviewed either.
I'll send a v2 later today that has been rebased on master.
Alistair
>
> >
> > Alistair
> >
> >>
> >> > Signed-off-by: Alistair Francis <address@hidden>
> >> > ---
> >> > target/riscv/cpu.c | 11 +++++++++--
> >> > target/riscv/cpu.h | 9 ++++++++-
> >> > target/riscv/cpu_helper.c | 30 +++++++++++++++---------------
> >> > target/riscv/csr.c | 20 ++++++++++----------
> >> > target/riscv/op_helper.c | 14 +++++++-------
> >> > 5 files changed, 49 insertions(+), 35 deletions(-)
> >> >
> >> > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> >> > index a07c5689b3..e61cf46a73 100644
> >> > --- a/target/riscv/cpu.c
> >> > +++ b/target/riscv/cpu.c
> >> > @@ -236,7 +236,7 @@ static void riscv_cpu_dump_state(CPUState *cs, FILE
> >> > *f, int flags)
> >> > qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "pc ", env->pc);
> >> > #ifndef CONFIG_USER_ONLY
> >> > qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mhartid ",
> >> > env->mhartid);
> >> > - qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ",
> >> > env->mstatus);
> >> > + qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ",
> >> > *env->mstatus);
> >> > if (riscv_has_ext(env, RVH)) {
> >> > qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "hstatus ",
> >> > env->hstatus);
> >> > qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "vsstatus ",
> >> > env->vsstatus);
> >> > @@ -336,7 +336,7 @@ static void riscv_cpu_reset(CPUState *cs)
> >> > mcc->parent_reset(cs);
> >> > #ifndef CONFIG_USER_ONLY
> >> > env->priv = PRV_M;
> >> > - env->mstatus &= ~(MSTATUS_MIE | MSTATUS_MPRV);
> >> > + *env->mstatus &= ~(MSTATUS_MIE | MSTATUS_MPRV);
> >> > env->mcause = 0;
> >> > env->pc = env->resetvec;
> >> > #endif
> >> > @@ -465,8 +465,15 @@ static void riscv_cpu_realize(DeviceState *dev,
> >> > Error **errp)
> >> > static void riscv_cpu_init(Object *obj)
> >> > {
> >> > RISCVCPU *cpu = RISCV_CPU(obj);
> >> > +#ifndef CONFIG_USER_ONLY
> >> > + CPURISCVState *env = &cpu->env;
> >> > +#endif
> >> >
> >> > cpu_set_cpustate_pointers(cpu);
> >> > +
> >> > +#ifndef CONFIG_USER_ONLY
> >> > + env->mstatus = &env->mstatus_novirt;
> >> > +#endif
> >> > }
> >> >
> >> > static const VMStateDescription vmstate_riscv_cpu = {
> >> > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> >> > index 21ae5a8b19..9dc8303c62 100644
> >> > --- a/target/riscv/cpu.h
> >> > +++ b/target/riscv/cpu.h
> >> > @@ -122,7 +122,7 @@ struct CPURISCVState {
> >> > target_ulong resetvec;
> >> >
> >> > target_ulong mhartid;
> >> > - target_ulong mstatus;
> >> > + target_ulong *mstatus;
> >> >
> >> > target_ulong mip;
> >> > uint32_t miclaim;
> >> > @@ -145,6 +145,13 @@ struct CPURISCVState {
> >> > target_ulong mcause;
> >> > target_ulong mtval; /* since: priv-1.10.0 */
> >> >
> >> > + /* The following registers are the "real" versions that the pointer
> >> > + * versions point to. These should never be used unless you know
> >> > what you
> >> > + * are doing. To access these use the pointer versions instead.
> >> > This is
> >> > + * required to handle the Hypervisor register swapping.
> >> > + */
> >> > + target_ulong mstatus_novirt;
> >> > +
> >> > /* Hypervisor CSRs */
> >> > target_ulong hstatus;
> >> > target_ulong hedeleg;
> >> > diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> >> > index b00f66824a..9684da7f7d 100644
> >> > --- a/target/riscv/cpu_helper.c
> >> > +++ b/target/riscv/cpu_helper.c
> >> > @@ -37,8 +37,8 @@ int riscv_cpu_mmu_index(CPURISCVState *env, bool
> >> > ifetch)
> >> > #ifndef CONFIG_USER_ONLY
> >> > static int riscv_cpu_local_irq_pending(CPURISCVState *env)
> >> > {
> >> > - target_ulong mstatus_mie = get_field(env->mstatus, MSTATUS_MIE);
> >> > - target_ulong mstatus_sie = get_field(env->mstatus, MSTATUS_SIE);
> >> > + target_ulong mstatus_mie = get_field(*env->mstatus, MSTATUS_MIE);
> >> > + target_ulong mstatus_sie = get_field(*env->mstatus, MSTATUS_SIE);
> >> > target_ulong pending = env->mip & env->mie;
> >> > target_ulong mie = env->priv < PRV_M || (env->priv == PRV_M &&
> >> > mstatus_mie);
> >> > target_ulong sie = env->priv < PRV_S || (env->priv == PRV_S &&
> >> > mstatus_sie);
> >> > @@ -75,7 +75,7 @@ bool riscv_cpu_exec_interrupt(CPUState *cs, int
> >> > interrupt_request)
> >> > /* Return true is floating point support is currently enabled */
> >> > bool riscv_cpu_fp_enabled(CPURISCVState *env)
> >> > {
> >> > - if (env->mstatus & MSTATUS_FS) {
> >> > + if (*env->mstatus & MSTATUS_FS) {
> >> > return true;
> >> > }
> >> >
> >> > @@ -198,8 +198,8 @@ static int get_physical_address(CPURISCVState *env,
> >> > hwaddr *physical,
> >> > int mode = mmu_idx;
> >> >
> >> > if (mode == PRV_M && access_type != MMU_INST_FETCH) {
> >> > - if (get_field(env->mstatus, MSTATUS_MPRV)) {
> >> > - mode = get_field(env->mstatus, MSTATUS_MPP);
> >> > + if (get_field(*env->mstatus, MSTATUS_MPRV)) {
> >> > + mode = get_field(*env->mstatus, MSTATUS_MPP);
> >> > }
> >> > }
> >> >
> >> > @@ -213,11 +213,11 @@ static int get_physical_address(CPURISCVState
> >> > *env, hwaddr *physical,
> >> >
> >> > hwaddr base;
> >> > int levels, ptidxbits, ptesize, vm, sum;
> >> > - int mxr = get_field(env->mstatus, MSTATUS_MXR);
> >> > + int mxr = get_field(*env->mstatus, MSTATUS_MXR);
> >> >
> >> > if (env->priv_ver >= PRIV_VERSION_1_10_0) {
> >> > base = (hwaddr)get_field(env->satp, SATP_PPN) << PGSHIFT;
> >> > - sum = get_field(env->mstatus, MSTATUS_SUM);
> >> > + sum = get_field(*env->mstatus, MSTATUS_SUM);
> >> > vm = get_field(env->satp, SATP_MODE);
> >> > switch (vm) {
> >> > case VM_1_10_SV32:
> >> > @@ -237,8 +237,8 @@ static int get_physical_address(CPURISCVState *env,
> >> > hwaddr *physical,
> >> > }
> >> > } else {
> >> > base = (hwaddr)(env->sptbr) << PGSHIFT;
> >> > - sum = !get_field(env->mstatus, MSTATUS_PUM);
> >> > - vm = get_field(env->mstatus, MSTATUS_VM);
> >> > + sum = !get_field(*env->mstatus, MSTATUS_PUM);
> >> > + vm = get_field(*env->mstatus, MSTATUS_VM);
> >> > switch (vm) {
> >> > case VM_1_09_SV32:
> >> > levels = 2; ptidxbits = 10; ptesize = 4; break;
> >> > @@ -492,8 +492,8 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address,
> >> > int size,
> >> > ret = get_physical_address(env, &pa, &prot, address, access_type,
> >> > mmu_idx);
> >> >
> >> > if (mode == PRV_M && access_type != MMU_INST_FETCH) {
> >> > - if (get_field(env->mstatus, MSTATUS_MPRV)) {
> >> > - mode = get_field(env->mstatus, MSTATUS_MPP);
> >> > + if (get_field(*env->mstatus, MSTATUS_MPRV)) {
> >> > + mode = get_field(*env->mstatus, MSTATUS_MPP);
> >> > }
> >> > }
> >> >
> >> > @@ -599,12 +599,12 @@ void riscv_cpu_do_interrupt(CPUState *cs)
> >> > if (env->priv <= PRV_S &&
> >> > cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
> >> > /* handle the trap in S-mode */
> >> > - target_ulong s = env->mstatus;
> >> > + target_ulong s = *env->mstatus;
> >> > s = set_field(s, MSTATUS_SPIE, env->priv_ver >=
> >> > PRIV_VERSION_1_10_0 ?
> >> > get_field(s, MSTATUS_SIE) : get_field(s, MSTATUS_UIE <<
> >> > env->priv));
> >> > s = set_field(s, MSTATUS_SPP, env->priv);
> >> > s = set_field(s, MSTATUS_SIE, 0);
> >> > - env->mstatus = s;
> >> > + *env->mstatus = s;
> >> > env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS
> >> > - 1));
> >> > env->sepc = env->pc;
> >> > env->sbadaddr = tval;
> >> > @@ -613,12 +613,12 @@ void riscv_cpu_do_interrupt(CPUState *cs)
> >> > riscv_cpu_set_mode(env, PRV_S);
> >> > } else {
> >> > /* handle the trap in M-mode */
> >> > - target_ulong s = env->mstatus;
> >> > + target_ulong s = *env->mstatus;
> >> > s = set_field(s, MSTATUS_MPIE, env->priv_ver >=
> >> > PRIV_VERSION_1_10_0 ?
> >> > get_field(s, MSTATUS_MIE) : get_field(s, MSTATUS_UIE <<
> >> > env->priv));
> >> > s = set_field(s, MSTATUS_MPP, env->priv);
> >> > s = set_field(s, MSTATUS_MIE, 0);
> >> > - env->mstatus = s;
> >> > + *env->mstatus = s;
> >> > env->mcause = cause | ~(((target_ulong)-1) >> async);
> >> > env->mepc = env->pc;
> >> > env->mbadaddr = tval;
> >> > diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> >> > index 74e911af08..a4b598d49a 100644
> >> > --- a/target/riscv/csr.c
> >> > +++ b/target/riscv/csr.c
> >> > @@ -136,7 +136,7 @@ static int write_fflags(CPURISCVState *env, int
> >> > csrno, target_ulong val)
> >> > if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
> >> > return -1;
> >> > }
> >> > - env->mstatus |= MSTATUS_FS;
> >> > + *env->mstatus |= MSTATUS_FS;
> >> > #endif
> >> > riscv_cpu_set_fflags(env, val & (FSR_AEXC >> FSR_AEXC_SHIFT));
> >> > return 0;
> >> > @@ -159,7 +159,7 @@ static int write_frm(CPURISCVState *env, int csrno,
> >> > target_ulong val)
> >> > if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
> >> > return -1;
> >> > }
> >> > - env->mstatus |= MSTATUS_FS;
> >> > + *env->mstatus |= MSTATUS_FS;
> >> > #endif
> >> > env->frm = val & (FSR_RD >> FSR_RD_SHIFT);
> >> > return 0;
> >> > @@ -183,7 +183,7 @@ static int write_fcsr(CPURISCVState *env, int csrno,
> >> > target_ulong val)
> >> > if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
> >> > return -1;
> >> > }
> >> > - env->mstatus |= MSTATUS_FS;
> >> > + *env->mstatus |= MSTATUS_FS;
> >> > #endif
> >> > env->frm = (val & FSR_RD) >> FSR_RD_SHIFT;
> >> > riscv_cpu_set_fflags(env, (val & FSR_AEXC) >> FSR_AEXC_SHIFT);
> >> > @@ -313,7 +313,7 @@ static int read_mhartid(CPURISCVState *env, int
> >> > csrno, target_ulong *val)
> >> > /* Machine Trap Setup */
> >> > static int read_mstatus(CPURISCVState *env, int csrno, target_ulong
> >> > *val)
> >> > {
> >> > - *val = env->mstatus;
> >> > + *val = *env->mstatus;
> >> > return 0;
> >> > }
> >> >
> >> > @@ -325,7 +325,7 @@ static int validate_vm(CPURISCVState *env,
> >> > target_ulong vm)
> >> >
> >> > static int write_mstatus(CPURISCVState *env, int csrno, target_ulong
> >> > val)
> >> > {
> >> > - target_ulong mstatus = env->mstatus;
> >> > + target_ulong mstatus = *env->mstatus;
> >> > target_ulong mask = 0;
> >> > int dirty;
> >> >
> >> > @@ -365,7 +365,7 @@ static int write_mstatus(CPURISCVState *env, int
> >> > csrno, target_ulong val)
> >> > ((mstatus & MSTATUS_FS) == MSTATUS_FS)) |
> >> > ((mstatus & MSTATUS_XS) == MSTATUS_XS);
> >> > mstatus = set_field(mstatus, MSTATUS_SD, dirty);
> >> > - env->mstatus = mstatus;
> >> > + *env->mstatus = mstatus;
> >> >
> >> > return 0;
> >> > }
> >> > @@ -614,7 +614,7 @@ static int read_sstatus(CPURISCVState *env, int
> >> > csrno, target_ulong *val)
> >> > {
> >> > target_ulong mask = ((env->priv_ver >= PRIV_VERSION_1_10_0) ?
> >> > sstatus_v1_10_mask : sstatus_v1_9_mask);
> >> > - *val = env->mstatus & mask;
> >> > + *val = *env->mstatus & mask;
> >> > return 0;
> >> > }
> >> >
> >> > @@ -622,7 +622,7 @@ static int write_sstatus(CPURISCVState *env, int
> >> > csrno, target_ulong val)
> >> > {
> >> > target_ulong mask = ((env->priv_ver >= PRIV_VERSION_1_10_0) ?
> >> > sstatus_v1_10_mask : sstatus_v1_9_mask);
> >> > - target_ulong newval = (env->mstatus & ~mask) | (val & mask);
> >> > + target_ulong newval = (*env->mstatus & ~mask) | (val & mask);
> >> > return write_mstatus(env, CSR_MSTATUS, newval);
> >> > }
> >> >
> >> > @@ -737,7 +737,7 @@ static int read_satp(CPURISCVState *env, int csrno,
> >> > target_ulong *val)
> >> > if (!riscv_feature(env, RISCV_FEATURE_MMU)) {
> >> > *val = 0;
> >> > } else if (env->priv_ver >= PRIV_VERSION_1_10_0) {
> >> > - if (env->priv == PRV_S && get_field(env->mstatus, MSTATUS_TVM))
> >> > {
> >> > + if (env->priv == PRV_S && get_field(*env->mstatus,
> >> > MSTATUS_TVM)) {
> >> > return -1;
> >> > } else {
> >> > *val = env->satp;
> >> > @@ -762,7 +762,7 @@ static int write_satp(CPURISCVState *env, int csrno,
> >> > target_ulong val)
> >> > validate_vm(env, get_field(val, SATP_MODE)) &&
> >> > ((val ^ env->satp) & (SATP_MODE | SATP_ASID | SATP_PPN)))
> >> > {
> >> > - if (env->priv == PRV_S && get_field(env->mstatus, MSTATUS_TVM))
> >> > {
> >> > + if (env->priv == PRV_S && get_field(*env->mstatus,
> >> > MSTATUS_TVM)) {
> >> > return -1;
> >> > } else {
> >> > if((val ^ env->satp) & SATP_ASID) {
> >> > diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
> >> > index 331cc36232..d150551bc9 100644
> >> > --- a/target/riscv/op_helper.c
> >> > +++ b/target/riscv/op_helper.c
> >> > @@ -83,11 +83,11 @@ target_ulong helper_sret(CPURISCVState *env,
> >> > target_ulong cpu_pc_deb)
> >> > }
> >> >
> >> > if (env->priv_ver >= PRIV_VERSION_1_10_0 &&
> >> > - get_field(env->mstatus, MSTATUS_TSR)) {
> >> > + get_field(*env->mstatus, MSTATUS_TSR)) {
> >> > riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
> >> > }
> >> >
> >> > - target_ulong mstatus = env->mstatus;
> >> > + target_ulong mstatus = *env->mstatus;
> >> > target_ulong prev_priv = get_field(mstatus, MSTATUS_SPP);
> >> > mstatus = set_field(mstatus,
> >> > env->priv_ver >= PRIV_VERSION_1_10_0 ?
> >> > @@ -96,7 +96,7 @@ target_ulong helper_sret(CPURISCVState *env,
> >> > target_ulong cpu_pc_deb)
> >> > mstatus = set_field(mstatus, MSTATUS_SPIE, 0);
> >> > mstatus = set_field(mstatus, MSTATUS_SPP, PRV_U);
> >> > riscv_cpu_set_mode(env, prev_priv);
> >> > - env->mstatus = mstatus;
> >> > + *env->mstatus = mstatus;
> >> >
> >> > return retpc;
> >> > }
> >> > @@ -112,7 +112,7 @@ target_ulong helper_mret(CPURISCVState *env,
> >> > target_ulong cpu_pc_deb)
> >> > riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC());
> >> > }
> >> >
> >> > - target_ulong mstatus = env->mstatus;
> >> > + target_ulong mstatus = *env->mstatus;
> >> > target_ulong prev_priv = get_field(mstatus, MSTATUS_MPP);
> >> > mstatus = set_field(mstatus,
> >> > env->priv_ver >= PRIV_VERSION_1_10_0 ?
> >> > @@ -121,7 +121,7 @@ target_ulong helper_mret(CPURISCVState *env,
> >> > target_ulong cpu_pc_deb)
> >> > mstatus = set_field(mstatus, MSTATUS_MPIE, 0);
> >> > mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
> >> > riscv_cpu_set_mode(env, prev_priv);
> >> > - env->mstatus = mstatus;
> >> > + *env->mstatus = mstatus;
> >> >
> >> > return retpc;
> >> > }
> >> > @@ -132,7 +132,7 @@ void helper_wfi(CPURISCVState *env)
> >> >
> >> > if (env->priv == PRV_S &&
> >> > env->priv_ver >= PRIV_VERSION_1_10_0 &&
> >> > - get_field(env->mstatus, MSTATUS_TW)) {
> >> > + get_field(*env->mstatus, MSTATUS_TW)) {
> >> > riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
> >> > } else {
> >> > cs->halted = 1;
> >> > @@ -147,7 +147,7 @@ void helper_tlb_flush(CPURISCVState *env)
> >> > if (!(env->priv >= PRV_S) ||
> >> > (env->priv == PRV_S &&
> >> > env->priv_ver >= PRIV_VERSION_1_10_0 &&
> >> > - get_field(env->mstatus, MSTATUS_TVM))) {
> >> > + get_field(*env->mstatus, MSTATUS_TVM))) {
> >> > riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
> >> > } else {
> >> > tlb_flush(cs);