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Re: [RFC PATCH v2 1/4] target/riscv: Add smstateen support
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From: |
Mayuresh Chitale |
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Subject: |
Re: [RFC PATCH v2 1/4] target/riscv: Add smstateen support |
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Date: |
Thu, 24 Mar 2022 14:16:16 +0530 |
On Wed, Mar 23, 2022 at 6:31 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
>
>
> 在 2022/3/23 下午7:13, Mayuresh Chitale 写道:
> > Smstateen extension specifies a mechanism to close
> > the potential covert channels that could cause security issues.
> >
> > This patch adds the CSRs defined in the specification and
> > the corresponding predicates and read/write functions.
> >
> > Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
> > ---
> > target/riscv/cpu.c | 2 +
> > target/riscv/cpu.h | 4 +
> > target/riscv/cpu_bits.h | 36 +++++++
> > target/riscv/csr.c | 210 ++++++++++++++++++++++++++++++++++++++++
> > target/riscv/machine.c | 22 ++++-
> > 5 files changed, 273 insertions(+), 1 deletion(-)
> >
> > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> > index 8e338daf72..832602d91f 100644
> > --- a/target/riscv/cpu.c
> > +++ b/target/riscv/cpu.c
> > @@ -807,6 +807,7 @@ static Property riscv_cpu_properties[] = {
> > DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
> > DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),
> > DEFINE_PROP_BOOL("sstc", RISCVCPU, cfg.ext_sstc, true),
> > + DEFINE_PROP_BOOL("smstateen", RISCVCPU, cfg.ext_smstateen, true),
> >
> > DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
> > DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec),
> > @@ -970,6 +971,7 @@ static void riscv_isa_string_ext(RISCVCPU *cpu, char
> > **isa_str, int max_str_len)
> > ISA_EDATA_ENTRY(svinval, ext_svinval),
> > ISA_EDATA_ENTRY(svnapot, ext_svnapot),
> > ISA_EDATA_ENTRY(svpbmt, ext_svpbmt),
> > + ISA_EDATA_ENTRY(smstateen, ext_smstateen),
> > };
> >
> > for (i = 0; i < ARRAY_SIZE(isa_edata_arr); i++) {
> > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> > index ea23666e8e..8e61edca6f 100644
> > --- a/target/riscv/cpu.h
> > +++ b/target/riscv/cpu.h
> > @@ -338,6 +338,9 @@ struct CPURISCVState {
> >
> > /* CSRs for execution enviornment configuration */
> > uint64_t menvcfg;
> > + uint64_t mstateen[SMSTATEEN_MAX_COUNT];
> > + uint64_t hstateen[SMSTATEEN_MAX_COUNT];
> > + uint64_t sstateen[SMSTATEEN_MAX_COUNT];
> > target_ulong senvcfg;
> > uint64_t henvcfg;
> > #endif
> > @@ -416,6 +419,7 @@ struct RISCVCPUConfig {
> > bool ext_zve32f;
> > bool ext_zve64f;
> > bool ext_sscofpmf;
> > + bool ext_smstateen;
> >
> > /* Vendor-specific custom extensions */
> > bool ext_XVentanaCondOps;
> > diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> > index 7454f4087f..66edb26686 100644
> > --- a/target/riscv/cpu_bits.h
> > +++ b/target/riscv/cpu_bits.h
> > @@ -205,6 +205,12 @@
> > /* Supervisor Configuration CSRs */
> > #define CSR_SENVCFG 0x10A
> >
> > +/* Supervisor state CSRs */
> > +#define CSR_SSTATEEN0 0x10C
> > +#define CSR_SSTATEEN1 0x10D
> > +#define CSR_SSTATEEN2 0x10E
> > +#define CSR_SSTATEEN3 0x10F
> > +
> > /* Supervisor Trap Handling */
> > #define CSR_SSCRATCH 0x140
> > #define CSR_SEPC 0x141
> > @@ -258,6 +264,16 @@
> > #define CSR_HENVCFG 0x60A
> > #define CSR_HENVCFGH 0x61A
> >
> > +/* Hypervisor state CSRs */
> > +#define CSR_HSTATEEN0 0x60C
> > +#define CSR_HSTATEEN0H 0x61C
> > +#define CSR_HSTATEEN1 0x60D
> > +#define CSR_HSTATEEN1H 0x61D
> > +#define CSR_HSTATEEN2 0x60E
> > +#define CSR_HSTATEEN2H 0x61E
> > +#define CSR_HSTATEEN3 0x60F
> > +#define CSR_HSTATEEN3H 0x61F
> > +
> > /* Virtual CSRs */
> > #define CSR_VSSTATUS 0x200
> > #define CSR_VSIE 0x204
> > @@ -309,6 +325,26 @@
> > #define CSR_MENVCFG 0x30A
> > #define CSR_MENVCFGH 0x31A
> >
> > +/* Machine state CSRs */
> > +#define CSR_MSTATEEN0 0x30C
> > +#define CSR_MSTATEEN0H 0x31C
> > +#define CSR_MSTATEEN1 0x30D
> > +#define CSR_MSTATEEN1H 0x31D
> > +#define CSR_MSTATEEN2 0x30E
> > +#define CSR_MSTATEEN2H 0x31E
> > +#define CSR_MSTATEEN3 0x30F
> > +#define CSR_MSTATEEN3H 0x31F
> > +
> > +/* Common defines for all smstateen */
> > +#define SMSTATEEN_MAX_COUNT 4
> > +#define SMSTATEEN0_CS 0
> > +#define SMSTATEEN0_FCSR 0
> > +#define SMSTATEEN0_IMSIC 58
> > +#define SMSTATEEN0_AIA 59
> > +#define SMSTATEEN0_SVSLCT 60
> > +#define SMSTATEEN0_HSENVCFG 62
> > +#define SMSTATEEN_STATEN 63
> > +
> > /* Enhanced Physical Memory Protection (ePMP) */
> > #define CSR_MSECCFG 0x747
> > #define CSR_MSECCFGH 0x757
> > diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> > index d3d16d71de..215c8ecef1 100644
> > --- a/target/riscv/csr.c
> > +++ b/target/riscv/csr.c
> > @@ -265,6 +265,42 @@ static RISCVException hmode32(CPURISCVState *env, int
> > csrno)
> >
> > }
> >
> > +static RISCVException mstateen(CPURISCVState *env, int csrno)
> > +{
> > + CPUState *cs = env_cpu(env);
> > + RISCVCPU *cpu = RISCV_CPU(cs);
> > +
> > + if (!cpu->cfg.ext_smstateen) {
> > + return RISCV_EXCP_ILLEGAL_INST;
> > + }
> > +
> > + return any(env, csrno);
> > +}
> > +
> > +static RISCVException hstateen(CPURISCVState *env, int csrno)
> > +{
> > + CPUState *cs = env_cpu(env);
> > + RISCVCPU *cpu = RISCV_CPU(cs);
> > +
> > + if (!cpu->cfg.ext_smstateen) {
> > + return RISCV_EXCP_ILLEGAL_INST;
> > + }
> > +
> > + return hmode(env, csrno);
> > +}
> > +
> > +static RISCVException sstateen(CPURISCVState *env, int csrno)
> > +{
> > + CPUState *cs = env_cpu(env);
> > + RISCVCPU *cpu = RISCV_CPU(cs);
> > +
> > + if (!cpu->cfg.ext_smstateen) {
> > + return RISCV_EXCP_ILLEGAL_INST;
> > + }
> > +
> > + return smode(env, csrno);
> > +}
> > +
> > /* Checks if PointerMasking registers could be accessed */
> > static RISCVException pointer_masking(CPURISCVState *env, int csrno)
> > {
> > @@ -1882,6 +1918,129 @@ static RISCVException write_henvcfgh(CPURISCVState
> > *env, int csrno,
> > return RISCV_EXCP_NONE;
> > }
> >
> > +static inline void write_smstateen(CPURISCVState *env, uint64_t *reg,
> > + uint64_t wr_mask, uint64_t new_val)
>
> It's better that 'uint64_t' is aligned with 'CPURISCVState' here. The
> same to following similar cases.
Ok. Will fix it in the next version.
>
> > +{
> > + *reg = (*reg & ~wr_mask) | (new_val & wr_mask);
> > +}
> > +
> > +static RISCVException read_mstateen(CPURISCVState *env, int csrno,
> > + target_ulong *val)
> > +{
> > + *val = env->mstateen[csrno - CSR_MSTATEEN0];
> > +
> > + return RISCV_EXCP_NONE;
> > +}
> > +
> > +static RISCVException write_mstateen(CPURISCVState *env, int csrno,
> > + target_ulong new_val)
> > +{
> > + uint64_t *reg;
> > + uint64_t wr_mask = 1UL << SMSTATEEN_STATEN;
> > +
> > + reg = &env->mstateen[csrno - CSR_MSTATEEN0];
> > + write_smstateen(env, reg, wr_mask, new_val);
> > +
> > + return RISCV_EXCP_NONE;
> > +}
> > +
> > +static RISCVException read_mstateenh(CPURISCVState *env, int csrno,
> > + target_ulong *val)
> > +{
> > + *val = env->mstateen[csrno - CSR_MSTATEEN0H - 0x10] >> 32;
> > +
> > + return RISCV_EXCP_NONE;
> > +}
>
> Why minus 0x10 here?
>
> when read CSR_MSTATEEN0H, the csrno should be CSR_MSTATEEN0H, and the
> expected result is mstateen[0] >> 32.
>
> So, minus 0x10 seems unnecessary.
>
> The same to following similar cases.
Correct. I will fix in the next version.
>
> > +
> > +static RISCVException write_mstateenh(CPURISCVState *env, int csrno,
> > + target_ulong new_val)
> > +{
> > + uint64_t *reg;
> > + uint64_t val;
> > + uint64_t wr_mask = 1UL << SMSTATEEN_STATEN;
> > +
> > + reg = &env->mstateen[csrno - CSR_MSTATEEN0H - 0x10];
> > + val = (uint64_t)new_val << 32;
> > + val |= *reg & 0xFFFFFFFF;
> > + write_smstateen(env, reg, wr_mask, val);
> > +
> > + return RISCV_EXCP_NONE;
> > +}
> > +
> > +static RISCVException read_hstateen(CPURISCVState *env, int csrno,
> > + target_ulong *val)
> > +{
> > + *val = env->hstateen[csrno - CSR_HSTATEEN0];
> > +
> > + return RISCV_EXCP_NONE;
> > +}
> > +
> > +static RISCVException write_hstateen(CPURISCVState *env, int csrno,
> > + target_ulong new_val)
> > +{
> > + uint64_t *reg;
> > + uint64_t wr_mask = 1UL << SMSTATEEN_STATEN;
> > + int index = csrno - CSR_HSTATEEN0;
> > +
> > + reg = &env->hstateen[index];
> > + wr_mask &= env->mstateen[index];
> > + write_smstateen(env, reg, wr_mask, new_val);
> > +
> > + return RISCV_EXCP_NONE;
> > +}
> > +
> > +static RISCVException read_hstateenh(CPURISCVState *env, int csrno,
> > + target_ulong *val)
> > +{
> > + *val = env->hstateen[csrno - CSR_HSTATEEN0H - 0x10] >> 32;
> > +
> > + return RISCV_EXCP_NONE;
> > +}
> > +
> > +static RISCVException write_hstateenh(CPURISCVState *env, int csrno,
> > + target_ulong new_val)
> > +{
> > + uint64_t *reg;
> > + uint64_t val;
> > + uint64_t wr_mask = 1UL << SMSTATEEN_STATEN;
> > + int index = csrno - CSR_HSTATEEN0H - 0x10;
> > +
> > + reg = &env->hstateen[index];
> > + val = (uint64_t)new_val << 32;
> > + val |= *reg & 0xFFFFFFFF;
> > + wr_mask &= env->mstateen[index];
> > +
> > + write_smstateen(env, reg, wr_mask, val);
> > + return RISCV_EXCP_NONE;
> > +}
> > +
> > +static RISCVException read_sstateen(CPURISCVState *env, int csrno,
> > + target_ulong *val)
> > +{
> > + *val = env->sstateen[csrno - CSR_SSTATEEN0];
> > +
> > + return RISCV_EXCP_NONE;
> > +}
> > +
> > +static RISCVException write_sstateen(CPURISCVState *env, int csrno,
> > + target_ulong new_val)
> > +{
> > + uint64_t *reg;
> > + uint64_t wr_mask = 0;
> > + int index = csrno - CSR_SSTATEEN0;
> > + bool virt = riscv_cpu_virt_enabled(env);
> > +
> > + reg = &env->sstateen[index];
> > + if (virt) {
> > + wr_mask &= env->mstateen[index];
> > + } else {
> > + wr_mask &= env->hstateen[index];
> > + }
> > + write_smstateen(env, reg, wr_mask, new_val);
> > +
> > + return RISCV_EXCP_NONE;
> > +}
> > +
> > static RISCVException rmw_mip64(CPURISCVState *env, int csrno,
> > uint64_t *ret_val,
> > uint64_t new_val, uint64_t wr_mask)
> > @@ -3664,6 +3823,57 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
> > [CSR_HENVCFGH] = { "henvcfgh", hmode32, read_henvcfgh, write_henvcfgh,
> > .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> >
> > + /* Smstateen extension CSRs */
> > + [CSR_MSTATEEN0] = { "mstateen0", mstateen, read_mstateen,
> > write_mstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_MSTATEEN0H] = { "mstateen0h", mstateen, read_mstateenh,
> > + write_mstateenh,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
>
> It' better to aligned with CSR_MSTATEEN0 here.
>
> Regards,
>
> Weiwei Li
>
> > + [CSR_MSTATEEN1] = { "mstateen1", mstateen, read_mstateen,
> > write_mstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_MSTATEEN1H] = { "mstateen1h", mstateen, read_mstateenh,
> > + write_mstateenh,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_MSTATEEN2] = { "mstateen2", mstateen, read_mstateen,
> > write_mstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_MSTATEEN2H] = { "mstateen2h", mstateen, read_mstateenh,
> > + write_mstateenh,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_MSTATEEN3] = { "mstateen3", mstateen, read_mstateen,
> > write_mstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_MSTATEEN3H] = { "mstateen3h", mstateen, read_mstateenh,
> > + write_mstateenh,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > +
> > + [CSR_HSTATEEN0] = { "hstateen0", hstateen, read_hstateen,
> > write_hstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_HSTATEEN0H] = { "hstateen0h", hstateen, read_hstateenh,
> > + write_hstateenh,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_HSTATEEN1] = { "hstateen1", hstateen, read_hstateen,
> > write_hstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_HSTATEEN1H] = { "hstateen1h", hstateen, read_hstateenh,
> > + write_hstateenh,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_HSTATEEN2] = { "hstateen2", hstateen, read_hstateen,
> > write_hstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_HSTATEEN2H] = { "hstateen2h", hstateen, read_hstateenh,
> > + write_hstateenh,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_HSTATEEN3] = { "hstateen3", hstateen, read_hstateen,
> > write_hstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_HSTATEEN3H] = { "hstateen3h", hstateen, read_hstateenh,
> > + write_hstateenh,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > +
> > + [CSR_SSTATEEN0] = { "sstateen0", sstateen, read_sstateen,
> > write_sstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_SSTATEEN1] = { "sstateen1", sstateen, read_sstateen,
> > write_sstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_SSTATEEN2] = { "sstateen2", sstateen, read_sstateen,
> > write_sstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > + [CSR_SSTATEEN3] = { "sstateen3", sstateen, read_sstateen,
> > write_sstateen,
> > + .min_priv_ver =
> > PRIV_VERSION_1_12_0 },
> > /* Supervisor Trap Setup */
> > [CSR_SSTATUS] = { "sstatus", smode, read_sstatus,
> > write_sstatus, NULL,
> > read_sstatus_i128
> > },
> > diff --git a/target/riscv/machine.c b/target/riscv/machine.c
> > index aa968dc29c..e376f82ca0 100644
> > --- a/target/riscv/machine.c
> > +++ b/target/riscv/machine.c
> > @@ -232,6 +232,26 @@ static int riscv_cpu_post_load(void *opaque, int
> > version_id)
> > return 0;
> > }
> >
> > +static bool smstateen_needed(void *opaque)
> > +{
> > + RISCVCPU *cpu = opaque;
> > +
> > + return cpu->cfg.ext_smstateen;
> > +}
> > +
> > +static const VMStateDescription vmstate_smstateen = {
> > + .name = "cpu/smtateen",
> > + .version_id = 1,
> > + .minimum_version_id = 1,
> > + .needed = smstateen_needed,
> > + .fields = (VMStateField[]) {
> > + VMSTATE_UINT64_ARRAY(env.mstateen, RISCVCPU, 4),
> > + VMSTATE_UINT64_ARRAY(env.hstateen, RISCVCPU, 4),
> > + VMSTATE_UINT64_ARRAY(env.sstateen, RISCVCPU, 4),
> > + VMSTATE_END_OF_LIST()
> > + }
> > +};
> > +
> > static bool envcfg_needed(void *opaque)
> > {
> > RISCVCPU *cpu = opaque;
> > @@ -331,7 +351,6 @@ const VMStateDescription vmstate_riscv_cpu = {
> > VMSTATE_UINT64(env.mtohost, RISCVCPU),
> > VMSTATE_UINT64(env.mtimecmp, RISCVCPU),
> > VMSTATE_UINT64(env.stimecmp, RISCVCPU),
> > -
> > VMSTATE_END_OF_LIST()
> > },
> > .subsections = (const VMStateDescription * []) {
> > @@ -342,6 +361,7 @@ const VMStateDescription vmstate_riscv_cpu = {
> > &vmstate_rv128,
> > &vmstate_kvmtimer,
> > &vmstate_envcfg,
> > + &vmstate_smstateen,
> > NULL
> > }
> > };
>