On Tue, Mar 29, 2022 at 3:24 AM Mayuresh Chitale <mchit...@ventanamicro.com> wrote: > > 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 <mchit...@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 | 21 ++++ > 5 files changed, 273 insertions(+) > > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c > index 3aa2ef5cce..dc5472834d 100644 > --- a/target/riscv/cpu.c > +++ b/target/riscv/cpu.c > @@ -788,6 +788,7 @@ static Property riscv_cpu_properties[] = { > DEFINE_PROP_BOOL("Zve64f", RISCVCPU, cfg.ext_zve64f, false), > DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true), > DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true), > + DEFINE_PROP_BOOL("smstateen", RISCVCPU, cfg.ext_smstateen, true),
I'm not convinced this should be enabled by default. Does OpenSBI and other M-mode firmware currently handle support enabling this? Also, if you do think it should be enabled by default, it should be enabled in a separate patch at the end of the series. The idea is to add the feature first, then enable it. > > DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec), > DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec), > @@ -929,6 +930,7 @@ static void riscv_isa_string_ext(RISCVCPU *cpu, char > **isa_str, int max_str_len) > ISA_EDATA_ENTRY(zhinxmin, ext_zhinxmin), > ISA_EDATA_ENTRY(zve32f, ext_zve32f), > ISA_EDATA_ENTRY(zve64f, ext_zve64f), > + 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 c9956513bc..4a3b5a6c23 100644 > --- a/target/riscv/cpu.h > +++ b/target/riscv/cpu.h > @@ -307,6 +307,9 @@ struct CPUArchState { > > /* 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 > @@ -378,6 +381,7 @@ struct RISCVCPUConfig { > bool ext_zhinxmin; > bool ext_zve32f; > bool ext_zve64f; > + 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 bb47cf7e77..b2b0bcb929 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 > @@ -254,6 +260,16 @@ > #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 > @@ -301,6 +317,26 @@ > #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 Should this be 1? Alistair > +#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 2c0319ad12..e3dafc37ef 100644 > --- a/target/riscv/csr.c > +++ b/target/riscv/csr.c > @@ -245,6 +245,42 @@ 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) > { > @@ -1493,6 +1529,129 @@ 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) > +{ > + *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] >> 32; > + > + return RISCV_EXCP_NONE; > +} > + > +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]; > + 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] >> 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; > + > + 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) > @@ -3268,6 +3427,57 @@ 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 }, > + [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 243f567949..40e146c578 100644 > --- a/target/riscv/machine.c > +++ b/target/riscv/machine.c > @@ -231,6 +231,26 @@ 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; > @@ -315,6 +335,7 @@ const VMStateDescription vmstate_riscv_cpu = { > &vmstate_rv128, > &vmstate_kvmtimer, > &vmstate_envcfg, > + &vmstate_smstateen, > NULL > } > }; > -- > 2.17.1 > >