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), 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 +#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