diff mbox series

[v10,1/5] target/riscv: Add smstateen support

Message ID 20221003114718.30659-2-mchitale@ventanamicro.com
State New
Headers show
Series RISC-V Smstateen support | expand

Commit Message

Mayuresh Chitale Oct. 3, 2022, 11:47 a.m. UTC
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>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
---
 target/riscv/cpu.h      |   4 +
 target/riscv/cpu_bits.h |  37 +++++
 target/riscv/csr.c      | 316 ++++++++++++++++++++++++++++++++++++++++
 target/riscv/machine.c  |  21 +++
 4 files changed, 378 insertions(+)
diff mbox series

Patch

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index b131fa8c8e..e02e0bd7df 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -366,6 +366,9 @@  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
@@ -441,6 +444,7 @@  struct RISCVCPUConfig {
     bool ext_ifencei;
     bool ext_icsr;
     bool ext_zihintpause;
+    bool ext_smstateen;
     bool ext_sstc;
     bool ext_svinval;
     bool ext_svnapot;
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index d8f5f0abed..8b0d7e20ea 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -197,6 +197,12 @@ 
 /* 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
@@ -244,6 +250,16 @@ 
 #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
@@ -289,6 +305,27 @@ 
 #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       (1ULL << 0)
+#define SMSTATEEN0_FCSR     (1ULL << 1)
+#define SMSTATEEN0_HSCONTXT (1ULL << 57)
+#define SMSTATEEN0_IMSIC    (1ULL << 58)
+#define SMSTATEEN0_AIA      (1ULL << 59)
+#define SMSTATEEN0_SVSLCT   (1ULL << 60)
+#define SMSTATEEN0_HSENVCFG (1ULL << 62)
+#define SMSTATEEN_STATEEN   (1ULL << 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 5c9a7ee287..c861424e85 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -283,6 +283,72 @@  static RISCVException umode32(CPURISCVState *env, int csrno)
     return umode(env, 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_pred(CPURISCVState *env, int csrno, int base)
+{
+    CPUState *cs = env_cpu(env);
+    RISCVCPU *cpu = RISCV_CPU(cs);
+
+    if (!cpu->cfg.ext_smstateen) {
+        return RISCV_EXCP_ILLEGAL_INST;
+    }
+
+    if (env->priv < PRV_M) {
+        if (!(env->mstateen[csrno - base] & SMSTATEEN_STATEEN)) {
+            return RISCV_EXCP_ILLEGAL_INST;
+        }
+    }
+
+    return hmode(env, csrno);
+}
+
+static RISCVException hstateen(CPURISCVState *env, int csrno)
+{
+    return hstateen_pred(env, csrno, CSR_HSTATEEN0);
+}
+
+static RISCVException hstateenh(CPURISCVState *env, int csrno)
+{
+    return hstateen_pred(env, csrno, CSR_HSTATEEN0H);
+}
+
+static RISCVException sstateen(CPURISCVState *env, int csrno)
+{
+    bool virt = riscv_cpu_virt_enabled(env);
+    int index = csrno - CSR_SSTATEEN0;
+    CPUState *cs = env_cpu(env);
+    RISCVCPU *cpu = RISCV_CPU(cs);
+
+    if (!cpu->cfg.ext_smstateen) {
+        return RISCV_EXCP_ILLEGAL_INST;
+    }
+
+    if (env->priv < PRV_M) {
+        if (!(env->mstateen[index] & SMSTATEEN_STATEEN)) {
+            return RISCV_EXCP_ILLEGAL_INST;
+        }
+
+        if (virt) {
+            if (!(env->hstateen[index] & SMSTATEEN_STATEEN)) {
+                return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+            }
+        }
+    }
+
+    return smode(env, csrno);
+}
+
 /* Checks if PointerMasking registers could be accessed */
 static RISCVException pointer_masking(CPURISCVState *env, int csrno)
 {
@@ -1861,6 +1927,197 @@  static RISCVException write_henvcfgh(CPURISCVState *env, int csrno,
     return RISCV_EXCP_NONE;
 }
 
+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,
+                                     uint64_t wr_mask, target_ulong new_val)
+{
+    uint64_t *reg;
+
+    reg = &env->mstateen[csrno - CSR_MSTATEEN0];
+    *reg = (*reg & ~wr_mask) | (new_val & wr_mask);
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_mstateen0(CPURISCVState *env, int csrno,
+                                      target_ulong new_val)
+{
+    uint64_t wr_mask = SMSTATEEN_STATEEN;
+
+    return write_mstateen(env, csrno, wr_mask, new_val);
+}
+
+static RISCVException write_mstateen_1_3(CPURISCVState *env, int csrno,
+                                      target_ulong new_val)
+{
+    return write_mstateen(env, csrno, SMSTATEEN_STATEEN, new_val);
+}
+
+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,
+                                      uint64_t wr_mask, target_ulong new_val)
+{
+    uint64_t *reg, val;
+
+    reg = &env->mstateen[csrno - CSR_MSTATEEN0H];
+    val = (uint64_t)new_val << 32;
+    val |= *reg & 0xFFFFFFFF;
+    *reg = (*reg & ~wr_mask) | (val & wr_mask);
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_mstateen0h(CPURISCVState *env, int csrno,
+                                      target_ulong new_val)
+{
+    uint64_t wr_mask = SMSTATEEN_STATEEN;
+
+    return write_mstateenh(env, csrno, wr_mask, new_val);
+}
+
+static RISCVException write_mstateenh_1_3(CPURISCVState *env, int csrno,
+                                      target_ulong new_val)
+{
+    return write_mstateenh(env, csrno, SMSTATEEN_STATEEN, new_val);
+}
+
+static RISCVException read_hstateen(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
+{
+    int index = csrno - CSR_HSTATEEN0;
+
+    *val = env->hstateen[index] & env->mstateen[index];
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_hstateen(CPURISCVState *env, int csrno,
+                                     uint64_t mask, target_ulong new_val)
+{
+    int index = csrno - CSR_HSTATEEN0;
+    uint64_t *reg, wr_mask;
+
+    reg = &env->hstateen[index];
+    wr_mask = env->mstateen[index] & mask;
+    *reg = (*reg & ~wr_mask) | (new_val & wr_mask);
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_hstateen0(CPURISCVState *env, int csrno,
+                                      target_ulong new_val)
+{
+    uint64_t wr_mask = SMSTATEEN_STATEEN;
+
+    return write_hstateen(env, csrno, wr_mask, new_val);
+}
+
+static RISCVException write_hstateen_1_3(CPURISCVState *env, int csrno,
+                                      target_ulong new_val)
+{
+    return write_hstateen(env, csrno, SMSTATEEN_STATEEN, new_val);
+}
+
+static RISCVException read_hstateenh(CPURISCVState *env, int csrno,
+                                     target_ulong *val)
+{
+    int index = csrno - CSR_HSTATEEN0H;
+
+    *val = (env->hstateen[index] >> 32) & (env->mstateen[index] >> 32);
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_hstateenh(CPURISCVState *env, int csrno,
+                                      uint64_t mask, target_ulong new_val)
+{
+    int index = csrno - CSR_HSTATEEN0H;
+    uint64_t *reg, wr_mask, val;
+
+    reg = &env->hstateen[index];
+    val = (uint64_t)new_val << 32;
+    val |= *reg & 0xFFFFFFFF;
+    wr_mask = env->mstateen[index] & mask;
+    *reg = (*reg & ~wr_mask) | (val & wr_mask);
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_hstateen0h(CPURISCVState *env, int csrno,
+                                       target_ulong new_val)
+{
+    uint64_t wr_mask = SMSTATEEN_STATEEN;
+
+    return write_hstateenh(env, csrno, wr_mask, new_val);
+}
+
+static RISCVException write_hstateenh_1_3(CPURISCVState *env, int csrno,
+                                       target_ulong new_val)
+{
+    return write_hstateenh(env, csrno, SMSTATEEN_STATEEN, new_val);
+}
+
+static RISCVException read_sstateen(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
+{
+    bool virt = riscv_cpu_virt_enabled(env);
+    int index = csrno - CSR_SSTATEEN0;
+
+    *val = env->sstateen[index] & env->mstateen[index];
+    if (virt) {
+        *val &= env->hstateen[index];
+    }
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_sstateen(CPURISCVState *env, int csrno,
+                                     uint64_t mask, target_ulong new_val)
+{
+    bool virt = riscv_cpu_virt_enabled(env);
+    int index = csrno - CSR_SSTATEEN0;
+    uint64_t wr_mask;
+    uint64_t *reg;
+
+    wr_mask = env->mstateen[index] & mask;
+    if (virt) {
+        wr_mask &= env->hstateen[index];
+    }
+
+    reg = &env->sstateen[index];
+    *reg = (*reg & ~wr_mask) | (new_val & wr_mask);
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_sstateen0(CPURISCVState *env, int csrno,
+                                      target_ulong new_val)
+{
+    uint64_t wr_mask = SMSTATEEN_STATEEN;
+
+    return write_sstateen(env, csrno, wr_mask, new_val);
+}
+
+static RISCVException write_sstateen_1_3(CPURISCVState *env, int csrno,
+                                      target_ulong new_val)
+{
+    return write_sstateen(env, csrno, SMSTATEEN_STATEEN, new_val);
+}
+
 static RISCVException rmw_mip64(CPURISCVState *env, int csrno,
                                 uint64_t *ret_val,
                                 uint64_t new_val, uint64_t wr_mask)
@@ -3744,6 +4001,65 @@  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_mstateen0,
+                        .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_MSTATEEN0H] = { "mstateen0h", mstateen, read_mstateenh,
+                          write_mstateen0h,
+                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_MSTATEEN1] = { "mstateen1", mstateen, read_mstateen,
+                        write_mstateen_1_3,
+                        .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_MSTATEEN1H] = { "mstateen1h", mstateen, read_mstateenh,
+                         write_mstateenh_1_3,
+                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_MSTATEEN2] = { "mstateen2", mstateen, read_mstateen,
+                        write_mstateen_1_3,
+                        .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_MSTATEEN2H] = { "mstateen2h", mstateen, read_mstateenh,
+                         write_mstateenh_1_3,
+                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_MSTATEEN3] = { "mstateen3", mstateen, read_mstateen,
+                        write_mstateen_1_3,
+                        .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_MSTATEEN3H] = { "mstateen3h", mstateen, read_mstateenh,
+                         write_mstateenh_1_3,
+                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HSTATEEN0] = { "hstateen0", hstateen, read_hstateen, write_hstateen0,
+                        .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HSTATEEN0H] = { "hstateen0h", hstateenh, read_hstateenh,
+                         write_hstateen0h,
+                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HSTATEEN1] = { "hstateen1", hstateen, read_hstateen,
+                        write_hstateen_1_3,
+                        .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HSTATEEN1H] = { "hstateen1h", hstateenh, read_hstateenh,
+                         write_hstateenh_1_3,
+                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HSTATEEN2] = { "hstateen2", hstateen, read_hstateen,
+                        write_hstateen_1_3,
+                        .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HSTATEEN2H] = { "hstateen2h", hstateenh, read_hstateenh,
+                         write_hstateenh_1_3,
+                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HSTATEEN3] = { "hstateen3", hstateen, read_hstateen,
+                        write_hstateen_1_3,
+                        .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HSTATEEN3H] = { "hstateen3h", hstateenh, read_hstateenh,
+                         write_hstateenh_1_3,
+                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_SSTATEEN0] = { "sstateen0", sstateen, read_sstateen, write_sstateen0,
+                        .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_SSTATEEN1] = { "sstateen1", sstateen, read_sstateen,
+                        write_sstateen_1_3,
+                        .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_SSTATEEN2] = { "sstateen2", sstateen, read_sstateen,
+                        write_sstateen_1_3,
+                        .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_SSTATEEN3] = { "sstateen3", sstateen, read_sstateen,
+                        write_sstateen_1_3,
+                        .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 c2a94a82b3..e687f9fce0 100644
--- a/target/riscv/machine.c
+++ b/target/riscv/machine.c
@@ -253,6 +253,26 @@  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;
@@ -364,6 +384,7 @@  const VMStateDescription vmstate_riscv_cpu = {
         &vmstate_kvmtimer,
         &vmstate_envcfg,
         &vmstate_debug,
+        &vmstate_smstateen,
         NULL
     }
 };