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RISC-V Smstateen support

PATCH Applied Mayuresh Chitale 3 participants 14 messages Oct 16, 2022 – Mar 28, 2023 RISC-V

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#0 lore raw

v11 cover RISC-V Smstateen support

This series adds support for the Smstateen specification which provides a mechanism to plug the potential covert channels which are opened by extensions that add to processor state that may not get context-switched. Currently access to *envcfg registers and floating point(fcsr) is controlled via smstateen.

These patches can also be found on riscv_smstateen_v11 branch at:
https://github.com/mdchitale/qemu.git

Changes in v11:
- Rebase to latest riscv-to-apply.next
- set virt_inst_excp at the begining of decode_opc
- Add reviewed by in patch 4

Changes in v10:
- Add support to generate virt instruction exception after decode failure. Use this change for smstateen fcsr failure when virt is enabled.
- Implement single write function for *smstateen1 to *smstateen3 registers.

Changes in v9:
- Rebase to latest riscv-to-apply.next
- Add reviewed by in patches 2 and 4

Changes in v8:
- Rebase to latest riscv-to-apply.next
- Fix m-mode check for hstateen
- Fix return exception type for VU mode
- Improve commit description for patch3

Changes in v7:
- Update smstateen check as per discussion on the following issue:
https://github.com/riscv/riscv-state-enable/issues/9
- Drop the smstateen AIA patch for now.
- Indentation and other fixes

Changes in v6:
- Sync with latest riscv-to-apply.next
- Make separate read/write ops for m/h/s/stateen1/2/3 regs
- Add check for mstateen.staten when reading or using h/s/stateen regs
- Add smstateen fcsr check for all floating point operations
- Move knobs to enable smstateen in a separate patch.

Changes in v5:
- Fix the order in which smstateen extension is added to the isa_edata_arr as
described in rule #3 the comment.

Changes in v4:
- Fix build issue with riscv32/riscv64-linux-user targets

Changes in v3:
- Fix coding style issues
- Fix *stateen0h index calculation

Changes in v2:
- Make h/s/envcfg bits in m/h/stateen registers as writeable by default.

Mayuresh Chitale (5):
target/riscv: Add smstateen support target/riscv: smstateen check for h/s/envcfg target/riscv: generate virtual instruction exception target/riscv: smstateen check for fcsr target/riscv: smstateen knobs

 target/riscv/cpu.c                        |   2 +
 target/riscv/cpu.h                        |   4 +
 target/riscv/cpu_bits.h                   |  37 ++
 target/riscv/csr.c                        | 414 +++++++++++++++++++++-
 target/riscv/insn_trans/trans_rvf.c.inc   |  43 ++-
 target/riscv/insn_trans/trans_rvzfh.c.inc |  12 +
 target/riscv/machine.c                    |  21 ++
 target/riscv/translate.c                  |   8 +-
 8 files changed, 536 insertions(+), 5 deletions(-)
Signature · 1 line
2.25.1
#1 lore raw

PATCH v11 1/5 target/riscv: Add smstateen support

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.

---
 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(+)
target/riscv/cpu.h +4 -0
index 3a9e25053f..040ed13675 100644
@@ -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;
target/riscv/cpu_bits.h +37 -0
index d8f5f0abed..8b0d7e20ea 100644
@@ -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
target/riscv/csr.c +316 -0

334 lines not on this page · raw message

target/riscv/machine.c +21 -0
index c2a94a82b3..e687f9fce0 100644
@@ -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
     }
 };
Signature · 1 line
2.25.1
Reviewed-by on v11 1/5
#2 lore raw

Re: [PATCH v11 1/5] target/riscv: Add smstateen support

Quoted 9 lines · Mayuresh Chitale

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.

Alistair

Quoted 475 lines
---
 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(+)
target/riscv/cpu.h +4 -0
index 3a9e25053f..040ed13675 100644
@@ -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;
target/riscv/cpu_bits.h +37 -0
index d8f5f0abed..8b0d7e20ea 100644
@@ -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
target/riscv/csr.c +316 -0
index 5c9a7ee287..c861424e85 100644
@@ -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               },
target/riscv/machine.c +21 -1
index c2a94a82b3..e687f9fce0 100644
@@ -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
     }
 };
--

2.25.1

#3 lore raw

PATCH v11 2/5 target/riscv: smstateen check for h/s/envcfg

In reply to Mayuresh Chitale

Accesses to henvcfg, henvcfgh and senvcfg are allowed only if the corresponding bit in mstateen0/hstateen0 is enabled. Otherwise an illegal instruction trap is generated.

---
 target/riscv/csr.c | 87 ++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 80 insertions(+), 7 deletions(-)
target/riscv/csr.c +80 -7
index c861424e85..71236f2b5d 100644
@@ -41,6 +41,42 @@ void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops)
 }
 
 /* Predicates */
+#if !defined(CONFIG_USER_ONLY)
+static RISCVException smstateen_acc_ok(CPURISCVState *env, int index,
+                                       uint64_t bit)
+{
+    bool virt = riscv_cpu_virt_enabled(env);
+    CPUState *cs = env_cpu(env);
+    RISCVCPU *cpu = RISCV_CPU(cs);
+
+    if (env->priv == PRV_M || !cpu->cfg.ext_smstateen) {
+        return RISCV_EXCP_NONE;
+    }
+
+    if (!(env->mstateen[index] & bit)) {
+        return RISCV_EXCP_ILLEGAL_INST;
+    }
+
+    if (virt) {
+        if (!(env->hstateen[index] & bit)) {
+            return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+        }
+
+        if (env->priv == PRV_U && !(env->sstateen[index] & bit)) {
+            return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+        }
+    }
+
+    if (env->priv == PRV_U && riscv_has_ext(env, RVS)) {
+        if (!(env->sstateen[index] & bit)) {
+            return RISCV_EXCP_ILLEGAL_INST;
+        }
+    }
+
+    return RISCV_EXCP_NONE;
+}
+#endif
+
 static RISCVException fs(CPURISCVState *env, int csrno)
 {
 #if !defined(CONFIG_USER_ONLY)
@@ -1874,6 +1910,13 @@ static RISCVException write_menvcfgh(CPURISCVState *env, int csrno,
 static RISCVException read_senvcfg(CPURISCVState *env, int csrno,
                                  target_ulong *val)
 {
+    RISCVException ret;
+
+    ret = smstateen_acc_ok(env, 0, SMSTATEEN0_HSENVCFG);
+    if (ret != RISCV_EXCP_NONE) {
+        return ret;
+    }
+
     *val = env->senvcfg;
     return RISCV_EXCP_NONE;
 }
@@ -1882,15 +1925,27 @@ static RISCVException write_senvcfg(CPURISCVState *env, int csrno,
                                   target_ulong val)
 {
     uint64_t mask = SENVCFG_FIOM | SENVCFG_CBIE | SENVCFG_CBCFE | SENVCFG_CBZE;
+    RISCVException ret;
 
-    env->senvcfg = (env->senvcfg & ~mask) | (val & mask);
+    ret = smstateen_acc_ok(env, 0, SMSTATEEN0_HSENVCFG);
+    if (ret != RISCV_EXCP_NONE) {
+        return ret;
+    }
 
+    env->senvcfg = (env->senvcfg & ~mask) | (val & mask);
     return RISCV_EXCP_NONE;
 }
 
 static RISCVException read_henvcfg(CPURISCVState *env, int csrno,
                                  target_ulong *val)
 {
+    RISCVException ret;
+
+    ret = smstateen_acc_ok(env, 0, SMSTATEEN0_HSENVCFG);
+    if (ret != RISCV_EXCP_NONE) {
+        return ret;
+    }
+
     *val = env->henvcfg;
     return RISCV_EXCP_NONE;
 }
@@ -1899,6 +1954,12 @@ static RISCVException write_henvcfg(CPURISCVState *env, int csrno,
                                   target_ulong val)
 {
     uint64_t mask = HENVCFG_FIOM | HENVCFG_CBIE | HENVCFG_CBCFE | HENVCFG_CBZE;
+    RISCVException ret;
+
+    ret = smstateen_acc_ok(env, 0, SMSTATEEN0_HSENVCFG);
+    if (ret != RISCV_EXCP_NONE) {
+        return ret;
+    }
 
     if (riscv_cpu_mxl(env) == MXL_RV64) {
         mask |= HENVCFG_PBMTE | HENVCFG_STCE;
@@ -1912,6 +1973,13 @@ static RISCVException write_henvcfg(CPURISCVState *env, int csrno,
 static RISCVException read_henvcfgh(CPURISCVState *env, int csrno,
                                  target_ulong *val)
 {
+    RISCVException ret;
+
+    ret = smstateen_acc_ok(env, 0, SMSTATEEN0_HSENVCFG);
+    if (ret != RISCV_EXCP_NONE) {
+        return ret;
+    }
+
     *val = env->henvcfg >> 32;
     return RISCV_EXCP_NONE;
 }
@@ -1921,9 +1989,14 @@ static RISCVException write_henvcfgh(CPURISCVState *env, int csrno,
 {
     uint64_t mask = HENVCFG_PBMTE | HENVCFG_STCE;
     uint64_t valh = (uint64_t)val << 32;
+    RISCVException ret;
 
-    env->henvcfg = (env->henvcfg & ~mask) | (valh & mask);
+    ret = smstateen_acc_ok(env, 0, SMSTATEEN0_HSENVCFG);
+    if (ret != RISCV_EXCP_NONE) {
+        return ret;
+    }
 
+    env->henvcfg = (env->henvcfg & ~mask) | (valh & mask);
     return RISCV_EXCP_NONE;
 }
 
@@ -1949,7 +2022,7 @@ static RISCVException write_mstateen(CPURISCVState *env, int csrno,
 static RISCVException write_mstateen0(CPURISCVState *env, int csrno,
                                       target_ulong new_val)
 {
-    uint64_t wr_mask = SMSTATEEN_STATEEN;
+    uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
     return write_mstateen(env, csrno, wr_mask, new_val);
 }
@@ -1984,7 +2057,7 @@ static RISCVException write_mstateenh(CPURISCVState *env, int csrno,
 static RISCVException write_mstateen0h(CPURISCVState *env, int csrno,
                                       target_ulong new_val)
 {
-    uint64_t wr_mask = SMSTATEEN_STATEEN;
+    uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
     return write_mstateenh(env, csrno, wr_mask, new_val);
 }
@@ -2021,7 +2094,7 @@ static RISCVException write_hstateen(CPURISCVState *env, int csrno,
 static RISCVException write_hstateen0(CPURISCVState *env, int csrno,
                                       target_ulong new_val)
 {
-    uint64_t wr_mask = SMSTATEEN_STATEEN;
+    uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
     return write_hstateen(env, csrno, wr_mask, new_val);
 }
@@ -2060,7 +2133,7 @@ static RISCVException write_hstateenh(CPURISCVState *env, int csrno,
 static RISCVException write_hstateen0h(CPURISCVState *env, int csrno,
                                        target_ulong new_val)
 {
-    uint64_t wr_mask = SMSTATEEN_STATEEN;
+    uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
     return write_hstateenh(env, csrno, wr_mask, new_val);
 }
@@ -2107,7 +2180,7 @@ static RISCVException write_sstateen(CPURISCVState *env, int csrno,
 static RISCVException write_sstateen0(CPURISCVState *env, int csrno,
                                       target_ulong new_val)
 {
-    uint64_t wr_mask = SMSTATEEN_STATEEN;
+    uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
     return write_sstateen(env, csrno, wr_mask, new_val);
 }
Signature · 1 line
2.25.1
#4 lore raw

PATCH v11 3/5 target/riscv: generate virtual instruction exception

In reply to Mayuresh Chitale

This patch adds a mechanism to generate a virtual instruction instruction exception instead of an illegal instruction exception during instruction decode when virt is enabled.

---
 target/riscv/translate.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
target/riscv/translate.c +7 -1
index db123da5ec..8b0bd38bb2 100644
@@ -76,6 +76,7 @@ typedef struct DisasContext {
        to reset this known value.  */
     int frm;
     RISCVMXL ol;
+    bool virt_inst_excp;
     bool virt_enabled;
     const RISCVCPUConfig *cfg_ptr;
     bool hlsx;
@@ -243,7 +244,11 @@ static void gen_exception_illegal(DisasContext *ctx)
 {
     tcg_gen_st_i32(tcg_constant_i32(ctx->opcode), cpu_env,
                    offsetof(CPURISCVState, bins));
-    generate_exception(ctx, RISCV_EXCP_ILLEGAL_INST);
+    if (ctx->virt_inst_excp) {
+        generate_exception(ctx, RISCV_EXCP_VIRT_INSTRUCTION_FAULT);
+    } else {
+        generate_exception(ctx, RISCV_EXCP_ILLEGAL_INST);
+    }
 }
 
 static void gen_exception_inst_addr_mis(DisasContext *ctx)
@@ -1062,6 +1067,7 @@ static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t opcode)
         { has_XVentanaCondOps_p,  decode_XVentanaCodeOps },
     };
 
+    ctx->virt_inst_excp = false;
     /* Check for compressed insn */
     if (insn_len(opcode) == 2) {
         if (!has_ext(ctx, RVC)) {
Signature · 1 line
2.25.1
Reviewed-by on v11 3/5
#5 lore raw

Re: [PATCH v11 3/5] target/riscv: generate virtual instruction exception

Quoted 35 lines · Mayuresh Chitale

This patch adds a mechanism to generate a virtual instruction instruction exception instead of an illegal instruction exception during instruction decode when virt is enabled.

---
  target/riscv/translate.c | 8 +++++++-
  1 file changed, 7 insertions(+), 1 deletion(-)
target/riscv/translate.c +6 -1
index db123da5ec..8b0bd38bb2 100644
@@ -76,6 +76,7 @@ typedef struct DisasContext {
         to reset this known value.  */
      int frm;
      RISCVMXL ol;
+    bool virt_inst_excp;
      bool virt_enabled;
      const RISCVCPUConfig *cfg_ptr;
      bool hlsx;
@@ -243,7 +244,11 @@ static void gen_exception_illegal(DisasContext *ctx)
  {
      tcg_gen_st_i32(tcg_constant_i32(ctx->opcode), cpu_env,
                     offsetof(CPURISCVState, bins));
-    generate_exception(ctx, RISCV_EXCP_ILLEGAL_INST);
+    if (ctx->virt_inst_excp) {
+        generate_exception(ctx, RISCV_EXCP_VIRT_INSTRUCTION_FAULT);
+    } else {
+        generate_exception(ctx, RISCV_EXCP_ILLEGAL_INST);
+    }
  }
 
  static void gen_exception_inst_addr_mis(DisasContext *ctx)

target/riscv/translate.c static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t opcode) · line 1073

Quoted 7 lines
target/riscv/translate.c +1 -0
@@ -1062,6 +1067,7 @@ static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t opcode)
          { has_XVentanaCondOps_p,  decode_XVentanaCodeOps },
      };
 
+    ctx->virt_inst_excp = false;
      /* Check for compressed insn */
      if (insn_len(opcode) == 2) {
          if (!has_ext(ctx, RVC)) {

Regards,
Weiwei Li

Reviewed-by on v11 3/5
#6 lore raw

Re: [PATCH v11 3/5] target/riscv: generate virtual instruction exception

In reply to Mayuresh Chitale
Quoted 6 lines · Mayuresh Chitale

This patch adds a mechanism to generate a virtual instruction instruction exception instead of an illegal instruction exception during instruction decode when virt is enabled.

Alistair

Quoted 41 lines
---
 target/riscv/translate.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
target/riscv/translate.c +7 -2
index db123da5ec..8b0bd38bb2 100644
@@ -76,6 +76,7 @@ typedef struct DisasContext {
        to reset this known value.  */
     int frm;
     RISCVMXL ol;
+    bool virt_inst_excp;
     bool virt_enabled;
     const RISCVCPUConfig *cfg_ptr;
     bool hlsx;
@@ -243,7 +244,11 @@ static void gen_exception_illegal(DisasContext *ctx)
 {
     tcg_gen_st_i32(tcg_constant_i32(ctx->opcode), cpu_env,
                    offsetof(CPURISCVState, bins));
-    generate_exception(ctx, RISCV_EXCP_ILLEGAL_INST);
+    if (ctx->virt_inst_excp) {
+        generate_exception(ctx, RISCV_EXCP_VIRT_INSTRUCTION_FAULT);
+    } else {
+        generate_exception(ctx, RISCV_EXCP_ILLEGAL_INST);
+    }
 }
 
 static void gen_exception_inst_addr_mis(DisasContext *ctx)
@@ -1062,6 +1067,7 @@ static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t opcode)
         { has_XVentanaCondOps_p,  decode_XVentanaCodeOps },
     };
 
+    ctx->virt_inst_excp = false;
     /* Check for compressed insn */
     if (insn_len(opcode) == 2) {
         if (!has_ext(ctx, RVC)) {
--

2.25.1

#7 lore raw

PATCH v11 4/5 target/riscv: smstateen check for fcsr

In reply to Mayuresh Chitale

If smstateen is implemented and sstateen0.fcsr is clear then the floating point operations must return illegal instruction exception or virtual instruction trap, if relevant.

---
 target/riscv/csr.c                        | 23 ++++++++++++
 target/riscv/insn_trans/trans_rvf.c.inc   | 43 +++++++++++++++++++++--
 target/riscv/insn_trans/trans_rvzfh.c.inc | 12 +++++++
 3 files changed, 75 insertions(+), 3 deletions(-)
target/riscv/csr.c +23 -0
index 71236f2b5d..8b25f885ec 100644
@@ -84,6 +84,10 @@ static RISCVException fs(CPURISCVState *env, int csrno)
         !RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
         return RISCV_EXCP_ILLEGAL_INST;
     }
+
+    if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
+        return smstateen_acc_ok(env, 0, SMSTATEEN0_FCSR);
+    }
 #endif
     return RISCV_EXCP_NONE;
 }
@@ -2023,6 +2027,9 @@ static RISCVException write_mstateen0(CPURISCVState *env, int csrno,
                                       target_ulong new_val)
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
 
     return write_mstateen(env, csrno, wr_mask, new_val);
 }
@@ -2059,6 +2066,10 @@ static RISCVException write_mstateen0h(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_mstateenh(env, csrno, wr_mask, new_val);
 }
 
@@ -2096,6 +2107,10 @@ static RISCVException write_hstateen0(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_hstateen(env, csrno, wr_mask, new_val);
 }
 
@@ -2135,6 +2150,10 @@ static RISCVException write_hstateen0h(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_hstateenh(env, csrno, wr_mask, new_val);
 }
 
@@ -2182,6 +2201,10 @@ static RISCVException write_sstateen0(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_sstateen(env, csrno, wr_mask, new_val);
 }
 
target/riscv/insn_trans/trans_rvf.c.inc +40 -3

49 lines not on this page · raw message

target/riscv/insn_trans/trans_rvzfh.c.inc +12 -0
index 5d07150cd0..6c2e338c0a 100644
@@ -20,18 +20,27 @@
     if (!ctx->cfg_ptr->ext_zfh) {      \
         return false;         \
     }                         \
+    if (!smstateen_fcsr_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZHINX_OR_ZFH(ctx) do { \
     if (!ctx->cfg_ptr->ext_zhinx && !ctx->cfg_ptr->ext_zfh) { \
         return false;                  \
     }                                  \
+    if (!smstateen_fcsr_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZFH_OR_ZFHMIN(ctx) do {       \
     if (!(ctx->cfg_ptr->ext_zfh || ctx->cfg_ptr->ext_zfhmin)) { \
         return false;                         \
     }                                         \
+    if (!smstateen_fcsr_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZFH_OR_ZFHMIN_OR_ZHINX_OR_ZHINXMIN(ctx) do { \
@@ -39,6 +48,9 @@
           ctx->cfg_ptr->ext_zhinx || ctx->cfg_ptr->ext_zhinxmin)) {     \
         return false;                                        \
     }                                                        \
+    if (!smstateen_fcsr_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 static bool trans_flh(DisasContext *ctx, arg_flh *a)
Signature · 1 line
2.25.1
Reviewed-by on v11 4/5
#8 lore raw

Re: [PATCH v11 4/5] target/riscv: smstateen check for fcsr

Quoted 7 lines · Mayuresh Chitale

If smstateen is implemented and sstateen0.fcsr is clear then the floating point operations must return illegal instruction exception or virtual instruction trap, if relevant.

Alistair

Quoted 175 lines
---
 target/riscv/csr.c                        | 23 ++++++++++++
 target/riscv/insn_trans/trans_rvf.c.inc   | 43 +++++++++++++++++++++--
 target/riscv/insn_trans/trans_rvzfh.c.inc | 12 +++++++
 3 files changed, 75 insertions(+), 3 deletions(-)
target/riscv/csr.c +23 -0
index 71236f2b5d..8b25f885ec 100644
@@ -84,6 +84,10 @@ static RISCVException fs(CPURISCVState *env, int csrno)
         !RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
         return RISCV_EXCP_ILLEGAL_INST;
     }
+
+    if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
+        return smstateen_acc_ok(env, 0, SMSTATEEN0_FCSR);
+    }
 #endif
     return RISCV_EXCP_NONE;
 }
@@ -2023,6 +2027,9 @@ static RISCVException write_mstateen0(CPURISCVState *env, int csrno,
                                       target_ulong new_val)
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
 
     return write_mstateen(env, csrno, wr_mask, new_val);
 }
@@ -2059,6 +2066,10 @@ static RISCVException write_mstateen0h(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_mstateenh(env, csrno, wr_mask, new_val);
 }
 
@@ -2096,6 +2107,10 @@ static RISCVException write_hstateen0(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_hstateen(env, csrno, wr_mask, new_val);
 }
 
@@ -2135,6 +2150,10 @@ static RISCVException write_hstateen0h(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_hstateenh(env, csrno, wr_mask, new_val);
 }
 
@@ -2182,6 +2201,10 @@ static RISCVException write_sstateen0(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_sstateen(env, csrno, wr_mask, new_val);
 }
 
target/riscv/insn_trans/trans_rvf.c.inc +40 -3
index a1d3eb52ad..93657680c6 100644
@@ -24,9 +24,46 @@
             return false; \
 } while (0)
 
-#define REQUIRE_ZFINX_OR_F(ctx) do {\
-    if (!ctx->cfg_ptr->ext_zfinx) { \
-        REQUIRE_EXT(ctx, RVF); \
+#ifndef CONFIG_USER_ONLY
+static inline bool smstateen_fcsr_check(DisasContext *ctx, int index)
+{
+    CPUState *cpu = ctx->cs;
+    CPURISCVState *env = cpu->env_ptr;
+    uint64_t stateen = env->mstateen[index];
+
+    if (!ctx->cfg_ptr->ext_smstateen || env->priv == PRV_M) {
+        return true;
+    }
+
+    if (ctx->virt_enabled) {
+        stateen &= env->hstateen[index];
+    }
+
+    if (env->priv == PRV_U && has_ext(ctx, RVS)) {
+        stateen &= env->sstateen[index];
+    }
+
+    if (!(stateen & SMSTATEEN0_FCSR)) {
+        if (ctx->virt_enabled) {
+            ctx->virt_inst_excp = true;
+        }
+        return false;
+    }
+
+    return true;
+}
+#else
+#define smstateen_fcsr_check(ctx, index) (true)
+#endif
+
+#define REQUIRE_ZFINX_OR_F(ctx) do { \
+    if (!has_ext(ctx, RVF)) { \
+        if (!ctx->cfg_ptr->ext_zfinx) { \
+            return false; \
+        } \
+        if (!smstateen_fcsr_check(ctx, 0)) { \
+            return false; \
+        } \
     } \
 } while (0)
 
target/riscv/insn_trans/trans_rvzfh.c.inc +12 -1
index 5d07150cd0..6c2e338c0a 100644
@@ -20,18 +20,27 @@
     if (!ctx->cfg_ptr->ext_zfh) {      \
         return false;         \
     }                         \
+    if (!smstateen_fcsr_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZHINX_OR_ZFH(ctx) do { \
     if (!ctx->cfg_ptr->ext_zhinx && !ctx->cfg_ptr->ext_zfh) { \
         return false;                  \
     }                                  \
+    if (!smstateen_fcsr_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZFH_OR_ZFHMIN(ctx) do {       \
     if (!(ctx->cfg_ptr->ext_zfh || ctx->cfg_ptr->ext_zfhmin)) { \
         return false;                         \
     }                                         \
+    if (!smstateen_fcsr_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZFH_OR_ZFHMIN_OR_ZHINX_OR_ZHINXMIN(ctx) do { \
@@ -39,6 +48,9 @@
           ctx->cfg_ptr->ext_zhinx || ctx->cfg_ptr->ext_zhinxmin)) {     \
         return false;                                        \
     }                                                        \
+    if (!smstateen_fcsr_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 static bool trans_flh(DisasContext *ctx, arg_flh *a)
--

2.25.1

#9 lore raw

Re: [PATCH v11 4/5] target/riscv: smstateen check for fcsr

In reply to Mayuresh Chitale
Quoted 89 lines · Mayuresh Chitale

If smstateen is implemented and sstateen0.fcsr is clear then the floating point operations must return illegal instruction exception or virtual instruction trap, if relevant.

---
 target/riscv/csr.c                        | 23 ++++++++++++
 target/riscv/insn_trans/trans_rvf.c.inc   | 43 +++++++++++++++++++++--
 target/riscv/insn_trans/trans_rvzfh.c.inc | 12 +++++++
 3 files changed, 75 insertions(+), 3 deletions(-)
target/riscv/csr.c +23 -0
index 71236f2b5d..8b25f885ec 100644
@@ -84,6 +84,10 @@ static RISCVException fs(CPURISCVState *env, int csrno)
         !RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
         return RISCV_EXCP_ILLEGAL_INST;
     }
+
+    if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
+        return smstateen_acc_ok(env, 0, SMSTATEEN0_FCSR);
+    }
 #endif
     return RISCV_EXCP_NONE;
 }
@@ -2023,6 +2027,9 @@ static RISCVException write_mstateen0(CPURISCVState *env, int csrno,
                                       target_ulong new_val)
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
 
     return write_mstateen(env, csrno, wr_mask, new_val);
 }
@@ -2059,6 +2066,10 @@ static RISCVException write_mstateen0h(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_mstateenh(env, csrno, wr_mask, new_val);
 }
 
@@ -2096,6 +2107,10 @@ static RISCVException write_hstateen0(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_hstateen(env, csrno, wr_mask, new_val);
 }
 
@@ -2135,6 +2150,10 @@ static RISCVException write_hstateen0h(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_hstateenh(env, csrno, wr_mask, new_val);
 }
 
@@ -2182,6 +2201,10 @@ static RISCVException write_sstateen0(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_sstateen(env, csrno, wr_mask, new_val);
 }
 
target/riscv/insn_trans/trans_rvf.c.inc +0 -0
index a1d3eb52ad..93657680c6 100644
@@ -24,9 +24,46 @@
             return false; \
 } while (0)

target/riscv/insn_trans/trans_rvf.c.inc line 32

Quoted 10 lines
target/riscv/insn_trans/trans_rvf.c.inc +6 -3
 
-#define REQUIRE_ZFINX_OR_F(ctx) do {\
-    if (!ctx->cfg_ptr->ext_zfinx) { \
-        REQUIRE_EXT(ctx, RVF); \
+#ifndef CONFIG_USER_ONLY
+static inline bool smstateen_fcsr_check(DisasContext *ctx, int index)
+{
+    CPUState *cpu = ctx->cs;
+    CPURISCVState *env = cpu->env_ptr;
+    uint64_t stateen = env->mstateen[index];

Sorry I missed this the first time around. You can't access env here

Richard pointed it out here:
https://patchwork.kernel.org/project/qemu-devel/patch/[email protected]/#25095773

I'm going to drop this patch and patch v5

Alistair

#10 lore raw

Re: [PATCH v11 4/5] target/riscv: smstateen check for fcsr

Quoted 102 lines · Alistair Francis
Quoted 88 lines · Mayuresh Chitale

If smstateen is implemented and sstateen0.fcsr is clear then the floating point operations must return illegal instruction exception or virtual instruction trap, if relevant.

---
  target/riscv/csr.c                        | 23 ++++++++++++
  target/riscv/insn_trans/trans_rvf.c.inc   | 43 +++++++++++++++++++++--
  target/riscv/insn_trans/trans_rvzfh.c.inc | 12 +++++++
  3 files changed, 75 insertions(+), 3 deletions(-)
target/riscv/csr.c +23 -0
index 71236f2b5d..8b25f885ec 100644
@@ -84,6 +84,10 @@ static RISCVException fs(CPURISCVState *env, int csrno)
          !RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
          return RISCV_EXCP_ILLEGAL_INST;
      }
+
+    if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
+        return smstateen_acc_ok(env, 0, SMSTATEEN0_FCSR);
+    }
  #endif
      return RISCV_EXCP_NONE;
  }
@@ -2023,6 +2027,9 @@ static RISCVException write_mstateen0(CPURISCVState *env, int csrno,
                                        target_ulong new_val)
  {
      uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
 
      return write_mstateen(env, csrno, wr_mask, new_val);
  }
@@ -2059,6 +2066,10 @@ static RISCVException write_mstateen0h(CPURISCVState *env, int csrno,
  {
      uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
      return write_mstateenh(env, csrno, wr_mask, new_val);
  }
 
@@ -2096,6 +2107,10 @@ static RISCVException write_hstateen0(CPURISCVState *env, int csrno,
  {
      uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
      return write_hstateen(env, csrno, wr_mask, new_val);
  }
 
@@ -2135,6 +2150,10 @@ static RISCVException write_hstateen0h(CPURISCVState *env, int csrno,
  {
      uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
      return write_hstateenh(env, csrno, wr_mask, new_val);
  }
 
@@ -2182,6 +2201,10 @@ static RISCVException write_sstateen0(CPURISCVState *env, int csrno,
  {
      uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
      return write_sstateen(env, csrno, wr_mask, new_val);
  }
 
target/riscv/insn_trans/trans_rvf.c.inc +0 -0
index a1d3eb52ad..93657680c6 100644
@@ -24,9 +24,46 @@
              return false; \
  } while (0)

target/riscv/insn_trans/trans_rvf.c.inc line 32

Quoted 10 lines
target/riscv/insn_trans/trans_rvf.c.inc +6 -3
 
-#define REQUIRE_ZFINX_OR_F(ctx) do {\
-    if (!ctx->cfg_ptr->ext_zfinx) { \
-        REQUIRE_EXT(ctx, RVF); \
+#ifndef CONFIG_USER_ONLY
+static inline bool smstateen_fcsr_check(DisasContext *ctx, int index)
+{
+    CPUState *cpu = ctx->cs;
+    CPURISCVState *env = cpu->env_ptr;
+    uint64_t stateen = env->mstateen[index];

Sorry I missed this the first time around. You can't access env here

Quoted 6 lines

Richard pointed it out here:
https://patchwork.kernel.org/project/qemu-devel/patch/[email protected]/#25095773

I'm going to drop this patch and patch v5

Alistair

Hi, Any new updates for the last two patches after they were dropped?

Regards,

Weiwei Li

#11 lore raw

Re: [PATCH v11 4/5] target/riscv: smstateen check for fcsr

Quoted 110 lines · liweiwei
Quoted 107 lines · Alistair Francis
Quoted 88 lines · Mayuresh Chitale

If smstateen is implemented and sstateen0.fcsr is clear then the floating point operations must return illegal instruction exception or virtual instruction trap, if relevant.

---
  target/riscv/csr.c                        | 23 ++++++++++++
  target/riscv/insn_trans/trans_rvf.c.inc   | 43 +++++++++++++++++++++--
  target/riscv/insn_trans/trans_rvzfh.c.inc | 12 +++++++
  3 files changed, 75 insertions(+), 3 deletions(-)
target/riscv/csr.c +23 -0
index 71236f2b5d..8b25f885ec 100644
@@ -84,6 +84,10 @@ static RISCVException fs(CPURISCVState *env, int csrno)
          !RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
          return RISCV_EXCP_ILLEGAL_INST;
      }
+
+    if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
+        return smstateen_acc_ok(env, 0, SMSTATEEN0_FCSR);
+    }
  #endif
      return RISCV_EXCP_NONE;
  }
@@ -2023,6 +2027,9 @@ static RISCVException write_mstateen0(CPURISCVState *env, int csrno,
                                        target_ulong new_val)
  {
      uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
 
      return write_mstateen(env, csrno, wr_mask, new_val);
  }
@@ -2059,6 +2066,10 @@ static RISCVException write_mstateen0h(CPURISCVState *env, int csrno,
  {
      uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
      return write_mstateenh(env, csrno, wr_mask, new_val);
  }
 
@@ -2096,6 +2107,10 @@ static RISCVException write_hstateen0(CPURISCVState *env, int csrno,
  {
      uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
      return write_hstateen(env, csrno, wr_mask, new_val);
  }
 
@@ -2135,6 +2150,10 @@ static RISCVException write_hstateen0h(CPURISCVState *env, int csrno,
  {
      uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
      return write_hstateenh(env, csrno, wr_mask, new_val);
  }
 
@@ -2182,6 +2201,10 @@ static RISCVException write_sstateen0(CPURISCVState *env, int csrno,
  {
      uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
      return write_sstateen(env, csrno, wr_mask, new_val);
  }
 
target/riscv/insn_trans/trans_rvf.c.inc +0 -0
index a1d3eb52ad..93657680c6 100644
@@ -24,9 +24,46 @@
              return false; \
  } while (0)

target/riscv/insn_trans/trans_rvf.c.inc line 32

Quoted 10 lines
target/riscv/insn_trans/trans_rvf.c.inc +6 -3
 
-#define REQUIRE_ZFINX_OR_F(ctx) do {\
-    if (!ctx->cfg_ptr->ext_zfinx) { \
-        REQUIRE_EXT(ctx, RVF); \
+#ifndef CONFIG_USER_ONLY
+static inline bool smstateen_fcsr_check(DisasContext *ctx, int index)
+{
+    CPUState *cpu = ctx->cs;
+    CPURISCVState *env = cpu->env_ptr;
+    uint64_t stateen = env->mstateen[index];

Sorry I missed this the first time around. You can't access env here

Richard pointed it out here:
https://patchwork.kernel.org/project/qemu-devel/patch/[email protected]/#25095773

I'm going to drop this patch and patch v5

Quoted 8 lines
Quoted 1 line

Alistair

Hi, Any new updates for the last two patches after they were dropped?

Regards,

Weiwei Li

Looks like I missed the original comments from Richard and Alistair. I am not yet clear how to implement it but I am looking into it.

#12 lore raw

PATCH v11 5/5 target/riscv: smstateen knobs

In reply to Mayuresh Chitale

Add knobs to allow users to enable smstateen and also export it via the ISA extension string.

---
 target/riscv/cpu.c | 2 ++
 1 file changed, 2 insertions(+)
target/riscv/cpu.c +2 -0
index e6d9c706bb..ae3f57a72b 100644
@@ -102,6 +102,7 @@ static const struct isa_ext_data isa_edata_arr[] = {
     ISA_EXT_DATA_ENTRY(zhinx, true, PRIV_VERSION_1_12_0, ext_zhinx),
     ISA_EXT_DATA_ENTRY(zhinxmin, true, PRIV_VERSION_1_12_0, ext_zhinxmin),
     ISA_EXT_DATA_ENTRY(smaia, true, PRIV_VERSION_1_12_0, ext_smaia),
+    ISA_EXT_DATA_ENTRY(smstateen, true, PRIV_VERSION_1_12_0, ext_smstateen),
     ISA_EXT_DATA_ENTRY(ssaia, true, PRIV_VERSION_1_12_0, ext_ssaia),
     ISA_EXT_DATA_ENTRY(sscofpmf, true, PRIV_VERSION_1_12_0, ext_sscofpmf),
     ISA_EXT_DATA_ENTRY(sstc, true, PRIV_VERSION_1_12_0, ext_sstc),
@@ -1024,6 +1025,7 @@ static Property riscv_cpu_extensions[] = {
     DEFINE_PROP_UINT16("vlen", RISCVCPU, cfg.vlen, 128),
     DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
 
+    DEFINE_PROP_BOOL("smstateen", RISCVCPU, cfg.ext_smstateen, false),
     DEFINE_PROP_BOOL("svinval", RISCVCPU, cfg.ext_svinval, false),
     DEFINE_PROP_BOOL("svnapot", RISCVCPU, cfg.ext_svnapot, false),
     DEFINE_PROP_BOOL("svpbmt", RISCVCPU, cfg.ext_svpbmt, false),
Signature · 1 line
2.25.1
#13 lore raw
In reply to Mayuresh Chitale
Quoted 57 lines · Mayuresh Chitale

This series adds support for the Smstateen specification which provides a mechanism to plug the potential covert channels which are opened by extensions that add to processor state that may not get context-switched. Currently access to *envcfg registers and floating point(fcsr) is controlled via smstateen.

These patches can also be found on riscv_smstateen_v11 branch at:
https://github.com/mdchitale/qemu.git

Changes in v11:
- Rebase to latest riscv-to-apply.next
- set virt_inst_excp at the begining of decode_opc
- Add reviewed by in patch 4

Changes in v10:
- Add support to generate virt instruction exception after decode failure. Use this change for smstateen fcsr failure when virt is enabled.
- Implement single write function for *smstateen1 to *smstateen3 registers.

Changes in v9:
- Rebase to latest riscv-to-apply.next
- Add reviewed by in patches 2 and 4

Changes in v8:
- Rebase to latest riscv-to-apply.next
- Fix m-mode check for hstateen
- Fix return exception type for VU mode
- Improve commit description for patch3

Changes in v7:
- Update smstateen check as per discussion on the following issue:
https://github.com/riscv/riscv-state-enable/issues/9
- Drop the smstateen AIA patch for now.
- Indentation and other fixes

Changes in v6:
- Sync with latest riscv-to-apply.next
- Make separate read/write ops for m/h/s/stateen1/2/3 regs
- Add check for mstateen.staten when reading or using h/s/stateen regs
- Add smstateen fcsr check for all floating point operations
- Move knobs to enable smstateen in a separate patch.

Changes in v5:
- Fix the order in which smstateen extension is added to the isa_edata_arr as
described in rule #3 the comment.

Changes in v4:
- Fix build issue with riscv32/riscv64-linux-user targets

Changes in v3:
- Fix coding style issues
- Fix *stateen0h index calculation

Changes in v2:
- Make h/s/envcfg bits in m/h/stateen registers as writeable by default.

Quoted 6 lines

Mayuresh Chitale (5):
target/riscv: Add smstateen support target/riscv: smstateen check for h/s/envcfg target/riscv: generate virtual instruction exception target/riscv: smstateen check for fcsr target/riscv: smstateen knobs

Thanks!

Applied to riscv-to-apply.next

Alistair

Quoted 15 lines
 target/riscv/cpu.c                        |   2 +
 target/riscv/cpu.h                        |   4 +
 target/riscv/cpu_bits.h                   |  37 ++
 target/riscv/csr.c                        | 414 +++++++++++++++++++++-
 target/riscv/insn_trans/trans_rvf.c.inc   |  43 ++-
 target/riscv/insn_trans/trans_rvzfh.c.inc |  12 +
 target/riscv/machine.c                    |  21 ++
 target/riscv/translate.c                  |   8 +-
 8 files changed, 536 insertions(+), 5 deletions(-)

--
2.25.1