[Qemu-devel] [PATCH v1 16/28] target/riscv: Add hypvervisor trap support

[Alistair Francis]

Signed-off-by: Alistair Francis <address@hidden>
---
 target/riscv/cpu_bits.h   |  4 +--
 target/riscv/cpu_helper.c | 71 +++++++++++++++++++++++++++++++++------
 target/riscv/csr.c        |  4 +--
 3 files changed, 65 insertions(+), 14 deletions(-)

diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 5cee72b726..353fc9a24a 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -513,8 +513,8 @@
 #define RISCV_EXCP_STORE_AMO_ADDR_MIS      0x6
 #define RISCV_EXCP_STORE_AMO_ACCESS_FAULT  0x7
 #define RISCV_EXCP_U_ECALL                 0x8
-#define RISCV_EXCP_S_ECALL                 0x9
-#define RISCV_EXCP_H_ECALL                 0xa
+#define RISCV_EXCP_HS_ECALL                0x9
+#define RISCV_EXCP_VS_ECALL                0xa
 #define RISCV_EXCP_M_ECALL                 0xb
 #define RISCV_EXCP_INST_PAGE_FAULT         0xc /* since: priv-1.10.0 */
 #define RISCV_EXCP_LOAD_PAGE_FAULT         0xd /* since: priv-1.10.0 */
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 8e8b156fc0..17eec6217b 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -668,6 +668,7 @@ void riscv_cpu_do_interrupt(CPUState *cs)
 
     RISCVCPU *cpu = RISCV_CPU(cs);
     CPURISCVState *env = &cpu->env;
+    target_ulong s;
 
     /* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
      * so we mask off the MSB and separate into trap type and cause.
@@ -677,13 +678,6 @@ void riscv_cpu_do_interrupt(CPUState *cs)
     target_ulong deleg = async ? env->mideleg : env->medeleg;
     target_ulong tval = 0;
 
-    static const int ecall_cause_map[] = {
-        [PRV_U] = RISCV_EXCP_U_ECALL,
-        [PRV_S] = RISCV_EXCP_S_ECALL,
-        [PRV_H] = RISCV_EXCP_H_ECALL,
-        [PRV_M] = RISCV_EXCP_M_ECALL
-    };
-
     if (!async) {
         /* set tval to badaddr for traps with address information */
         switch (cause) {
@@ -704,7 +698,16 @@ void riscv_cpu_do_interrupt(CPUState *cs)
         /* ecall is dispatched as one cause so translate based on mode */
         if (cause == RISCV_EXCP_U_ECALL) {
             assert(env->priv <= 3);
-            cause = ecall_cause_map[env->priv];
+
+            if (env->priv == PRV_M) {
+                cause = RISCV_EXCP_M_ECALL;
+            } else if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
+                cause = RISCV_EXCP_VS_ECALL;
+            } else if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) {
+                cause = RISCV_EXCP_HS_ECALL;
+            } else if (env->priv == PRV_U) {
+                cause = RISCV_EXCP_U_ECALL;
+            }
         }
     }
 
@@ -714,7 +717,42 @@ void riscv_cpu_do_interrupt(CPUState *cs)
     if (env->priv <= PRV_S &&
             cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
         /* handle the trap in S-mode */
-        target_ulong s = *env->mstatus;
+        if (riscv_has_ext(env, RVH)) {
+            target_ulong hdeleg = async ? env->hideleg : env->hedeleg;
+
+            if (riscv_cpu_virt_enabled(env) && ((hdeleg >> cause) & 1) &&
+                !riscv_cpu_force_hs_excep_enabled(env)) {
+                /* Trap to VS mode */
+            } else if (riscv_cpu_virt_enabled(env)) {
+                /* Trap into HS mode, from virt */
+                riscv_cpu_swap_hypervisor_regs(env);
+                env->hstatus = set_field(env->hstatus, HSTATUS_SP2V,
+                                         get_field(env->hstatus, HSTATUS_SPV));
+                env->hstatus = set_field(env->hstatus, HSTATUS_SP2P,
+                                         get_field(*env->mstatus, 
SSTATUS_SPP));
+                env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
+                                         riscv_cpu_virt_enabled(env));
+
+                if (riscv_cpu_force_hs_excep_enabled(env)) {
+                    env->hstatus = set_field(env->hstatus, HSTATUS_STL, 1);
+                } else {
+                    env->hstatus = set_field(env->hstatus, HSTATUS_STL, 0);
+                }
+
+                riscv_cpu_set_virt_enabled(env, VIRT_OFF);
+                riscv_cpu_set_force_hs_excep(env, CLEAR_HS_EXCEP);
+            } else {
+                /* Trap into HS mode */
+                env->hstatus = set_field(env->hstatus, HSTATUS_SP2V,
+                                         get_field(env->hstatus, HSTATUS_SPV));
+                env->hstatus = set_field(env->hstatus, HSTATUS_SP2P,
+                                         get_field(*env->mstatus, 
SSTATUS_SPP));
+                env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
+                                         riscv_cpu_virt_enabled(env));
+            }
+        }
+
+        s = *env->mstatus;
         s = set_field(s, MSTATUS_SPIE, env->priv_ver >= PRIV_VERSION_1_10_0 ?
             get_field(s, MSTATUS_SIE) : get_field(s, MSTATUS_UIE << 
env->priv));
         s = set_field(s, MSTATUS_SPP, env->priv);
@@ -728,7 +766,20 @@ void riscv_cpu_do_interrupt(CPUState *cs)
         riscv_cpu_set_mode(env, PRV_S);
     } else {
         /* handle the trap in M-mode */
-        target_ulong s = *env->mstatus;
+        if (riscv_has_ext(env, RVH)) {
+            if (riscv_cpu_virt_enabled(env)) {
+                riscv_cpu_swap_hypervisor_regs(env);
+            }
+            *env->mstatus = set_field(*env->mstatus, MSTATUS_MPV,
+                                      riscv_cpu_virt_enabled(env));
+            *env->mstatus = set_field(*env->mstatus, MSTATUS_MTL,
+                                      riscv_cpu_force_hs_excep_enabled(env));
+
+            /* Trapping to M mode, virt is disabled */
+            riscv_cpu_set_virt_enabled(env, VIRT_OFF);
+        }
+
+        s = *env->mstatus;
         s = set_field(s, MSTATUS_MPIE, env->priv_ver >= PRIV_VERSION_1_10_0 ?
             get_field(s, MSTATUS_MIE) : get_field(s, MSTATUS_UIE << 
env->priv));
         s = set_field(s, MSTATUS_MPP, env->priv);
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 30ec8c0a8e..47be4b1d42 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -255,8 +255,8 @@ static const target_ulong delegable_excps =
     (1ULL << (RISCV_EXCP_STORE_AMO_ADDR_MIS)) |
     (1ULL << (RISCV_EXCP_STORE_AMO_ACCESS_FAULT)) |
     (1ULL << (RISCV_EXCP_U_ECALL)) |
-    (1ULL << (RISCV_EXCP_S_ECALL)) |
-    (1ULL << (RISCV_EXCP_H_ECALL)) |
+    (1ULL << (RISCV_EXCP_VS_ECALL)) |
+    (1ULL << (RISCV_EXCP_HS_ECALL)) |
     (1ULL << (RISCV_EXCP_M_ECALL)) |
     (1ULL << (RISCV_EXCP_INST_PAGE_FAULT)) |
     (1ULL << (RISCV_EXCP_LOAD_PAGE_FAULT)) |
-- 
2.22.0