target/riscv: Implement hgeie and hgeip CSRs

The hgeie and hgeip CSRs are required for emulating an external
interrupt controller capable of injecting virtual external interrupt
to Guest/VM running at VS-level.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Message-id: 20220204174700.534953-4-anup@brainfault.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

1 files changed, 47 insertions, 20 deletions

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index e1224d2..f1c2684 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -663,27 +663,53 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
 static void riscv_cpu_set_irq(void *opaque, int irq, int level)
 {
     RISCVCPU *cpu = RISCV_CPU(opaque);
+    CPURISCVState *env = &cpu->env;
 
-    switch (irq) {
-    case IRQ_U_SOFT:
-    case IRQ_S_SOFT:
-    case IRQ_VS_SOFT:
-    case IRQ_M_SOFT:
-    case IRQ_U_TIMER:
-    case IRQ_S_TIMER:
-    case IRQ_VS_TIMER:
-    case IRQ_M_TIMER:
-    case IRQ_U_EXT:
-    case IRQ_S_EXT:
-    case IRQ_VS_EXT:
-    case IRQ_M_EXT:
-        if (kvm_enabled()) {
-            kvm_riscv_set_irq(cpu, irq, level);
-        } else {
-            riscv_cpu_update_mip(cpu, 1 << irq, BOOL_TO_MASK(level));
+    if (irq < IRQ_LOCAL_MAX) {
+        switch (irq) {
+        case IRQ_U_SOFT:
+        case IRQ_S_SOFT:
+        case IRQ_VS_SOFT:
+        case IRQ_M_SOFT:
+        case IRQ_U_TIMER:
+        case IRQ_S_TIMER:
+        case IRQ_VS_TIMER:
+        case IRQ_M_TIMER:
+        case IRQ_U_EXT:
+        case IRQ_S_EXT:
+        case IRQ_VS_EXT:
+        case IRQ_M_EXT:
+             if (kvm_enabled()) {
+                kvm_riscv_set_irq(cpu, irq, level);
+             } else {
+                riscv_cpu_update_mip(cpu, 1 << irq, BOOL_TO_MASK(level));
+             }
+             break;
+        default:
+            g_assert_not_reached();
         }
-        break;
-    default:
+    } else if (irq < (IRQ_LOCAL_MAX + IRQ_LOCAL_GUEST_MAX)) {
+        /* Require H-extension for handling guest local interrupts */
+        if (!riscv_has_ext(env, RVH)) {
+            g_assert_not_reached();
+        }
+
+        /* Compute bit position in HGEIP CSR */
+        irq = irq - IRQ_LOCAL_MAX + 1;
+        if (env->geilen < irq) {
+            g_assert_not_reached();
+        }
+
+        /* Update HGEIP CSR */
+        env->hgeip &= ~((target_ulong)1 << irq);
+        if (level) {
+            env->hgeip |= (target_ulong)1 << irq;
+        }
+
+        /* Update mip.SGEIP bit */
+        riscv_cpu_update_mip(cpu, MIP_SGEIP,
+                             BOOL_TO_MASK(!!(env->hgeie & env->hgeip)));
+    } else {
         g_assert_not_reached();
     }
 }
@@ -696,7 +722,8 @@ static void riscv_cpu_init(Object *obj)
     cpu_set_cpustate_pointers(cpu);
 
 #ifndef CONFIG_USER_ONLY
-    qdev_init_gpio_in(DEVICE(cpu), riscv_cpu_set_irq, IRQ_LOCAL_MAX);
+    qdev_init_gpio_in(DEVICE(cpu), riscv_cpu_set_irq,
+                      IRQ_LOCAL_MAX + IRQ_LOCAL_GUEST_MAX);
 #endif /* CONFIG_USER_ONLY */
 }