[PATCH 1/1] target/riscv: enable floating point unit

[Heinrich Schuchardt]

OpenSBI enables the floating point in mstatus. For consistency QEMU/KVM
should do the same.

Without this patch EDK II with TLS enabled crashes when hitting the first
floating point instruction while running QEMU with --accel kvm and runs
fine with --accel tcg.

Additionally to this patch EDK II should be changed to make no assumptions
about the state of the floating point unit.

Signed-off-by: Heinrich Schuchardt <heinrich.schucha...@canonical.com>
---
 target/riscv/cpu.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 4bda754b01..c32e2721d4 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -923,6 +923,13 @@ static void riscv_cpu_reset_hold(Object *obj, ResetType 
type)
     if (mcc->parent_phases.hold) {
         mcc->parent_phases.hold(obj, type);
     }
+    if (riscv_has_ext(env, RVF) || riscv_has_ext(env, RVD)) {
+        env->mstatus = set_field(env->mstatus, MSTATUS_FS, env->misa_mxl);
+        for (int regnr = 0; regnr < 32; ++regnr) {
+            env->fpr[regnr] = 0;
+        }
+        riscv_csrrw(env, CSR_FCSR, NULL, 0, -1);
+    }
 #ifndef CONFIG_USER_ONLY
     env->misa_mxl = mcc->misa_mxl_max;
     env->priv = PRV_M;
-- 
2.45.2