From 8747c9eeb2aaec8441d0900b198725ab33af4951 Mon Sep 17 00:00:00 2001
From: Alistair Francis <alistair.francis@wdc.com>
Date: Fri, 31 Jan 2020 17:02:07 -0800
Subject: [PATCH] target/riscv: Add Hypervisor virtual CSRs accesses

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/csr.c | 116 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index bee639e92e..3fa8d2cfda 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -273,6 +273,7 @@ static const target_ulong sstatus_v1_10_mask = SSTATUS_SIE | SSTATUS_SPIE |
     SSTATUS_SUM | SSTATUS_MXR | SSTATUS_SD;
 static const target_ulong sip_writable_mask = SIP_SSIP | MIP_USIP | MIP_UEIP;
 static const target_ulong hip_writable_mask = MIP_VSSIP | MIP_VSTIP | MIP_VSEIP;
+static const target_ulong vsip_writable_mask = MIP_VSSIP;
 
 #if defined(TARGET_RISCV32)
 static const char valid_vm_1_09[16] = {
@@ -878,6 +879,111 @@ static int write_hgatp(CPURISCVState *env, int csrno, target_ulong val)
     return 0;
 }
 
+/* Virtual CSR Registers */
+static int read_vsstatus(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vsstatus;
+    return 0;
+}
+
+static int write_vsstatus(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vsstatus = val;
+    return 0;
+}
+
+static int rmw_vsip(CPURISCVState *env, int csrno, target_ulong *ret_value,
+                    target_ulong new_value, target_ulong write_mask)
+{
+    int ret = rmw_mip(env, 0, ret_value, new_value,
+                      write_mask & env->mideleg & vsip_writable_mask);
+    return ret;
+}
+
+static int read_vsie(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->mie & env->mideleg & VS_MODE_INTERRUPTS;
+    return 0;
+}
+
+static int write_vsie(CPURISCVState *env, int csrno, target_ulong val)
+{
+    target_ulong newval = (env->mie & ~env->mideleg) | (val & env->mideleg & MIP_VSSIP);
+    return write_mie(env, CSR_MIE, newval);
+}
+
+static int read_vstvec(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vstvec;
+    return 0;
+}
+
+static int write_vstvec(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vstvec = val;
+    return 0;
+}
+
+static int read_vsscratch(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vsscratch;
+    return 0;
+}
+
+static int write_vsscratch(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vsscratch = val;
+    return 0;
+}
+
+static int read_vsepc(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vsepc;
+    return 0;
+}
+
+static int write_vsepc(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vsepc = val;
+    return 0;
+}
+
+static int read_vscause(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vscause;
+    return 0;
+}
+
+static int write_vscause(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vscause = val;
+    return 0;
+}
+
+static int read_vstval(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vstval;
+    return 0;
+}
+
+static int write_vstval(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vstval = val;
+    return 0;
+}
+
+static int read_vsatp(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vsatp;
+    return 0;
+}
+
+static int write_vsatp(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vsatp = val;
+    return 0;
+}
+
 /* Physical Memory Protection */
 static int read_pmpcfg(CPURISCVState *env, int csrno, target_ulong *val)
 {
@@ -1091,6 +1197,16 @@ static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_HTINST] =              { hmode,   read_htinst,      write_htinst     },
     [CSR_HGATP] =               { hmode,   read_hgatp,       write_hgatp      },
 
+    [CSR_VSSTATUS] =            { hmode,   read_vsstatus,    write_vsstatus   },
+    [CSR_VSIP] =                { hmode,   NULL,     NULL,     rmw_vsip       },
+    [CSR_VSIE] =                { hmode,   read_vsie,        write_vsie       },
+    [CSR_VSTVEC] =              { hmode,   read_vstvec,      write_vstvec     },
+    [CSR_VSSCRATCH] =           { hmode,   read_vsscratch,   write_vsscratch  },
+    [CSR_VSEPC] =               { hmode,   read_vsepc,       write_vsepc      },
+    [CSR_VSCAUSE] =             { hmode,   read_vscause,     write_vscause    },
+    [CSR_VSTVAL] =              { hmode,   read_vstval,      write_vstval     },
+    [CSR_VSATP] =               { hmode,   read_vsatp,       write_vsatp      },
+
     /* Physical Memory Protection */
     [CSR_PMPCFG0  ... CSR_PMPADDR9] =  { pmp,   read_pmpcfg,  write_pmpcfg   },
     [CSR_PMPADDR0 ... CSR_PMPADDR15] = { pmp,   read_pmpaddr, write_pmpaddr  },