From 028616130d5f0abc8a3b96f28963da51a875024b Mon Sep 17 00:00:00 2001
From: Alistair Francis
Date: Fri, 31 Jan 2020 17:01:38 -0800
Subject: target/riscv: Convert MIP CSR to target_ulong

The MIP CSR is a xlen CSR, it was only 32-bits to allow atomic access.
Now that we don't use atomics for MIP we can change this back to a xlen
CSR.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'target/riscv/cpu.h')

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index de0a8d893a..95de9e58a2 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -121,7 +121,7 @@ struct CPURISCVState {
     target_ulong mhartid;
     target_ulong mstatus;
 
-    uint32_t mip;
+    target_ulong mip;
     uint32_t miclaim;
 
     target_ulong mie;
-- 
cgit v1.2.3-55-g7522


From af1fa0039c799a350bcde07b3d8a71dfde07d11b Mon Sep 17 00:00:00 2001
From: Alistair Francis
Date: Fri, 31 Jan 2020 17:01:41 -0800
Subject: target/riscv: Add the Hypervisor extension

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Chih-Min Chao <chihmin.chao@sifive.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h | 1 +
 1 file changed, 1 insertion(+)

(limited to 'target/riscv/cpu.h')

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 95de9e58a2..010125efd6 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -67,6 +67,7 @@
 #define RVC RV('C')
 #define RVS RV('S')
 #define RVU RV('U')
+#define RVH RV('H')
 
 /* S extension denotes that Supervisor mode exists, however it is possible
    to have a core that support S mode but does not have an MMU and there
-- 
cgit v1.2.3-55-g7522


From bd023ce33b85d73791b7bc78fd04a8115c60995e Mon Sep 17 00:00:00 2001
From: Alistair Francis
Date: Fri, 31 Jan 2020 17:01:43 -0800
Subject: target/riscv: Add the Hypervisor CSRs to CPUState

Add the Hypervisor CSRs to CPUState and at the same time (to avoid
bisect issues) update the CSR macros for the v0.5 Hyp spec.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h      | 21 +++++++++++++++++++++
 target/riscv/cpu_bits.h | 34 +++++++++++++++++++++-------------
 target/riscv/gdbstub.c  | 11 ++++++-----
 3 files changed, 48 insertions(+), 18 deletions(-)

(limited to 'target/riscv/cpu.h')

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 010125efd6..c7f7ae5c38 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -143,6 +143,27 @@ struct CPURISCVState {
     target_ulong mcause;
     target_ulong mtval;  /* since: priv-1.10.0 */
 
+    /* Hypervisor CSRs */
+    target_ulong hstatus;
+    target_ulong hedeleg;
+    target_ulong hideleg;
+    target_ulong hcounteren;
+    target_ulong htval;
+    target_ulong htinst;
+    target_ulong hgatp;
+
+    /* Virtual CSRs */
+    target_ulong vsstatus;
+    target_ulong vstvec;
+    target_ulong vsscratch;
+    target_ulong vsepc;
+    target_ulong vscause;
+    target_ulong vstval;
+    target_ulong vsatp;
+
+    target_ulong mtval2;
+    target_ulong mtinst;
+
     target_ulong scounteren;
     target_ulong mcounteren;
 
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index e99834856c..25c0fb258d 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -177,8 +177,14 @@
 #define CSR_HSTATUS         0x600
 #define CSR_HEDELEG         0x602
 #define CSR_HIDELEG         0x603
-#define CSR_HCOUNTERNEN     0x606
+#define CSR_HIE             0x604
+#define CSR_HCOUNTEREN      0x606
+#define CSR_HTVAL           0x643
+#define CSR_HIP             0x644
+#define CSR_HTINST          0x64A
 #define CSR_HGATP           0x680
+#define CSR_HTIMEDELTA      0x605
+#define CSR_HTIMEDELTAH     0x615
 
 #if defined(TARGET_RISCV32)
 #define HGATP_MODE           SATP32_MODE
@@ -191,6 +197,20 @@
 #define HGATP_PPN            SATP64_PPN
 #endif
 
+/* Virtual CSRs */
+#define CSR_VSSTATUS        0x200
+#define CSR_VSIE            0x204
+#define CSR_VSTVEC          0x205
+#define CSR_VSSCRATCH       0x240
+#define CSR_VSEPC           0x241
+#define CSR_VSCAUSE         0x242
+#define CSR_VSTVAL          0x243
+#define CSR_VSIP            0x244
+#define CSR_VSATP           0x280
+
+#define CSR_MTINST          0x34a
+#define CSR_MTVAL2          0x34b
+
 /* Physical Memory Protection */
 #define CSR_PMPCFG0         0x3a0
 #define CSR_PMPCFG1         0x3a1
@@ -313,17 +333,6 @@
 #define CSR_MHPMCOUNTER30H  0xb9e
 #define CSR_MHPMCOUNTER31H  0xb9f
 
-/* Legacy Hypervisor Trap Setup (priv v1.9.1) */
-#define CSR_HIE             0x204
-#define CSR_HTVEC           0x205
-
-/* Legacy Hypervisor Trap Handling (priv v1.9.1) */
-#define CSR_HSCRATCH        0x240
-#define CSR_HEPC            0x241
-#define CSR_HCAUSE          0x242
-#define CSR_HBADADDR        0x243
-#define CSR_HIP             0x244
-
 /* Legacy Machine Protection and Translation (priv v1.9.1) */
 #define CSR_MBASE           0x380
 #define CSR_MBOUND          0x381
@@ -400,7 +409,6 @@
 
 /* hstatus CSR bits */
 #define HSTATUS_SPRV         0x00000001
-#define HSTATUS_STL          0x00000040
 #define HSTATUS_SPV          0x00000080
 #define HSTATUS_SP2P         0x00000100
 #define HSTATUS_SP2V         0x00000200
diff --git a/target/riscv/gdbstub.c b/target/riscv/gdbstub.c
index 1a72f7be9c..2f32750f2f 100644
--- a/target/riscv/gdbstub.c
+++ b/target/riscv/gdbstub.c
@@ -130,6 +130,8 @@ static int csr_register_map[] = {
     CSR_MCAUSE,
     CSR_MTVAL,
     CSR_MIP,
+    CSR_MTINST,
+    CSR_MTVAL2,
     CSR_PMPCFG0,
     CSR_PMPCFG1,
     CSR_PMPCFG2,
@@ -252,12 +254,11 @@ static int csr_register_map[] = {
     CSR_HEDELEG,
     CSR_HIDELEG,
     CSR_HIE,
-    CSR_HTVEC,
-    CSR_HSCRATCH,
-    CSR_HEPC,
-    CSR_HCAUSE,
-    CSR_HBADADDR,
+    CSR_HCOUNTEREN,
+    CSR_HTVAL,
     CSR_HIP,
+    CSR_HTINST,
+    CSR_HGATP,
     CSR_MBASE,
     CSR_MBOUND,
     CSR_MIBASE,
-- 
cgit v1.2.3-55-g7522


From ef6bb7b62682badefdcb744831510aaa5971684f Mon Sep 17 00:00:00 2001
From: Alistair Francis
Date: Fri, 31 Jan 2020 17:01:51 -0800
Subject: target/riscv: Add the virtulisation mode

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h        |  4 ++++
 target/riscv/cpu_bits.h   |  3 +++
 target/riscv/cpu_helper.c | 18 ++++++++++++++++++
 3 files changed, 25 insertions(+)

(limited to 'target/riscv/cpu.h')

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index c7f7ae5c38..a9cbd8584e 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -117,6 +117,8 @@ struct CPURISCVState {
 
 #ifndef CONFIG_USER_ONLY
     target_ulong priv;
+    /* This contains QEMU specific information about the virt state. */
+    target_ulong virt;
     target_ulong resetvec;
 
     target_ulong mhartid;
@@ -269,6 +271,8 @@ int riscv_cpu_gdb_read_register(CPUState *cpu, uint8_t *buf, int reg);
 int riscv_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
 bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request);
 bool riscv_cpu_fp_enabled(CPURISCVState *env);
+bool riscv_cpu_virt_enabled(CPURISCVState *env);
+void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable);
 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch);
 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
 void  riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index eeaa03c0f8..2cdb0de4fe 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -430,6 +430,9 @@
 #define PRV_H 2 /* Reserved */
 #define PRV_M 3
 
+/* Virtulisation Register Fields */
+#define VIRT_ONOFF          1
+
 /* RV32 satp CSR field masks */
 #define SATP32_MODE         0x80000000
 #define SATP32_ASID         0x7fc00000
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index a10582b310..e5311160e7 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -82,6 +82,24 @@ bool riscv_cpu_fp_enabled(CPURISCVState *env)
     return false;
 }
 
+bool riscv_cpu_virt_enabled(CPURISCVState *env)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return false;
+    }
+
+    return get_field(env->virt, VIRT_ONOFF);
+}
+
+void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return;
+    }
+
+    env->virt = set_field(env->virt, VIRT_ONOFF, enable);
+}
+
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
 {
     CPURISCVState *env = &cpu->env;
-- 
cgit v1.2.3-55-g7522


From c7b1bbc80fc2af17395d3986c346fd2307e57829 Mon Sep 17 00:00:00 2001
From: Alistair Francis
Date: Fri, 31 Jan 2020 17:01:54 -0800
Subject: target/riscv: Add the force HS exception mode

Add a FORCE_HS_EXCEP mode to the RISC-V virtulisation status. This bit
specifies if an exeption should be taken to HS mode no matter the
current delegation status. This is used when an exeption must be taken
to HS mode, such as when handling interrupts.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h        |  2 ++
 target/riscv/cpu_bits.h   |  6 ++++++
 target/riscv/cpu_helper.c | 18 ++++++++++++++++++
 3 files changed, 26 insertions(+)

(limited to 'target/riscv/cpu.h')

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index a9cbd8584e..42720d65f9 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -273,6 +273,8 @@ bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request);
 bool riscv_cpu_fp_enabled(CPURISCVState *env);
 bool riscv_cpu_virt_enabled(CPURISCVState *env);
 void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable);
+bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env);
+void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable);
 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch);
 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
 void  riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 2cdb0de4fe..ad6479796c 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -432,6 +432,12 @@
 
 /* Virtulisation Register Fields */
 #define VIRT_ONOFF          1
+/* This is used to save state for when we take an exception. If this is set
+ * that means that we want to force a HS level exception (no matter what the
+ * delegation is set to). This will occur for things such as a second level
+ * page table fault.
+ */
+#define FORCE_HS_EXCEP      2
 
 /* RV32 satp CSR field masks */
 #define SATP32_MODE         0x80000000
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index e5311160e7..e36ee7d58e 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -100,6 +100,24 @@ void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
     env->virt = set_field(env->virt, VIRT_ONOFF, enable);
 }
 
+bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return false;
+    }
+
+    return get_field(env->virt, FORCE_HS_EXCEP);
+}
+
+void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return;
+    }
+
+    env->virt = set_field(env->virt, FORCE_HS_EXCEP, enable);
+}
+
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
 {
     CPURISCVState *env = &cpu->env;
-- 
cgit v1.2.3-55-g7522


From 66e594f2800ddc55f908830bf9e8dc4cda1304fe Mon Sep 17 00:00:00 2001
From: Alistair Francis
Date: Fri, 31 Jan 2020 17:02:12 -0800
Subject: target/riscv: Add virtual register swapping function

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h        | 11 +++++++++
 target/riscv/cpu_bits.h   |  7 ++++++
 target/riscv/cpu_helper.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+)

(limited to 'target/riscv/cpu.h')

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 42720d65f9..5b889a0065 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -125,6 +125,7 @@ struct CPURISCVState {
     target_ulong mstatus;
 
     target_ulong mip;
+
     uint32_t miclaim;
 
     target_ulong mie;
@@ -166,6 +167,15 @@ struct CPURISCVState {
     target_ulong mtval2;
     target_ulong mtinst;
 
+    /* HS Backup CSRs */
+    target_ulong stvec_hs;
+    target_ulong sscratch_hs;
+    target_ulong sepc_hs;
+    target_ulong scause_hs;
+    target_ulong stval_hs;
+    target_ulong satp_hs;
+    target_ulong mstatus_hs;
+
     target_ulong scounteren;
     target_ulong mcounteren;
 
@@ -296,6 +306,7 @@ void riscv_cpu_list(void);
 #define cpu_mmu_index riscv_cpu_mmu_index
 
 #ifndef CONFIG_USER_ONLY
+void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env);
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts);
 uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value);
 #define BOOL_TO_MASK(x) (-!!(x)) /* helper for riscv_cpu_update_mip value */
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index ad6479796c..a24654d137 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -553,4 +553,11 @@
 #define SIP_STIP                           MIP_STIP
 #define SIP_SEIP                           MIP_SEIP
 
+/* MIE masks */
+#define MIE_SEIE                           (1 << IRQ_S_EXT)
+#define MIE_UEIE                           (1 << IRQ_U_EXT)
+#define MIE_STIE                           (1 << IRQ_S_TIMER)
+#define MIE_UTIE                           (1 << IRQ_U_TIMER)
+#define MIE_SSIE                           (1 << IRQ_S_SOFT)
+#define MIE_USIE                           (1 << IRQ_U_SOFT)
 #endif
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index e36ee7d58e..9d5a06499f 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -82,6 +82,67 @@ bool riscv_cpu_fp_enabled(CPURISCVState *env)
     return false;
 }
 
+void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
+{
+    target_ulong mstatus_mask = MSTATUS_MXR | MSTATUS_SUM | MSTATUS_FS |
+                                MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE;
+    bool current_virt = riscv_cpu_virt_enabled(env);
+
+    g_assert(riscv_has_ext(env, RVH));
+
+#if defined(TARGET_RISCV64)
+    mstatus_mask |= MSTATUS64_UXL;
+#endif
+
+    if (current_virt) {
+        /* Current V=1 and we are about to change to V=0 */
+        env->vsstatus = env->mstatus & mstatus_mask;
+        env->mstatus &= ~mstatus_mask;
+        env->mstatus |= env->mstatus_hs;
+
+        env->vstvec = env->stvec;
+        env->stvec = env->stvec_hs;
+
+        env->vsscratch = env->sscratch;
+        env->sscratch = env->sscratch_hs;
+
+        env->vsepc = env->sepc;
+        env->sepc = env->sepc_hs;
+
+        env->vscause = env->scause;
+        env->scause = env->scause_hs;
+
+        env->vstval = env->sbadaddr;
+        env->sbadaddr = env->stval_hs;
+
+        env->vsatp = env->satp;
+        env->satp = env->satp_hs;
+    } else {
+        /* Current V=0 and we are about to change to V=1 */
+        env->mstatus_hs = env->mstatus & mstatus_mask;
+        env->mstatus &= ~mstatus_mask;
+        env->mstatus |= env->vsstatus;
+
+        env->stvec_hs = env->stvec;
+        env->stvec = env->vstvec;
+
+        env->sscratch_hs = env->sscratch;
+        env->sscratch = env->vsscratch;
+
+        env->sepc_hs = env->sepc;
+        env->sepc = env->vsepc;
+
+        env->scause_hs = env->scause;
+        env->scause = env->vscause;
+
+        env->stval_hs = env->sbadaddr;
+        env->sbadaddr = env->vstval;
+
+        env->satp_hs = env->satp;
+        env->satp = env->vsatp;
+    }
+}
+
 bool riscv_cpu_virt_enabled(CPURISCVState *env)
 {
     if (!riscv_has_ext(env, RVH)) {
-- 
cgit v1.2.3-55-g7522


From e28eaed87902c5e852c3ed043b27204e879aa4e2 Mon Sep 17 00:00:00 2001
From: Alistair Francis
Date: Fri, 31 Jan 2020 17:02:41 -0800
Subject: target/riscv: Only set TB flags with FP status if enabled

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'target/riscv/cpu.h')

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 5b889a0065..aa04e5cca7 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -332,7 +332,10 @@ static inline void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
 #ifdef CONFIG_USER_ONLY
     *flags = TB_FLAGS_MSTATUS_FS;
 #else
-    *flags = cpu_mmu_index(env, 0) | (env->mstatus & MSTATUS_FS);
+    *flags = cpu_mmu_index(env, 0);
+    if (riscv_cpu_fp_enabled(env)) {
+        *flags |= env->mstatus & MSTATUS_FS;
+    }
 #endif
 }
 
-- 
cgit v1.2.3-55-g7522


From 36a18664bafcfafa5e997b47458387f6fe53d537 Mon Sep 17 00:00:00 2001
From: Alistair Francis
Date: Fri, 31 Jan 2020 17:02:56 -0800
Subject: target/riscv: Implement second stage MMU

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h        |   1 +
 target/riscv/cpu_helper.c | 193 +++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 175 insertions(+), 19 deletions(-)

(limited to 'target/riscv/cpu.h')

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index aa04e5cca7..a8534fdf2b 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -104,6 +104,7 @@ struct CPURISCVState {
     target_ulong frm;
 
     target_ulong badaddr;
+    target_ulong guest_phys_fault_addr;
 
     target_ulong priv_ver;
     target_ulong misa;
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 8ae1038bcd..584b0c71fb 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -285,11 +285,12 @@ void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
  * @mmu_idx: Indicates current privilege level
  * @first_stage: Are we in first stage translation?
  *               Second stage is used for hypervisor guest translation
+ * @two_stage: Are we going to perform two stage translation
  */
 static int get_physical_address(CPURISCVState *env, hwaddr *physical,
                                 int *prot, target_ulong addr,
                                 int access_type, int mmu_idx,
-                                bool first_stage)
+                                bool first_stage, bool two_stage)
 {
     /* NOTE: the env->pc value visible here will not be
      * correct, but the value visible to the exception handler
@@ -297,13 +298,40 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
     MemTxResult res;
     MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
     int mode = mmu_idx;
+    bool use_background = false;
 
+    /*
+     * Check if we should use the background registers for the two
+     * stage translation. We don't need to check if we actually need
+     * two stage translation as that happened before this function
+     * was called. Background registers will be used if the guest has
+     * forced a two stage translation to be on (in HS or M mode).
+     */
     if (mode == PRV_M && access_type != MMU_INST_FETCH) {
         if (get_field(env->mstatus, MSTATUS_MPRV)) {
             mode = get_field(env->mstatus, MSTATUS_MPP);
+
+            if (riscv_has_ext(env, RVH) &&
+                get_field(env->mstatus, MSTATUS_MPV)) {
+                use_background = true;
+            }
+        }
+    }
+
+    if (mode == PRV_S && access_type != MMU_INST_FETCH &&
+        riscv_has_ext(env, RVH) && !riscv_cpu_virt_enabled(env)) {
+        if (get_field(env->hstatus, HSTATUS_SPRV)) {
+            mode = get_field(env->mstatus, SSTATUS_SPP);
+            use_background = true;
         }
     }
 
+    if (first_stage == false) {
+        /* We are in stage 2 translation, this is similar to stage 1. */
+        /* Stage 2 is always taken as U-mode */
+        mode = PRV_U;
+    }
+
     if (mode == PRV_M || !riscv_feature(env, RISCV_FEATURE_MMU)) {
         *physical = addr;
         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
@@ -313,13 +341,30 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
     *prot = 0;
 
     hwaddr base;
-    int levels, ptidxbits, ptesize, vm, sum;
-    int mxr = get_field(env->mstatus, MSTATUS_MXR);
+    int levels, ptidxbits, ptesize, vm, sum, mxr, widened;
+
+    if (first_stage == true) {
+        mxr = get_field(env->mstatus, MSTATUS_MXR);
+    } else {
+        mxr = get_field(env->vsstatus, MSTATUS_MXR);
+    }
 
     if (env->priv_ver >= PRIV_VERSION_1_10_0) {
-        base = (hwaddr)get_field(env->satp, SATP_PPN) << PGSHIFT;
+        if (first_stage == true) {
+            if (use_background) {
+                base = (hwaddr)get_field(env->vsatp, SATP_PPN) << PGSHIFT;
+                vm = get_field(env->vsatp, SATP_MODE);
+            } else {
+                base = (hwaddr)get_field(env->satp, SATP_PPN) << PGSHIFT;
+                vm = get_field(env->satp, SATP_MODE);
+            }
+            widened = 0;
+        } else {
+            base = (hwaddr)get_field(env->hgatp, HGATP_PPN) << PGSHIFT;
+            vm = get_field(env->hgatp, HGATP_MODE);
+            widened = 2;
+        }
         sum = get_field(env->mstatus, MSTATUS_SUM);
-        vm = get_field(env->satp, SATP_MODE);
         switch (vm) {
         case VM_1_10_SV32:
           levels = 2; ptidxbits = 10; ptesize = 4; break;
@@ -337,6 +382,7 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
           g_assert_not_reached();
         }
     } else {
+        widened = 0;
         base = (hwaddr)(env->sptbr) << PGSHIFT;
         sum = !get_field(env->mstatus, MSTATUS_PUM);
         vm = get_field(env->mstatus, MSTATUS_VM);
@@ -357,9 +403,16 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
     }
 
     CPUState *cs = env_cpu(env);
-    int va_bits = PGSHIFT + levels * ptidxbits;
-    target_ulong mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
-    target_ulong masked_msbs = (addr >> (va_bits - 1)) & mask;
+    int va_bits = PGSHIFT + levels * ptidxbits + widened;
+    target_ulong mask, masked_msbs;
+
+    if (TARGET_LONG_BITS > (va_bits - 1)) {
+        mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
+    } else {
+        mask = 0;
+    }
+    masked_msbs = (addr >> (va_bits - 1)) & mask;
+
     if (masked_msbs != 0 && masked_msbs != mask) {
         return TRANSLATE_FAIL;
     }
@@ -371,11 +424,29 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
 restart:
 #endif
     for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
-        target_ulong idx = (addr >> (PGSHIFT + ptshift)) &
+        target_ulong idx;
+        if (i == 0) {
+            idx = (addr >> (PGSHIFT + ptshift)) &
+                           ((1 << (ptidxbits + widened)) - 1);
+        } else {
+            idx = (addr >> (PGSHIFT + ptshift)) &
                            ((1 << ptidxbits) - 1);
+        }
 
         /* check that physical address of PTE is legal */
-        hwaddr pte_addr = base + idx * ptesize;
+        hwaddr pte_addr;
+
+        if (two_stage && first_stage) {
+            hwaddr vbase;
+
+            /* Do the second stage translation on the base PTE address. */
+            get_physical_address(env, &vbase, prot, base, access_type,
+                                 mmu_idx, false, true);
+
+            pte_addr = vbase + idx * ptesize;
+        } else {
+            pte_addr = base + idx * ptesize;
+        }
 
         if (riscv_feature(env, RISCV_FEATURE_PMP) &&
             !pmp_hart_has_privs(env, pte_addr, sizeof(target_ulong),
@@ -472,7 +543,12 @@ restart:
             /* for superpage mappings, make a fake leaf PTE for the TLB's
                benefit. */
             target_ulong vpn = addr >> PGSHIFT;
-            *physical = (ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT;
+            if (i == 0) {
+                *physical = (ppn | (vpn & ((1L << (ptshift + widened)) - 1))) <<
+                             PGSHIFT;
+            } else {
+                *physical = (ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT;
+            }
 
             /* set permissions on the TLB entry */
             if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
@@ -531,14 +607,23 @@ static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
 {
     RISCVCPU *cpu = RISCV_CPU(cs);
+    CPURISCVState *env = &cpu->env;
     hwaddr phys_addr;
     int prot;
     int mmu_idx = cpu_mmu_index(&cpu->env, false);
 
-    if (get_physical_address(&cpu->env, &phys_addr, &prot, addr, 0, mmu_idx,
-                             true)) {
+    if (get_physical_address(env, &phys_addr, &prot, addr, 0, mmu_idx,
+                             true, riscv_cpu_virt_enabled(env))) {
         return -1;
     }
+
+    if (riscv_cpu_virt_enabled(env)) {
+        if (get_physical_address(env, &phys_addr, &prot, phys_addr,
+                                 0, mmu_idx, false, true)) {
+            return -1;
+        }
+    }
+
     return phys_addr;
 }
 
@@ -592,17 +677,37 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
     RISCVCPU *cpu = RISCV_CPU(cs);
     CPURISCVState *env = &cpu->env;
 #ifndef CONFIG_USER_ONLY
+    vaddr im_address;
     hwaddr pa = 0;
     int prot;
     bool pmp_violation = false;
+    bool m_mode_two_stage = false;
+    bool hs_mode_two_stage = false;
+    bool first_stage_error = true;
     int ret = TRANSLATE_FAIL;
     int mode = mmu_idx;
 
+    env->guest_phys_fault_addr = 0;
+
     qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
                   __func__, address, access_type, mmu_idx);
 
-    ret = get_physical_address(env, &pa, &prot, address, access_type, mmu_idx,
-                               true);
+    /*
+     * Determine if we are in M mode and MPRV is set or in HS mode and SPRV is
+     * set and we want to access a virtulisation address.
+     */
+    if (riscv_has_ext(env, RVH)) {
+        m_mode_two_stage = env->priv == PRV_M &&
+                           access_type != MMU_INST_FETCH &&
+                           get_field(env->mstatus, MSTATUS_MPRV) &&
+                           get_field(env->mstatus, MSTATUS_MPV);
+
+        hs_mode_two_stage = env->priv == PRV_S &&
+                            !riscv_cpu_virt_enabled(env) &&
+                            access_type != MMU_INST_FETCH &&
+                            get_field(env->hstatus, HSTATUS_SPRV) &&
+                            get_field(env->hstatus, HSTATUS_SPV);
+    }
 
     if (mode == PRV_M && access_type != MMU_INST_FETCH) {
         if (get_field(env->mstatus, MSTATUS_MPRV)) {
@@ -610,9 +715,55 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
         }
     }
 
-    qemu_log_mask(CPU_LOG_MMU,
-                  "%s address=%" VADDR_PRIx " ret %d physical " TARGET_FMT_plx
-                  " prot %d\n", __func__, address, ret, pa, prot);
+    if (riscv_cpu_virt_enabled(env) || m_mode_two_stage || hs_mode_two_stage) {
+        /* Two stage lookup */
+        ret = get_physical_address(env, &pa, &prot, address, access_type,
+                                   mmu_idx, true, true);
+
+        qemu_log_mask(CPU_LOG_MMU,
+                      "%s 1st-stage address=%" VADDR_PRIx " ret %d physical "
+                      TARGET_FMT_plx " prot %d\n",
+                      __func__, address, ret, pa, prot);
+
+        if (ret != TRANSLATE_FAIL) {
+            /* Second stage lookup */
+            im_address = pa;
+
+            ret = get_physical_address(env, &pa, &prot, im_address,
+                                       access_type, mmu_idx, false, true);
+
+            qemu_log_mask(CPU_LOG_MMU,
+                    "%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
+                    TARGET_FMT_plx " prot %d\n",
+                    __func__, im_address, ret, pa, prot);
+
+            if (riscv_feature(env, RISCV_FEATURE_PMP) &&
+                (ret == TRANSLATE_SUCCESS) &&
+                !pmp_hart_has_privs(env, pa, size, 1 << access_type, mode)) {
+                ret = TRANSLATE_PMP_FAIL;
+            }
+
+            if (ret != TRANSLATE_SUCCESS) {
+                /*
+                 * Guest physical address translation failed, this is a HS
+                 * level exception
+                 */
+                first_stage_error = false;
+                env->guest_phys_fault_addr = (im_address |
+                                              (address &
+                                               (TARGET_PAGE_SIZE - 1))) >> 2;
+            }
+        }
+    } else {
+        /* Single stage lookup */
+        ret = get_physical_address(env, &pa, &prot, address, access_type,
+                                   mmu_idx, true, false);
+
+        qemu_log_mask(CPU_LOG_MMU,
+                      "%s address=%" VADDR_PRIx " ret %d physical "
+                      TARGET_FMT_plx " prot %d\n",
+                      __func__, address, ret, pa, prot);
+    }
 
     if (riscv_feature(env, RISCV_FEATURE_PMP) &&
         (ret == TRANSLATE_SUCCESS) &&
@@ -622,6 +773,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
     if (ret == TRANSLATE_PMP_FAIL) {
         pmp_violation = true;
     }
+
     if (ret == TRANSLATE_SUCCESS) {
         tlb_set_page(cs, address & TARGET_PAGE_MASK, pa & TARGET_PAGE_MASK,
                      prot, mmu_idx, TARGET_PAGE_SIZE);
@@ -629,9 +781,12 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
     } else if (probe) {
         return false;
     } else {
-        raise_mmu_exception(env, address, access_type, pmp_violation, true);
+        raise_mmu_exception(env, address, access_type, pmp_violation, first_stage_error);
         riscv_raise_exception(env, cs->exception_index, retaddr);
     }
+
+    return true;
+
 #else
     switch (access_type) {
     case MMU_INST_FETCH:
-- 
cgit v1.2.3-55-g7522


From 551fa7e8a695ea5fd1cca8ffd318556855bbf54f Mon Sep 17 00:00:00 2001
From: Alistair Francis
Date: Fri, 31 Jan 2020 17:03:05 -0800
Subject: target/riscv: Add support for the 32-bit MSTATUSH CSR

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.c        |  3 +++
 target/riscv/cpu.h        | 10 ++++++++++
 target/riscv/cpu_bits.h   |  3 +++
 target/riscv/cpu_helper.c | 17 +++++++++++++++++
 target/riscv/csr.c        | 25 +++++++++++++++++++++++++
 target/riscv/op_helper.c  |  4 ++++
 6 files changed, 62 insertions(+)

(limited to 'target/riscv/cpu.h')

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 44ad768a84..b27066f6a7 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -237,6 +237,9 @@ static void riscv_cpu_dump_state(CPUState *cs, FILE *f, int flags)
 #ifndef CONFIG_USER_ONLY
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mhartid ", env->mhartid);
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ", env->mstatus);
+#ifdef TARGET_RISCV32
+    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatush ", env->mstatush);
+#endif
     if (riscv_has_ext(env, RVH)) {
         qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "hstatus ", env->hstatus);
         qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "vsstatus ", env->vsstatus);
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index a8534fdf2b..6f9c29322a 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -127,6 +127,10 @@ struct CPURISCVState {
 
     target_ulong mip;
 
+#ifdef TARGET_RISCV32
+    target_ulong mstatush;
+#endif
+
     uint32_t miclaim;
 
     target_ulong mie;
@@ -164,6 +168,9 @@ struct CPURISCVState {
     target_ulong vscause;
     target_ulong vstval;
     target_ulong vsatp;
+#ifdef TARGET_RISCV32
+    target_ulong vsstatush;
+#endif
 
     target_ulong mtval2;
     target_ulong mtinst;
@@ -176,6 +183,9 @@ struct CPURISCVState {
     target_ulong stval_hs;
     target_ulong satp_hs;
     target_ulong mstatus_hs;
+#ifdef TARGET_RISCV32
+    target_ulong mstatush_hs;
+#endif
 
     target_ulong scounteren;
     target_ulong mcounteren;
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index a24654d137..049032f2ae 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -135,6 +135,9 @@
 #define CSR_MTVEC           0x305
 #define CSR_MCOUNTEREN      0x306
 
+/* 32-bit only */
+#define CSR_MSTATUSH        0x310
+
 /* Legacy Counter Setup (priv v1.9.1) */
 /* Update to #define CSR_MCOUNTINHIBIT 0x320 for 1.11.0 */
 #define CSR_MUCOUNTEREN     0x320
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index d3b764e694..10f246ddf8 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -126,6 +126,11 @@ void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
         env->mstatus &= ~mstatus_mask;
         env->mstatus |= env->mstatus_hs;
 
+#if defined(TARGET_RISCV32)
+        env->vsstatush = env->mstatush;
+        env->mstatush |= env->mstatush_hs;
+#endif
+
         env->vstvec = env->stvec;
         env->stvec = env->stvec_hs;
 
@@ -149,6 +154,11 @@ void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
         env->mstatus &= ~mstatus_mask;
         env->mstatus |= env->vsstatus;
 
+#if defined(TARGET_RISCV32)
+        env->mstatush_hs = env->mstatush;
+        env->mstatush |= env->vsstatush;
+#endif
+
         env->stvec_hs = env->stvec;
         env->stvec = env->vstvec;
 
@@ -939,10 +949,17 @@ void riscv_cpu_do_interrupt(CPUState *cs)
             if (riscv_cpu_virt_enabled(env)) {
                 riscv_cpu_swap_hypervisor_regs(env);
             }
+#ifdef TARGET_RISCV32
+            env->mstatush = set_field(env->mstatush, MSTATUS_MPV,
+                                       riscv_cpu_virt_enabled(env));
+            env->mstatush = set_field(env->mstatush, MSTATUS_MTL,
+                                       riscv_cpu_force_hs_excep_enabled(env));
+#else
             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));
+#endif
 
             mtval2 = env->guest_phys_fault_addr;
 
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 2e6700bbeb..572a478e8c 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -371,6 +371,27 @@ static int write_mstatus(CPURISCVState *env, int csrno, target_ulong val)
     return 0;
 }
 
+#ifdef TARGET_RISCV32
+static int read_mstatush(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->mstatush;
+    return 0;
+}
+
+static int write_mstatush(CPURISCVState *env, int csrno, target_ulong val)
+{
+    if ((val ^ env->mstatush) & (MSTATUS_MPV)) {
+        tlb_flush(env_cpu(env));
+    }
+
+    val &= MSTATUS_MPV | MSTATUS_MTL;
+
+    env->mstatush = val;
+
+    return 0;
+}
+#endif
+
 static int read_misa(CPURISCVState *env, int csrno, target_ulong *val)
 {
     *val = env->misa;
@@ -1214,6 +1235,10 @@ static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_MTVEC] =               { any,  read_mtvec,       write_mtvec       },
     [CSR_MCOUNTEREN] =          { any,  read_mcounteren,  write_mcounteren  },
 
+#if defined(TARGET_RISCV32)
+    [CSR_MSTATUSH] =            { any,  read_mstatush,    write_mstatush    },
+#endif
+
     /* Legacy Counter Setup (priv v1.9.1) */
     [CSR_MUCOUNTEREN] =         { any,  read_mucounteren, write_mucounteren },
     [CSR_MSCOUNTEREN] =         { any,  read_mscounteren, write_mscounteren },
diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index 804936e9d5..dca68fa96e 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -153,7 +153,11 @@ target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb)
         get_field(mstatus, MSTATUS_MPIE));
     mstatus = set_field(mstatus, MSTATUS_MPIE, 1);
     mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
+#ifdef TARGET_RISCV32
+    env->mstatush = set_field(env->mstatush, MSTATUS_MPV, 0);
+#else
     mstatus = set_field(mstatus, MSTATUS_MPV, 0);
+#endif
     env->mstatus = mstatus;
     riscv_cpu_set_mode(env, prev_priv);
 
-- 
cgit v1.2.3-55-g7522


From c9eefe05a42d05d7a6dc49805f123579e5558d5d Mon Sep 17 00:00:00 2001
From: Alistair Francis
Date: Fri, 31 Jan 2020 17:03:11 -0800
Subject: target/riscv: Allow enabling the Hypervisor extension

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/cpu.c | 5 +++++
 target/riscv/cpu.h | 1 +
 2 files changed, 6 insertions(+)

(limited to 'target/riscv/cpu.h')

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index b27066f6a7..c47d10b739 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -453,6 +453,9 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         if (cpu->cfg.ext_u) {
             target_misa |= RVU;
         }
+        if (cpu->cfg.ext_h) {
+            target_misa |= RVH;
+        }
 
         set_misa(env, RVXLEN | target_misa);
     }
@@ -488,6 +491,8 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("c", RISCVCPU, cfg.ext_c, true),
     DEFINE_PROP_BOOL("s", RISCVCPU, cfg.ext_s, true),
     DEFINE_PROP_BOOL("u", RISCVCPU, cfg.ext_u, true),
+    /* This is experimental so mark with 'x-' */
+    DEFINE_PROP_BOOL("x-h", RISCVCPU, cfg.ext_h, false),
     DEFINE_PROP_BOOL("Counters", RISCVCPU, cfg.ext_counters, true),
     DEFINE_PROP_BOOL("Zifencei", RISCVCPU, cfg.ext_ifencei, true),
     DEFINE_PROP_BOOL("Zicsr", RISCVCPU, cfg.ext_icsr, true),
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 6f9c29322a..d52f209361 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -258,6 +258,7 @@ typedef struct RISCVCPU {
         bool ext_c;
         bool ext_s;
         bool ext_u;
+        bool ext_h;
         bool ext_counters;
         bool ext_ifencei;
         bool ext_icsr;
-- 
cgit v1.2.3-55-g7522


From c695724868ce4049fd79c5a509880dbdf171e744 Mon Sep 17 00:00:00 2001
From: Anup Patel
Date: Sun, 2 Feb 2020 19:12:16 +0530
Subject: target/riscv: Emulate TIME CSRs for privileged mode

Currently, TIME CSRs are emulated only for user-only mode. This
patch add TIME CSRs emulation for privileged mode.

For privileged mode, the TIME CSRs will return value provided
by rdtime callback which is registered by QEMU machine/platform
emulation (i.e. CLINT emulation). If rdtime callback is not
available then the monitor (i.e. OpenSBI) will trap-n-emulate
TIME CSRs in software.

We see 25+% performance improvement in hackbench numbers when
TIME CSRs are not trap-n-emulated.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h        |  5 +++
 target/riscv/cpu_helper.c |  5 +++
 target/riscv/csr.c        | 86 ++++++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 92 insertions(+), 4 deletions(-)

(limited to 'target/riscv/cpu.h')

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index d52f209361..3dcdf92227 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -159,6 +159,7 @@ struct CPURISCVState {
     target_ulong htval;
     target_ulong htinst;
     target_ulong hgatp;
+    uint64_t htimedelta;
 
     /* Virtual CSRs */
     target_ulong vsstatus;
@@ -201,6 +202,9 @@ struct CPURISCVState {
     /* physical memory protection */
     pmp_table_t pmp_state;
 
+    /* machine specific rdtime callback */
+    uint64_t (*rdtime_fn)(void);
+
     /* True if in debugger mode.  */
     bool debugger;
 #endif
@@ -322,6 +326,7 @@ void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env);
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts);
 uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value);
 #define BOOL_TO_MASK(x) (-!!(x)) /* helper for riscv_cpu_update_mip value */
+void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(void));
 #endif
 void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv);
 
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 29a1b37d88..5ea5d133aa 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -258,6 +258,11 @@ uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value)
     return old;
 }
 
+void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(void))
+{
+    env->rdtime_fn = fn;
+}
+
 void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
 {
     if (newpriv > PRV_M) {
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 572a478e8c..11d184cd16 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -238,6 +238,32 @@ static int read_timeh(CPURISCVState *env, int csrno, target_ulong *val)
 
 #else /* CONFIG_USER_ONLY */
 
+static int read_time(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    uint64_t delta = riscv_cpu_virt_enabled(env) ? env->htimedelta : 0;
+
+    if (!env->rdtime_fn) {
+        return -1;
+    }
+
+    *val = env->rdtime_fn() + delta;
+    return 0;
+}
+
+#if defined(TARGET_RISCV32)
+static int read_timeh(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    uint64_t delta = riscv_cpu_virt_enabled(env) ? env->htimedelta : 0;
+
+    if (!env->rdtime_fn) {
+        return -1;
+    }
+
+    *val = (env->rdtime_fn() + delta) >> 32;
+    return 0;
+}
+#endif
+
 /* Machine constants */
 
 #define M_MODE_INTERRUPTS  (MIP_MSIP | MIP_MTIP | MIP_MEIP)
@@ -930,6 +956,56 @@ static int write_hgatp(CPURISCVState *env, int csrno, target_ulong val)
     return 0;
 }
 
+static int read_htimedelta(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    if (!env->rdtime_fn) {
+        return -1;
+    }
+
+#if defined(TARGET_RISCV32)
+    *val = env->htimedelta & 0xffffffff;
+#else
+    *val = env->htimedelta;
+#endif
+    return 0;
+}
+
+static int write_htimedelta(CPURISCVState *env, int csrno, target_ulong val)
+{
+    if (!env->rdtime_fn) {
+        return -1;
+    }
+
+#if defined(TARGET_RISCV32)
+    env->htimedelta = deposit64(env->htimedelta, 0, 32, (uint64_t)val);
+#else
+    env->htimedelta = val;
+#endif
+    return 0;
+}
+
+#if defined(TARGET_RISCV32)
+static int read_htimedeltah(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    if (!env->rdtime_fn) {
+        return -1;
+    }
+
+    *val = env->htimedelta >> 32;
+    return 0;
+}
+
+static int write_htimedeltah(CPURISCVState *env, int csrno, target_ulong val)
+{
+    if (!env->rdtime_fn) {
+        return -1;
+    }
+
+    env->htimedelta = deposit64(env->htimedelta, 32, 32, (uint64_t)val);
+    return 0;
+}
+#endif
+
 /* Virtual CSR Registers */
 static int read_vsstatus(CPURISCVState *env, int csrno, target_ulong *val)
 {
@@ -1202,14 +1278,12 @@ static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_INSTRETH] =            { ctr,  read_instreth                       },
 #endif
 
-    /* User-level time CSRs are only available in linux-user
-     * In privileged mode, the monitor emulates these CSRs */
-#if defined(CONFIG_USER_ONLY)
+    /* In privileged mode, the monitor will have to emulate TIME CSRs only if
+     * rdtime callback is not provided by machine/platform emulation */
     [CSR_TIME] =                { ctr,  read_time                           },
 #if defined(TARGET_RISCV32)
     [CSR_TIMEH] =               { ctr,  read_timeh                          },
 #endif
-#endif
 
 #if !defined(CONFIG_USER_ONLY)
     /* Machine Timers and Counters */
@@ -1275,6 +1349,10 @@ static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_HTVAL] =               { hmode,   read_htval,       write_htval      },
     [CSR_HTINST] =              { hmode,   read_htinst,      write_htinst     },
     [CSR_HGATP] =               { hmode,   read_hgatp,       write_hgatp      },
+    [CSR_HTIMEDELTA] =          { hmode,   read_htimedelta,  write_htimedelta },
+#if defined(TARGET_RISCV32)
+    [CSR_HTIMEDELTAH] =         { hmode,   read_htimedeltah, write_htimedeltah},
+#endif
 
     [CSR_VSSTATUS] =            { hmode,   read_vsstatus,    write_vsstatus   },
     [CSR_VSIP] =                { hmode,   NULL,     NULL,     rmw_vsip       },
-- 
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