[PATCH v2 0/5] Implement Sstc extension

[PATCH v2 0/5] Implement Sstc extension

[Atish Patra]

This series implements Sstc extension[1] which was ratified recently.

The first patch is a prepartory patches while PATCH 2 adds stimecmp
support while PATCH 3 adds vstimecmp support. This series is based on
on top of upstream commit (faee5441a038).

The series can also be found at
https://github.com/atishp04/qemu/tree/sstc_v2

It is tested on RV32 & RV64 with additional OpenSBI[2] & Linux kernel[3]
patches.

Changes from v1->v2:
1. Rebased on the latest upstream commit.
2. Replaced PATCH 1 with another patch where mtimer/timecmp is
   moved from CPU to ACLINT.
3. Added ACLINT migration support.

[1] https://drive.google.com/file/d/1m84Re2yK8m_vbW7TspvevCDR82MOBaSX/view
[2] https://github.com/atishp04/opensbi/tree/sstc_v2
[3] https://github.com/atishp04/linux/tree/sstc_v3

Atish Patra (5):
hw/intc: Move mtimer/mtimecmp to aclint
migration: Add 64bit variable array data type
hw/intc: Support migration of aclint device
target/riscv: Add stimecmp support
target/riscv: Add vstimecmp support

hw/intc/riscv_aclint.c         |  41 +++++---
hw/timer/ibex_timer.c          |  20 ++--
include/hw/intc/riscv_aclint.h |   2 +
include/hw/timer/ibex_timer.h  |   2 +
include/migration/vmstate.h    |  11 ++
migration/vmstate.c            |   2 +
target/riscv/cpu.c             |   8 ++
target/riscv/cpu.h             |  10 +-
target/riscv/cpu_bits.h        |   8 ++
target/riscv/cpu_helper.c      |  11 +-
target/riscv/csr.c             | 181 +++++++++++++++++++++++++++++++++
target/riscv/machine.c         |   3 +-
target/riscv/meson.build       |   3 +-
target/riscv/time_helper.c     | 114 +++++++++++++++++++++
target/riscv/time_helper.h     |  30 ++++++
15 files changed, 415 insertions(+), 31 deletions(-)
create mode 100644 target/riscv/time_helper.c
create mode 100644 target/riscv/time_helper.h

--
2.25.1

[PATCH v2 1/5] hw/intc: Move mtimer/mtimecmp to aclint

[Atish Patra]

Historically, The mtimer/mtimecmp has been part of the CPU because
they are per hart entities. However, they actually belong to aclint
which is a MMIO device.

Move them to the ACLINT device. This also emulates the real hardware
more closely.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 hw/intc/riscv_aclint.c         | 27 +++++++++++++++------------
 hw/timer/ibex_timer.c          | 20 ++++++++------------
 include/hw/intc/riscv_aclint.h |  2 ++
 include/hw/timer/ibex_timer.h  |  2 ++
 target/riscv/cpu.h             |  2 --
 target/riscv/machine.c         |  1 -
 6 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/hw/intc/riscv_aclint.c b/hw/intc/riscv_aclint.c
index 0412edc98257..1bddb99bda47 100644
--- a/hw/intc/riscv_aclint.c
+++ b/hw/intc/riscv_aclint.c
@@ -65,8 +65,8 @@ static void riscv_aclint_mtimer_write_timecmp(RISCVAclintMTimerState *mtimer,
 
     uint64_t rtc_r = cpu_riscv_read_rtc(mtimer);
 
-    cpu->env.timecmp = value;
-    if (cpu->env.timecmp <= rtc_r) {
+    mtimer->timecmp[hartid] = value;
+    if (mtimer->timecmp[hartid] <= rtc_r) {
         /*
          * If we're setting an MTIMECMP value in the "past",
          * immediately raise the timer interrupt
@@ -77,7 +77,7 @@ static void riscv_aclint_mtimer_write_timecmp(RISCVAclintMTimerState *mtimer,
 
     /* otherwise, set up the future timer interrupt */
     qemu_irq_lower(mtimer->timer_irqs[hartid - mtimer->hartid_base]);
-    diff = cpu->env.timecmp - rtc_r;
+    diff = mtimer->timecmp[hartid] - rtc_r;
     /* back to ns (note args switched in muldiv64) */
     uint64_t ns_diff = muldiv64(diff, NANOSECONDS_PER_SECOND, timebase_freq);
 
@@ -102,7 +102,7 @@ static void riscv_aclint_mtimer_write_timecmp(RISCVAclintMTimerState *mtimer,
         next = MIN(next, INT64_MAX);
     }
 
-    timer_mod(cpu->env.timer, next);
+    timer_mod(mtimer->timers[hartid], next);
 }
 
 /*
@@ -133,11 +133,11 @@ static uint64_t riscv_aclint_mtimer_read(void *opaque, hwaddr addr,
                           "aclint-mtimer: invalid hartid: %zu", hartid);
         } else if ((addr & 0x7) == 0) {
             /* timecmp_lo for RV32/RV64 or timecmp for RV64 */
-            uint64_t timecmp = env->timecmp;
+            uint64_t timecmp = mtimer->timecmp[hartid];
             return (size == 4) ? (timecmp & 0xFFFFFFFF) : timecmp;
         } else if ((addr & 0x7) == 4) {
             /* timecmp_hi */
-            uint64_t timecmp = env->timecmp;
+            uint64_t timecmp = mtimer->timecmp[hartid];
             return (timecmp >> 32) & 0xFFFFFFFF;
         } else {
             qemu_log_mask(LOG_UNIMP,
@@ -177,7 +177,7 @@ static void riscv_aclint_mtimer_write(void *opaque, hwaddr addr,
         } else if ((addr & 0x7) == 0) {
             if (size == 4) {
                 /* timecmp_lo for RV32/RV64 */
-                uint64_t timecmp_hi = env->timecmp >> 32;
+                uint64_t timecmp_hi = mtimer->timecmp[hartid] >> 32;
                 riscv_aclint_mtimer_write_timecmp(mtimer, RISCV_CPU(cpu), hartid,
                     timecmp_hi << 32 | (value & 0xFFFFFFFF));
             } else {
@@ -188,7 +188,7 @@ static void riscv_aclint_mtimer_write(void *opaque, hwaddr addr,
         } else if ((addr & 0x7) == 4) {
             if (size == 4) {
                 /* timecmp_hi for RV32/RV64 */
-                uint64_t timecmp_lo = env->timecmp;
+                uint64_t timecmp_lo = mtimer->timecmp[hartid];
                 riscv_aclint_mtimer_write_timecmp(mtimer, RISCV_CPU(cpu), hartid,
                     value << 32 | (timecmp_lo & 0xFFFFFFFF));
             } else {
@@ -233,7 +233,7 @@ static void riscv_aclint_mtimer_write(void *opaque, hwaddr addr,
                 continue;
             }
             riscv_aclint_mtimer_write_timecmp(mtimer, RISCV_CPU(cpu),
-                                              i, env->timecmp);
+                                              i, mtimer->timecmp[i]);
         }
         return;
     }
@@ -283,6 +283,8 @@ static void riscv_aclint_mtimer_realize(DeviceState *dev, Error **errp)
     s->timer_irqs = g_new(qemu_irq, s->num_harts);
     qdev_init_gpio_out(dev, s->timer_irqs, s->num_harts);
 
+    s->timers = g_malloc0(s->num_harts * sizeof(QEMUTimer));
+    s->timecmp = g_new(uint64_t, s->num_harts);
     /* Claim timer interrupt bits */
     for (i = 0; i < s->num_harts; i++) {
         RISCVCPU *cpu = RISCV_CPU(qemu_get_cpu(s->hartid_base + i));
@@ -335,6 +337,7 @@ DeviceState *riscv_aclint_mtimer_create(hwaddr addr, hwaddr size,
 {
     int i;
     DeviceState *dev = qdev_new(TYPE_RISCV_ACLINT_MTIMER);
+    RISCVAclintMTimerState *s = RISCV_ACLINT_MTIMER(dev);
 
     assert(num_harts <= RISCV_ACLINT_MAX_HARTS);
     assert(!(addr & 0x7));
@@ -365,11 +368,11 @@ DeviceState *riscv_aclint_mtimer_create(hwaddr addr, hwaddr size,
             riscv_cpu_set_rdtime_fn(env, cpu_riscv_read_rtc, dev);
         }
 
-        cb->s = RISCV_ACLINT_MTIMER(dev);
+        cb->s = s;
         cb->num = i;
-        env->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+        s->timers[i] = timer_new_ns(QEMU_CLOCK_VIRTUAL,
                                   &riscv_aclint_mtimer_cb, cb);
-        env->timecmp = 0;
+        s->timecmp[i] = 0;
 
         qdev_connect_gpio_out(dev, i,
                               qdev_get_gpio_in(DEVICE(rvcpu), IRQ_M_TIMER));
diff --git a/hw/timer/ibex_timer.c b/hw/timer/ibex_timer.c
index 8c2ca364daab..d7786b35101a 100644
--- a/hw/timer/ibex_timer.c
+++ b/hw/timer/ibex_timer.c
@@ -30,8 +30,8 @@
 #include "qemu/timer.h"
 #include "hw/timer/ibex_timer.h"
 #include "hw/irq.h"
-#include "hw/qdev-properties.h"
 #include "target/riscv/cpu.h"
+#include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
 
 REG32(ALERT_TEST, 0x00)
@@ -60,8 +60,6 @@ static uint64_t cpu_riscv_read_rtc(uint32_t timebase_freq)
 
 static void ibex_timer_update_irqs(IbexTimerState *s)
 {
-    CPUState *cs = qemu_get_cpu(0);
-    RISCVCPU *cpu = RISCV_CPU(cs);
     uint64_t value = s->timer_compare_lower0 |
                          ((uint64_t)s->timer_compare_upper0 << 32);
     uint64_t next, diff;
@@ -73,9 +71,9 @@ static void ibex_timer_update_irqs(IbexTimerState *s)
     }
 
     /* Update the CPUs mtimecmp */
-    cpu->env.timecmp = value;
+    s->mtimecmp = value;
 
-    if (cpu->env.timecmp <= now) {
+    if (s->mtimecmp <= now) {
         /*
          * If the mtimecmp was in the past raise the interrupt now.
          */
@@ -91,7 +89,7 @@ static void ibex_timer_update_irqs(IbexTimerState *s)
     qemu_irq_lower(s->m_timer_irq);
     qemu_set_irq(s->irq, false);
 
-    diff = cpu->env.timecmp - now;
+    diff = s->mtimecmp - now;
     next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
                                  muldiv64(diff,
                                           NANOSECONDS_PER_SECOND,
@@ -99,9 +97,9 @@ static void ibex_timer_update_irqs(IbexTimerState *s)
 
     if (next < qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)) {
         /* We overflowed the timer, just set it as large as we can */
-        timer_mod(cpu->env.timer, 0x7FFFFFFFFFFFFFFF);
+        timer_mod(s->mtimer, 0x7FFFFFFFFFFFFFFF);
     } else {
-        timer_mod(cpu->env.timer, next);
+        timer_mod(s->mtimer, next);
     }
 }
 
@@ -120,11 +118,9 @@ static void ibex_timer_reset(DeviceState *dev)
 {
     IbexTimerState *s = IBEX_TIMER(dev);
 
-    CPUState *cpu = qemu_get_cpu(0);
-    CPURISCVState *env = cpu->env_ptr;
-    env->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+    s->mtimer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
                               &ibex_timer_cb, s);
-    env->timecmp = 0;
+    s->mtimecmp = 0;
 
     s->timer_ctrl = 0x00000000;
     s->timer_cfg0 = 0x00010000;
diff --git a/include/hw/intc/riscv_aclint.h b/include/hw/intc/riscv_aclint.h
index 26d4048687fb..693415eb6def 100644
--- a/include/hw/intc/riscv_aclint.h
+++ b/include/hw/intc/riscv_aclint.h
@@ -32,6 +32,8 @@ typedef struct RISCVAclintMTimerState {
     /*< private >*/
     SysBusDevice parent_obj;
     uint64_t time_delta;
+    uint64_t *timecmp;
+    QEMUTimer **timers;
 
     /*< public >*/
     MemoryRegion mmio;
diff --git a/include/hw/timer/ibex_timer.h b/include/hw/timer/ibex_timer.h
index 1a0a28d5fab5..41f5c82a920b 100644
--- a/include/hw/timer/ibex_timer.h
+++ b/include/hw/timer/ibex_timer.h
@@ -33,6 +33,8 @@ OBJECT_DECLARE_SIMPLE_TYPE(IbexTimerState, IBEX_TIMER)
 struct IbexTimerState {
     /* <private> */
     SysBusDevice parent_obj;
+    uint64_t mtimecmp;
+    QEMUTimer *mtimer; /* Internal timer for M-mode interrupt */
 
     /* <public> */
     MemoryRegion mmio;
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 34c22d5d3be3..1119d5201066 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -275,7 +275,6 @@ struct CPUArchState {
     /* temporary htif regs */
     uint64_t mfromhost;
     uint64_t mtohost;
-    uint64_t timecmp;
 
     /* physical memory protection */
     pmp_table_t pmp_state;
@@ -330,7 +329,6 @@ struct CPUArchState {
     float_status fp_status;
 
     /* Fields from here on are preserved across CPU reset. */
-    QEMUTimer *timer; /* Internal timer */
 
     hwaddr kernel_addr;
     hwaddr fdt_addr;
diff --git a/target/riscv/machine.c b/target/riscv/machine.c
index 2a437b29a1ce..14a3c1d775bc 100644
--- a/target/riscv/machine.c
+++ b/target/riscv/machine.c
@@ -334,7 +334,6 @@ const VMStateDescription vmstate_riscv_cpu = {
         VMSTATE_UINTTL(env.mscratch, RISCVCPU),
         VMSTATE_UINT64(env.mfromhost, RISCVCPU),
         VMSTATE_UINT64(env.mtohost, RISCVCPU),
-        VMSTATE_UINT64(env.timecmp, RISCVCPU),
 
         VMSTATE_END_OF_LIST()
     },
-- 
2.25.1

[PATCH v2 2/5] migration: Add 64bit variable array data type

[Atish Patra]

unsigned 64bit variable array data type support is missing.
Add the required code to support it.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 include/migration/vmstate.h | 11 +++++++++++
 migration/vmstate.c         |  2 ++
 2 files changed, 13 insertions(+)

diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index ad24aa193451..d289caea0143 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -147,6 +147,7 @@ enum VMStateFlags {
      * VMStateField.struct_version_id to tell which version of the
      * structure we are referencing to use. */
     VMS_VSTRUCT           = 0x8000,
+    VMS_VARRAY_UINT64     = 0x10000,
 };
 
 typedef enum {
@@ -428,6 +429,16 @@ extern const VMStateInfo vmstate_info_qlist;
     .offset     = vmstate_offset_pointer(_state, _field, _type),     \
 }
 
+#define VMSTATE_VARRAY_UINT64(_field, _state, _field_num, _version, _info, _type) {\
+    .name       = (stringify(_field)),                               \
+    .version_id = (_version),                                        \
+    .num_offset = vmstate_offset_value(_state, _field_num, uint32_t),\
+    .info       = &(_info),                                          \
+    .size       = sizeof(_type),                                     \
+    .flags      = VMS_VARRAY_UINT64 | VMS_POINTER,                   \
+    .offset     = vmstate_offset_pointer(_state, _field, _type),     \
+}
+
 #define VMSTATE_VARRAY_UINT16_ALLOC(_field, _state, _field_num, _version, _info, _type) {\
     .name       = (stringify(_field)),                               \
     .version_id = (_version),                                        \
diff --git a/migration/vmstate.c b/migration/vmstate.c
index 36ae8b9e1918..3cd5e37ebe2d 100644
--- a/migration/vmstate.c
+++ b/migration/vmstate.c
@@ -35,6 +35,8 @@ static int vmstate_n_elems(void *opaque, const VMStateField *field)
         n_elems = *(int32_t *)(opaque + field->num_offset);
     } else if (field->flags & VMS_VARRAY_UINT32) {
         n_elems = *(uint32_t *)(opaque + field->num_offset);
+    } else if (field->flags & VMS_VARRAY_UINT64) {
+        n_elems = *(uint64_t *)(opaque + field->num_offset);
     } else if (field->flags & VMS_VARRAY_UINT16) {
         n_elems = *(uint16_t *)(opaque + field->num_offset);
     } else if (field->flags & VMS_VARRAY_UINT8) {
-- 
2.25.1

[PATCH v2 3/5] hw/intc: Support migration of aclint device

[Atish Patra]

mtimecmp is part of ACLINT device now. This needs to preserved across
migration.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 hw/intc/riscv_aclint.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/hw/intc/riscv_aclint.c b/hw/intc/riscv_aclint.c
index 1bddb99bda47..0bbc5e65737e 100644
--- a/hw/intc/riscv_aclint.c
+++ b/hw/intc/riscv_aclint.c
@@ -32,6 +32,7 @@
 #include "hw/intc/riscv_aclint.h"
 #include "qemu/timer.h"
 #include "hw/irq.h"
+#include "migration/vmstate.h"
 
 typedef struct riscv_aclint_mtimer_callback {
     RISCVAclintMTimerState *s;
@@ -311,6 +312,18 @@ static void riscv_aclint_mtimer_reset_enter(Object *obj, ResetType type)
     riscv_aclint_mtimer_write(mtimer, mtimer->time_base, 0, 8);
 }
 
+static const VMStateDescription vmstate_riscv_mtimer = {
+    .name = "riscv_mtimer",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+            VMSTATE_VARRAY_UINT64(timecmp, RISCVAclintMTimerState,
+                                  num_harts, 0,
+                                  vmstate_info_uint64, uint64_t),
+            VMSTATE_END_OF_LIST()
+        }
+};
+
 static void riscv_aclint_mtimer_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -318,6 +331,7 @@ static void riscv_aclint_mtimer_class_init(ObjectClass *klass, void *data)
     device_class_set_props(dc, riscv_aclint_mtimer_properties);
     ResettableClass *rc = RESETTABLE_CLASS(klass);
     rc->phases.enter = riscv_aclint_mtimer_reset_enter;
+    dc->vmsd = &vmstate_riscv_mtimer;
 }
 
 static const TypeInfo riscv_aclint_mtimer_info = {
-- 
2.25.1

[PATCH v2 4/5] target/riscv: Add stimecmp support

[Atish Patra]

stimecmp allows the supervisor mode to update stimecmp CSR directly
to program the next timer interrupt. This CSR is part of the Sstc
extension which was ratified recently.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 target/riscv/cpu.c         |  8 ++++
 target/riscv/cpu.h         |  5 ++
 target/riscv/cpu_bits.h    |  4 ++
 target/riscv/csr.c         | 83 ++++++++++++++++++++++++++++++++
 target/riscv/machine.c     |  1 +
 target/riscv/meson.build   |  3 +-
 target/riscv/time_helper.c | 98 ++++++++++++++++++++++++++++++++++++++
 target/riscv/time_helper.h | 30 ++++++++++++
 8 files changed, 231 insertions(+), 1 deletion(-)
 create mode 100644 target/riscv/time_helper.c
 create mode 100644 target/riscv/time_helper.h

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 0c774056c5c3..6d16aeeacf0c 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -23,6 +23,7 @@
 #include "qemu/log.h"
 #include "cpu.h"
 #include "internals.h"
+#include "time_helper.h"
 #include "exec/exec-all.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
@@ -777,7 +778,12 @@ static void riscv_cpu_init(Object *obj)
 #ifndef CONFIG_USER_ONLY
     qdev_init_gpio_in(DEVICE(cpu), riscv_cpu_set_irq,
                       IRQ_LOCAL_MAX + IRQ_LOCAL_GUEST_MAX);
+
+    if (cpu->cfg.ext_sstc) {
+        riscv_timer_init(cpu);
+    }
 #endif /* CONFIG_USER_ONLY */
+
 }
 
 static Property riscv_cpu_properties[] = {
@@ -804,6 +810,7 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
     DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),
     DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
+    DEFINE_PROP_BOOL("sstc", RISCVCPU, cfg.ext_sstc, true),
 
     DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
     DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec),
@@ -963,6 +970,7 @@ static void riscv_isa_string_ext(RISCVCPU *cpu, char **isa_str, int max_str_len)
         ISA_EDATA_ENTRY(zbs, ext_zbs),
         ISA_EDATA_ENTRY(zve32f, ext_zve32f),
         ISA_EDATA_ENTRY(zve64f, ext_zve64f),
+        ISA_EDATA_ENTRY(sstc, ext_sstc),
         ISA_EDATA_ENTRY(svinval, ext_svinval),
         ISA_EDATA_ENTRY(svnapot, ext_svnapot),
         ISA_EDATA_ENTRY(svpbmt, ext_svpbmt),
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 1119d5201066..9a5e02f217ba 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -276,6 +276,9 @@ struct CPUArchState {
     uint64_t mfromhost;
     uint64_t mtohost;
 
+    /* Sstc CSRs */
+    uint64_t stimecmp;
+
     /* physical memory protection */
     pmp_table_t pmp_state;
     target_ulong mseccfg;
@@ -329,6 +332,7 @@ struct CPUArchState {
     float_status fp_status;
 
     /* Fields from here on are preserved across CPU reset. */
+    QEMUTimer *stimer; /* Internal timer for S-mode interrupt */
 
     hwaddr kernel_addr;
     hwaddr fdt_addr;
@@ -379,6 +383,7 @@ struct RISCVCPUConfig {
     bool ext_counters;
     bool ext_ifencei;
     bool ext_icsr;
+    bool ext_sstc;
     bool ext_svinval;
     bool ext_svnapot;
     bool ext_svpbmt;
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 4a9e4f7d09d9..631b7c32b38f 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -212,6 +212,10 @@
 #define CSR_STVAL           0x143
 #define CSR_SIP             0x144
 
+/* Sstc supervisor CSRs */
+#define CSR_STIMECMP        0x14D
+#define CSR_STIMECMPH       0x15D
+
 /* Supervisor Protection and Translation */
 #define CSR_SPTBR           0x180
 #define CSR_SATP            0x180
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 6ba85e7b5da2..c51c05d2ea74 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -21,6 +21,7 @@
 #include "qemu/log.h"
 #include "qemu/timer.h"
 #include "cpu.h"
+#include "time_helper.h"
 #include "qemu/main-loop.h"
 #include "exec/exec-all.h"
 #include "sysemu/cpu-timers.h"
@@ -537,6 +538,78 @@ static RISCVException read_timeh(CPURISCVState *env, int csrno,
     return RISCV_EXCP_NONE;
 }
 
+static RISCVException sstc(CPURISCVState *env, int csrno)
+{
+    CPUState *cs = env_cpu(env);
+    RISCVCPU *cpu = RISCV_CPU(cs);
+
+    if (!cpu->cfg.ext_sstc || !env->rdtime_fn) {
+        return RISCV_EXCP_ILLEGAL_INST;
+    }
+
+    if (env->priv == PRV_M) {
+        return RISCV_EXCP_NONE;
+    }
+
+    if (env->priv != PRV_S) {
+        return RISCV_EXCP_ILLEGAL_INST;
+    }
+
+    /*
+     * No need of separate function for rv32 as menvcfg stores both menvcfg
+     * menvcfgh for RV32.
+     */
+    if (!(get_field(env->mcounteren, COUNTEREN_TM) &&
+          get_field(env->menvcfg, MENVCFG_STCE))) {
+        return RISCV_EXCP_ILLEGAL_INST;
+    }
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException read_stimecmp(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
+{
+    *val = env->stimecmp;
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException read_stimecmph(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
+{
+    *val = env->stimecmp >> 32;
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_stimecmp(CPURISCVState *env, int csrno,
+                                    target_ulong val)
+{
+    RISCVCPU *cpu = env_archcpu(env);
+
+    if (riscv_cpu_mxl(env) == MXL_RV32) {
+        uint64_t stimecmp_hi = env->stimecmp >> 32;
+        env->stimecmp = (stimecmp_hi << 32) | (val & 0xFFFFFFFF);
+    } else {
+        env->stimecmp = val;
+        riscv_timer_write_timecmp(cpu, env->stimer, env->stimecmp, 0, MIP_STIP);
+    }
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_stimecmph(CPURISCVState *env, int csrno,
+                                    target_ulong val)
+{
+    RISCVCPU *cpu = env_archcpu(env);
+    uint64_t timer_val = 0;
+
+    timer_val = (uint64_t)val << 32 | (env->stimecmp & 0xFFFFFFFF);
+    env->stimecmp = timer_val;
+    riscv_timer_write_timecmp(cpu, env->stimer, env->stimecmp, 0, MIP_STIP);
+
+    return RISCV_EXCP_NONE;
+}
+
 /* Machine constants */
 
 #define M_MODE_INTERRUPTS  ((uint64_t)(MIP_MSIP | MIP_MTIP | MIP_MEIP))
@@ -1515,6 +1588,12 @@ static RISCVException rmw_mip64(CPURISCVState *env, int csrno,
         new_val |= env->external_seip * MIP_SEIP;
     }
 
+    if (cpu->cfg.ext_sstc && (env->priv == PRV_M) &&
+        get_field(env->menvcfg, MENVCFG_STCE)) {
+        /* sstc extension forbids STIP & VSTIP to be writeable in mip */
+        mask = mask & ~(MIP_STIP | MIP_VSTIP);
+    }
+
     if (mask) {
         old_mip = riscv_cpu_update_mip(cpu, mask, (new_val & mask));
     } else {
@@ -3339,6 +3418,10 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_SCAUSE]   = { "scause",   smode, read_scause,   write_scause   },
     [CSR_STVAL]    = { "stval",    smode, read_stval,   write_stval   },
     [CSR_SIP]      = { "sip",      smode, NULL,    NULL, rmw_sip        },
+    [CSR_STIMECMP] = { "stimecmp", sstc, read_stimecmp, write_stimecmp,
+                                          .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_STIMECMPH] = { "stimecmph", sstc, read_stimecmph, write_stimecmph,
+                                          .min_priv_ver = PRIV_VERSION_1_12_0 },
 
     /* Supervisor Protection and Translation */
     [CSR_SATP]     = { "satp",     smode, read_satp,    write_satp      },
diff --git a/target/riscv/machine.c b/target/riscv/machine.c
index 14a3c1d775bc..e50d82a6085e 100644
--- a/target/riscv/machine.c
+++ b/target/riscv/machine.c
@@ -334,6 +334,7 @@ const VMStateDescription vmstate_riscv_cpu = {
         VMSTATE_UINTTL(env.mscratch, RISCVCPU),
         VMSTATE_UINT64(env.mfromhost, RISCVCPU),
         VMSTATE_UINT64(env.mtohost, RISCVCPU),
+        VMSTATE_UINT64(env.stimecmp, RISCVCPU),
 
         VMSTATE_END_OF_LIST()
     },
diff --git a/target/riscv/meson.build b/target/riscv/meson.build
index 2c20f3dd8e9c..1243d019148e 100644
--- a/target/riscv/meson.build
+++ b/target/riscv/meson.build
@@ -29,7 +29,8 @@ riscv_softmmu_ss.add(files(
   'pmp.c',
   'debug.c',
   'monitor.c',
-  'machine.c'
+  'machine.c',
+  'time_helper.c'
 ))
 
 target_arch += {'riscv': riscv_ss}
diff --git a/target/riscv/time_helper.c b/target/riscv/time_helper.c
new file mode 100644
index 000000000000..f3fb5eac7b7b
--- /dev/null
+++ b/target/riscv/time_helper.c
@@ -0,0 +1,98 @@
+/*
+ * RISC-V timer helper implementation.
+ *
+ * Copyright (c) 2022 Rivos Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "cpu_bits.h"
+#include "time_helper.h"
+#include "hw/intc/riscv_aclint.h"
+
+static void riscv_stimer_cb(void *opaque)
+{
+    RISCVCPU *cpu = opaque;
+    riscv_cpu_update_mip(cpu, MIP_STIP, BOOL_TO_MASK(1));
+}
+
+/*
+ * Called when timecmp is written to update the QEMU timer or immediately
+ * trigger timer interrupt if mtimecmp <= current timer value.
+ */
+void riscv_timer_write_timecmp(RISCVCPU *cpu, QEMUTimer *timer,
+                               uint64_t timecmp, uint64_t delta,
+                               uint32_t timer_irq)
+{
+    uint64_t diff, ns_diff, next;
+    CPURISCVState *env = &cpu->env;
+    RISCVAclintMTimerState *mtimer = env->rdtime_fn_arg;
+    uint32_t timebase_freq = mtimer->timebase_freq;
+    uint64_t rtc_r = env->rdtime_fn(env->rdtime_fn_arg) + delta;
+
+    if (timecmp <= rtc_r) {
+        /*
+         * If we're setting an stimecmp value in the "past",
+         * immediately raise the timer interrupt
+         */
+        riscv_cpu_update_mip(cpu, timer_irq, BOOL_TO_MASK(1));
+        return;
+    }
+
+    /* Clear the [V]STIP bit in mip */
+    riscv_cpu_update_mip(cpu, timer_irq, BOOL_TO_MASK(0));
+
+    /* otherwise, set up the future timer interrupt */
+    diff = timecmp - rtc_r;
+    /* back to ns (note args switched in muldiv64) */
+    ns_diff = muldiv64(diff, NANOSECONDS_PER_SECOND, timebase_freq);
+
+    /*
+     * check if ns_diff overflowed and check if the addition would potentially
+     * overflow
+     */
+    if ((NANOSECONDS_PER_SECOND > timebase_freq && ns_diff < diff) ||
+        ns_diff > INT64_MAX) {
+        next = INT64_MAX;
+    } else {
+        /*
+         * as it is very unlikely qemu_clock_get_ns will return a value
+         * greater than INT64_MAX, no additional check is needed for an
+         * unsigned integer overflow.
+         */
+        next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + ns_diff;
+        /*
+         * if ns_diff is INT64_MAX next may still be outside the range
+         * of a signed integer.
+         */
+        next = MIN(next, INT64_MAX);
+    }
+
+    timer_mod(timer, next);
+}
+
+void riscv_timer_init(RISCVCPU *cpu)
+{
+    CPURISCVState *env;
+
+    if (!cpu) {
+        return;
+    }
+
+    env = &cpu->env;
+    env->stimer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &riscv_stimer_cb, cpu);
+    env->stimecmp = 0;
+
+}
diff --git a/target/riscv/time_helper.h b/target/riscv/time_helper.h
new file mode 100644
index 000000000000..7b3cdcc35020
--- /dev/null
+++ b/target/riscv/time_helper.h
@@ -0,0 +1,30 @@
+/*
+ * RISC-V timer header file.
+ *
+ * Copyright (c) 2022 Rivos Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef RISCV_TIME_HELPER_H
+#define RISCV_TIME_HELPER_H
+
+#include "cpu.h"
+#include "qemu/timer.h"
+
+void riscv_timer_write_timecmp(RISCVCPU *cpu, QEMUTimer *timer,
+                               uint64_t timecmp, uint64_t delta,
+                               uint32_t timer_irq);
+void riscv_timer_init(RISCVCPU *cpu);
+
+#endif
-- 
2.25.1

[PATCH v2 5/5] target/riscv: Add vstimecmp support

[Atish Patra]

vstimecmp CSR allows the guest OS or to program the next guest timer
interrupt directly. Thus, hypervisor no longer need to inject the
timer interrupt to the guest if vstimecmp is used. This was ratified
as a part of the Sstc extension.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 target/riscv/cpu.h         |   3 ++
 target/riscv/cpu_bits.h    |   4 ++
 target/riscv/cpu_helper.c  |  11 ++--
 target/riscv/csr.c         | 102 ++++++++++++++++++++++++++++++++++++-
 target/riscv/machine.c     |   1 +
 target/riscv/time_helper.c |  16 ++++++
 6 files changed, 132 insertions(+), 5 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 9a5e02f217ba..29d8ab1aaca6 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -278,6 +278,7 @@ struct CPUArchState {
 
     /* Sstc CSRs */
     uint64_t stimecmp;
+    uint64_t vstimecmp;
 
     /* physical memory protection */
     pmp_table_t pmp_state;
@@ -333,6 +334,8 @@ struct CPUArchState {
 
     /* Fields from here on are preserved across CPU reset. */
     QEMUTimer *stimer; /* Internal timer for S-mode interrupt */
+    QEMUTimer *vstimer; /* Internal timer for VS-mode interrupt */
+    bool vstime_irq;
 
     hwaddr kernel_addr;
     hwaddr fdt_addr;
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 631b7c32b38f..ce33bf8befbb 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -269,6 +269,10 @@
 #define CSR_VSIP            0x244
 #define CSR_VSATP           0x280
 
+/* Sstc virtual CSRs */
+#define CSR_VSTIMECMP       0x24D
+#define CSR_VSTIMECMPH      0x25D
+
 #define CSR_MTINST          0x34a
 #define CSR_MTVAL2          0x34b
 
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index e1aa4f2097c1..2715021c022e 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -344,8 +344,9 @@ static uint64_t riscv_cpu_all_pending(CPURISCVState *env)
 {
     uint32_t gein = get_field(env->hstatus, HSTATUS_VGEIN);
     uint64_t vsgein = (env->hgeip & (1ULL << gein)) ? MIP_VSEIP : 0;
+    uint64_t vstip = (env->vstime_irq) ? MIP_VSTIP : 0;
 
-    return (env->mip | vsgein) & env->mie;
+    return (env->mip | vsgein | vstip) & env->mie;
 }
 
 int riscv_cpu_mirq_pending(CPURISCVState *env)
@@ -604,7 +605,7 @@ uint64_t riscv_cpu_update_mip(RISCVCPU *cpu, uint64_t mask, uint64_t value)
 {
     CPURISCVState *env = &cpu->env;
     CPUState *cs = CPU(cpu);
-    uint64_t gein, vsgein = 0, old = env->mip;
+    uint64_t gein, vsgein = 0, vstip = 0, old = env->mip;
     bool locked = false;
 
     if (riscv_cpu_virt_enabled(env)) {
@@ -612,6 +613,10 @@ uint64_t riscv_cpu_update_mip(RISCVCPU *cpu, uint64_t mask, uint64_t value)
         vsgein = (env->hgeip & (1ULL << gein)) ? MIP_VSEIP : 0;
     }
 
+    /* No need to update mip for VSTIP */
+    mask = ((mask == MIP_VSTIP) && env->vstime_irq) ? 0 : mask;
+    vstip = env->vstime_irq ? MIP_VSTIP : 0;
+
     if (!qemu_mutex_iothread_locked()) {
         locked = true;
         qemu_mutex_lock_iothread();
@@ -619,7 +624,7 @@ uint64_t riscv_cpu_update_mip(RISCVCPU *cpu, uint64_t mask, uint64_t value)
 
     env->mip = (env->mip & ~mask) | (value & mask);
 
-    if (env->mip | vsgein) {
+    if (env->mip | vsgein | vstip) {
         cpu_interrupt(cs, CPU_INTERRUPT_HARD);
     } else {
         cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index c51c05d2ea74..c96c12a8ac74 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -567,17 +567,100 @@ static RISCVException sstc(CPURISCVState *env, int csrno)
     return RISCV_EXCP_NONE;
 }
 
+static RISCVException sstc_hmode(CPURISCVState *env, int csrno)
+{
+    CPUState *cs = env_cpu(env);
+    RISCVCPU *cpu = RISCV_CPU(cs);
+
+    if (!cpu->cfg.ext_sstc || !env->rdtime_fn) {
+        return RISCV_EXCP_ILLEGAL_INST;
+    }
+
+    if (env->priv == PRV_M) {
+        return RISCV_EXCP_NONE;
+    }
+
+    if (!(get_field(env->mcounteren, COUNTEREN_TM) &
+          get_field(env->menvcfg, MENVCFG_STCE))) {
+        return RISCV_EXCP_ILLEGAL_INST;
+    }
+
+    if (!(get_field(env->hcounteren, COUNTEREN_TM) &
+          get_field(env->henvcfg, HENVCFG_STCE))) {
+        return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+    }
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException read_vstimecmp(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
+{
+    *val = env->vstimecmp;
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException read_vstimecmph(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
+{
+    *val = env->vstimecmp >> 32;
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_vstimecmp(CPURISCVState *env, int csrno,
+                                    target_ulong val)
+{
+    RISCVCPU *cpu = env_archcpu(env);
+
+    if (riscv_cpu_mxl(env) == MXL_RV32) {
+        uint64_t vstimecmp_hi = env->vstimecmp >> 32;
+        env->vstimecmp = (vstimecmp_hi << 32) | (val & 0xFFFFFFFF);
+    } else {
+        env->vstimecmp = val;
+        riscv_timer_write_timecmp(cpu, env->vstimer, env->vstimecmp,
+                                  env->htimedelta, MIP_VSTIP);
+    }
+
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_vstimecmph(CPURISCVState *env, int csrno,
+                                    target_ulong val)
+{
+    RISCVCPU *cpu = env_archcpu(env);
+    uint64_t timer_val = 0;
+
+    timer_val = (uint64_t)val << 32 | (env->vstimecmp & 0xFFFFFFFF);
+    env->vstimecmp = timer_val;
+    riscv_timer_write_timecmp(cpu, env->vstimer, env->vstimecmp,
+                              env->htimedelta, MIP_VSTIP);
+
+    return RISCV_EXCP_NONE;
+}
+
 static RISCVException read_stimecmp(CPURISCVState *env, int csrno,
                                     target_ulong *val)
 {
-    *val = env->stimecmp;
+    if (riscv_cpu_virt_enabled(env)) {
+        *val = env->vstimecmp;
+    } else {
+        *val = env->stimecmp;
+    }
+
     return RISCV_EXCP_NONE;
 }
 
 static RISCVException read_stimecmph(CPURISCVState *env, int csrno,
                                     target_ulong *val)
 {
-    *val = env->stimecmp >> 32;
+    if (riscv_cpu_virt_enabled(env)) {
+        *val = env->vstimecmp >> 32;
+    } else {
+        *val = env->stimecmp >> 32;
+    }
+
     return RISCV_EXCP_NONE;
 }
 
@@ -586,6 +669,10 @@ static RISCVException write_stimecmp(CPURISCVState *env, int csrno,
 {
     RISCVCPU *cpu = env_archcpu(env);
 
+    if (riscv_cpu_virt_enabled(env)) {
+        return write_vstimecmp(env, csrno, val);
+    }
+
     if (riscv_cpu_mxl(env) == MXL_RV32) {
         uint64_t stimecmp_hi = env->stimecmp >> 32;
         env->stimecmp = (stimecmp_hi << 32) | (val & 0xFFFFFFFF);
@@ -603,6 +690,10 @@ static RISCVException write_stimecmph(CPURISCVState *env, int csrno,
     RISCVCPU *cpu = env_archcpu(env);
     uint64_t timer_val = 0;
 
+    if (riscv_cpu_virt_enabled(env)) {
+        return write_vstimecmph(env, csrno, val);
+    }
+
     timer_val = (uint64_t)val << 32 | (env->stimecmp & 0xFFFFFFFF);
     env->stimecmp = timer_val;
     riscv_timer_write_timecmp(cpu, env->stimer, env->stimecmp, 0, MIP_STIP);
@@ -1603,6 +1694,7 @@ static RISCVException rmw_mip64(CPURISCVState *env, int csrno,
     if (csrno != CSR_HVIP) {
         gin = get_field(env->hstatus, HSTATUS_VGEIN);
         old_mip |= (env->hgeip & ((target_ulong)1 << gin)) ? MIP_VSEIP : 0;
+        old_mip |= env->vstime_irq ? MIP_VSTIP : 0;
     }
 
     if (ret_val) {
@@ -3422,6 +3514,12 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
                                           .min_priv_ver = PRIV_VERSION_1_12_0 },
     [CSR_STIMECMPH] = { "stimecmph", sstc, read_stimecmph, write_stimecmph,
                                           .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VSTIMECMP] = { "vstimecmp", sstc_hmode, read_vstimecmp,
+                                          write_vstimecmp,
+                                          .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VSTIMECMPH] = { "vstimecmph", sstc_hmode, read_vstimecmph,
+                                          write_vstimecmph,
+                                          .min_priv_ver = PRIV_VERSION_1_12_0 },
 
     /* Supervisor Protection and Translation */
     [CSR_SATP]     = { "satp",     smode, read_satp,    write_satp      },
diff --git a/target/riscv/machine.c b/target/riscv/machine.c
index e50d82a6085e..c3628c949640 100644
--- a/target/riscv/machine.c
+++ b/target/riscv/machine.c
@@ -92,6 +92,7 @@ static const VMStateDescription vmstate_hyper = {
         VMSTATE_UINTTL(env.hgeie, RISCVCPU),
         VMSTATE_UINTTL(env.hgeip, RISCVCPU),
         VMSTATE_UINT64(env.htimedelta, RISCVCPU),
+        VMSTATE_UINT64(env.vstimecmp, RISCVCPU),
 
         VMSTATE_UINTTL(env.hvictl, RISCVCPU),
         VMSTATE_UINT8_ARRAY(env.hviprio, RISCVCPU, 64),
diff --git a/target/riscv/time_helper.c b/target/riscv/time_helper.c
index f3fb5eac7b7b..8cce667dfd47 100644
--- a/target/riscv/time_helper.c
+++ b/target/riscv/time_helper.c
@@ -22,6 +22,14 @@
 #include "time_helper.h"
 #include "hw/intc/riscv_aclint.h"
 
+static void riscv_vstimer_cb(void *opaque)
+{
+    RISCVCPU *cpu = opaque;
+    CPURISCVState *env = &cpu->env;
+    env->vstime_irq = 1;
+    riscv_cpu_update_mip(cpu, MIP_VSTIP, BOOL_TO_MASK(1));
+}
+
 static void riscv_stimer_cb(void *opaque)
 {
     RISCVCPU *cpu = opaque;
@@ -47,10 +55,16 @@ void riscv_timer_write_timecmp(RISCVCPU *cpu, QEMUTimer *timer,
          * If we're setting an stimecmp value in the "past",
          * immediately raise the timer interrupt
          */
+        if (timer_irq == MIP_VSTIP) {
+            env->vstime_irq = 1;
+        }
         riscv_cpu_update_mip(cpu, timer_irq, BOOL_TO_MASK(1));
         return;
     }
 
+    if (timer_irq == MIP_VSTIP) {
+        env->vstime_irq = 0;
+    }
     /* Clear the [V]STIP bit in mip */
     riscv_cpu_update_mip(cpu, timer_irq, BOOL_TO_MASK(0));
 
@@ -95,4 +109,6 @@ void riscv_timer_init(RISCVCPU *cpu)
     env->stimer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &riscv_stimer_cb, cpu);
     env->stimecmp = 0;
 
+    env->vstimer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &riscv_vstimer_cb, cpu);
+    env->vstimecmp = 0;
 }
-- 
2.25.1

Re: [PATCH v2 2/5] migration: Add 64bit variable array data type

[Richard Henderson]

On 4/26/22 16:08, Atish Patra wrote:
> +    .num_offset = vmstate_offset_value(_state, _field_num, uint32_t),\
...
>       } else if (field->flags & VMS_VARRAY_UINT32) {
>           n_elems = *(uint32_t *)(opaque + field->num_offset);
> +    } else if (field->flags & VMS_VARRAY_UINT64) {
> +        n_elems = *(uint64_t *)(opaque + field->num_offset);

Offset type mismatch.  Since num_harts is uint32_t, I don't believe you need this patch at 
all.


r~

Re: [PATCH v2 1/5] hw/intc: Move mtimer/mtimecmp to aclint

[Richard Henderson]

On 4/26/22 16:08, Atish Patra wrote:
> @@ -334,7 +334,6 @@ const VMStateDescription vmstate_riscv_cpu = {
>           VMSTATE_UINTTL(env.mscratch, RISCVCPU),
>           VMSTATE_UINT64(env.mfromhost, RISCVCPU),
>           VMSTATE_UINT64(env.mtohost, RISCVCPU),
> -        VMSTATE_UINT64(env.timecmp, RISCVCPU),
>   

Must bump version_id and minimum_version_id.

r~

Re: [PATCH v2 3/5] hw/intc: Support migration of aclint device

[Richard Henderson]

On 4/26/22 16:08, Atish Patra wrote:
> mtimecmp is part of ACLINT device now. This needs to preserved across
> migration.
> 
> Signed-off-by: Atish Patra <atishp@rivosinc.com>

This must be squashed with patch 1.

> +    .fields = (VMStateField[]) {
> +            VMSTATE_VARRAY_UINT64(timecmp, RISCVAclintMTimerState,

And this must be UINT32 to match num_harts.


r~

Re: [PATCH v2 4/5] target/riscv: Add stimecmp support

[Richard Henderson]

On 4/26/22 16:08, Atish Patra wrote:
> +static RISCVException write_stimecmp(CPURISCVState *env, int csrno,
> +                                    target_ulong val)
> +{
> +    RISCVCPU *cpu = env_archcpu(env);
> +
> +    if (riscv_cpu_mxl(env) == MXL_RV32) {
> +        uint64_t stimecmp_hi = env->stimecmp >> 32;
> +        env->stimecmp = (stimecmp_hi << 32) | (val & 0xFFFFFFFF);
> +    } else {
> +        env->stimecmp = val;
> +        riscv_timer_write_timecmp(cpu, env->stimer, env->stimecmp, 0, MIP_STIP);
> +    }
> +
> +    return RISCV_EXCP_NONE;
> +}
> +
> +static RISCVException write_stimecmph(CPURISCVState *env, int csrno,
> +                                    target_ulong val)
> +{
> +    RISCVCPU *cpu = env_archcpu(env);
> +    uint64_t timer_val = 0;
> +
> +    timer_val = (uint64_t)val << 32 | (env->stimecmp & 0xFFFFFFFF);
> +    env->stimecmp = timer_val;
> +    riscv_timer_write_timecmp(cpu, env->stimer, env->stimecmp, 0, MIP_STIP);
> +
> +    return RISCV_EXCP_NONE;
> +}

Use deposit64() instead of open-coding the inserts.


r~

Re: [PATCH v2 1/5] hw/intc: Move mtimer/mtimecmp to aclint

[Atish Kumar Patra]

On Tue, Apr 26, 2022 at 5:50 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 4/26/22 16:08, Atish Patra wrote:
> > @@ -334,7 +334,6 @@ const VMStateDescription vmstate_riscv_cpu = {
> >           VMSTATE_UINTTL(env.mscratch, RISCVCPU),
> >           VMSTATE_UINT64(env.mfromhost, RISCVCPU),
> >           VMSTATE_UINT64(env.mtohost, RISCVCPU),
> > -        VMSTATE_UINT64(env.timecmp, RISCVCPU),
> >
>
> Must bump version_id and minimum_version_id.
>

Yeah. Fixed that. Thanks.

> r~

Re: [PATCH v2 2/5] migration: Add 64bit variable array data type

[Atish Kumar Patra]

On Tue, Apr 26, 2022 at 5:50 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 4/26/22 16:08, Atish Patra wrote:
> > +    .num_offset = vmstate_offset_value(_state, _field_num, uint32_t),\
> ...
> >       } else if (field->flags & VMS_VARRAY_UINT32) {
> >           n_elems = *(uint32_t *)(opaque + field->num_offset);
> > +    } else if (field->flags & VMS_VARRAY_UINT64) {
> > +        n_elems = *(uint64_t *)(opaque + field->num_offset);
>
> Offset type mismatch.  Since num_harts is uint32_t, I don't believe you need this patch at
> all.
>

Ahh yes. You are right. I read the function description wrong and
assumed that VMSTATE_VARRAY_UINT32
creates an variable array of uint32_t elements only. Thanks for the
clarification.

>
> r~

Re: [PATCH v2 1/5] hw/intc: Move mtimer/mtimecmp to aclint

[Dr. David Alan Gilbert]

* Atish Kumar Patra (atishp@rivosinc.com) wrote:
> On Tue, Apr 26, 2022 at 5:50 PM Richard Henderson
> <richard.henderson@linaro.org> wrote:
> >
> > On 4/26/22 16:08, Atish Patra wrote:
> > > @@ -334,7 +334,6 @@ const VMStateDescription vmstate_riscv_cpu = {
> > >           VMSTATE_UINTTL(env.mscratch, RISCVCPU),
> > >           VMSTATE_UINT64(env.mfromhost, RISCVCPU),
> > >           VMSTATE_UINT64(env.mtohost, RISCVCPU),
> > > -        VMSTATE_UINT64(env.timecmp, RISCVCPU),
> > >
> >
> > Must bump version_id and minimum_version_id.
> >
> 
> Yeah. Fixed that. Thanks.

When you start getting stable machine type versions it'll become harder
and you might have to put dummy entries in to keep compatibility.

Dave

> > r~
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK