[PATCH v2 0/1] fix the way riscv_plic_hart_config_string() gets the CPUState

[PATCH v2 0/1] fix the way riscv_plic_hart_config_string() gets the CPUState

[Chao Liu]

Hi, all:

I made the following changes in version 2 of the patch:

Regarding the plic initialization phase to get CPUState by traversing
qemu_get_cpu(), this is an early design flaw, a better approach would be to use
riscv's hartid for indexing via the interface cpu_by_arch_id().

PATCH v1: 
https://lore.kernel.org/qemu-riscv/416e68f4-bf12-4218-ae2d-0246cc8ea8ec@linaro.org/T/#u

--
Regards,
Chao


Chao Liu (1):
  hw/riscv: fix PLIC hart topology configuration string when not getting
    CPUState correctly

 hw/intc/sifive_plic.c      | 2 +-
 hw/riscv/boot.c            | 4 ++--
 hw/riscv/microchip_pfsoc.c | 2 +-
 hw/riscv/sifive_u.c        | 5 +++--
 hw/riscv/virt.c            | 2 +-
 include/hw/riscv/boot.h    | 2 +-
 6 files changed, 9 insertions(+), 8 deletions(-)

-- 
2.48.1

[PATCH v2 1/1] hw/riscv: fix PLIC hart topology configuration string when not getting CPUState correctly

[Chao Liu]

riscv_plic_hart_config_string() when getting CPUState via qemu_get_cpu()
should be consistent with keeping sifive_plic_realize()
by hartid_base + cpu_index.

A better approach is to use cpu_by_arch_id() instead of qemu_get_cpu(),
in riscv cpu_by_arch_id() uses the mhartid.

For non-numa or single-cluster machines, hartid_base should be 0.

Signed-off-by: Chao Liu <lc00631@tecorigin.com>
Reviewed-by: Qingze Zhao <zqz00548@tecorigin.com>
Reviewed-by: Tingjian Zhang <zhangtj@tecorigin.com>
---
 hw/intc/sifive_plic.c      | 2 +-
 hw/riscv/boot.c            | 4 ++--
 hw/riscv/microchip_pfsoc.c | 2 +-
 hw/riscv/sifive_u.c        | 5 +++--
 hw/riscv/virt.c            | 2 +-
 include/hw/riscv/boot.h    | 2 +-
 6 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/hw/intc/sifive_plic.c b/hw/intc/sifive_plic.c
index a5b0f6ef1b..0a91c5dca7 100644
--- a/hw/intc/sifive_plic.c
+++ b/hw/intc/sifive_plic.c
@@ -399,7 +399,7 @@ static void sifive_plic_realize(DeviceState *dev, Error **errp)
      * hardware controlled when a PLIC is attached.
      */
     for (i = 0; i < s->num_harts; i++) {
-        RISCVCPU *cpu = RISCV_CPU(qemu_get_cpu(s->hartid_base + i));
+        RISCVCPU *cpu = RISCV_CPU(cpu_by_arch_id(s->hartid_base + i));
         if (riscv_cpu_claim_interrupts(cpu, MIP_SEIP) < 0) {
             error_setg(errp, "SEIP already claimed");
             return;
diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
index 765b9e2b1a..4cd29221c2 100644
--- a/hw/riscv/boot.c
+++ b/hw/riscv/boot.c
@@ -44,13 +44,13 @@ bool riscv_is_32bit(RISCVHartArrayState *harts)
  * Return the per-socket PLIC hart topology configuration string
  * (caller must free with g_free())
  */
-char *riscv_plic_hart_config_string(int hart_count)
+char *riscv_plic_hart_config_string(int hart_base, int hart_count)
 {
     g_autofree const char **vals = g_new(const char *, hart_count + 1);
     int i;
 
     for (i = 0; i < hart_count; i++) {
-        CPUState *cs = qemu_get_cpu(i);
+        CPUState *cs = cpu_by_arch_id(hart_base + i);
         CPURISCVState *env = &RISCV_CPU(cs)->env;
 
         if (kvm_enabled()) {
diff --git a/hw/riscv/microchip_pfsoc.c b/hw/riscv/microchip_pfsoc.c
index 9c846f9b5b..5269336346 100644
--- a/hw/riscv/microchip_pfsoc.c
+++ b/hw/riscv/microchip_pfsoc.c
@@ -275,7 +275,7 @@ static void microchip_pfsoc_soc_realize(DeviceState *dev, Error **errp)
                                 l2lim_mem);
 
     /* create PLIC hart topology configuration string */
-    plic_hart_config = riscv_plic_hart_config_string(ms->smp.cpus);
+    plic_hart_config = riscv_plic_hart_config_string(0, ms->smp.cpus);
 
     /* PLIC */
     s->plic = sifive_plic_create(memmap[MICROCHIP_PFSOC_PLIC].base,
diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
index 679f2024bc..516912c4f4 100644
--- a/hw/riscv/sifive_u.c
+++ b/hw/riscv/sifive_u.c
@@ -790,10 +790,11 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
     MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
     MemoryRegion *l2lim_mem = g_new(MemoryRegion, 1);
     char *plic_hart_config;
+    int hartid_base = 1;
     int i, j;
 
     qdev_prop_set_uint32(DEVICE(&s->u_cpus), "num-harts", ms->smp.cpus - 1);
-    qdev_prop_set_uint32(DEVICE(&s->u_cpus), "hartid-base", 1);
+    qdev_prop_set_uint32(DEVICE(&s->u_cpus), "hartid-base", hartid_base);
     qdev_prop_set_string(DEVICE(&s->u_cpus), "cpu-type", s->cpu_type);
     qdev_prop_set_uint64(DEVICE(&s->u_cpus), "resetvec", 0x1004);
 
@@ -829,7 +830,7 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
                                 l2lim_mem);
 
     /* create PLIC hart topology configuration string */
-    plic_hart_config = riscv_plic_hart_config_string(ms->smp.cpus);
+    plic_hart_config = riscv_plic_hart_config_string(hartid_base, ms->smp.cpus);
 
     /* MMIO */
     s->plic = sifive_plic_create(memmap[SIFIVE_U_DEV_PLIC].base,
diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
index e517002fdf..41fdfd2bc8 100644
--- a/hw/riscv/virt.c
+++ b/hw/riscv/virt.c
@@ -1280,7 +1280,7 @@ static DeviceState *virt_create_plic(const MemMapEntry *memmap, int socket,
     g_autofree char *plic_hart_config = NULL;
 
     /* Per-socket PLIC hart topology configuration string */
-    plic_hart_config = riscv_plic_hart_config_string(hart_count);
+    plic_hart_config = riscv_plic_hart_config_string(base_hartid, hart_count);
 
     /* Per-socket PLIC */
     ret = sifive_plic_create(
diff --git a/include/hw/riscv/boot.h b/include/hw/riscv/boot.h
index 7d59b2e6c6..5937298646 100644
--- a/include/hw/riscv/boot.h
+++ b/include/hw/riscv/boot.h
@@ -40,7 +40,7 @@ typedef struct RISCVBootInfo {
 
 bool riscv_is_32bit(RISCVHartArrayState *harts);
 
-char *riscv_plic_hart_config_string(int hart_count);
+char *riscv_plic_hart_config_string(int hart_base, int hart_count);
 
 void riscv_boot_info_init(RISCVBootInfo *info, RISCVHartArrayState *harts);
 target_ulong riscv_calc_kernel_start_addr(RISCVBootInfo *info,
-- 
2.48.1