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[V4,0/6] Support RISC-V migration

Message ID 20201026115530.304-1-jiangyifei@huawei.com
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Series Support RISC-V migration | expand

Message

Jiangyifei Oct. 26, 2020, 11:55 a.m. UTC
This patches supported RISC-V migration based on tcg accel. And we have
verified related migration features such as snapshot and live migration.

A few weeks ago, we submitted RFC patches about supporting RISC-V migration
based on kvm accel: https://www.spinics.net/lists/kvm/msg223605.html.
And we found that tcg accelerated migration can be supported with a few
changes. Most of the devices have already implemented the migration
interface, so, to achieve the tcg accelerated migration, we just need to
add vmstate of both cpu and sifive_plic.

changes since v3
1. Apply Alistair's patch to exend get/set_field():
   https://www.mail-archive.com/qemu-devel@nongnu.org/msg753575.html
2. Remake the patch: Merge m/vsstatus and m/vsstatush into one uint64_t
   unit.

Changes since v2:
1. Move vmstate_riscv_cpu declaration to internals.h.
2. Merge m/vsstatus and m/vsstatush into one uint64_t unit.

Changes since v1:
1. Add license head to target/riscv/machine.c.
2. Regenerate some state of PMP at post_load hook.

Yifei Jiang (6):
  target/riscv: Merge m/vsstatus and m/vsstatush into one uint64_t unit
  target/riscv: Add basic vmstate description of CPU
  target/riscv: Add PMP state description
  target/riscv: Add H extension state description
  target/riscv: Add V extension state description
  target/riscv: Add sifive_plic vmstate

 hw/intc/sifive_plic.c     |  26 ++++-
 hw/intc/sifive_plic.h     |   1 +
 target/riscv/cpu.c        |  16 ++--
 target/riscv/cpu.h        |  24 +++--
 target/riscv/cpu_bits.h   |  19 +---
 target/riscv/cpu_helper.c |  35 ++-----
 target/riscv/csr.c        |  18 ++--
 target/riscv/internals.h  |   4 +
 target/riscv/machine.c    | 196 ++++++++++++++++++++++++++++++++++++++
 target/riscv/meson.build  |   3 +-
 target/riscv/op_helper.c  |  11 +--
 target/riscv/pmp.c        |  29 +++---
 target/riscv/pmp.h        |   2 +
 13 files changed, 290 insertions(+), 94 deletions(-)
 create mode 100644 target/riscv/machine.c

Comments

Alistair Francis Oct. 27, 2020, 6:40 p.m. UTC | #1
On Tue, Oct 27, 2020 at 11:47 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 10/26/20 4:55 AM, Yifei Jiang wrote:
> > -    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ", env->mstatus);
> > +    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ", (target_ulong)env->mstatus);
>
> This is truncating mstatus to target_ulong, i.e. breaking the output for
> riscv32.  You should use PRIx64 and print the whole 64-bit value.

That is what we want to do though. For RV32 the mstatus CSR is only
32-bits, where the upper 32-bit are stored in mstatush (the top
32-bits of QEMU's internal mstatus).

Alistair

>
>
> r~
>
Richard Henderson Oct. 27, 2020, 6:45 p.m. UTC | #2
On 10/26/20 4:55 AM, Yifei Jiang wrote:
> -    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ", env->mstatus);
> +    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ", (target_ulong)env->mstatus);

This is truncating mstatus to target_ulong, i.e. breaking the output for
riscv32.  You should use PRIx64 and print the whole 64-bit value.


r~
Alistair Francis Oct. 27, 2020, 8:26 p.m. UTC | #3
On Mon, Oct 26, 2020 at 4:58 AM Yifei Jiang <jiangyifei@huawei.com> wrote:
>
> mstatus/mstatush and vsstatus/vsstatush are two halved for RISCV32.
> This patch expands mstatus and vsstatus to uint64_t instead of
> target_ulong so that it can be saved as one unit and reduce some
> ifdefs in the code.
>
> Signed-off-by: Yifei Jiang <jiangyifei@huawei.com>
> Signed-off-by: Yipeng Yin <yinyipeng1@huawei.com>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  target/riscv/cpu.c        |  8 +++++---
>  target/riscv/cpu.h        | 24 +++++++++++-------------
>  target/riscv/cpu_bits.h   | 19 ++++---------------
>  target/riscv/cpu_helper.c | 35 +++++++----------------------------
>  target/riscv/csr.c        | 18 ++++++++++--------
>  target/riscv/op_helper.c  | 11 ++++-------
>  6 files changed, 41 insertions(+), 74 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 0bbfd7f457..dd05a220c7 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -216,13 +216,15 @@ static void riscv_cpu_dump_state(CPUState *cs, FILE *f, int flags)
>      qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "pc      ", env->pc);
>  #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);
> +    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ", (target_ulong)env->mstatus);
>  #ifdef TARGET_RISCV32
> -    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatush ", env->mstatush);
> +    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatush ",
> +                 (target_ulong)(env->mstatus >> 32));
>  #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);
> +        qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "vsstatus ",
> +                     (target_ulong)env->vsstatus);
>      }
>      qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mip     ", env->mip);
>      qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mie     ", env->mie);
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index de275782e6..e430670b60 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -140,14 +140,14 @@ struct CPURISCVState {
>      target_ulong resetvec;
>
>      target_ulong mhartid;
> -    target_ulong mstatus;
> +    /*
> +     * For RV32 this is 32-bit mstatus and 32-bit mstatush.
> +     * For RV64 this is a 64-bit mstatus.
> +     */
> +    uint64_t mstatus;
>
>      target_ulong mip;
>
> -#ifdef TARGET_RISCV32
> -    target_ulong mstatush;
> -#endif
> -
>      uint32_t miclaim;
>
>      target_ulong mie;
> @@ -179,16 +179,17 @@ struct CPURISCVState {
>      uint64_t htimedelta;
>
>      /* Virtual CSRs */
> -    target_ulong vsstatus;
> +    /*
> +     * For RV32 this is 32-bit vsstatus and 32-bit vsstatush.
> +     * For RV64 this is a 64-bit vsstatus.
> +     */
> +    uint64_t vsstatus;
>      target_ulong vstvec;
>      target_ulong vsscratch;
>      target_ulong vsepc;
>      target_ulong vscause;
>      target_ulong vstval;
>      target_ulong vsatp;
> -#ifdef TARGET_RISCV32
> -    target_ulong vsstatush;
> -#endif
>
>      target_ulong mtval2;
>      target_ulong mtinst;
> @@ -200,10 +201,7 @@ struct CPURISCVState {
>      target_ulong scause_hs;
>      target_ulong stval_hs;
>      target_ulong satp_hs;
> -    target_ulong mstatus_hs;
> -#ifdef TARGET_RISCV32
> -    target_ulong mstatush_hs;
> -#endif
> +    uint64_t mstatus_hs;
>
>      target_ulong scounteren;
>      target_ulong mcounteren;
> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> index bd36062877..daedad8691 100644
> --- a/target/riscv/cpu_bits.h
> +++ b/target/riscv/cpu_bits.h
> @@ -4,10 +4,10 @@
>  #define TARGET_RISCV_CPU_BITS_H
>
>  #define get_field(reg, mask) (((reg) & \
> -                 (target_ulong)(mask)) / ((mask) & ~((mask) << 1)))
> -#define set_field(reg, mask, val) (((reg) & ~(target_ulong)(mask)) | \
> -                 (((target_ulong)(val) * ((mask) & ~((mask) << 1))) & \
> -                 (target_ulong)(mask)))
> +                 (uint64_t)(mask)) / ((mask) & ~((mask) << 1)))
> +#define set_field(reg, mask, val) (((reg) & ~(uint64_t)(mask)) | \
> +                 (((uint64_t)(val) * ((mask) & ~((mask) << 1))) & \
> +                 (uint64_t)(mask)))
>
>  /* Floating point round mode */
>  #define FSR_RD_SHIFT        5
> @@ -381,19 +381,8 @@
>  #define MSTATUS_TVM         0x00100000 /* since: priv-1.10 */
>  #define MSTATUS_TW          0x20000000 /* since: priv-1.10 */
>  #define MSTATUS_TSR         0x40000000 /* since: priv-1.10 */
> -#if defined(TARGET_RISCV64)
>  #define MSTATUS_GVA         0x4000000000ULL
>  #define MSTATUS_MPV         0x8000000000ULL
> -#elif defined(TARGET_RISCV32)
> -#define MSTATUS_GVA         0x00000040
> -#define MSTATUS_MPV         0x00000080
> -#endif
> -
> -#ifdef TARGET_RISCV32
> -# define MSTATUS_MPV_ISSET(env)  get_field(env->mstatush, MSTATUS_MPV)
> -#else
> -# define MSTATUS_MPV_ISSET(env)  get_field(env->mstatus, MSTATUS_MPV)
> -#endif
>
>  #define MSTATUS64_UXL       0x0000000300000000ULL
>  #define MSTATUS64_SXL       0x0000000C00000000ULL
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 904899054d..109ee4bad6 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -110,27 +110,19 @@ bool riscv_cpu_fp_enabled(CPURISCVState *env)
>
>  void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
>  {
> -    target_ulong mstatus_mask = MSTATUS_MXR | MSTATUS_SUM | MSTATUS_FS |
> -                                MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE;
> +    uint64_t mstatus_mask = MSTATUS_MXR | MSTATUS_SUM | MSTATUS_FS |
> +                            MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE |
> +                            MSTATUS64_UXL;
>      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;
>
> -#if defined(TARGET_RISCV32)
> -        env->vsstatush = env->mstatush;
> -        env->mstatush |= env->mstatush_hs;
> -#endif
> -
>          env->vstvec = env->stvec;
>          env->stvec = env->stvec_hs;
>
> @@ -154,11 +146,6 @@ 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;
>
> @@ -720,7 +707,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
>      if (riscv_has_ext(env, RVH) && env->priv == PRV_M &&
>          access_type != MMU_INST_FETCH &&
>          get_field(env->mstatus, MSTATUS_MPRV) &&
> -        MSTATUS_MPV_ISSET(env)) {
> +        get_field(env->mstatus, MSTATUS_MPV)) {
>          riscv_cpu_set_two_stage_lookup(env, true);
>      }
>
> @@ -781,7 +768,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
>      if (riscv_has_ext(env, RVH) && env->priv == PRV_M &&
>          access_type != MMU_INST_FETCH &&
>          get_field(env->mstatus, MSTATUS_MPRV) &&
> -        MSTATUS_MPV_ISSET(env)) {
> +        get_field(env->mstatus, MSTATUS_MPV)) {
>          riscv_cpu_set_two_stage_lookup(env, false);
>      }
>
> @@ -844,7 +831,7 @@ void riscv_cpu_do_interrupt(CPUState *cs)
>      RISCVCPU *cpu = RISCV_CPU(cs);
>      CPURISCVState *env = &cpu->env;
>      bool force_hs_execp = riscv_cpu_force_hs_excep_enabled(env);
> -    target_ulong s;
> +    uint64_t s;
>
>      /* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
>       * so we mask off the MSB and separate into trap type and cause.
> @@ -969,19 +956,11 @@ 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));
> -            if (riscv_cpu_virt_enabled(env) && tval) {
> -                env->mstatush = set_field(env->mstatush, MSTATUS_GVA, 1);
> -            }
> -#else
>              env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
> -                                      riscv_cpu_virt_enabled(env));
> +                                     riscv_cpu_virt_enabled(env));
>              if (riscv_cpu_virt_enabled(env) && tval) {
>                  env->mstatus = set_field(env->mstatus, MSTATUS_GVA, 1);
>              }
> -#endif
>
>              mtval2 = env->guest_phys_fault_addr;
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index aaef6c6f20..e33f6cdc11 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -446,8 +446,8 @@ static int validate_vm(CPURISCVState *env, target_ulong vm)
>
>  static int write_mstatus(CPURISCVState *env, int csrno, target_ulong val)
>  {
> -    target_ulong mstatus = env->mstatus;
> -    target_ulong mask = 0;
> +    uint64_t mstatus = env->mstatus;
> +    uint64_t mask = 0;
>      int dirty;
>
>      /* flush tlb on mstatus fields that affect VM */
> @@ -480,19 +480,20 @@ static int write_mstatus(CPURISCVState *env, int csrno, target_ulong val)
>  #ifdef TARGET_RISCV32
>  static int read_mstatush(CPURISCVState *env, int csrno, target_ulong *val)
>  {
> -    *val = env->mstatush;
> +    *val = env->mstatus >> 32;
>      return 0;
>  }
>
>  static int write_mstatush(CPURISCVState *env, int csrno, target_ulong val)
>  {
> -    if ((val ^ env->mstatush) & (MSTATUS_MPV)) {
> +    uint64_t valh = (uint64_t)val << 32;
> +    uint64_t mask = MSTATUS_MPV | MSTATUS_GVA;
> +
> +    if ((valh ^ env->mstatus) & (MSTATUS_MPV)) {
>          tlb_flush(env_cpu(env));
>      }
>
> -    val &= MSTATUS_MPV | MSTATUS_GVA;
> -
> -    env->mstatush = val;
> +    env->mstatus = (env->mstatus & ~mask) | (valh & mask);
>
>      return 0;
>  }
> @@ -1105,7 +1106,8 @@ static int read_vsstatus(CPURISCVState *env, int csrno, target_ulong *val)
>
>  static int write_vsstatus(CPURISCVState *env, int csrno, target_ulong val)
>  {
> -    env->vsstatus = val;
> +    uint64_t mask = (target_ulong)-1;
> +    env->vsstatus = (env->vsstatus & ~mask) | (uint64_t)val;
>      return 0;
>  }
>
> diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
> index 9b9ada45a9..e0b45e5eb7 100644
> --- a/target/riscv/op_helper.c
> +++ b/target/riscv/op_helper.c
> @@ -79,7 +79,8 @@ target_ulong helper_csrrc(CPURISCVState *env, target_ulong src,
>
>  target_ulong helper_sret(CPURISCVState *env, target_ulong cpu_pc_deb)
>  {
> -    target_ulong prev_priv, prev_virt, mstatus;
> +    uint64_t mstatus;
> +    target_ulong prev_priv, prev_virt;
>
>      if (!(env->priv >= PRV_S)) {
>          riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
> @@ -148,18 +149,14 @@ target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb)
>          riscv_raise_exception(env, RISCV_EXCP_INST_ADDR_MIS, GETPC());
>      }
>
> -    target_ulong mstatus = env->mstatus;
> +    uint64_t mstatus = env->mstatus;
>      target_ulong prev_priv = get_field(mstatus, MSTATUS_MPP);
> -    target_ulong prev_virt = MSTATUS_MPV_ISSET(env);
> +    target_ulong prev_virt = get_field(env->mstatus, MSTATUS_MPV);
>      mstatus = set_field(mstatus, MSTATUS_MIE,
>                          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);
>
> --
> 2.19.1
>
>
Alistair Francis Oct. 27, 2020, 8:26 p.m. UTC | #4
On Mon, Oct 26, 2020 at 4:58 AM Yifei Jiang <jiangyifei@huawei.com> wrote:
>
> This patches supported RISC-V migration based on tcg accel. And we have
> verified related migration features such as snapshot and live migration.
>
> A few weeks ago, we submitted RFC patches about supporting RISC-V migration
> based on kvm accel: https://www.spinics.net/lists/kvm/msg223605.html.
> And we found that tcg accelerated migration can be supported with a few
> changes. Most of the devices have already implemented the migration
> interface, so, to achieve the tcg accelerated migration, we just need to
> add vmstate of both cpu and sifive_plic.
>
> changes since v3
> 1. Apply Alistair's patch to exend get/set_field():
>    https://www.mail-archive.com/qemu-devel@nongnu.org/msg753575.html
> 2. Remake the patch: Merge m/vsstatus and m/vsstatush into one uint64_t
>    unit.
>
> Changes since v2:
> 1. Move vmstate_riscv_cpu declaration to internals.h.
> 2. Merge m/vsstatus and m/vsstatush into one uint64_t unit.
>
> Changes since v1:
> 1. Add license head to target/riscv/machine.c.
> 2. Regenerate some state of PMP at post_load hook.
>
> Yifei Jiang (6):
>   target/riscv: Merge m/vsstatus and m/vsstatush into one uint64_t unit
>   target/riscv: Add basic vmstate description of CPU
>   target/riscv: Add PMP state description
>   target/riscv: Add H extension state description
>   target/riscv: Add V extension state description
>   target/riscv: Add sifive_plic vmstate

Thanks!

Applied to riscv-to-apply.next

Alistair

>
>  hw/intc/sifive_plic.c     |  26 ++++-
>  hw/intc/sifive_plic.h     |   1 +
>  target/riscv/cpu.c        |  16 ++--
>  target/riscv/cpu.h        |  24 +++--
>  target/riscv/cpu_bits.h   |  19 +---
>  target/riscv/cpu_helper.c |  35 ++-----
>  target/riscv/csr.c        |  18 ++--
>  target/riscv/internals.h  |   4 +
>  target/riscv/machine.c    | 196 ++++++++++++++++++++++++++++++++++++++
>  target/riscv/meson.build  |   3 +-
>  target/riscv/op_helper.c  |  11 +--
>  target/riscv/pmp.c        |  29 +++---
>  target/riscv/pmp.h        |   2 +
>  13 files changed, 290 insertions(+), 94 deletions(-)
>  create mode 100644 target/riscv/machine.c
>
> --
> 2.19.1
>
>