[PATCH v3 11/12] target/riscv: Implement virtual time adjusting with vm state changing

[Alistair Francis]

On Tue, Dec 21, 2021 at 3:45 AM Yifei Jiang via <qemu-devel at nongnu.org> wrote:
>
> We hope that virtual time adjusts with vm state changing. When a vm
> is stopped, guest virtual time should stop counting and kvm_timer
> should be stopped. When the vm is resumed, guest virtual time should
> continue to count and kvm_timer should be restored.
>
> Signed-off-by: Yifei Jiang <jiangyifei at huawei.com>
> Signed-off-by: Mingwang Li <limingwang at huawei.com>
> Reviewed-by: Anup Patel <anup.patel at wdc.com>

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

Alistair

> ---
>  target/riscv/kvm.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
> index 3c20ec5ad3..6c0306bd2b 100644
> --- a/target/riscv/kvm.c
> +++ b/target/riscv/kvm.c
> @@ -42,6 +42,7 @@
>  #include "chardev/char-fe.h"
>  #include "semihosting/console.h"
>  #include "migration/migration.h"
> +#include "sysemu/runstate.h"
>
>  static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type, uint64_t idx)
>  {
> @@ -378,6 +379,17 @@ unsigned long kvm_arch_vcpu_id(CPUState *cpu)
>      return cpu->cpu_index;
>  }
>
> +static void kvm_riscv_vm_state_change(void *opaque, bool running, RunState state)
> +{
> +    CPUState *cs = opaque;
> +
> +    if (running) {
> +        kvm_riscv_put_regs_timer(cs);
> +    } else {
> +        kvm_riscv_get_regs_timer(cs);
> +    }
> +}
> +
>  void kvm_arch_init_irq_routing(KVMState *s)
>  {
>  }
> @@ -390,6 +402,8 @@ int kvm_arch_init_vcpu(CPUState *cs)
>      CPURISCVState *env = &cpu->env;
>      uint64_t id;
>
> +    qemu_add_vm_change_state_handler(kvm_riscv_vm_state_change, cs);
> +
>      id = kvm_riscv_reg_id(env, KVM_REG_RISCV_CONFIG, KVM_REG_RISCV_CONFIG_REG(isa));
>      ret = kvm_get_one_reg(cs, id, &isa);
>      if (ret) {
> --
> 2.19.1
>
>