On Mon, Jan 10, 2022 at 11:54 AM Yifei Jiang via wrote:
>
> Add kvm_riscv_get/put_regs_timer to synchronize virtual time context
> from KVM.
>
> To set register of RISCV_TIMER_REG(state) will occur a error from KVM
> on kvm_timer_state == 0. It's better to adapt in KVM, but it doesn't matter
> that adaping in QEMU.
>
> Signed-off-by: Yifei Jiang
> Signed-off-by: Mingwang Li
> Reviewed-by: Anup Patel
Acked-by: Alistair Francis
Alistair
> ---
> target/riscv/cpu.h | 7 +
> target/riscv/kvm.c | 72 ++
> 2 files changed, 79 insertions(+)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 5f54fae7cc..9eceded96c 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -261,6 +261,13 @@ struct CPURISCVState {
>
> hwaddr kernel_addr;
> hwaddr fdt_addr;
> +
> +/* kvm timer */
> +bool kvm_timer_dirty;
> +uint64_t kvm_timer_time;
> +uint64_t kvm_timer_compare;
> +uint64_t kvm_timer_state;
> +uint64_t kvm_timer_frequency;
> };
>
> OBJECT_DECLARE_TYPE(RISCVCPU, RISCVCPUClass,
> diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
> index ded2a8c29d..b1f1d55f29 100644
> --- a/target/riscv/kvm.c
> +++ b/target/riscv/kvm.c
> @@ -40,6 +40,7 @@
> #include "kvm_riscv.h"
> #include "sbi_ecall_interface.h"
> #include "chardev/char-fe.h"
> +#include "migration/migration.h"
>
> static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type, uint64_t
> idx)
> {
> @@ -64,6 +65,9 @@ static uint64_t kvm_riscv_reg_id(CPURISCVState *env,
> uint64_t type, uint64_t idx
> #define RISCV_CSR_REG(env, name) kvm_riscv_reg_id(env, KVM_REG_RISCV_CSR, \
> KVM_REG_RISCV_CSR_REG(name))
>
> +#define RISCV_TIMER_REG(env, name) kvm_riscv_reg_id(env,
> KVM_REG_RISCV_TIMER, \
> + KVM_REG_RISCV_TIMER_REG(name))
> +
> #define RISCV_FP_F_REG(env, idx) kvm_riscv_reg_id(env, KVM_REG_RISCV_FP_F,
> idx)
>
> #define RISCV_FP_D_REG(env, idx) kvm_riscv_reg_id(env, KVM_REG_RISCV_FP_D,
> idx)
> @@ -84,6 +88,22 @@ static uint64_t kvm_riscv_reg_id(CPURISCVState *env,
> uint64_t type, uint64_t idx
> } \
> } while(0)
>
> +#define KVM_RISCV_GET_TIMER(cs, env, name, reg) \
> +do { \
> +int ret = kvm_get_one_reg(cs, RISCV_TIMER_REG(env, name), ); \
> +if (ret) { \
> +abort(); \
> +} \
> +} while(0)
> +
> +#define KVM_RISCV_SET_TIMER(cs, env, name, reg) \
> +do { \
> +int ret = kvm_set_one_reg(cs, RISCV_TIMER_REG(env, time), ); \
> +if (ret) { \
> +abort(); \
> +} \
> +} while (0)
> +
> static int kvm_riscv_get_regs_core(CPUState *cs)
> {
> int ret = 0;
> @@ -235,6 +255,58 @@ static int kvm_riscv_put_regs_fp(CPUState *cs)
> return ret;
> }
>
> +static void kvm_riscv_get_regs_timer(CPUState *cs)
> +{
> +CPURISCVState *env = _CPU(cs)->env;
> +
> +if (env->kvm_timer_dirty) {
> +return;
> +}
> +
> +KVM_RISCV_GET_TIMER(cs, env, time, env->kvm_timer_time);
> +KVM_RISCV_GET_TIMER(cs, env, compare, env->kvm_timer_compare);
> +KVM_RISCV_GET_TIMER(cs, env, state, env->kvm_timer_state);
> +KVM_RISCV_GET_TIMER(cs, env, frequency, env->kvm_timer_frequency);
> +
> +env->kvm_timer_dirty = true;
> +}
> +
> +static void kvm_riscv_put_regs_timer(CPUState *cs)
> +{
> +uint64_t reg;
> +CPURISCVState *env = _CPU(cs)->env;
> +
> +if (!env->kvm_timer_dirty) {
> +return;
> +}
> +
> +KVM_RISCV_SET_TIMER(cs, env, time, env->kvm_timer_time);
> +KVM_RISCV_SET_TIMER(cs, env, compare, env->kvm_timer_compare);
> +
> +/*
> + * To set register of RISCV_TIMER_REG(state) will occur a error from KVM
> + * on env->kvm_timer_state == 0, It's better to adapt in KVM, but it
> + * doesn't matter that adaping in QEMU now.
> + * TODO If KVM changes, adapt here.
> + */
> +if (env->kvm_timer_state) {
> +KVM_RISCV_SET_TIMER(cs, env, state, env->kvm_timer_state);
> +}
> +
> +/*
> + * For now, migration will not work between Hosts with different timer
> + * frequency. Therefore, we should check whether they are the same here
> + * during the migration.
> + */
> +if (migration_is_running(migrate_get_current()->state)) {
> +KVM_RISCV_GET_TIMER(cs, env, frequency, reg);
> +if (reg != env->kvm_timer_frequency) {
> +error_report("Dst Hosts timer frequency != Src Hosts");
> +}
> +}
> +
> +env->kvm_timer_dirty = false;
> +}
>
> const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
> KVM_CAP_LAST_INFO
> --
> 2.19.1
>
>
