On Mon, Dec 20, 2021 at 6:39 PM Yifei Jiang <jiangyifei@xxxxxxxxxx> 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 <jiangyifei@xxxxxxxxxx>
> Signed-off-by: Mingwang Li <limingwang@xxxxxxxxxx>
Looks good to me.
Reviewed-by: Anup Patel <anup.patel@xxxxxxx>
Regards,
Anup
> ---
> 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 e7dba35acb..c892a2c8b7 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -259,6 +259,13 @@ 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 4d08669c81..3c20ec5ad3 100644
> --- a/target/riscv/kvm.c
> +++ b/target/riscv/kvm.c
> @@ -41,6 +41,7 @@
> #include "sbi_ecall_interface.h"
> #include "chardev/char-fe.h"
> #include "semihosting/console.h"
> +#include "migration/migration.h"
>
> static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type, uint64_t idx)
> {
> @@ -65,6 +66,9 @@ 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)
> @@ -85,6 +89,22 @@ 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;
> @@ -236,6 +256,58 @@ static int kvm_riscv_put_regs_fp(CPUState *cs)
> return ret;
> }
>
> +static void kvm_riscv_get_regs_timer(CPUState *cs)
> +{
> + CPURISCVState *env = &RISCV_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 = &RISCV_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
>
