[PATCH v2 12/13] RISC-V: KVM: selftests: Add steal_time test support

[Anup Patel]

On Thu, Dec 14, 2023 at 3:46 PM Andrew Jones <ajones at ventanamicro.com> wrote:
>
> With the introduction of steal-time accounting support for
> RISC-V KVM we can add RISC-V support to the steal_time test.
>
> Signed-off-by: Andrew Jones <ajones at ventanamicro.com>

LGTM.

Reviewed-by: Anup Patel <anup at brainfault.org>

Regards,
Anup

> ---
>  tools/testing/selftests/kvm/Makefile          |  5 +-
>  .../selftests/kvm/include/riscv/processor.h   |  1 +
>  tools/testing/selftests/kvm/steal_time.c      | 99 +++++++++++++++++++
>  3 files changed, 103 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> index 963435959a92..4bf4f52341a8 100644
> --- a/tools/testing/selftests/kvm/Makefile
> +++ b/tools/testing/selftests/kvm/Makefile
> @@ -194,12 +194,13 @@ TEST_GEN_PROGS_s390x += kvm_binary_stats_test
>
>  TEST_GEN_PROGS_riscv += demand_paging_test
>  TEST_GEN_PROGS_riscv += dirty_log_test
> -TEST_GEN_PROGS_riscv += guest_print_test
>  TEST_GEN_PROGS_riscv += get-reg-list
> +TEST_GEN_PROGS_riscv += guest_print_test
> +TEST_GEN_PROGS_riscv += kvm_binary_stats_test
>  TEST_GEN_PROGS_riscv += kvm_create_max_vcpus
>  TEST_GEN_PROGS_riscv += kvm_page_table_test
>  TEST_GEN_PROGS_riscv += set_memory_region_test
> -TEST_GEN_PROGS_riscv += kvm_binary_stats_test
> +TEST_GEN_PROGS_riscv += steal_time
>
>  SPLIT_TESTS += get-reg-list
>
> diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h
> index dc50ad62e150..a0f9efe5a2a8 100644
> --- a/tools/testing/selftests/kvm/include/riscv/processor.h
> +++ b/tools/testing/selftests/kvm/include/riscv/processor.h
> @@ -128,6 +128,7 @@ static inline uint64_t __kvm_reg_id(uint64_t type, uint64_t subtype,
>
>  enum sbi_ext_id {
>         SBI_EXT_BASE = 0x10,
> +       SBI_EXT_STA = 0x535441,
>  };
>
>  enum sbi_ext_base_fid {
> diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c
> index 171adfb2a6cb..bae0c5026f82 100644
> --- a/tools/testing/selftests/kvm/steal_time.c
> +++ b/tools/testing/selftests/kvm/steal_time.c
> @@ -11,7 +11,9 @@
>  #include <pthread.h>
>  #include <linux/kernel.h>
>  #include <asm/kvm.h>
> +#ifndef __riscv
>  #include <asm/kvm_para.h>
> +#endif
>
>  #include "test_util.h"
>  #include "kvm_util.h"
> @@ -203,6 +205,103 @@ static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
>         pr_info("    st_time: %ld\n", st->st_time);
>  }
>
> +#elif defined(__riscv)
> +
> +/* SBI STA shmem must have 64-byte alignment */
> +#define STEAL_TIME_SIZE                ((sizeof(struct sta_struct) + 63) & ~63)
> +
> +static vm_paddr_t st_gpa[NR_VCPUS];
> +
> +struct sta_struct {
> +       uint32_t sequence;
> +       uint32_t flags;
> +       uint64_t steal;
> +       uint8_t preempted;
> +       uint8_t pad[47];
> +} __packed;
> +
> +static void sta_set_shmem(vm_paddr_t gpa, unsigned long flags)
> +{
> +       unsigned long lo = (unsigned long)gpa;
> +#if __riscv_xlen == 32
> +       unsigned long hi = (unsigned long)(gpa >> 32);
> +#else
> +       unsigned long hi = gpa == -1 ? -1 : 0;
> +#endif
> +       struct sbiret ret = sbi_ecall(SBI_EXT_STA, 0, lo, hi, flags, 0, 0, 0);
> +
> +       GUEST_ASSERT(ret.value == 0 && ret.error == 0);
> +}
> +
> +static void check_status(struct sta_struct *st)
> +{
> +       GUEST_ASSERT(!(READ_ONCE(st->sequence) & 1));
> +       GUEST_ASSERT(READ_ONCE(st->flags) == 0);
> +       GUEST_ASSERT(READ_ONCE(st->preempted) == 0);
> +}
> +
> +static void guest_code(int cpu)
> +{
> +       struct sta_struct *st = st_gva[cpu];
> +       uint32_t sequence;
> +       long out_val = 0;
> +       bool probe;
> +
> +       probe = guest_sbi_probe_extension(SBI_EXT_STA, &out_val);
> +       GUEST_ASSERT(probe && out_val == 1);
> +
> +       sta_set_shmem(st_gpa[cpu], 0);
> +       GUEST_SYNC(0);
> +
> +       check_status(st);
> +       WRITE_ONCE(guest_stolen_time[cpu], st->steal);
> +       sequence = READ_ONCE(st->sequence);
> +       check_status(st);
> +       GUEST_SYNC(1);
> +
> +       check_status(st);
> +       GUEST_ASSERT(sequence < READ_ONCE(st->sequence));
> +       WRITE_ONCE(guest_stolen_time[cpu], st->steal);
> +       check_status(st);
> +       GUEST_DONE();
> +}
> +
> +static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
> +{
> +       uint64_t id = RISCV_SBI_EXT_REG(KVM_RISCV_SBI_EXT_STA);
> +       unsigned long enabled;
> +
> +       vcpu_get_reg(vcpu, id, &enabled);
> +       TEST_ASSERT(enabled == 0 || enabled == 1, "Expected boolean result");
> +
> +       return enabled;
> +}
> +
> +static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i)
> +{
> +       /* ST_GPA_BASE is identity mapped */
> +       st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
> +       st_gpa[i] = addr_gva2gpa(vcpu->vm, (vm_vaddr_t)st_gva[i]);
> +       sync_global_to_guest(vcpu->vm, st_gva[i]);
> +       sync_global_to_guest(vcpu->vm, st_gpa[i]);
> +}
> +
> +static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx)
> +{
> +       struct sta_struct *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]);
> +       int i;
> +
> +       pr_info("VCPU%d:\n", vcpu_idx);
> +       pr_info("    sequence:  %d\n", st->sequence);
> +       pr_info("    flags:     %d\n", st->flags);
> +       pr_info("    steal:     %"PRIu64"\n", st->steal);
> +       pr_info("    preempted: %d\n", st->preempted);
> +       pr_info("    pad:      ");
> +       for (i = 0; i < 47; ++i)
> +               pr_info("%d", st->pad[i]);
> +       pr_info("\n");
> +}
> +
>  #endif
>
>  static void *do_steal_time(void *arg)
> --
> 2.43.0
>