[RFC PATCH 14/14] KVM: selftests: riscv: Add steal_time test support

Andrew Jones
2023-04-17T11:46:07Z

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@ventanamicro.com>
---
tools/testing/selftests/kvm/Makefile | 3 +-
.../selftests/kvm/include/riscv/processor.h | 1 +
tools/testing/selftests/kvm/steal_time.c | 100 ++++++++++++++++++
3 files changed, 103 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 84a627c43795..6b8aae3604bf 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -171,10 +171,11 @@ 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 += 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

TEST_PROGS += $(TEST_PROGS_$(ARCH_DIR))
TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(ARCH_DIR))
diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h
index f052e8be0e42..4870c6107e10 100644
--- a/tools/testing/selftests/kvm/include/riscv/processor.h
+++ b/tools/testing/selftests/kvm/include/riscv/processor.h
@@ -123,6 +123,7 @@ 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 c87f38712073..f35739e858fe 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 +205,104 @@ 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)
+{
+ unsigned long enabled;
+ uint64_t id = RISCV_SBI_EXT_REG(KVM_REG_RISCV_SBI_SINGLE,
+ KVM_RISCV_SBI_EXT_STA);
+
+ 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)
--
2.39.2