On Wed, Nov 10, 2021 at 4:03 PM David Matlack <dmatlack@xxxxxxxxxx> wrote:
>
> From: Sean Christopherson <seanjc@xxxxxxxxxx>
>
> Copy perf_test_args to the guest during VM creation instead of relying on
> the caller to do so at their leisure. Ideally, tests wouldn't even be
> able to modify perf_test_args, i.e. they would have no motivation to do
> the sync, but enforcing that is arguably a net negative for readability.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> [Set wr_fract=1 by default and add helper to override it since the new
> access_tracking_perf_test needs to set it dynamically.]
> Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
Reviewed-by: Ben Gardon <bgardon@xxxxxxxxxx>
> ---
> .../selftests/kvm/access_tracking_perf_test.c | 3 +--
> tools/testing/selftests/kvm/demand_paging_test.c | 5 -----
> tools/testing/selftests/kvm/dirty_log_perf_test.c | 4 +---
> tools/testing/selftests/kvm/include/perf_test_util.h | 2 ++
> tools/testing/selftests/kvm/lib/perf_test_util.c | 12 ++++++++++++
> .../selftests/kvm/memslot_modification_stress_test.c | 5 -----
> 6 files changed, 16 insertions(+), 15 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/access_tracking_perf_test.c b/tools/testing/selftests/kvm/access_tracking_perf_test.c
> index fdef6c906388..5364a2ed7c68 100644
> --- a/tools/testing/selftests/kvm/access_tracking_perf_test.c
> +++ b/tools/testing/selftests/kvm/access_tracking_perf_test.c
> @@ -277,8 +277,7 @@ static void run_iteration(struct kvm_vm *vm, int vcpus, const char *description)
> static void access_memory(struct kvm_vm *vm, int vcpus, enum access_type access,
> const char *description)
> {
> - perf_test_args.wr_fract = (access == ACCESS_READ) ? INT_MAX : 1;
> - sync_global_to_guest(vm, perf_test_args);
> + perf_test_set_wr_fract(vm, (access == ACCESS_READ) ? INT_MAX : 1);
> iteration_work = ITERATION_ACCESS_MEMORY;
> run_iteration(vm, vcpus, description);
> }
> diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c
> index 0fee44f5e5ae..26f8fd8a57ec 100644
> --- a/tools/testing/selftests/kvm/demand_paging_test.c
> +++ b/tools/testing/selftests/kvm/demand_paging_test.c
> @@ -295,8 +295,6 @@ static void run_test(enum vm_guest_mode mode, void *arg)
> vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
> p->src_type, p->partition_vcpu_memory_access);
>
> - perf_test_args.wr_fract = 1;
> -
> demand_paging_size = get_backing_src_pagesz(p->src_type);
>
> guest_data_prototype = malloc(demand_paging_size);
> @@ -345,9 +343,6 @@ static void run_test(enum vm_guest_mode mode, void *arg)
> }
> }
>
> - /* Export the shared variables to the guest */
> - sync_global_to_guest(vm, perf_test_args);
> -
> pr_info("Finished creating vCPUs and starting uffd threads\n");
>
> clock_gettime(CLOCK_MONOTONIC, &start);
> diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
> index 62f9cc2a3146..583b4d95aa98 100644
> --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
> +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
> @@ -189,7 +189,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
> p->slots, p->backing_src,
> p->partition_vcpu_memory_access);
>
> - perf_test_args.wr_fract = p->wr_fract;
> + perf_test_set_wr_fract(vm, p->wr_fract);
>
> guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm);
> guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
> @@ -207,8 +207,6 @@ static void run_test(enum vm_guest_mode mode, void *arg)
> vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads));
> TEST_ASSERT(vcpu_threads, "Memory allocation failed");
>
> - sync_global_to_guest(vm, perf_test_args);
> -
> /* Start the iterations */
> iteration = 0;
> host_quit = false;
> diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/perf_test_util.h
> index 91804be1cf53..74e3622b3a6e 100644
> --- a/tools/testing/selftests/kvm/include/perf_test_util.h
> +++ b/tools/testing/selftests/kvm/include/perf_test_util.h
> @@ -43,4 +43,6 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
> bool partition_vcpu_memory_access);
> void perf_test_destroy_vm(struct kvm_vm *vm);
>
> +void perf_test_set_wr_fract(struct kvm_vm *vm, int wr_fract);
> +
> #endif /* SELFTEST_KVM_PERF_TEST_UTIL_H */
> diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c
> index 13c8bc22f4e1..77f9eb5667c9 100644
> --- a/tools/testing/selftests/kvm/lib/perf_test_util.c
> +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c
> @@ -94,6 +94,9 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
>
> pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
>
> + /* By default vCPUs will write to memory. */
> + pta->wr_fract = 1;
> +
> /*
> * Snapshot the non-huge page size. This is used by the guest code to
> * access/dirty pages at the logging granularity.
> @@ -157,6 +160,9 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
>
> ucall_init(vm, NULL);
>
> + /* Export the shared variables to the guest. */
> + sync_global_to_guest(vm, perf_test_args);
> +
> return vm;
> }
>
> @@ -165,3 +171,9 @@ void perf_test_destroy_vm(struct kvm_vm *vm)
> ucall_uninit(vm);
> kvm_vm_free(vm);
> }
> +
> +void perf_test_set_wr_fract(struct kvm_vm *vm, int wr_fract)
> +{
> + perf_test_args.wr_fract = wr_fract;
> + sync_global_to_guest(vm, perf_test_args);
> +}
> diff --git a/tools/testing/selftests/kvm/memslot_modification_stress_test.c b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
> index 27af0bb8deb7..df431d0da1ee 100644
> --- a/tools/testing/selftests/kvm/memslot_modification_stress_test.c
> +++ b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
> @@ -108,14 +108,9 @@ static void run_test(enum vm_guest_mode mode, void *arg)
> VM_MEM_SRC_ANONYMOUS,
> p->partition_vcpu_memory_access);
>
> - perf_test_args.wr_fract = 1;
> -
> vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads));
> TEST_ASSERT(vcpu_threads, "Memory allocation failed");
>
> - /* Export the shared variables to the guest */
> - sync_global_to_guest(vm, perf_test_args);
> -
> pr_info("Finished creating vCPUs\n");
>
> for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
> --
> 2.34.0.rc1.387.gb447b232ab-goog
>
