On Thu, Sep 28, 2023, Jim Mattson wrote:
> Verify the following:
> * Attempts to set bits 3, 6, or 8 are ignored
> * Bits 18 and 24 are the only bits that can be set
> * Any bit that can be set can also be cleared
>
> Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/Makefile | 1 +
> .../selftests/kvm/x86_64/hwcr_msr_test.c | 52 +++++++++++++++++++
> 2 files changed, 53 insertions(+)
> create mode 100644 tools/testing/selftests/kvm/x86_64/hwcr_msr_test.c
>
> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> index a3bb36fb3cfc..6b0219ca65eb 100644
> --- a/tools/testing/selftests/kvm/Makefile
> +++ b/tools/testing/selftests/kvm/Makefile
> @@ -135,6 +135,7 @@ TEST_GEN_PROGS_x86_64 += set_memory_region_test
> TEST_GEN_PROGS_x86_64 += steal_time
> TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test
> TEST_GEN_PROGS_x86_64 += system_counter_offset_test
> +TEST_GEN_PROGS_x86_64 += x86_64/hwcr_msr_test
Please place this with the other x86_64 specific tests.
Somewhat of a forward looking question, what do folks think about adding an
"msr_tests" subdirectory? I really want to effectively replace KUT's msr.c test
with a supserset of functionality in selftests, e.g. KUT can't test userspace
writes. But I don't want to end up with a single massive msr_test.c. If we add
a subdirectory, then I think that would make it easier to share "private" APIs
and infrastructure without creating a giant monolithic test.
> # Compiled outputs used by test targets
> TEST_GEN_PROGS_EXTENDED_x86_64 += x86_64/nx_huge_pages_test
> diff --git a/tools/testing/selftests/kvm/x86_64/hwcr_msr_test.c b/tools/testing/selftests/kvm/x86_64/hwcr_msr_test.c
> new file mode 100644
> index 000000000000..1a6a09791ac3
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/x86_64/hwcr_msr_test.c
> @@ -0,0 +1,52 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023, Google LLC.
> + *
> + * Tests for the K7_HWCR MSR.
> + */
> +
> +#define _GNU_SOURCE /* for program_invocation_short_name */
> +#include <sys/ioctl.h>
> +
> +#include "test_util.h"
> +#include "kvm_util.h"
> +#include "vmx.h"
> +
> +void test_hwcr_bit(struct kvm_vcpu *vcpu, unsigned int bit)
> +{
> + const unsigned long long ignored = BIT_ULL(3) | BIT_ULL(6) | BIT_ULL(8);
uint64_t instead of "unsigned long long".
> + const unsigned long long valid = BIT_ULL(18) | BIT_ULL(24);
> + const unsigned long long legal = ignored | valid;
> + uint64_t val = BIT_ULL(bit);
> + uint64_t check;
> + int r;
> +
> + r = _vcpu_set_msr(vcpu, MSR_K7_HWCR, val);
> + TEST_ASSERT((r == 1 && (val & legal)) || (r == 0 && !(val & legal)),
> + "Unexpected result (%d) when setting HWCR[bit %u]", r, bit);
> + check = vcpu_get_msr(vcpu, MSR_K7_HWCR);
> + if (val & valid) {
> + TEST_ASSERT(check == val,
> + "Bit %u: unexpected HWCR %lx; expected %lx", bit,
> + check, val);
> + vcpu_set_msr(vcpu, MSR_K7_HWCR, 0);
> + } else {
> + TEST_ASSERT(!check,
> + "Bit %u: unexpected HWCR %lx; expected 0", bit,
> + check);
> + }
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + struct kvm_vm *vm;
> + struct kvm_vcpu *vcpu;
> + unsigned int bit;
> +
> + vm = vm_create_with_one_vcpu(&vcpu, NULL);
> +
> + for (bit = 0; bit < BITS_PER_LONG; bit++)
> + test_hwcr_bit(vcpu, bit);
> +
> + kvm_vm_free(vm);
> +}
> --
> 2.42.0.582.g8ccd20d70d-goog
>
