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| author | Sean Christopherson <seanjc@google.com> | 2023-03-11 03:46:09 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-04-07 00:58:44 +0300 |
| commit | f138258565d18f0f9a8d07f04162c68eee997ce6 (patch) | |
| tree | 6547c492bfab8c9196038e1d7e1d60c4b6704118 /tools/testing/selftests/kvm/include/x86_64 | |
| parent | 22234c2495eafd6b8f1f26c6c6adc12aca60fd7f (diff) | |
| download | linux-f138258565d18f0f9a8d07f04162c68eee997ce6.tar.xz | |
KVM: selftests: Verify KVM preserves userspace writes to "durable" MSRs
Assert that KVM provides "read what you wrote" semantics for all "durable"
MSRs (for lack of a better name). The extra coverage is cheap from a
runtime performance perspective, and verifying the behavior in the common
helper avoids gratuitous copy+paste in individual tests.
Note, this affects all tests that set MSRs from userspace!
Link: https://lore.kernel.org/r/20230311004618.920745-13-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'tools/testing/selftests/kvm/include/x86_64')
| -rw-r--r-- | tools/testing/selftests/kvm/include/x86_64/processor.h | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 293a9085311d..e1d65d933310 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -945,12 +945,27 @@ do { \ } \ } while (0) +/* + * Returns true if KVM should return the last written value when reading an MSR + * from userspace, e.g. the MSR isn't a command MSR, doesn't emulate state that + * is changing, etc. This is NOT an exhaustive list! The intent is to filter + * out MSRs that are not durable _and_ that a selftest wants to write. + */ +static inline bool is_durable_msr(uint32_t msr) +{ + return msr != MSR_IA32_TSC; +} + #define vcpu_set_msr(vcpu, msr, val) \ do { \ - uint64_t v = val; \ + uint64_t r, v = val; \ \ TEST_ASSERT_MSR(_vcpu_set_msr(vcpu, msr, v) == 1, \ "KVM_SET_MSRS failed on %s, value = 0x%lx", msr, #msr, v); \ + if (!is_durable_msr(msr)) \ + break; \ + r = vcpu_get_msr(vcpu, msr); \ + TEST_ASSERT_MSR(r == v, "Set %s to '0x%lx', got back '0x%lx'", msr, #msr, v, r);\ } while (0) void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits); |