| Message ID | 20241003234337.273364-3-seanjc@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: selftests: AVX support + fixes | expand |
Sean Christopherson <seanjc@google.com> writes: > When comparing vCPU CPUID entries against KVM's supported CPUID, mask off > only the dynamic fields/bits instead of skipping the entire entry. > Precisely masking bits isn't meaningfully more difficult than skipping > entire entries, and will be necessary to maintain test coverage when a > future commit enables OSXSAVE by default, i.e. makes one bit in all of > CPUID.0x1 dynamic. > > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > .../testing/selftests/kvm/x86_64/cpuid_test.c | 61 +++++++++++-------- > 1 file changed, 36 insertions(+), 25 deletions(-) > > diff --git a/tools/testing/selftests/kvm/x86_64/cpuid_test.c b/tools/testing/selftests/kvm/x86_64/cpuid_test.c > index fec03b11b059..f7fdcef5fa59 100644 > --- a/tools/testing/selftests/kvm/x86_64/cpuid_test.c > +++ b/tools/testing/selftests/kvm/x86_64/cpuid_test.c > @@ -12,17 +12,16 @@ > #include "kvm_util.h" > #include "processor.h" > > -/* CPUIDs known to differ */ > -struct { > - u32 function; > - u32 index; > -} mangled_cpuids[] = { > - /* > - * These entries depend on the vCPU's XCR0 register and IA32_XSS MSR, > - * which are not controlled for by this test. > - */ > - {.function = 0xd, .index = 0}, > - {.function = 0xd, .index = 1}, > +struct cpuid_mask { > + union { > + struct { > + u32 eax; > + u32 ebx; > + u32 ecx; > + u32 edx; > + }; > + u32 regs[4]; > + }; > }; > > static void test_guest_cpuids(struct kvm_cpuid2 *guest_cpuid) > @@ -56,17 +55,23 @@ static void guest_main(struct kvm_cpuid2 *guest_cpuid) > GUEST_DONE(); > } > > -static bool is_cpuid_mangled(const struct kvm_cpuid_entry2 *entrie) > +static struct cpuid_mask get_const_cpuid_mask(const struct kvm_cpuid_entry2 *entry) > { > - int i; > + struct cpuid_mask mask; > > - for (i = 0; i < ARRAY_SIZE(mangled_cpuids); i++) { > - if (mangled_cpuids[i].function == entrie->function && > - mangled_cpuids[i].index == entrie->index) > - return true; > + memset(&mask, 0xff, sizeof(mask)); > + > + switch (entry->function) { > + case 0xd: > + /* > + * CPUID.0xD.{0,1}.EBX enumerate XSAVE size based on the current > + * XCR0 and IA32_XSS MSR values. > + */ > + if (entry->index < 2) > + mask.ebx = 0; > + break; > } > - > - return false; > + return mask; > } > > static void compare_cpuids(const struct kvm_cpuid2 *cpuid1, > @@ -79,6 +84,8 @@ static void compare_cpuids(const struct kvm_cpuid2 *cpuid1, > "CPUID nent mismatch: %d vs. %d", cpuid1->nent, cpuid2->nent); > > for (i = 0; i < cpuid1->nent; i++) { > + struct cpuid_mask mask; > + > e1 = &cpuid1->entries[i]; > e2 = &cpuid2->entries[i]; > > @@ -88,15 +95,19 @@ static void compare_cpuids(const struct kvm_cpuid2 *cpuid1, > i, e1->function, e1->index, e1->flags, > e2->function, e2->index, e2->flags); > > - if (is_cpuid_mangled(e1)) > - continue; > + /* Mask off dynamic bits, e.g. OSXSAVE, when comparing entries. */ > + mask = get_const_cpuid_mask(e1); > > - TEST_ASSERT(e1->eax == e2->eax && e1->ebx == e2->ebx && > - e1->ecx == e2->ecx && e1->edx == e2->edx, > + TEST_ASSERT((e1->eax & mask.eax) == (e2->eax & mask.eax) && > + (e1->ebx & mask.ebx) == (e2->ebx & mask.ebx) && > + (e1->ecx & mask.ecx) == (e2->ecx & mask.ecx) && > + (e1->edx & mask.edx) == (e2->edx & mask.edx), > "CPUID 0x%x.%x differ: 0x%x:0x%x:0x%x:0x%x vs 0x%x:0x%x:0x%x:0x%x", > e1->function, e1->index, > - e1->eax, e1->ebx, e1->ecx, e1->edx, > - e2->eax, e2->ebx, e2->ecx, e2->edx); > + e1->eax & mask.eax, e1->ebx & mask.ebx, > + e1->ecx & mask.ecx, e1->edx & mask.edx, > + e2->eax & mask.eax, e2->ebx & mask.ebx, > + e2->ecx & mask.ecx, e2->edx & mask.edx); > } > } Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
diff --git a/tools/testing/selftests/kvm/x86_64/cpuid_test.c b/tools/testing/selftests/kvm/x86_64/cpuid_test.c index fec03b11b059..f7fdcef5fa59 100644 --- a/tools/testing/selftests/kvm/x86_64/cpuid_test.c +++ b/tools/testing/selftests/kvm/x86_64/cpuid_test.c @@ -12,17 +12,16 @@ #include "kvm_util.h" #include "processor.h" -/* CPUIDs known to differ */ -struct { - u32 function; - u32 index; -} mangled_cpuids[] = { - /* - * These entries depend on the vCPU's XCR0 register and IA32_XSS MSR, - * which are not controlled for by this test. - */ - {.function = 0xd, .index = 0}, - {.function = 0xd, .index = 1}, +struct cpuid_mask { + union { + struct { + u32 eax; + u32 ebx; + u32 ecx; + u32 edx; + }; + u32 regs[4]; + }; }; static void test_guest_cpuids(struct kvm_cpuid2 *guest_cpuid) @@ -56,17 +55,23 @@ static void guest_main(struct kvm_cpuid2 *guest_cpuid) GUEST_DONE(); } -static bool is_cpuid_mangled(const struct kvm_cpuid_entry2 *entrie) +static struct cpuid_mask get_const_cpuid_mask(const struct kvm_cpuid_entry2 *entry) { - int i; + struct cpuid_mask mask; - for (i = 0; i < ARRAY_SIZE(mangled_cpuids); i++) { - if (mangled_cpuids[i].function == entrie->function && - mangled_cpuids[i].index == entrie->index) - return true; + memset(&mask, 0xff, sizeof(mask)); + + switch (entry->function) { + case 0xd: + /* + * CPUID.0xD.{0,1}.EBX enumerate XSAVE size based on the current + * XCR0 and IA32_XSS MSR values. + */ + if (entry->index < 2) + mask.ebx = 0; + break; } - - return false; + return mask; } static void compare_cpuids(const struct kvm_cpuid2 *cpuid1, @@ -79,6 +84,8 @@ static void compare_cpuids(const struct kvm_cpuid2 *cpuid1, "CPUID nent mismatch: %d vs. %d", cpuid1->nent, cpuid2->nent); for (i = 0; i < cpuid1->nent; i++) { + struct cpuid_mask mask; + e1 = &cpuid1->entries[i]; e2 = &cpuid2->entries[i]; @@ -88,15 +95,19 @@ static void compare_cpuids(const struct kvm_cpuid2 *cpuid1, i, e1->function, e1->index, e1->flags, e2->function, e2->index, e2->flags); - if (is_cpuid_mangled(e1)) - continue; + /* Mask off dynamic bits, e.g. OSXSAVE, when comparing entries. */ + mask = get_const_cpuid_mask(e1); - TEST_ASSERT(e1->eax == e2->eax && e1->ebx == e2->ebx && - e1->ecx == e2->ecx && e1->edx == e2->edx, + TEST_ASSERT((e1->eax & mask.eax) == (e2->eax & mask.eax) && + (e1->ebx & mask.ebx) == (e2->ebx & mask.ebx) && + (e1->ecx & mask.ecx) == (e2->ecx & mask.ecx) && + (e1->edx & mask.edx) == (e2->edx & mask.edx), "CPUID 0x%x.%x differ: 0x%x:0x%x:0x%x:0x%x vs 0x%x:0x%x:0x%x:0x%x", e1->function, e1->index, - e1->eax, e1->ebx, e1->ecx, e1->edx, - e2->eax, e2->ebx, e2->ecx, e2->edx); + e1->eax & mask.eax, e1->ebx & mask.ebx, + e1->ecx & mask.ecx, e1->edx & mask.edx, + e2->eax & mask.eax, e2->ebx & mask.ebx, + e2->ecx & mask.ecx, e2->edx & mask.edx); } }
When comparing vCPU CPUID entries against KVM's supported CPUID, mask off only the dynamic fields/bits instead of skipping the entire entry. Precisely masking bits isn't meaningfully more difficult than skipping entire entries, and will be necessary to maintain test coverage when a future commit enables OSXSAVE by default, i.e. makes one bit in all of CPUID.0x1 dynamic. Signed-off-by: Sean Christopherson <seanjc@google.com> --- .../testing/selftests/kvm/x86_64/cpuid_test.c | 61 +++++++++++-------- 1 file changed, 36 insertions(+), 25 deletions(-)