Skip selftests that require EPT support in the VM when it is not
available. For example, if running on a machine where kvm_intel.ept=N
since KVM does not offer EPT support to guests if EPT is not supported
on the host.

This commit causes vmx_dirty_log_test to be skipped instead of failing
on hosts where kvm_intel.ept=N.

Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20220926171457.532542-1-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Change the mov in KVM_ASM_SAFE() that zeroes @vector to a movb to
make it unambiguous.

This fixes a build failure with Clang since, unlike the GNU assembler,
the LLVM integrated assembler rejects ambiguous X86 instructions that
don't have suffixes:

  In file included from x86_64/hyperv_features.c:13:
  include/x86_64/processor.h:825:9: error: ambiguous instructions require an explicit suffix (could be 'movb', 'movw', 'movl', or 'movq')
          return kvm_asm_safe("wrmsr", "a"(val & -1u), "d"(val >> 32), "c"(msr));
                 ^
  include/x86_64/processor.h:802:15: note: expanded from macro 'kvm_asm_safe'
          asm volatile(KVM_ASM_SAFE(insn)                 \
                       ^
  include/x86_64/processor.h:788:16: note: expanded from macro 'KVM_ASM_SAFE'
          "1: " insn "\n\t"                                       \
                        ^
  <inline asm>:5:2: note: instantiated into assembly here
          mov $0, 15(%rsp)
          ^

It seems like this change could introduce undesirable behavior in the
future, e.g. if someone used a type larger than a u8 for @vector, since
KVM_ASM_SAFE() will only zero the bottom byte. I tried changing the type
of @vector to an int to see what would happen. GCC failed to compile due
to a size mismatch between `movb` and `%eax`. Clang succeeded in
compiling, but the generated code looked correct, so perhaps it will not
be an issue. That being said it seems like there could be a better
solution to this issue that does not assume @vector is a u8.

Fixes: 3b23054cd3f5 ("KVM: selftests: Add x86-64 support for exception fixup")
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722234838.2160385-3-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Change KVM_EXCEPTION_MAGIC to use the all-caps "ULL", rather than lower
case. This fixes a build failure with Clang:

  In file included from x86_64/hyperv_features.c:13:
  include/x86_64/processor.h:825:9: error: unexpected token in argument list
          return kvm_asm_safe("wrmsr", "a"(val & -1u), "d"(val >> 32), "c"(msr));
                 ^
  include/x86_64/processor.h:802:15: note: expanded from macro 'kvm_asm_safe'
          asm volatile(KVM_ASM_SAFE(insn)                 \
                       ^
  include/x86_64/processor.h:785:2: note: expanded from macro 'KVM_ASM_SAFE'
          "mov $" __stringify(KVM_EXCEPTION_MAGIC) ", %%r9\n\t"   \
          ^
  <inline asm>:1:18: note: instantiated into assembly here
          mov $0xabacadabaull, %r9
                          ^

Fixes: 3b23054cd3f5 ("KVM: selftests: Add x86-64 support for exception fixup")
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220722234838.2160385-2-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Verify that KVM allows toggling VMX MSR bits to be "more" restrictive,
and also allows restoring each MSR to KVM's original, less restrictive
value.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220607213604.3346000-16-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Drop SVM_CPUID_FUNC to reduce the probability of tests open coding CPUID
checks instead of using kvm_cpu_has() or this_cpu_has().

Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-43-seanjc@google.com

Provide informative error messages for the various checks related to
requesting access to XSAVE features that are buried behind XSAVE Feature
Disabling (XFD).

Opportunistically rename the helper to have "require" in the name so that
it's somewhat obvious that the helper may skip the test.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-41-seanjc@google.com

Use kvm_cpu_has() to check for XFD supported in vm_xsave_req_perm(),
simply checking host CPUID doesn't guarantee KVM supports AMX/XFD.

Opportunistically hoist the check above the bit check; if XFD isn't
supported, it's far better to get a "not supported at all" message, as
opposed to a "feature X isn't supported" message".

Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-39-seanjc@google.com

Make the "get max CPUID leaf" helpers static inline, there's no reason to
bury the one liners in processor.c.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-38-seanjc@google.com

Rename kvm_get_supported_cpuid_index() to __kvm_get_supported_cpuid_entry()
to better show its relationship to kvm_get_supported_cpuid_entry(), and
because the helper returns a CPUID entry, not the index of an entry.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-37-seanjc@google.com

Replace an evil open coded instance of querying CPUID from L1 with
this_cpu_has(X86_FEATURE_SVM).

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-35-seanjc@google.com