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| author | Sean Christopherson <seanjc@google.com> | 2022-11-02 11:46:52 -0700 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2022-11-16 16:59:01 -0800 |
| commit | b9635930f0a73c1ef7b465121896c3fb2e3b77cd (patch) | |
| tree | f4d66b0836d9059226fbf9e99320c4a8d45facf0 /tools/testing/selftests/kvm/lib/x86_64 | |
| parent | f2e5b53b4ba9bc10d3febc3682bdf22e946bf6eb (diff) | |
| download | linux-b9635930f0a73c1ef7b465121896c3fb2e3b77cd.tar.bz2 | |
KVM: selftests: Provide error code as a KVM_ASM_SAFE() output
Provide the error code on a fault in KVM_ASM_SAFE(), e.g. to allow tests
to assert that #PF generates the correct error code without needing to
manually install a #PF handler. Use r10 as the scratch register for the
error code, as it's already clobbered by the asm blob (loaded with the
RIP of the to-be-executed instruction). Deliberately load the output
"error_code" even in the non-faulting path so that error_code is always
initialized with deterministic data (the aforementioned RIP), i.e to
ensure a selftest won't end up with uninitialized consumption regardless
of how KVM_ASM_SAFE() is used.
Don't clear r10 in the non-faulting case and instead load error code with
the RIP (see above). The error code is valid if and only if an exception
occurs, and '0' isn't necessarily a better "invalid" value, e.g. '0'
could result in false passes for a buggy test.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-9-dmatlack@google.com
Diffstat (limited to 'tools/testing/selftests/kvm/lib/x86_64')
| -rw-r--r-- | tools/testing/selftests/kvm/lib/x86_64/processor.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 999576146d69..4623874a805b 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -1068,6 +1068,7 @@ static bool kvm_fixup_exception(struct ex_regs *regs) regs->rip = regs->r11; regs->r9 = regs->vector; + regs->r10 = regs->error_code; return true; } |