Use the host CPU's native hypercall instruction, i.e. VMCALL vs. VMMCALL, in kvm_hypercall(), as relying on KVM to patch in the native hypercall on a #UD for the "wrong" hypercall requires KVM_X86_QUIRK_FIX_HYPERCALL_INSN to be enabled and flat out doesn't work if guest memory is encrypted with a private key, e.g. for SEV VMs.
Suggested-by: Sean Christopherson seanjc@google.com Reviewed-by: David Matlack dmatlack@google.com Signed-off-by: Vishal Annapurve vannapurve@google.com --- tools/testing/selftests/kvm/lib/x86_64/processor.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 84915bc7d689..ae1e573d94ce 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -1144,9 +1144,15 @@ uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2, { uint64_t r;
- asm volatile("vmcall" + asm volatile("test %[use_vmmcall], %[use_vmmcall]\n\t" + "jnz 1f\n\t" + "vmcall\n\t" + "jmp 2f\n\t" + "1: vmmcall\n\t" + "2:" : "=a"(r) - : "a"(nr), "b"(a0), "c"(a1), "d"(a2), "S"(a3)); + : "a"(nr), "b"(a0), "c"(a1), "d"(a2), "S"(a3), + [use_vmmcall] "r" (host_cpu_is_amd)); return r; }