[PATCH v2 1/4] KVM: selftests: Move the guts of kvm_hypercall() to a separate macro

From: Sean Christopherson
Date: Fri Feb 03 2023 - 21:42:10 EST


Extract the guts of kvm_hypercall() to a macro so that Xen hypercalls,
which have a different register ABI, can reuse the VMCALL vs. VMMCALL
logic.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
.../selftests/kvm/lib/x86_64/processor.c | 29 +++++++++++--------
1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index ae1e573d94ce..ff901cb47ffc 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -1139,21 +1139,26 @@ const struct kvm_cpuid_entry2 *get_cpuid_entry(const struct kvm_cpuid2 *cpuid,
return NULL;
}

+#define X86_HYPERCALL(inputs...) \
+({ \
+ uint64_t r; \
+ \
+ 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) \
+ : [use_vmmcall] "r" (host_cpu_is_amd), inputs); \
+ \
+ r; \
+})
+
uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
uint64_t a3)
{
- uint64_t r;
-
- 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),
- [use_vmmcall] "r" (host_cpu_is_amd));
- return r;
+ return X86_HYPERCALL("a"(nr), "b"(a0), "c"(a1), "d"(a2), "S"(a3));
}

const struct kvm_cpuid2 *kvm_get_supported_hv_cpuid(void)
--
2.39.1.519.gcb327c4b5f-goog