[kvm-unit-tests PATCH 4/8] x86/hypercall: enable the test on non-KVM environment

[Nadav Amit <nadav.amit@xxxxxxxxx>]

From: Nadav Amit <nadav.amit@xxxxxxxxx>

KVM knows to emulate both vmcall and vmmcall regardless of the
actual architecture. Native hardware does not behave this way. Based on
the availability of test-device, figure out that the test is run on
non-KVM environment, and if so, run vmcall/vmmcall based on the actual
architecture.

Signed-off-by: Nadav Amit <nadav.amit@xxxxxxxxx>
---
 lib/x86/processor.h |  8 ++++++++
 x86/hypercall.c     | 31 +++++++++++++++++++++++--------
 2 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/lib/x86/processor.h b/lib/x86/processor.h
index abc04b0..517ee70 100644
--- a/lib/x86/processor.h
+++ b/lib/x86/processor.h
@@ -118,6 +118,14 @@ static inline u8 cpuid_maxphyaddr(void)
     return raw_cpuid(0x80000008, 0).a & 0xff;
 }
 
+static inline bool is_intel(void)
+{
+	struct cpuid c = cpuid(0);
+	u32 name[4] = {c.b, c.d, c.c };
+
+	return strcmp((char *)name, "GenuineIntel") == 0;
+}
+
 #define	CPUID(a, b, c, d) ((((unsigned long long) a) << 32) | (b << 16) | \
 			  (c << 8) | d)
 
diff --git a/x86/hypercall.c b/x86/hypercall.c
index 28760e3..a02ee33 100644
--- a/x86/hypercall.c
+++ b/x86/hypercall.c
@@ -2,6 +2,7 @@
 #include "vm.h"
 #include "desc.h"
 #include "alloc_page.h"
+#include "fwcfg.h"
 
 #define KVM_HYPERCALL_INTEL ".byte 0x0f,0x01,0xc1"
 #define KVM_HYPERCALL_AMD ".byte 0x0f,0x01,0xd9"
@@ -51,10 +52,18 @@ test_edge(void)
 
 int main(int ac, char **av)
 {
-	kvm_hypercall0_intel(-1u);
-	printf("Hypercall via VMCALL: OK\n");
-	kvm_hypercall0_amd(-1u);
-	printf("Hypercall via VMMCALL: OK\n");
+	bool test_vmcall = !no_test_device || is_intel();
+	bool test_vmmcall = !no_test_device || !is_intel();
+
+	if (test_vmcall) {
+		kvm_hypercall0_intel(-1u);
+		printf("Hypercall via VMCALL: OK\n");
+	}
+
+	if (test_vmmcall) {
+		kvm_hypercall0_amd(-1u);
+		printf("Hypercall via VMMCALL: OK\n");
+	}
 
 #ifdef __x86_64__
 	setup_vm();
@@ -70,12 +79,18 @@ int main(int ac, char **av)
 	topmost[4093] = 0x0f;
 	topmost[4094] = 0x01;
 	topmost[4095] = 0xc1;
-	report(test_edge(),
-	       "VMCALL on edge of canonical address space (intel)");
+
+	if (test_vmcall) {
+		report(test_edge(),
+		       "VMCALL on edge of canonical address space (intel)");
+	}
 
 	topmost[4095] = 0xd9;
-	report(test_edge(),
-	       "VMMCALL on edge of canonical address space (AMD)");
+
+	if (test_vmmcall) {
+		report(test_edge(),
+		       "VMMCALL on edge of canonical address space (AMD)");
+	}
 #endif
 
 	return report_summary();
-- 
2.25.1