KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test

vittyvk · bonzini · commit 13ffbd8db1dd · 2020-06-01T11:58:23.000-04:00
vmx_tsc_adjust_test fails with: IA32_TSC_ADJUST is -4294969448 (-1 * TSC_ADJUST_VALUE + -2152). IA32_TSC_ADJUST is -4294969448 (-1 * TSC_ADJUST_VALUE + -2152). IA32_TSC_ADJUST is 281470681738540 (65534 * TSC_ADJUST_VALUE + 4294962476). ==== Test Assertion Failure ==== x86_64/vmx_tsc_adjust_test.c:153: false pid=19738 tid=19738 - Interrupted system call 1 0x0000000000401192: main at vmx_tsc_adjust_test.c:153 2 0x00007fe1ef8583d4: ?? ??:0 3 0x0000000000401201: _start at ??:? Failed guest assert: (adjust <= max) The problem is that is 'tsc_val' should be u64, not u32 or the reading gets truncated. Fixes: 8d7fbf0 ("KVM: selftests: VMX preemption timer migration test") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200601154726.261868-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -79,7 +79,7 @@ static inline uint64_t get_desc64_base(const struct desc64 *desc)
 static inline uint64_t rdtsc(void)
 {
 	uint32_t eax, edx;
-	uint32_t tsc_val;
+	uint64_t tsc_val;
 	/*
 	 * The lfence is to wait (on Intel CPUs) until all previous
 	 * instructions have been executed. If software requires RDTSC to be

Original file line number	Diff line number	Diff line change
`@@ -79,7 +79,7 @@ static inline uint64_t get_desc64_base(const struct desc64 *desc)`
`79`	`79`	`static inline uint64_t rdtsc(void)`
`80`	`80`	`{`
`81`	`81`	`uint32_t eax, edx;`
`82`		`- uint32_t tsc_val;`
	`82`	`+ uint64_t tsc_val;`
`83`	`83`	`/*`
`84`	`84`	`* The lfence is to wait (on Intel CPUs) until all previous`
`85`	`85`	`* instructions have been executed. If software requires RDTSC to be`