On Fri, May 29, 2020 at 03:04:06PM +0200, Vitaly Kuznetsov wrote:
> More tests may want to check if the CPU is Intel or AMD in
> guest code, separate cpu_has_svm() and put it as static
> inline to svm_util.h.
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/include/x86_64/svm_util.h | 10 ++++++++++
> tools/testing/selftests/kvm/x86_64/state_test.c | 9 +--------
> 2 files changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/include/x86_64/svm_util.h b/tools/testing/selftests/kvm/include/x86_64/svm_util.h
> index cd037917fece..b1057773206a 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/svm_util.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/svm_util.h
> @@ -35,4 +35,14 @@ void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_r
> void run_guest(struct vmcb *vmcb, uint64_t vmcb_gpa);
> void nested_svm_check_supported(void);
>
> +static inline bool cpu_has_svm(void)
> +{
> + u32 eax = 0x80000001, ecx;
> +
> + asm volatile("cpuid" :
> + "=a" (eax), "=c" (ecx) : "0" (eax) : "ebx", "edx");
u32 eax, ecx;
asm("cpuid" : "=a" (eax), "=c" (ecx) : "a" (0x80000001) : "ebx", "edx");
The volatile shouldn't be needed, e.g. no one should be using this purely
for its seralization properties, and I don't see any reason to put the leaf
number into a variable.
Alternatively, adding a proper cpuid framework to processor.h would likely
be useful in the long run.
> +
> + return ecx & CPUID_SVM;
> +}
> +
