diff options
Diffstat (limited to 'tools/testing/selftests/kvm/lib/x86_64')
| -rw-r--r-- | tools/testing/selftests/kvm/lib/x86_64/svm.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/tools/testing/selftests/kvm/lib/x86_64/svm.c b/tools/testing/selftests/kvm/lib/x86_64/svm.c index 2ac98d70d02b..161eba7cd128 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/svm.c +++ b/tools/testing/selftests/kvm/lib/x86_64/svm.c @@ -54,6 +54,18 @@ static void vmcb_set_seg(struct vmcb_seg *seg, u16 selector, seg->base = base; } +/* + * Avoid using memset to clear the vmcb, since libc may not be + * available in L1 (and, even if it is, features that libc memset may + * want to use, like AVX, may not be enabled). + */ +static void clear_vmcb(struct vmcb *vmcb) +{ + int n = sizeof(*vmcb) / sizeof(u32); + + asm volatile ("rep stosl" : "+c"(n), "+D"(vmcb) : "a"(0) : "memory"); +} + void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_rsp) { struct vmcb *vmcb = svm->vmcb; @@ -70,7 +82,7 @@ void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_r wrmsr(MSR_EFER, efer | EFER_SVME); wrmsr(MSR_VM_HSAVE_PA, svm->save_area_gpa); - memset(vmcb, 0, sizeof(*vmcb)); + clear_vmcb(vmcb); asm volatile ("vmsave %0\n\t" : : "a" (vmcb_gpa) : "memory"); vmcb_set_seg(&save->es, get_es(), 0, -1U, data_seg_attr); vmcb_set_seg(&save->cs, get_cs(), 0, -1U, code_seg_attr); |