@@ -231,9 +231,9 @@ static void __attribute__((__flatten__)) guest_code(void *arg)
int main(int argc, char *argv[])
{
vm_vaddr_t nested_gva = 0;
-
+ struct kvm_cpuid2 empty_cpuid = {};
struct kvm_regs regs1, regs2;
- struct kvm_vcpu *vcpu;
+ struct kvm_vcpu *vcpu, *vcpuN;
struct kvm_vm *vm;
struct kvm_x86_state *state;
struct ucall uc;
@@ -286,6 +286,21 @@ int main(int argc, char *argv[])
/* Restore state in a new VM. */
vcpu = vm_recreate_with_one_vcpu(vm);
vcpu_load_state(vcpu, state);
+
+ /*
+ * Restore XSAVE state in a dummy vCPU, first without doing
+ * KVM_SET_CPUID2, and then with an empty guest CPUID. Except
+ * for off-by-default xfeatures, e.g. AMX, KVM is supposed to
+ * allow KVM_SET_XSAVE regardless of guest CPUID. Manually
+ * load only XSAVE state, MSRs in particular have a much more
+ * convoluted ABI.
+ */
+ vcpuN = __vm_vcpu_add(vm, vcpu->id + 1);
+ vcpu_xsave_set(vcpuN, state->xsave);
+
+ vcpu_init_cpuid(vcpuN, &empty_cpuid);
+ vcpu_xsave_set(vcpuN, state->xsave);
+
kvm_x86_state_cleanup(state);
memset(®s2, 0, sizeof(regs2));
Expand x86's state test to load XSAVE state into a "dummy" vCPU prior to KVM_SET_CPUID2, and again with an empty guest CPUID model. Except for off-by-default features, i.e. AMX, KVM's ABI for KVM_SET_XSAVE is that userspace is allowed to load xfeatures so long as they are supported by the host. This is a regression test for a combination of KVM bugs where the state saved by KVM_GET_XSAVE{2} could not be loaded via KVM_SET_XSAVE if the saved xstate_bv would load guest-unsupported xfeatures. Signed-off-by: Sean Christopherson <seanjc@google.com> --- .../testing/selftests/kvm/x86_64/state_test.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)