kvm: selftests: add basic test for state save and restore

The test calls KVM_RUN repeatedly, and creates an entirely new VM with the
old memory and vCPU state on every exit to userspace.  The kvm_util API is
expanded with two functions that manage the lifetime of a kvm_vm struct:
the first closes the file descriptors and leaves the memory allocated,
and the second opens the file descriptors and reuses the memory from
the previous incarnation of the kvm_vm struct.

For now the test is very basic, as it does not test for example XSAVE or
vCPU events.  However, it will test nested virtualization state starting
with the next patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 87e05664c7f9..d32632f71ab8 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -53,6 +53,8 @@ int kvm_check_cap(long cap);
 
 struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm);
 void kvm_vm_free(struct kvm_vm *vmp);
+void kvm_vm_restart(struct kvm_vm *vmp, int perm);
+void kvm_vm_release(struct kvm_vm *vmp);
 
 int kvm_memcmp_hva_gva(void *hva,
 	struct kvm_vm *vm, const vm_vaddr_t gva, size_t len);