KVM: selftests: set CPUID before setting sregs in vcpu creation

Recent kernels have checks to ensure the GPA values in special-purpose
registers like CR3 are within the maximum physical address range and
don't overlap with anything in the upper/reserved range. In the case of
SEV kselftest guests booting directly into 64-bit mode, CR3 needs to be
initialized to the GPA of the page table root, with the encryption bit
set. The kernel accounts for this encryption bit by removing it from
reserved bit range when the guest advertises the bit position via
KVM_SET_CPUID*, but kselftests currently call KVM_SET_SREGS as part of
vm_vcpu_add_default(), before KVM_SET_CPUID*.

As a result, KVM_SET_SREGS will return an error in these cases.
Address this by moving vcpu_set_cpuid() (which calls KVM_SET_CPUID*)
ahead of vcpu_setup() (which calls KVM_SET_SREGS).

While there, address a typo in the assertion that triggers when
KVM_SET_SREGS fails.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Message-Id: <20211006203617.13045-1-michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Nathan Tempelman <natet@google.com>

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 0fe66ca6139a80207c742e552b8762d0fe88b215..041004c0fda760733930bb3be105d12438e6d0ea 100644 (file)
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1792,7 +1792,7 @@ void vcpu_sregs_get(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_sregs *sregs)
 void vcpu_sregs_set(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_sregs *sregs)
 {
        int ret = _vcpu_sregs_set(vm, vcpuid, sregs);
-       TEST_ASSERT(ret == 0, "KVM_RUN IOCTL failed, "
+       TEST_ASSERT(ret == 0, "KVM_SET_SREGS IOCTL failed, "
                "rc: %i errno: %i", ret, errno);
 }
 

diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 28cb881f440d04f170af3cbaeca4e378e2aea545..82c39db913699949648974ecb3530bad60431bea 100644 (file)
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -660,6 +660,7 @@ void vm_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, void *guest_code)
 
        /* Create VCPU */
        vm_vcpu_add(vm, vcpuid);
+       vcpu_set_cpuid(vm, vcpuid, kvm_get_supported_cpuid());
        vcpu_setup(vm, vcpuid);
 
        /* Setup guest general purpose registers */
@@ -672,9 +673,6 @@ void vm_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, void *guest_code)
        /* Setup the MP state */
        mp_state.mp_state = 0;
        vcpu_set_mp_state(vm, vcpuid, &mp_state);
-
-       /* Setup supported CPUIDs */
-       vcpu_set_cpuid(vm, vcpuid, kvm_get_supported_cpuid());
 }
 
 /*