KVM: selftests: Rename vm_create() => vm_create_barebones(), drop param

Rename vm_create() to vm_create_barebones() and drop the @phys_pages
param. Pass '0' for the number of pages even though some callers pass
'DEFAULT_GUEST_PHY_PAGES', as the intent behind creating truly barebones
VMs is purely to create a VM, i.e. there aren't vCPUs, there's no guest
code loaded, etc..., and so there is nothing that will ever need or
consume guest memory.

Freeing up the name vm_create() will allow using the name for an inner
helper to the other VM creators, which need a "full" VM.

Opportunisticaly rewrite the function comment for addr_gpa2alias() to
focus on what the _function_ does, not what its _sole caller_ does.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

KVM: selftests: Simplify KVM_ENABLE_CAP helper APIs

Rework the KVM_ENABLE_CAP helpers to take the cap and arg0; literally
every current user, and likely every future user, wants to set 0 or 1
arguments and nothing else.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

KVM: selftests: Consolidate KVM_ENABLE_CAP usage

Add __vm_enable_cap() and use it for negative tests that expect
KVM_ENABLE_CAP to fail. Opportunistically clean up the MAX_VCPU_ID test
error messages.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

KVM: selftests: Get rid of kvm_util_internal.h

Fold kvm_util_internal.h into kvm_util_base.h, i.e. make all KVM utility
stuff "public". Hiding struct implementations from tests has been a
massive failure, as it has led to pointless and poorly named wrappers,
unnecessarily opaque code, etc...

Not to mention that the approach was a complete failure as evidenced by
the non-zero number of tests that were including kvm_util_internal.h.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

KVM: selftests: Drop @mode from common vm_create() helper

Drop @mode from vm_create() and have it use VM_MODE_DEFAULT. Add and use
an inner helper, __vm_create(), to service the handful of tests that want
something other than VM_MODE_DEFAULT.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

KVM: selftests: Always open VM file descriptors with O_RDWR

Drop the @perm param from vm_create() and always open VM file descriptors
with O_RDWR. There's no legitimate use case for other permissions, and
if a selftest wants to do oddball negative testing it can open code the
necessary bits instead of forcing a bunch of tests to provide useless
information.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

kvm: selftests: Add KVM_CAP_MAX_VCPU_ID cap test

Basic test coverage of KVM_CAP_MAX_VCPU_ID cap.

This capability can be enabled before vCPU creation and only allowed
to set once. if assigned vcpu id is beyond KVM_CAP_MAX_VCPU_ID
capability, vCPU creation will fail.

Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Message-Id: <20220422134456.26655-1-guang.zeng@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>