[PATCH kvmtool 3/4] virtio: Add helper for enabling VIRTIO_F_ACCESS_PLATFORM

[Will Deacon <will@kernel.org>]

In preparation for supporting protected guests on arm64, introduce a
virtio helper to advertise the VIRTIO_F_ACCESS_PLATFORM feature for the
modern transport.

Signed-off-by: Will Deacon <will@kernel.org>
---
 include/kvm/virtio.h | 1 +
 virtio/core.c        | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/include/kvm/virtio.h b/include/kvm/virtio.h
index c95183b..dd3117b 100644
--- a/include/kvm/virtio.h
+++ b/include/kvm/virtio.h
@@ -277,6 +277,7 @@ void virtio_vhost_reset_vring(struct kvm *kvm, int vhost_fd, u32 index,
 int virtio_vhost_set_features(int vhost_fd, u64 features);
 
 int virtio_transport_parser(const struct option *opt, const char *arg, int unset);
+void virtio_modern_enable_feat_access_platform(void);
 u64 virtio_get_modern_transport_features(void);
 
 #endif /* KVM__VIRTIO_H */
diff --git a/virtio/core.c b/virtio/core.c
index 8c5086d..96bbf96 100644
--- a/virtio/core.c
+++ b/virtio/core.c
@@ -355,6 +355,11 @@ bool virtio_access_config(struct kvm *kvm, struct virtio_device *vdev,
 
 static u64 virtio_modern_transport_features = 1ULL << VIRTIO_F_VERSION_1;
 
+void virtio_modern_enable_feat_access_platform(void)
+{
+	virtio_modern_transport_features |= 1ULL << VIRTIO_F_ACCESS_PLATFORM;
+}
+
 u64 virtio_get_modern_transport_features(void)
 {
 	return virtio_modern_transport_features;
-- 
2.55.0.rc0.738.g0c8ab3ebcc-goog