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authorJason Wang <jasowang@redhat.com>2021-06-02 10:15:34 +0800
committerMichael S. Tsirkin <mst@redhat.com>2021-07-08 07:49:01 -0400
commit0140b3d07617e71a8d9509776434ced107572fc8 (patch)
treeefc7f7241de3ea804dfadc3b19ebb4da9b52b8dd /drivers/virtio
parent530a5678bc0083e84f99f38f77ced8fbb3d18434 (diff)
virtio-pci library: introduce vp_modern_get_driver_features()
This patch introduce a helper to get driver/guest features from the device. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210602021536.39525-3-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Eli Cohen <elic@nvidia.com>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/virtio_pci_modern_dev.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio_pci_modern_dev.c
index 54f297028586..e11ed748e661 100644
--- a/drivers/virtio/virtio_pci_modern_dev.c
+++ b/drivers/virtio/virtio_pci_modern_dev.c
@@ -384,6 +384,27 @@ u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)
EXPORT_SYMBOL_GPL(vp_modern_get_features);
/*
+ * vp_modern_get_driver_features - get driver features from device
+ * @mdev: the modern virtio-pci device
+ *
+ * Returns the driver features read from the device
+ */
+u64 vp_modern_get_driver_features(struct virtio_pci_modern_device *mdev)
+{
+ struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
+
+ u64 features;
+
+ vp_iowrite32(0, &cfg->guest_feature_select);
+ features = vp_ioread32(&cfg->guest_feature);
+ vp_iowrite32(1, &cfg->guest_feature_select);
+ features |= ((u64)vp_ioread32(&cfg->guest_feature) << 32);
+
+ return features;
+}
+EXPORT_SYMBOL_GPL(vp_modern_get_driver_features);
+
+/*
* vp_modern_set_features - set features to device
* @mdev: the modern virtio-pci device
* @features: the features set to device