pull deps in for optimization, maybe slice back out later

overlay/virtio/features.go

@@ -0,0 +1,136 @@
+package virtio
+
+// Feature contains feature bits that describe a virtio device or driver.
+type Feature uint64
+
+// Device-independent feature bits.
+//
+// Source: https://docs.oasis-open.org/virtio/virtio/v1.2/csd01/virtio-v1.2-csd01.html#x1-6600006
+const (
+	// FeatureIndirectDescriptors indicates that the driver can use descriptors
+	// with an additional layer of indirection.
+	FeatureIndirectDescriptors Feature = 1 << 28
+
+	// FeatureVersion1 indicates compliance with version 1.0 of the virtio
+	// specification.
+	FeatureVersion1 Feature = 1 << 32
+)
+
+// Feature bits for networking devices.
+//
+// Source: https://docs.oasis-open.org/virtio/virtio/v1.2/csd01/virtio-v1.2-csd01.html#x1-2200003
+const (
+	// FeatureNetDeviceCsum indicates that the device can handle packets with
+	// partial checksum (checksum offload).
+	FeatureNetDeviceCsum Feature = 1 << 0
+
+	// FeatureNetDriverCsum indicates that the driver can handle packets with
+	// partial checksum.
+	FeatureNetDriverCsum Feature = 1 << 1
+
+	// FeatureNetCtrlDriverOffloads indicates support for dynamic offload state
+	// reconfiguration.
+	FeatureNetCtrlDriverOffloads Feature = 1 << 2
+
+	// FeatureNetMTU indicates that the device reports a maximum MTU value.
+	FeatureNetMTU Feature = 1 << 3
+
+	// FeatureNetMAC indicates that the device provides a MAC address.
+	FeatureNetMAC Feature = 1 << 5
+
+	// FeatureNetDriverTSO4 indicates that the driver supports the TCP
+	// segmentation offload for received IPv4 packets.
+	FeatureNetDriverTSO4 Feature = 1 << 7
+
+	// FeatureNetDriverTSO6 indicates that the driver supports the TCP
+	// segmentation offload for received IPv6 packets.
+	FeatureNetDriverTSO6 Feature = 1 << 8
+
+	// FeatureNetDriverECN indicates that the driver supports the TCP
+	// segmentation offload with ECN for received packets.
+	FeatureNetDriverECN Feature = 1 << 9
+
+	// FeatureNetDriverUFO indicates that the driver supports the UDP
+	// fragmentation offload for received packets.
+	FeatureNetDriverUFO Feature = 1 << 10
+
+	// FeatureNetDeviceTSO4 indicates that the device supports the TCP
+	// segmentation offload for received IPv4 packets.
+	FeatureNetDeviceTSO4 Feature = 1 << 11
+
+	// FeatureNetDeviceTSO6 indicates that the device supports the TCP
+	// segmentation offload for received IPv6 packets.
+	FeatureNetDeviceTSO6 Feature = 1 << 12
+
+	// FeatureNetDeviceECN indicates that the device supports the TCP
+	// segmentation offload with ECN for received packets.
+	FeatureNetDeviceECN Feature = 1 << 13
+
+	// FeatureNetDeviceUFO indicates that the device supports the UDP
+	// fragmentation offload for received packets.
+	FeatureNetDeviceUFO Feature = 1 << 14
+
+	// FeatureNetMergeRXBuffers indicates that the driver can handle merged
+	// receive buffers.
+	// When this feature is negotiated, devices may merge multiple descriptor
+	// chains together to transport large received packets. [NetHdr.NumBuffers]
+	// will then contain the number of merged descriptor chains.
+	FeatureNetMergeRXBuffers Feature = 1 << 15
+
+	// FeatureNetStatus indicates that the device configuration status field is
+	// available.
+	FeatureNetStatus Feature = 1 << 16
+
+	// FeatureNetCtrlVQ indicates that a control channel virtqueue is
+	// available.
+	FeatureNetCtrlVQ Feature = 1 << 17
+
+	// FeatureNetCtrlRX indicates support for RX mode control (e.g. promiscuous
+	// or all-multicast) for packet receive filtering.
+	FeatureNetCtrlRX Feature = 1 << 18
+
+	// FeatureNetCtrlVLAN indicates support for VLAN filtering through the
+	// control channel.
+	FeatureNetCtrlVLAN Feature = 1 << 19
+
+	// FeatureNetDriverAnnounce indicates that the driver can send gratuitous
+	// packets.
+	FeatureNetDriverAnnounce Feature = 1 << 21
+
+	// FeatureNetMQ indicates that the device supports multiqueue with automatic
+	// receive steering.
+	FeatureNetMQ Feature = 1 << 22
+
+	// FeatureNetCtrlMACAddr indicates that the MAC address can be set through
+	// the control channel.
+	FeatureNetCtrlMACAddr Feature = 1 << 23
+
+	// FeatureNetDeviceUSO indicates that the device supports the UDP
+	// segmentation offload for received packets.
+	FeatureNetDeviceUSO Feature = 1 << 56
+
+	// FeatureNetHashReport indicates that the device can report a per-packet
+	// hash value and type.
+	FeatureNetHashReport Feature = 1 << 57
+
+	// FeatureNetDriverHdrLen indicates that the driver can provide the exact
+	// header length value (see [NetHdr.HdrLen]).
+	// Devices may benefit from knowing the exact header length.
+	FeatureNetDriverHdrLen Feature = 1 << 59
+
+	// FeatureNetRSS indicates that the device supports RSS (receive-side
+	// scaling) with configurable hash parameters.
+	FeatureNetRSS Feature = 1 << 60
+
+	// FeatureNetRSCExt indicates that the device can process duplicated ACKs
+	// and report the number of coalesced segments and duplicated ACKs.
+	FeatureNetRSCExt Feature = 1 << 61
+
+	// FeatureNetStandby indicates that the device may act as a standby for a
+	// primary device with the same MAC address.
+	FeatureNetStandby Feature = 1 << 62
+
+	// FeatureNetSpeedDuplex indicates that the device can report link speed and
+	// duplex mode.
+	FeatureNetSpeedDuplex Feature = 1 << 63
+)