diff options
Diffstat (limited to 'virtio-v1.0-wd01-part1-specification.txt')
| -rw-r--r-- | virtio-v1.0-wd01-part1-specification.txt | 29 |
1 files changed, 13 insertions, 16 deletions
diff --git a/virtio-v1.0-wd01-part1-specification.txt b/virtio-v1.0-wd01-part1-specification.txt index 9af2072..e6f23ff 100644 --- a/virtio-v1.0-wd01-part1-specification.txt +++ b/virtio-v1.0-wd01-part1-specification.txt @@ -1373,9 +1373,7 @@ the different features the driver negotiated. Often a driver will suppress transmission interrupts using the VRING_AVAIL_F_NO_INTERRUPT flag (see "2.4.2. Receiving Used Buffers From The Device") and check for used packets in the transmit path of following -packets. However, it will still receive interrupts if the -VIRTIO_F_NOTIFY_ON_EMPTY feature is negotiated, indicating that -the transmission queue is completely emptied. +packets. The normal behavior in this interrupt handler is to retrieve and new descriptors from the used ring and free the corresponding @@ -2583,18 +2581,7 @@ contents of the event field. The following events are defined: 2.5. Reserved Feature Bits ========================= -Currently there are five device-independent feature bits defined: - - VIRTIO_F_NOTIFY_ON_EMPTY (24) Negotiating this feature - indicates that the driver wants an interrupt if the device runs - out of available descriptors on a virtqueue, even though - interrupts are suppressed using the VRING_AVAIL_F_NO_INTERRUPT - flag or the used_event field. An example of this is the - networking driver: it doesn't need to know every time a packet - is transmitted, but it does need to free the transmitted - packets a finite time after they are transmitted. It can avoid - using a timer if the device interrupts it when all the packets - are transmitted. +Currently there are four device-independent feature bits defined: VIRTIO_F_RING_INDIRECT_DESC (28) Negotiating this feature indicates that the driver can use descriptors with the VRING_DESC_F_INDIRECT @@ -2624,11 +2611,21 @@ and should not be used. Legacy or transitional devices may offer the following: +VIRTIO_F_NOTIFY_ON_EMPTY (24) Negotiating this feature + indicates that the driver wants an interrupt if the device runs + out of available descriptors on a virtqueue, even though + interrupts are suppressed using the VRING_AVAIL_F_NO_INTERRUPT + flag or the used_event field. An example of this is the + networking driver: it doesn't need to know every time a packet + is transmitted, but it does need to free the transmitted + packets a finite time after they are transmitted. It can avoid + using a timer if the device interrupts it when all the packets + are transmitted. + VIRTIO_F_ANY_LAYOUT (27) This feature indicates that the device accepts arbitrary descriptor layouts, as described in Section "2.1.4.2.1. Legacy Interface: Message Framing". - 2.6. virtio_ring.h ================= |