virtio — archive

Spec update.

From: Rusty Russell
To: [email protected]
Date: Mon, 12 Aug 2013 05:56:00 -0000

Hi all, I've gone through the post 0.9.5 git tree for pre-virtio OASIS and merged the equivalent of all my changes for consideration. I'd like MST and Pawel to do the same: I opened issues for both of you :) I'm going to chase up non-TC members (they'll need to post to the mailing list to cover IP issues) now. Many are RH, so they should be able to do that quite easily. FYI below are the outstanding commits since 0.9.5 which aren't yet in our base spec. I've invited Cornelia to join the TC, and we'll address whether virtio-ccw gets included later. Cheers, Rusty. commit be243ee8e26c10c69e2013fd30246e64271a2da5 Author: Paolo Bonzini <[email protected]> Date: Wed Jul 4 14:51:02 2012 +0930 Current QEMU and Linux drivers can export queue parameters via the virtio-blk configuration space. Document this, since the next patch will have to add another configuration field after these. Signed-off-by: Paolo Bonzini <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit 46430e822f4ed4c15c910864de3b95a710cfd65b Author: Paolo Bonzini <[email protected]> Date: Tue Jul 3 15:16:52 2012 +0200 virtio-blk spec: writeback cache enable improvements This patch introduces two improvements to writeback cache handling in the virtio-blk spec. 1) The VIRTIO_BLK_F_FLUSH feature is renamed to VIRTIO_BLK_F_WCE, and QEMU's behavior is documented explicitly as part of the spec: the host negotiates the feature only if its cache is writeback. The obvious dual requirement is imposed on the guest: it should negotiate the feature only if it is able to send flushes. And in order to protect against data loss, the spec now mandates that the host operates in writethrough mode if the guest does not negotiate VIRTIO_BLK_F_WCE (this behavior was already _allowed_ by the spec so far). This can change with every reset of course; typically the BIOS will run as writethrough, while the "main" OS will run in writeback mode. This is a backwards-compatible refinement geared towards old or limited guests, so there is no need for a new feature bit. 2) a second feature is added, VIRTIO_BLK_F_CONFIG_WCE, that provides the same information in the configuration. This will enable the driver to modify the write-cache setting at runtime (via sysfs for Linux, via MODE SELECT for Windows). Patches for QEMU and Linux will come soonish. Signed-off-by: Paolo Bonzini <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit 96b9a4d3656db6248b057a9d589fef5d9a3aa7d0 Author: Paolo Bonzini <[email protected]> Date: Wed Jul 4 16:02:36 2012 +0200 virtio-blk spec: document topology fields This completes the changes from yesterday. Signed-off-by: Paolo Bonzini <[email protected]> commit a6f08364ee605ebcaa2a16e6b294cb328ac18be0 Author: Paolo Bonzini <[email protected]> Date: Mon Jul 16 16:24:36 2012 +0200 virtio-scsi spec: unify event structs All currently defined event structs have the same fields. Simplify the driver by enforcing this also for future structs. Signed-off-by: Paolo Bonzini <[email protected]> commit 00871fd5ab31242d756a2d277dbe33854d6c2d0f Author: Paolo Bonzini <[email protected]> Date: Mon Jul 16 16:24:37 2012 +0200 virtio-scsi spec: add configuration change event This adds an event for changes to LUN parameters, for example capacity. These are reported in virtio-blk via configuration changes, and we want a similar functionality in virtio-scsi too. There is no list of supported parameter changes, instead we just refer to the list of sense codes in the SCSI specification. This event will usually be serviced in one of three ways: 1) call an OS service to revalidate the disk, either always or only for some specific sense codes; 2) somehow pass the sense directly to the upper-level driver; 3) inject a TEST UNIT READY command into the upper-level device, so that the OS will see the unit attention code and react. Of course a mix of the three is also possible, depending on how the driver writer prefers to have his layering violations served. Signed-off-by: Paolo Bonzini <[email protected]> commit cdbad68fd1ccb8b99b3853836e2b38e0bf74361b Author: Cornelia Huck <[email protected]> Date: Tue Sep 4 17:14:01 2012 +0200 virtio-spec: Add virtio-ccw spec. Add specifications for the new s390 specific virtio-ccw transport. Signed-off-by: Cornelia Huck <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit e945661b40bcfd29efc35dfa73465bcc960bd20b Author: Cornelia Huck <[email protected]> Date: Tue Sep 11 17:34:35 2012 +0200 virtio-ccw: Add secondary indicators. Add a ccw to specify the location of indicators for configuration changes and notice how they are to be used. Signed-off-by: Cornelia Huck <[email protected]> commit 67843fe9745e96c10e148f00ba0aa64397c64f06 Author: Cornelia Huck <[email protected]> Date: Mon Oct 29 14:02:38 2012 +0100 virtio-ccw: Clarifications. Clarify how indicator location is communicated and that the feature bits are little-endian. Signed-off-by: Cornelia Huck <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit 67023431c8796bc430ec0a79b15bab57e2e0f1f6 Author: Michael S. Tsirkin <[email protected]> Date: Mon Dec 10 12:40:25 2012 +0200 virtio-spec: virtio network device multiqueue support Add multiqueue support to virtio network device. Add a new feature flag VIRTIO_NET_F_MQ for this feature, a new configuration field max_virtqueue_pairs to detect supported number of virtqueues as well as a new command VIRTIO_NET_CTRL_MQ to program packet steering for unidirectional protocols. Signed-off-by: Michael S. Tsirkin <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit a4fcbee2c5198375fab01f30656cdac2133049b4 Author: Michael S. Tsirkin <[email protected]> Date: Sun Sep 9 14:08:37 2012 +0300 virtio-spec: fix thinko in multiport documentation spec numbers ports port0, port 1 etc, then goes on to say "ports 2 onwards only if MULTIPORT is set". An obvious thinko, should be port 1 onwards. Signed-off-by: Michael S. Tsirkin <[email protected]> Acked-by: Amit Shah <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit f1a218587d6e472a8a909a87cb9d4eb64629ec6d Author: Alexey Zaytsev <[email protected]> Date: Sat Dec 15 23:32:11 2012 +0200 Document VIRTIO_BLK_T_GET_ID Signed-off-by: Alexey Zaytsev <[email protected]> Reviewed-by: Stefan Hajnoczi <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit 3c600996f641614d3720c94dd52155aaaba670fa Author: Amos Kong <[email protected]> Date: Wed Jan 9 15:55:23 2013 +0800 virtio-spec: fix two typos VIRTIO_NET_F_VTRL_VQ -> VIRTIO_NET_F_CTRL_VQ VIRTIO_NET_CTRL_MQ is defined to 4 in kernel code Signed-off-by: Amos Kong <[email protected]> Reviewed-by: Stefan Hajnoczi <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit f058954d131e3dc73058778ad23b241a235ae8e1 Author: Amos Kong <[email protected]> Date: Fri Jan 18 19:05:41 2013 +0800 virtio-spec: set mac address by a new vq command Virtio-net driver currently programs MAC address byte by byte, this means that we have an intermediate step where mac is wrong. This patch introduced a new control command to set MAC address in one time, and added a new feature flag VIRTIO_NET_F_MAC_ADDR for this feature. "mac" field will be set to read-only when VIRTIO_NET_F_CTRL_MAC_ADDR is acked. Signed-off-by: Amos Kong <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit 88f37f9ec178b664213b77211fec03687b87958b Author: Pawel Moll <[email protected]> Date: Thu Feb 14 10:54:06 2013 +0000 virtio-spec: Define virtio-mmio registers as LE To solve the never-ending confusions between hosts and guests of different endianess, define all virtio-mmio registers as LE. This change should be safe at this stage, because no known working mixed-endian system exists so there is virtually no risk of breaking compatibility. Signed-off-by: Pawel Moll <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit 1de3c32e3687689b73b67622421adb656d80ec5b Author: Michael S. Tsirkin <[email protected]> Date: Thu Mar 7 20:02:21 2013 +0200 virtio-ccw: document GPR4/GPR2 cookie values virtio-ccw on kvm can use a cookie value passed to guest to optimize channel/VQ lookups. Document this. Signed-off-by: Michael S. Tsirkin <[email protected]> Reviewed-by: Cornelia Huck <[email protected]> Signed-off-by: Rusty Russell <[email protected]> (s/s390/ccw/) commit 721861222802d0ebc48564d727a3684f7b21cadd Author: Dmitry Fleytman <[email protected]> Date: Thu Apr 4 10:55:18 2013 +0300 virtio-spec: dynamic network offloads configuration Virtio-net driver currently negotiates network offloads on startup via features mechanism and have no ability to disable and re-enable offloads later. This patch introduced a new control command that allows to configure device network offloads state dynamically. The patch also introduces a new feature flag VIRTIO_NET_F_CTRL_GUEST_OFFLOADS. Signed-off-by: Dmitry Fleytman <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit a02d91f8729b4a333d525015d22138a86ce9b644 Author: Rusty Russell <[email protected]> Date: Mon Apr 15 12:27:01 2013 +0930 net: add note that you can defer rx queue init until mq enable. Signed-off-by: Rusty Russell <[email protected]> commit 6833b4aaa799fede8c9ae36412d21aa51d66899f Author: Sasha Levin <[email protected]> Date: Mon Apr 15 01:13:48 2013 -0400 virtio-spec: document virtio-9p Add basic documentation for virtio-9p. I can expand more on device operation, but I don't think there's anything significant enough for the spec to be mentioned there. Please let me know if I'm wrong. Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit 4480830192c0d7680d7516bc2d2138ca9ae2f5fb Author: Pranavkumar Sawargaonkar <[email protected]> Date: Mon May 13 12:21:05 2013 +0930 Documentation: virtio: Add emergency write (emerg_wr) config register in virtio console. [ Enhanced and applied to Lyx not text version --RR ] Signed-off-by: Pranavkumar Sawargaonkar <[email protected]> Signed-off-by: Anup Patel <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit f2e013065ef286e33c7e6d279a880551b43e9680 Author: Michael S. Tsirkin <[email protected]> Date: Mon May 20 15:20:52 2013 +0300 virtio-spec: tweak wording for console control vq control vq is only used if feature bit is negotiated - it's not enough that device supports it. Clarify this in the spec. Signed-off-by: Michael S. Tsirkin <[email protected]> Signed-off-by: Rusty Russell <[email protected]> commit c19f2dee4975db51fc189910df7d87011925aa82 Author: Rusty Russell <[email protected]> Date: Mon Jun 3 10:57:07 2013 +0930 virtio-spec: small English/punctuation corrections 1. s/These are devices are/These devices are 2. s/Thefirst/The first 3. s/, Guest should/. Guest should Signed-off-by: Luiz Capitulino <[email protected]> Signed-off-by: Rusty Russell <[email protected]> (minor mod)