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| -rw-r--r-- | cl-os.tex | 134 |
1 files changed, 1 insertions, 133 deletions
@@ -1,134 +1,2 @@ -540 & 11 Oct 2015 & Greg Kurz & {virtqueues: fix -trivial typo - -See -\ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Used Buffer Notification Suppression}. -} \\ -\hline -541 & 11 Oct 2015 & Paolo Bonzini & {virtio-blk: fix typo -in legacy framing requirements section - -See -\ref{sec:Device Types / Block Device / Legacy Interface: Framing Requirements}. -} \\ -\hline -545 & 18 Oct 2015 & Paolo Bonzini & {virtio-blk: restore VIRTIO_BLK_F_FLUSH and VIRTIO_BLK_F_CONFIG_WCE - -VIRTIO_BLK_F_CONFIG_WCE is important in order to achieve good performance -(up to 2x, though more realistically +30-40\%) in latency-bound workloads. -However, it was removed by mistake together with VIRTIO_BLK_F_FLUSH. - -In addition, even removing VIRTIO_BLK_F_FLUSH was probably not a great -idea, because it simplifies simple drivers (e.g. firmware) that are okay -with a writethrough cache but still need data to persist after power loss. -What really should have been removed is just the possibility that devices -not propose VIRTIO_BLK_F_FLUSH, but even that only deserves a "SHOULD" in -the new world of conformance statements. - -Restore these, with the following changes: - -* clarify and use conformance statements in order to define writeback -and writethrough caching according to what is commonly done by high-end -storage. - -* clarify (with conformance statements) the influence of the -VIRTIO_BLK_F_FLUSH feature on caching and how to proceed if only one of -VIRTIO_BLK_F_FLUSH and VIRTIO_BLK_F_CONFIG_WCE is negotiated. - -* strengthen the requirement for persisting writes to MUST after -a VIRTIO_BLK_T_FLUSH request (and in other cases too involving the -new features). - -The suggested behavior upon feature negotiation is okay for the Linux -implementation of virtio1, even after the implementation is modified to -support the two new features. - -This fixes VIRTIO-144. - -See \ref{sec:Device Types / Block Device}, -\ref{sec:Conformance / Driver Conformance / Block Driver Conformance} and -\ref{sec:Conformance / Device Conformance / Block Device Conformance}. -} \\ -\hline -546 & 18 Oct 2015 & Michael S. Tsirkin & {pci: clarify configuration access capability rules - -The point of the configuration access capability is to enable -access to other capabilities. The intent never was to allow -writes to a random place within device BARs. -Limiting drivers simplifies devices - and devices can always -add another capability if drivers ever want to access -some other range. - -This resolves VIRTIO-145. - -See \ref{drivernormative:Virtio Transport Options / Virtio Over -PCI Bus / PCI Device Layout / PCI configuration access -capability}. -} \\ -\hline -547 & 18 Oct 2015 & Michael S. Tsirkin & {add advice on transition from legacy interfaces - -Reading legacy chapters gives a hint about what changed, -let's help readers discover this useful shortcut. - -This resolves VIRTIO-146. - -See \ref{sec:Transition from earlier specification drafts}. -} \\ -\hline -554 & 16 Feb 2016 & Thomas Huth & {virtio-net: fix inconsistent legacy header size - - Current text says: - The legacy driver only presented num_buffers in the struct - virtio_net_hdr when VIRTIO_NET_F_MRG_RXBUF was not negotiated; - - Should be: - "\dots was negotiated \dots" instead of "\dots was not negotiated \dots" - - To be consistent with the following: - without that feature the structure was 2 bytes shorter. - -See \ref{sec:Device Types / Network Device / Device Operation / Legacy Interface: Device Operation}. -} \\ -\hline -555 & 16 Feb 2016 & Michael S. Tsirkin & {virtio header: tweak -change motivation - - The changes are not just to remove Linux assumptions, - we have also renamed ring->queue. - Tweak the header description accordingly. - -See \ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Helpers for Operating Virtqueues}. -} \\ -\hline -558 & 16 Feb 2016 & Michael S. Tsirkin & {rename virtio_ring.h to virtio_queue.h - - Since vring* and VRING* have been replaced with virtq* and VIRTQ* - respectively, rename the header virtio_ring.h to virtio_queue.h. - -See \ref{sec:virtio-queue.h}. -} \\ -\hline -559 & 16 Feb 2016 & Michael S. Tsirkin & {init: sort status bits - - Status bit order is inconsistent: they are neither in increasing - order nor in the order they are likely to be used. - - The second approach seems more useful since there aren't - that many bits, so the numerical order does not help much. - - A typical order of use would be: - -\begin{itemize} -\item ACKNOWLEDGE -\item DRIVER -\item then either FAILED or FEATURES_OK -\item then either FAILED or DRIVER_OK -\item then DEVICE_NEEDS_RESET (if device detects an error) -\end{itemize} - - Sort the bits accordingly. - -See \ref{sec:Basic Facilities of a Virtio Device / Device Status Field}. -} \\ +REV & DATE & Author & { Description: TODO } \\ \hline |