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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-18 09:24:01 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-18 09:24:01 -0800 |
commit | 53861af9a17022898619a2ae4ead0dfc601b7c13 (patch) | |
tree | dc11088d9e86fa1d8d8479974864153a8f976897 /Documentation/virtual | |
parent | 5c2770079fb9b8c5bfb7113d9e76de66e77a0e24 (diff) | |
parent | 5b40a7daf51812b35cf05d1601a779a7043f8414 (diff) | |
download | op-kernel-dev-53861af9a17022898619a2ae4ead0dfc601b7c13.zip op-kernel-dev-53861af9a17022898619a2ae4ead0dfc601b7c13.tar.gz |
Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull virtio updates from Rusty Russell:
"OK, this has the big virtio 1.0 implementation, as specified by OASIS.
On top of tht is the major rework of lguest, to use PCI and virtio
1.0, to double-check the implementation.
Then comes the inevitable fixes and cleanups from that work"
* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (80 commits)
virtio: don't set VIRTIO_CONFIG_S_DRIVER_OK twice.
virtio_net: unconditionally define struct virtio_net_hdr_v1.
tools/lguest: don't use legacy definitions for net device in example launcher.
virtio: Don't expose legacy net features when VIRTIO_NET_NO_LEGACY defined.
tools/lguest: use common error macros in the example launcher.
tools/lguest: give virtqueues names for better error messages
tools/lguest: more documentation and checking of virtio 1.0 compliance.
lguest: don't look in console features to find emerg_wr.
tools/lguest: don't start devices until DRIVER_OK status set.
tools/lguest: handle indirect partway through chain.
tools/lguest: insert driver references from the 1.0 spec (4.1 Virtio Over PCI)
tools/lguest: insert device references from the 1.0 spec (4.1 Virtio Over PCI)
tools/lguest: rename virtio_pci_cfg_cap field to match spec.
tools/lguest: fix features_accepted logic in example launcher.
tools/lguest: handle device reset correctly in example launcher.
virtual: Documentation: simplify and generalize paravirt_ops.txt
lguest: remove NOTIFY call and eventfd facility.
lguest: remove NOTIFY facility from demonstration launcher.
lguest: use the PCI console device's emerg_wr for early boot messages.
lguest: always put console in PCI slot #1.
...
Diffstat (limited to 'Documentation/virtual')
-rw-r--r-- | Documentation/virtual/00-INDEX | 3 | ||||
-rw-r--r-- | Documentation/virtual/paravirt_ops.txt | 32 |
2 files changed, 35 insertions, 0 deletions
diff --git a/Documentation/virtual/00-INDEX b/Documentation/virtual/00-INDEX index e952d30..af0d239 100644 --- a/Documentation/virtual/00-INDEX +++ b/Documentation/virtual/00-INDEX @@ -2,6 +2,9 @@ Virtualization support in the Linux kernel. 00-INDEX - this file. + +paravirt_ops.txt + - Describes the Linux kernel pv_ops to support different hypervisors kvm/ - Kernel Virtual Machine. See also http://linux-kvm.org uml/ diff --git a/Documentation/virtual/paravirt_ops.txt b/Documentation/virtual/paravirt_ops.txt new file mode 100644 index 0000000..d4881c0 --- /dev/null +++ b/Documentation/virtual/paravirt_ops.txt @@ -0,0 +1,32 @@ +Paravirt_ops +============ + +Linux provides support for different hypervisor virtualization technologies. +Historically different binary kernels would be required in order to support +different hypervisors, this restriction was removed with pv_ops. +Linux pv_ops is a virtualization API which enables support for different +hypervisors. It allows each hypervisor to override critical operations and +allows a single kernel binary to run on all supported execution environments +including native machine -- without any hypervisors. + +pv_ops provides a set of function pointers which represent operations +corresponding to low level critical instructions and high level +functionalities in various areas. pv-ops allows for optimizations at run +time by enabling binary patching of the low-ops critical operations +at boot time. + +pv_ops operations are classified into three categories: + +- simple indirect call + These operations correspond to high level functionality where it is + known that the overhead of indirect call isn't very important. + +- indirect call which allows optimization with binary patch + Usually these operations correspond to low level critical instructions. They + are called frequently and are performance critical. The overhead is + very important. + +- a set of macros for hand written assembly code + Hand written assembly codes (.S files) also need paravirtualization + because they include sensitive instructions or some of code paths in + them are very performance critical. |