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author | David S. Miller <davem@davemloft.net> | 2019-08-07 03:44:57 +0200 |
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committer | David S. Miller <davem@davemloft.net> | 2019-08-07 03:44:57 +0200 |
commit | 13dfb3fa494361ea9a5950f27c9cd8b06d28c04f (patch) | |
tree | 1bf30874f57c6c6b21160a10282191fcd0868055 /Documentation/virt/paravirt_ops.rst | |
parent | Merge branch '40GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirshe... (diff) | |
parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net (diff) | |
download | linux-13dfb3fa494361ea9a5950f27c9cd8b06d28c04f.tar.xz linux-13dfb3fa494361ea9a5950f27c9cd8b06d28c04f.zip |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Just minor overlapping changes in the conflicts here.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/virt/paravirt_ops.rst')
-rw-r--r-- | Documentation/virt/paravirt_ops.rst | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/Documentation/virt/paravirt_ops.rst b/Documentation/virt/paravirt_ops.rst new file mode 100644 index 000000000000..6b789d27cead --- /dev/null +++ b/Documentation/virt/paravirt_ops.rst @@ -0,0 +1,35 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============ +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. |