diff --git a/Documentation/virt/paravirt_ops.rst b/Documentation/virt/paravirt_ops.rst index 6b789d27cead..62d867e0d4d6 100644 --- a/Documentation/virt/paravirt_ops.rst +++ b/Documentation/virt/paravirt_ops.rst @@ -5,31 +5,31 @@ 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. +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 +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-level 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 + 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 + 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 + because they include sensitive instructions or some code paths in them are very performance critical.