Trait FsCacheReqHandler 

pub trait FsCacheReqHandler:
    Send
    + Sync
    + 'static {
    // Required methods
    fn map(
        &mut self,
        foffset: u64,
        moffset: u64,
        len: u64,
        flags: u64,
        fd: RawFd,
    ) -> Result<()>;
    fn unmap(&mut self, requests: Vec<RemovemappingOne>) -> Result<()>;
}

Trait to support virtio-fs DAX Window operations.

The virtio-fs DAX Window allows bypassing guest page cache and allows mapping host page cache directly in guest address space.

When a page of file is needed, guest sends a request to map that page (in host page cache) in VMM address space. Inside guest this is a physical memory range controlled by virtiofs device. And guest directly maps this physical address range using DAX and hence getsi access to file data on host.

This can speed up things considerably in many situations. Also this can result in substantial memory savings as file data does not have to be copied in guest and it is directly accessed from host page cache.

Required Methods

fn map( &mut self, foffset: u64, moffset: u64, len: u64, flags: u64, fd: RawFd, ) -> Result<()>

Setup a dedicated mapping so that guest can access file data in DAX style.

fn unmap(&mut self, requests: Vec<RemovemappingOne>) -> Result<()>

Remove those mappings that provide the access to file data.

Implementations on Foreign Types

impl FsCacheReqHandler for Backend

fn map( &mut self, foffset: u64, moffset: u64, len: u64, flags: u64, fd: RawFd, ) -> Result<()>

fn unmap(&mut self, requests: Vec<RemovemappingOne>) -> Result<()>

Implementors