Method map

pci/src/vfio_user.rs:559–590

(&self, iova: u64, gpa: u64, size: u64)

impl<M: GuestAddressSpace + Sync + Send> ExternalDmaMapping for VfioUserDmaMapping<M> {
    fn map(&self, iova: u64, gpa: u64, size: u64) -> std::result::Result<(), std::io::Error> {
        let mem = self.memory.memory();
        let guest_addr = GuestAddress(gpa);
        let Some(region) = mem.find_region(guest_addr) else {
            return Err(std::io::Error::other(format!(
                "Region not found for 0x{gpa:x}"
            )));
        };

        // Check that the range fits in the region.
        let region_offset = guest_addr
            .checked_offset_from(region.start_addr())
            .ok_or_else(|| std::io::Error::other(format!("gpa 0x{gpa:x} below region start")))?;
        let region_remaining = (region.len())
            .checked_sub(region_offset)
            .ok_or_else(|| std::io::Error::other(format!("gpa 0x{gpa:x} past region end")))?;
        if size > region_remaining {
            return Err(std::io::Error::other(format!(
                "DMA map (gpa 0x{gpa:x}, size 0x{size:x}) extends past region end"
            )));
        }

        // Unwrap is safe as we only do vfio with shared mem with a backing file.
        let file_offset = region.file_offset().unwrap();
        let offset = region_offset + file_offset.start();

        self.client
            .lock()
            .unwrap()
            .dma_map(offset, iova, size, file_offset.file().as_raw_fd())
            .map_err(|e| std::io::Error::other(format!("Error mapping region: {e}")))
    }

    fn unmap(&self, iova: u64, size: u64) -> std::result::Result<(), std::io::Error> {
        self.client