vm-virtio, vhost_user_{fs,block,backend}: Move EVENT_IDX handling

Move the method that is used to decide whether the guest should be
signalled into the Queue implementation from vm-virtio. This removes
duplicated code between vhost_user_backend and the vm-virtio block
implementation.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This commit is contained in:
Rob Bradford 2020-05-20 10:40:54 +01:00 committed by Sebastien Boeuf
parent 8ae7a38da5
commit a813b57f59
5 changed files with 44 additions and 57 deletions

View File

@ -163,8 +163,9 @@ impl<F: FileSystem + Send + Sync + 'static> VhostUserFsThread<F> {
let mut vring = vring_lock.write().unwrap();
if event_idx {
if let Some(used_idx) = vring.mut_queue().add_used(&mem, head_index, 0) {
if vring.needs_notification(&mem, Wrapping(used_idx)) {
let queue = vring.mut_queue();
if let Some(used_idx) = queue.add_used(&mem, head_index, 0) {
if queue.needs_notification(&mem, Wrapping(used_idx)) {
vring.signal_used_queue().unwrap();
}
}

View File

@ -210,8 +210,6 @@ pub struct Vring {
call: Option<EventFd>,
err: Option<EventFd>,
enabled: bool,
event_idx: bool,
signalled_used: Option<Wrapping<u16>>,
}
impl Vring {
@ -222,8 +220,6 @@ impl Vring {
call: None,
err: None,
enabled: false,
event_idx: false,
signalled_used: None,
}
}
@ -231,31 +227,6 @@ impl Vring {
&mut self.queue
}
pub fn set_event_idx(&mut self, enabled: bool) {
/* Also reset the last signalled event */
self.signalled_used = None;
self.event_idx = enabled;
}
pub fn needs_notification(&mut self, mem: &GuestMemoryMmap, used_idx: Wrapping<u16>) -> bool {
if !self.event_idx {
return true;
}
let mut notify = true;
if let Some(old_idx) = self.signalled_used {
if let Some(used_event) = self.mut_queue().get_used_event(&mem) {
if (used_idx - used_event - Wrapping(1u16)) >= (used_idx - old_idx) {
notify = false;
}
}
}
self.signalled_used = Some(used_idx);
notify
}
pub fn signal_used_queue(&mut self) -> result::Result<(), io::Error> {
if let Some(call) = self.call.as_ref() {
call.write(1)
@ -724,6 +695,7 @@ impl<S: VhostUserBackend> VhostUserSlaveReqHandler for VhostUserHandler<S> {
self.vrings[index as usize]
.write()
.unwrap()
.mut_queue()
.set_event_idx(event_idx);
self.backend.write().unwrap().set_event_idx(event_idx);
Ok(())

View File

@ -153,8 +153,9 @@ impl VhostUserBlkThread {
}
if self.event_idx {
if let Some(used_idx) = vring.mut_queue().add_used(mem, head.index, len) {
if vring.needs_notification(&mem, Wrapping(used_idx)) {
let queue = vring.mut_queue();
if let Some(used_idx) = queue.add_used(mem, head.index, len) {
if queue.needs_notification(&mem, Wrapping(used_idx)) {
debug!("signalling queue");
vring.signal_used_queue().unwrap();
} else {

View File

@ -23,7 +23,6 @@ use std::cmp;
use std::convert::TryInto;
use std::fs::{File, Metadata};
use std::io::{self, Read, Seek, SeekFrom, Write};
use std::num::Wrapping;
use std::ops::DerefMut;
use std::os::linux::fs::MetadataExt;
use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
@ -607,7 +606,6 @@ struct BlockEpollHandler<T: DiskFile> {
kill_evt: EventFd,
pause_evt: EventFd,
event_idx: bool,
signalled_used: Option<Wrapping<u16>>,
}
impl<T: DiskFile> BlockEpollHandler<T> {
@ -682,25 +680,6 @@ impl<T: DiskFile> BlockEpollHandler<T> {
Ok(())
}
fn needs_notification(&mut self, mem: &GuestMemoryMmap, used_idx: Wrapping<u16>) -> bool {
if !self.event_idx {
return true;
}
let mut notify = true;
if let Some(old_idx) = self.signalled_used {
if let Some(used_event) = self.queue.get_used_event(&mem) {
if (used_idx - used_event - Wrapping(1u16)) >= (used_idx - old_idx) {
notify = false;
}
}
}
self.signalled_used = Some(used_idx);
notify
}
fn run(
&mut self,
queue_evt: EventFd,
@ -772,7 +751,7 @@ impl<T: DiskFile> BlockEpollHandler<T> {
if self.process_queue() {
self.queue.update_avail_event(&self.mem.memory());
if self.needs_notification(
if self.queue.needs_notification(
&self.mem.memory(),
self.queue.next_used,
) {
@ -1176,9 +1155,10 @@ impl<T: 'static + DiskFile + Send> VirtioDevice for Block<T> {
kill_evt: kill_evt.try_clone().unwrap(),
pause_evt: pause_evt.try_clone().unwrap(),
event_idx,
signalled_used: None,
};
handler.queue.set_event_idx(event_idx);
let queue_evt = queue_evts.remove(0);
let paused = self.paused.clone();
thread::Builder::new()

View File

@ -401,7 +401,7 @@ pub struct Queue {
/// The queue size in elements the driver selected
pub size: u16,
/// Inidcates if the queue is finished with configuration
/// Indicates if the queue is finished with configuration
pub ready: bool,
/// Interrupt vector index of the queue
@ -424,6 +424,12 @@ pub struct Queue {
#[serde(skip)]
pub iommu_mapping_cb: Option<Arc<VirtioIommuRemapping>>,
/// VIRTIO_F_RING_EVENT_IDX negotiated
event_idx: bool,
/// The last used value when using EVENT_IDX
signalled_used: Option<Wrapping<u16>>,
}
impl Queue {
@ -440,6 +446,8 @@ impl Queue {
next_avail: Wrapping(0),
next_used: Wrapping(0),
iommu_mapping_cb: None,
event_idx: false,
signalled_used: None,
}
}
@ -678,6 +686,31 @@ impl Queue {
pub fn available_descriptors(&self, mem: &GuestMemoryMmap) -> Result<bool, Error> {
Ok(self.used_index_from_memory(mem)? < self.avail_index_from_memory(mem)?)
}
pub fn set_event_idx(&mut self, enabled: bool) {
/* Also reset the last signalled event */
self.signalled_used = None;
self.event_idx = enabled;
}
pub fn needs_notification(&mut self, mem: &GuestMemoryMmap, used_idx: Wrapping<u16>) -> bool {
if !self.event_idx {
return true;
}
let mut notify = true;
if let Some(old_idx) = self.signalled_used {
if let Some(used_event) = self.get_used_event(&mem) {
if (used_idx - used_event - Wrapping(1u16)) >= (used_idx - old_idx) {
notify = false;
}
}
}
self.signalled_used = Some(used_idx);
notify
}
}
#[cfg(test)]