From b0353992d6645b2f1b3ea316dd95619f61ef6462 Mon Sep 17 00:00:00 2001
From: Sebastien Boeuf <sebastien.boeuf@intel.com>
Date: Mon, 20 Apr 2020 16:12:59 +0200
Subject: [PATCH] vm-virtio: Implement userspace_mappings() for virtio-fs

This will help when we will implement the hot-unplug of the virtio-fs
device, as we will have to remove correctly the userspace mappings
associated with the device.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
---
 vm-virtio/src/vhost_user/fs.rs | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/vm-virtio/src/vhost_user/fs.rs b/vm-virtio/src/vhost_user/fs.rs
index 31095859c..14631184a 100644
--- a/vm-virtio/src/vhost_user/fs.rs
+++ b/vm-virtio/src/vhost_user/fs.rs
@@ -6,8 +6,8 @@ use super::Error as DeviceError;
 use super::{Error, Result};
 use crate::vhost_user::handler::{VhostUserEpollConfig, VhostUserEpollHandler};
 use crate::{
-    ActivateError, ActivateResult, Queue, VirtioDevice, VirtioDeviceType, VirtioInterrupt,
-    VirtioSharedMemoryList, VIRTIO_F_VERSION_1,
+    ActivateError, ActivateResult, Queue, UserspaceMapping, VirtioDevice, VirtioDeviceType,
+    VirtioInterrupt, VirtioSharedMemoryList, VIRTIO_F_VERSION_1,
 };
 use libc::{self, c_void, off64_t, pread64, pwrite64, EFD_NONBLOCK};
 use std::cmp;
@@ -567,6 +567,21 @@ impl VirtioDevice for Fs {
     fn update_memory(&mut self, mem: &GuestMemoryMmap) -> std::result::Result<(), crate::Error> {
         update_mem_table(&mut self.vu, mem).map_err(crate::Error::VhostUserUpdateMemory)
     }
+
+    fn userspace_mappings(&self) -> Vec<UserspaceMapping> {
+        let mut mappings = Vec::new();
+        if let Some(cache) = self.cache.as_ref() {
+            mappings.push(UserspaceMapping {
+                host_addr: cache.0.host_addr,
+                mem_slot: cache.0.mem_slot,
+                addr: cache.0.addr,
+                len: cache.0.len,
+                mergeable: false,
+            })
+        }
+
+        mappings
+    }
 }
 
 virtio_pausable!(Fs);