virtio-devices, vmm: Always restore virtio devices in paused state

Following the new restore design, it is not appropriate to set every
virtio device threads into a paused state after they've been started.

This is why we remove the line of code pausing the devices only after
they've been restored, and replace it with a small patch in every virtio
device implementation. When a virtio device is created as part of a
restored VM, the associated "paused" boolean is set to true. This
ensures the corresponding thread will be directly parked when being
started, avoiding the thread to be in a different state than the one it
was on the source VM during the snapshot.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit is contained in:
Sebastien Boeuf
2022-11-30 17:10:04 +01:00
parent 8f1e03fcf4
commit b62a40efae
15 changed files with 400 additions and 332 deletions
+30 -27
View File
@@ -879,34 +879,36 @@ impl Iommu {
msi_iova_space: (u64, u64),
state: Option<IommuState>,
) -> io::Result<(Self, Arc<IommuMapping>)> {
let (avail_features, acked_features, endpoints, domains) = if let Some(state) = state {
info!("Restoring virtio-iommu {}", id);
(
state.avail_features,
state.acked_features,
state.endpoints.into_iter().collect(),
state
.domains
.into_iter()
.map(|(k, v)| {
(
k,
Domain {
mappings: v.0.into_iter().collect(),
bypass: v.1,
},
)
})
.collect(),
)
} else {
let avail_features = 1u64 << VIRTIO_F_VERSION_1
| 1u64 << VIRTIO_IOMMU_F_MAP_UNMAP
| 1u64 << VIRTIO_IOMMU_F_PROBE
| 1u64 << VIRTIO_IOMMU_F_BYPASS_CONFIG;
let (avail_features, acked_features, endpoints, domains, paused) =
if let Some(state) = state {
info!("Restoring virtio-iommu {}", id);
(
state.avail_features,
state.acked_features,
state.endpoints.into_iter().collect(),
state
.domains
.into_iter()
.map(|(k, v)| {
(
k,
Domain {
mappings: v.0.into_iter().collect(),
bypass: v.1,
},
)
})
.collect(),
true,
)
} else {
let avail_features = 1u64 << VIRTIO_F_VERSION_1
| 1u64 << VIRTIO_IOMMU_F_MAP_UNMAP
| 1u64 << VIRTIO_IOMMU_F_PROBE
| 1u64 << VIRTIO_IOMMU_F_BYPASS_CONFIG;
(avail_features, 0, BTreeMap::new(), BTreeMap::new())
};
(avail_features, 0, BTreeMap::new(), BTreeMap::new(), false)
};
let config = VirtioIommuConfig {
page_size_mask: VIRTIO_IOMMU_PAGE_SIZE_MASK,
@@ -930,6 +932,7 @@ impl Iommu {
acked_features,
paused_sync: Some(Arc::new(Barrier::new(2))),
min_queues: NUM_QUEUES as u16,
paused: Arc::new(AtomicBool::new(paused)),
..Default::default()
},
config,