libavf: add API to configure swiotlb size
Test: TH
Bug: 382781129
Change-Id: I1b22a8e3fd6e3800f29c81cadbc47ba8c2e21b3b
diff --git a/android/virtmgr/src/aidl.rs b/android/virtmgr/src/aidl.rs
index 15a80a6..6a268f9 100644
--- a/android/virtmgr/src/aidl.rs
+++ b/android/virtmgr/src/aidl.rs
@@ -774,6 +774,7 @@
.ok()
.and_then(NonZeroU32::new)
.unwrap_or(NonZeroU32::new(256).unwrap()),
+ swiotlb_mib: config.swiotlbMib.try_into().ok().and_then(NonZeroU32::new),
cpus,
host_cpu_topology,
console_out_fd,
diff --git a/android/virtmgr/src/crosvm.rs b/android/virtmgr/src/crosvm.rs
index 2bfa4e1..affd430 100644
--- a/android/virtmgr/src/crosvm.rs
+++ b/android/virtmgr/src/crosvm.rs
@@ -112,6 +112,7 @@
pub protected: bool,
pub debug_config: DebugConfig,
pub memory_mib: NonZeroU32,
+ pub swiotlb_mib: Option<NonZeroU32>,
pub cpus: Option<NonZeroU32>,
pub host_cpu_topology: bool,
pub console_out_fd: Option<File>,
@@ -1000,11 +1001,18 @@
_ => command.arg("--protected-vm"),
};
- // 3 virtio-console devices + vsock = 4.
- let virtio_pci_device_count = 4 + config.disks.len();
- // crosvm virtio queue has 256 entries, so 2 MiB per device (2 pages per entry) should be
- // enough.
- let swiotlb_size_mib = 2 * virtio_pci_device_count as u32;
+ let swiotlb_size_mib = config.swiotlb_mib.map(u32::from).unwrap_or({
+ // 3 virtio-console devices + vsock = 4.
+ // TODO: Count more device types, like balloon, input, and sound.
+ let virtio_pci_device_count = 4 + config.disks.len();
+ // crosvm virtio queue has 256 entries, so 2 MiB per device (2 pages per entry) should
+ // be enough.
+ // NOTE: The above explanation isn't completely accurate, e.g., circa 2024q4, each
+ // virtio-block has 16 queues with 256 entries each and each virito-console has 2
+ // queues of 256 entries each. So, it is allocating less than 2 pages per entry, but
+ // seems to work well enough in practice.
+ 2 * virtio_pci_device_count as u32
+ });
command.arg("--swiotlb").arg(swiotlb_size_mib.to_string());
// b/346770542 for consistent "usable" memory across protected and non-protected VMs.