Remove warnings during build and unit test

[dianpopa]

Changes

• rust issue inserted a warning if a packed struct (i.e #[repr(C, packed)] which is unaligned (or has unaligned fields) has builtin derives.
  • per the aforementioned issue, the alternatives are: If your struct already derives Copy and has no generics, the compiler will generate code that copies the fields to locals and will therefore work. Otherwise, you'll have to write the derive implementations manually.
  • concluding, we could remove the derives at all or we could add the #[derive(Copy, Clone)]
  • I personally prefered to remove the derives at all and implement them or just add the Copy/Clone when the struct will actually be used.
• remove warning from virtio block that would appear with cargo test
• added patches directory for the virtio_sys containing the patch that should be applied whenever virtio_net will be regenerated with bindgen.

Testing

Build Time

Prerequisite

## add the necessary musl target to the active toolchain
rustup target add x86_64-unknown-linux-musl

Build tests

cargo fmt —all
cargo build # no warning
cargo build —release # no warning
sudo env "PATH=$PATH" cargo test --all #no warin
sudo env "PATH=$PATH" cargo kcov —all # overall 44.3%

Integration Testing

rm -f /tmp/firecracker.socket && \
target/debug/firecracker --api-sock=/tmp/firecracker.socket

• in another console start sending curl requests for starting basic firecracker guest

curl --unix-socket /tmp/firecracker.socket -i  \
     -X PUT "http://localhost/boot-source" \
     -H "accept: application/json" \
     -H "Content-Type: application/json" \
     -d "{ 
           \"boot_source_id\": \"alinux_kernel\",
           \"source_type\": \"LocalImage\", 
           \"local_image\": 
                { 
                    \"kernel_image_path\": \"${kernel_path}\" 
                }
        }"

echo 2
curl --unix-socket /tmp/firecracker.socket -i \
     -X PUT "http://localhost/machine-config" \
     -H "accept: application/json" \
     -H "Content-Type: application/json" \
     -d "{ \"vcpu_count\": 4, \"mem_size_mib\": 256}"

# Add root block device
echo 3
curl --unix-socket /tmp/firecracker.socket -i \
     -X PUT "http://localhost/drives/root" \
     -H "accept: application/json" \
     -H "Content-Type: application/json" \
     -d "{ 
            \"drive_id\": \"root\",
            \"path_on_host\": \"${rootfs_path}\", 
            \"is_root_device\": true, 
            \"permissions\": \"rw\", 
            \"state\": \"Attached\"
         }"


# Add readonly device
echo 4
curl --unix-socket /tmp/firecracker.socket -i \
     -X PUT "http://localhost/drives/read_only_drive" \
     -H "accept: application/json" \
     -H "Content-Type: application/json" \
     -d "{ 
            \"drive_id\": \"read_only_drive\",
            \"path_on_host\": \"${ro_drive_path}\", 
            \"is_root_device\": false, 
            \"permissions\": \"ro\", 
            \"state\": \"Attached\"
         }"

# Create a tap interface
ip tuntap add name vmtap33 mode tap
ifconfig vmtap33 192.168.241.1/24 up
echo 5
curl --unix-socket /tmp/firecracker.socket -i \
     -X PUT "http://localhost/network-interfaces/1" \
     -H "accept: application/json" \
     -H "Content-Type: application/json" \
     -d "{ 
            \"iface_id\": \"1\", 
            \"host_dev_name\": \"vmtap33\", 
            \"guest_mac\": \"06:00:00:00:00:01\", 
            \"state\": \"Attached\" 
        }"

echo 6
curl --unix-socket /tmp/firecracker.socket -i \
     -X PUT "http://localhost/actions/start" \
     -H  "accept: application/json" \
     -H  "Content-Type: application/json" \
     -d "{  
            \"action_id\": \"start\",  
            \"action_type\": \"InstanceStart\"
         }"

# Get the response of starting the instance
echo 7
curl --unix-socket /tmp/firecracker.socket -i \
     -X GET "http://localhost/actions/start" \
     -H "accept: application/json"

sudo ip link delete vmtap33

• in the initial console the guest should start up

# login: ...
# reboot

P.S. testing

Please do yourself a cargo build and cargo test to check that the warnings are not there anymore.

Miscellanous

• created patch with:

git format-patch -1 <sha>

• patch should be applied on a regenerated virtio_net.rs with:

patch -p1 < file.patch