Commit a8032f78 authored by Jörg Thalheim's avatar Jörg Thalheim
Browse files

buildInLinuxVM: switch from 9p to virtiofs 

$ nix-build pkgs/build-support/vm/test.nix -A buildPcmanrmInVM --builders ''

Before: Finished at 13:59:42 after 1m26s
After: Finished at 14:00:48 after 51s
=> ~60% speed-up
parent 581db021

pkgs/build-support/vm/default.nix

+10 −6
Original line number Diff line number Diff line
@@ -5,7 +5,7 @@ 
, img ? pkgs.stdenv.hostPlatform.linux-kernel.target

, storeDir ? builtins.storeDir

, rootModules ?

    [ "virtio_pci" "virtio_mmio" "virtio_blk" "virtio_balloon" "virtio_rng" "ext4" "unix" "9p" "9pnet_virtio" "crc32c_generic" ]

    [ "virtio_pci" "virtio_mmio" "virtio_blk" "virtio_balloon" "virtio_rng" "ext4" "unix" "virtiofs" "crc32c_generic" ]

}:



let
@@ -123,7 +123,7 @@ rec { 


    echo "mounting Nix store..."

    mkdir -p /fs${storeDir}

    mount -t 9p store /fs${storeDir} -o trans=virtio,version=9p2000.L,cache=loose,msize=131072

    mount -t virtiofs store /fs${storeDir}



    mkdir -p /fs/tmp /fs/run /fs/var

    mount -t tmpfs -o "mode=1777" none /fs/tmp
@@ -132,7 +132,7 @@ rec { 


    echo "mounting host's temporary directory..."

    mkdir -p /fs/tmp/xchg

    mount -t 9p xchg /fs/tmp/xchg -o trans=virtio,version=9p2000.L,msize=131072

    mount -t virtiofs xchg /fs/tmp/xchg



    mkdir -p /fs/proc

    mount -t proc none /fs/proc
@@ -222,8 +222,10 @@ rec { 
    ${if (customQemu != null) then customQemu else (qemu-common.qemuBinary qemu)} \

      -nographic -no-reboot \

      -device virtio-rng-pci \

      -virtfs local,path=${storeDir},security_model=none,mount_tag=store \

      -virtfs local,path=xchg,security_model=none,mount_tag=xchg \

      -chardev socket,id=store,path=virtio-store.sock \

      -device vhost-user-fs-pci,chardev=store,tag=store \

      -chardev socket,id=xchg,path=virtio-xchg.sock \

      -device vhost-user-fs-pci,chardev=xchg,tag=xchg \

      ''${diskImage:+-drive file=$diskImage,if=virtio,cache=unsafe,werror=report} \

      -kernel ${kernel}/${img} \

      -initrd ${initrd}/initrd \
@@ -259,6 +261,8 @@ rec { 
    cat > ./run-vm <<EOF

    #! ${bash}/bin/sh

    ''${diskImage:+diskImage=$diskImage}

    ${pkgs.virtiofsd}/bin/virtiofsd --xattr --socket-path virtio-store.sock --sandbox none --shared-dir "${storeDir}" &

    ${pkgs.virtiofsd}/bin/virtiofsd --xattr --socket-path virtio-xchg.sock --sandbox none --shared-dir xchg &

    ${qemuCommand}

    EOF
@@ -339,7 +343,7 @@ rec { 
    args = ["-e" (vmRunCommand qemuCommandLinux)];

    origArgs = args;

    origBuilder = builder;

    QEMU_OPTS = "${QEMU_OPTS} -m ${toString memSize}";

    QEMU_OPTS = "${QEMU_OPTS} -m ${toString memSize} -object memory-backend-memfd,id=mem,size=${toString memSize}M,share=on -machine memory-backend=mem";

    passAsFile = []; # HACK fix - see https://github.com/NixOS/nixpkgs/issues/16742

  });