Shared directory

.gitignore

@@ -4,3 +4,5 @@ qemu/qcow2/*
 !qemu/qcow2/.keep
 qemu/bin/*
 !qemu/bin/.keep
+share/*
+!share/.keep

qemu/qemu.template

@@ -9,12 +9,10 @@ if ! test -e "$NIX_DISK_IMAGE"; then
 fi
 
 # Create a directory for storing temporary data of the running VM.
-if [ -z "$TMPDIR" -o -z "$USE_TMPDIR" ]; then
-    TMPDIR=$(mktemp -d nix-vm.XXXXXXXXXX --tmpdir)
-fi
+TMPDIR=$(dirname ${NIX_DISK_IMAGE})/../../share/NAME_PLACEHOLDER
 
 # Create a directory for exchanging data with the VM.
-mkdir -p $TMPDIR/xchg
+mkdir -p $TMPDIR
 cd $TMPDIR
 
 NIX_SYSTEM="NIX_SYSTEM_PLACEHOLDER"
@@ -29,8 +27,8 @@ qemu-system-x86_64 -enable-kvm \
     -spice port=PORT_PLACEHOLDER,addr=127.200.0.1,disable-ticketing,image-compression=off,seamless-migration=on \
     -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
     -virtfs local,path=/nix/store,security_model=none,mount_tag=store,readonly \
-    -virtfs local,path=$TMPDIR/xchg,security_model=none,mount_tag=xchg \
-    -virtfs local,path=${SHARED_DIR:-$TMPDIR/xchg},security_model=none,mount_tag=shared \
+    -virtfs local,path=$TMPDIR,security_model=none,mount_tag=xchg \
+    -virtfs local,path=${SHARED_DIR:-$TMPDIR},security_model=none,mount_tag=shared \
     -drive index=0,id=drive$((0 + 1)),file=$NIX_DISK_IMAGE,cache=writeback,werror=report,if=virtio \
     -kernel ${NIX_SYSTEM}/kernel \
     -initrd ${NIX_SYSTEM}/initrd \