qemu/9pfs : Add 9pfs support for elfloader-basic

Signed-off-by: Neagu Dragos-Ionut <dragosneagu28@gmail.com>

Author: NDragos

elfloader-basic/README.md

@@ -243,6 +243,7 @@ For Firecracker, the `fc.x86_64.json` file needs to be updated similarly.
 For other ELFs, you need to follow the steps:
 
 1. Add / Build ELF in the `rootfs/` directory.
+
 1. Update the start command as above with the command to run the ELF.
    The command can also have arguments, similar to any other Linux command.
 
@@ -252,6 +253,94 @@ ELFs using require additional configuration of the ELF Loader.
 
 ### Enable Debug Messages
 
+
 You can customize the ELF Loader build debug messages.
+
 For that, use the ["Configure" step](#configure) enable the [`ukdebug` library](https://github.com/unikraft/unikraft/tree/staging/lib/ukdebug) and its other options.
+
 Then, build and run again.
+
+### Use a Different Filesystem Type for QEMU
+
+You can use [`9pfs`](https://github.com/unikraft/unikraft/tree/staging/lib/9pfs) as an alternate filesystem to initrd.
+
+Note that 9pfs does not work with Firecracker.
+
+And it requires re-building Xen to add 9pfs support.
+
+Below find instructions on running Nginx on QEMU with 9pfs support.
+
+You need to use these contents for the [`Config.uk`](Config.uk) configuration file:
+
+```text
+# Configure ELF loader application, with networking support.
+
+config APPELFLOADERNET
+bool "Configure ELF loader application (for binary compatibility) with networking support"
+default y
+
+	# Select app-elfloader component.
+	select APPELFLOADER_DEPENDENCIES
+
+	# Configurations options for app-elfloader
+	# (they can't be part of the template atm)
+	select APPELFLOADER_ARCH_PRCTL
+	select APPELFLOADER_BRK
+	select APPELFLOADER_CUSTOMAPPNAME
+	select APPELFLOADER_STACK_NBPAGES
+	select APPELFLOADER_VFSEXEC_EXECBIT
+	select APPELFLOADER_VFSEXEC
+	select APPELFLOADER_HFS
+	select APPELFLOADER_HFS_ETCRESOLVCONF
+	select APPELFLOADER_HFS_ETCHOSTS
+	select APPELFLOADER_HFS_ETCHOSTNAME
+	select APPELFLOADER_HFS_REPLACEEXIST
+
+	# Select filesystem implementation: cpio, ramfs, devfs.
+	select LIBVFSCORE
+	select LIBVFSCORE_AUTOMOUNT_UP
+	select LIBUK9P
+        select LIB9PFS
+	select LIBDEVFS
+	select LIBDEVFS_AUTOMOUNT
+```
+
+This means you replace these two lines in [`Config.uk`](Config.uk):
+
+```text
+        select LIBRAMFS
+        select LIBUKCPIO
+```
+
+with these lines:
+
+```text
+        select LIBUK9P
+        select LIB9PFS
+```
+
+Now go through the [configure](#configure) step.
+
+From the `Library Configuration` tab, select `uk9p` and `Process-related functions` ---> `Multiprocess support`.
+
+From the `Application Options` tab, select `Multiprocess application` 
+
+Then continue with the [build](#build) step.
+
+Finally, after configuring networking, use the commands below to run elfloader-basic on QEMU/x86_64 with 9pfs support:
+
+```console
+# Create a copy of the filesystem to be mounted as 9pfs.
+rm -fr 9pfs-rootfs
+cp -r rootfs 9pfs-rootfs
+sudo qemu-system-x86_64 \
+ -nographic \
+ -m 512 \
+ -cpu max \
+ -append "elfloader_qemu-x86_64 vfs.fstab=[ \"fs0:/:9pfs:::\" ] -- /hello-c" \
+ -kernel workdir/build/elfloader_qemu-x86_64 \
+ -fsdev local,id=myid,path=$(pwd)/9pfs-rootfs/,security_model=none \
+ -device virtio-9p-pci,fsdev=myid,mount_tag=fs0
+```
+
+You would use a similar command for QEMU/ARM64.

elfloader-basic/scripts/README.md

@@ -34,3 +34,15 @@ CC=/usr/bin/clang ./scripts/build/fc.x86_64
 ./scripts/run/qemu.x86_64
 ./scripts/run/fc.x86_64
 ```
+
+## Build and Run for <plat> / <arch> using a different file system  
+
+```console
+./scripts/run/<plat>.<arch>.<file_system>
+```
+
+e.g.
+
+```console
+./scripts/run/qemu.x86_64.9pfs
+```

elfloader-basic/scripts/build/qemu.x86_64.9pfs

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+make distclean
+UK_DEFCONFIG=$(pwd)/scripts/defconfig/qemu.x86_64.9pfs make defconfig
+touch Makefile.uk
+make prepare
+if test -z "$CC"; then
+    make -j $(nproc)
+else
+    make CC="$CC" -j $(nproc)
+fi

elfloader-basic/scripts/defconfig/qemu.x86_64.9pfs

@@ -0,0 +1,28 @@
+CONFIG_PLAT_KVM=y
+CONFIG_KVM_VMM_QEMU=y
+CONFIG_ARCH_X86_64=y
+CONFIG_APPELFLOADER_DEPENDENCIES=y
+CONFIG_APPELFLOADER_ARCH_PRCTL=y
+CONFIG_APPELFLOADER_BRK=y
+CONFIG_APPELFLOADER_MULTIPROCESS=y
+CONFIG_APPELFLOADER_CUSTOMAPPNAME=y
+CONFIG_APPELFLOADER_STACK_NBPAGES=128
+CONFIG_APPELFLOADER_VFSEXEC_EXECBIT=n
+CONFIG_APPELFLOADER_VFSEXEC=y
+CONFIG_APPELFLOADER_HFS=y
+CONFIG_APPELFLOADER_HFS_ETCRESOLVCONF=y
+CONFIG_APPELFLOADER_HFS_ETCHOSTS=y
+CONFIG_APPELFLOADER_HFS_ETCHOSTNAME=y
+CONFIG_APPELFLOADER_HFS_REPLACEEXIST=y
+CONFIG_LIBPOSIX_PROCESS_MULTIPROCESS=y
+CONFIG_LIBVFSCORE=y
+CONFIG_LIBVFSCORE_AUTOMOUNT_UP=y
+CONFIG_LIBUK9P=y
+CONFIG_LIB9PFS=y
+CONFIG_LIBDEVFS=y
+CONFIG_LIBDEVFS_AUTOMOUNT=y
+# Uncomment for debugging.
+#CONFIG_LIBUKDEBUG_PRINTD=y
+#CONFIG_LIBUKDEBUG_PRINTK_INFO=y
+#CONFIG_LIBSYSCALL_SHIM_STRACE=y
+#CONFIG_LIBSYSCALL_SHIM_DEBUG=y

elfloader-basic/scripts/run/qemu.x86_64.9pfs

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+if test ! -f "workdir/build/elfloader_qemu-x86_64"; then
+    echo "No kernel file workdir/build/elfloader_qemu-x86_64." 1>&2
+    echo "Did you run ./build.qemu.x86_64 ?" 1>&2
+    exit 1
+fi
+
+# Build ELFs.
+make -C rootfs/
+
+# Pack filesystem as 9pfs
+
+rm -fr 9pfs-rootfscd 
+cp -r rootfs 9pfs-rootfs
+
+sudo qemu-system-x86_64 \
+ -nographic \
+ -m 512 \
+ -cpu max \
+ -append "elfloader_qemu-x86_64 vfs.fstab=[ \"fs0:/:9pfs:::\" ] -- /hello-c" \
+ -kernel workdir/build/elfloader_qemu-x86_64 \
+ -fsdev local,id=myid,path=$(pwd)/9pfs-rootfs/,security_model=none \
+ -device virtio-9p-pci,fsdev=myid,mount_tag=fs0
+.

elfloader-basic/scripts/test/all.sh

@@ -29,3 +29,4 @@ test_build_run()
 test -d ./scripts/test/log || mkdir ./scripts/test/log
 test_build_run qemu.x86_64
 test_build_run fc.x86_64
+test_build_run qemu.x86_64.9pfs