Orchestration of various Virtio devices (reopened)

default.nix

@@ -1,4 +1,12 @@
-{ pkgs ? import <nixpkgs> {} }:
+{
+  pkgs ? import <nixpkgs> {},
+
+  virtiofsd_pinned ? import (fetchTarball {
+    name = "nixpkgs-pinned-for-virtiofsd";
+    url = "https://github.com/NixOS/nixpkgs/archive/13e8d35b7d6028b7198f8186bc0347c6abaa2701.tar.gz";
+    sha256 = "0nqbvgmm7pbpyd8ihg2bi62pxihj8r673bc9ll4qhi6xwlfqac5q";
+  }) {},
+ }:
 pkgs.python3.pkgs.buildPythonPackage rec {
   pname = "vmrunner";
   version = "0.16.0";
@@ -22,6 +30,7 @@ pkgs.python3.pkgs.buildPythonPackage rec {
 
   passthru = {
     inherit create_bridge;
+    virtiofsd = virtiofsd_pinned.virtiofsd;
   };
 
   meta = {

vmrunner/vm.schema.json

@@ -80,6 +80,43 @@
       }
     },
 
+    "virtiocon" : {
+      "description" : "VirtioCON device. Only used for testing Virtio queues for now",
+      "type" : "object",
+      "properties" : {
+        "path" : {
+          "description" : "The path to redirect the guest output",
+          "type" : "string"
+        }
+      }
+    },
+
+    "virtiofs" : {
+      "description" : "VirtioFS device",
+      "type" : "object",
+      "properties" : {
+        "socket" : { "type" : "string" },
+        "shared" : {
+          "description" : "Directory to be shared with guest", 
+          "type" : "string"
+        }
+      }
+    },
+
+    "virtiopmem": {
+      "description" : "VirtioPMEM device",
+      "type" : "object",
+      "properties" : {
+        "image" : { 
+          "description" : "Path to persistent image file",
+          "type" : "string" 
+        },
+        "size" : {
+          "description" : "Persistent memory size in megabytes",
+          "type" : "number"
+        }
+      }
+    },
 
     "mem" : {
       "description" : "Amount of memory in megabytes",

vmrunner/vmrunner.py

@@ -20,6 +20,7 @@
 import re
 import traceback
 import signal
+import time
 from enum import Enum
 import platform
 import psutil
@@ -186,6 +187,7 @@ def __init__(self, config):
         self._enable_kvm = False # must be explicitly turned on at boot.
         self._sudo = False # Set to true if sudo is available
         self._proc = None # A running subprocess
+        self._virtiofsd_proc = None
 
     # pylint: disable-next=unused-argument
     def boot_in_hypervisor(self, multiboot=False, debug=False, kernel_args="", image_name="", allow_sudo = False, enable_kvm = False):
@@ -516,6 +518,39 @@ def net_arg(self, backend, device, if_name = "net0", mac = None, bridge = None,
         return ["-device", device,
                 "-netdev", netdev]
 
+    def init_virtiocon(self, path):
+        """ creates a console device and redirects to the path given """
+        qemu_args = ["-device", "virtio-serial-pci,disable-legacy=on,id=virtio-serial0"]
+        qemu_args += ["-device", "virtserialport,chardev=char0"]
+        qemu_args += ["-chardev", f"file,id=char0,path={path}"]
+
+        return qemu_args
+
+    def init_virtiofs(self, socket, shared, mem):
+        """ initializes virtiofs by launching virtiofsd and creating a virtiofs device """
+        virtiofsd_args = ["virtiofsd", "--socket", socket, "--shared-dir", shared, "--sandbox", "none"]
+        self._virtiofsd_proc = subprocess.Popen(virtiofsd_args, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL) # pylint: disable=consider-using-with
+
+        time.sleep(0.1)
+        if self._virtiofsd_proc.poll():
+            raise Exception("VirtioFSD failed to start")
+
+        info("Successfully started VirtioFSD!")
+
+        qemu_args = ["-machine", "memory-backend=mem0"]
+        qemu_args += ["-chardev", f"socket,id=virtiofsd0,path={socket}"]
+        qemu_args += ["-device", "vhost-user-fs-pci,chardev=virtiofsd0,tag=virtiofs0"]
+        qemu_args += ["-object", f"memory-backend-memfd,id=mem0,size={mem}M,share=on"]
+
+        return qemu_args
+
+    def init_pmem(self, path, size):
+        """ creates a pmem device with image path as memory mapped backend """
+        qemu_args = ["-object", f"memory-backend-file,id=pmemdev0,mem-path={path},size={size}M,share=on"]
+        qemu_args += ["-device", "virtio-pmem-pci,memdev=pmemdev0"]
+
+        return qemu_args
+
     def kvm_present(self):
         """ returns true if KVM is present and available """
         if not self._enable_kvm:
@@ -660,7 +695,7 @@ def boot_in_hypervisor(self, multiboot=True, debug = False, kernel_args = "", im
 
         mem_arg = []
         if "mem" in self._config:
-            mem_arg = ["-m", str(self._config["mem"])]
+            mem_arg = ["-m", f"size={self._config["mem"]},maxmem={64}G"]
 
         vga_arg = ["-nographic" ]
         if "vga" in self._config:
@@ -674,6 +709,36 @@ def boot_in_hypervisor(self, multiboot=True, debug = False, kernel_args = "", im
         if "vfio" in self._config:
             pci_arg = ["-device", "vfio-pci,host=" + self._config["vfio"]]
 
+        virtiocon_args = []
+        if "virtiocon" in self._config:
+            if "path" not in self._config["virtiocon"]:
+                raise Exception("Missing redirection path for guest output")
+            virtiocon_args = self.init_virtiocon(self._config["virtiocon"]["path"])
+
+        virtiofs_args = []
+        if "virtiofs" in self._config:
+            socket = "/tmp/virtiofsd.sock"
+            if "socket" in self._config["virtiofs"]:
+                socket = self._config["virtiofs"]["socket"]
+
+            if "shared" not in self._config["virtiofs"]:
+                raise Exception("Shared directory not specified for VirtioFS!")
+            shared = self._config["virtiofs"]["shared"]
+
+            virtiofs_args = self.init_virtiofs(socket, shared, self._config["mem"])
+
+        virtiopmem_args = []
+        if "virtiopmem" in self._config:
+            if "image" not in self._config["virtiopmem"]:
+                raise Exception("Missing path to persistent image file")
+            image = self._config["virtiopmem"]["image"]
+
+            if "size" not in self._config["virtiopmem"]:
+                raise Exception("Missing persistent memory size")
+            size = self._config["virtiopmem"]["size"]
+
+            virtiopmem_args = self.init_pmem(image, size)
+
         # custom qemu binary/location
         qemu_binary = "qemu-system-x86_64"
         if "qemu" in self._config:
@@ -703,7 +768,8 @@ def boot_in_hypervisor(self, multiboot=True, debug = False, kernel_args = "", im
 
         command += kernel_args
         command += disk_args + debug_args + net_args + mem_arg + mod_args
-        command += vga_arg + trace_arg + pci_arg
+        command += vga_arg + trace_arg + pci_arg + virtiocon_args + virtiofs_args
+        command += virtiopmem_args
 
         #command_str = " ".join(command)
         #command_str.encode('ascii','ignore')