From 8743124b689e5947f5bee105bc3132ca1348bfc1 Mon Sep 17 00:00:00 2001
From: Mark Poliakov <mark@alnyan.me>
Date: Mon, 2 Dec 2024 12:32:22 +0200
Subject: [PATCH] xtask: qemu -drive option

---
 lib/qemu/src/device.rs | 29 ++++++++++++++++++++++++++++-
 xtask/src/main.rs      |  8 +++++++-
 xtask/src/qemu.rs      | 25 +++++++++++++++++++------
 3 files changed, 54 insertions(+), 8 deletions(-)

diff --git a/lib/qemu/src/device.rs b/lib/qemu/src/device.rs
index 099d3cdf..cf1623a4 100644
--- a/lib/qemu/src/device.rs
+++ b/lib/qemu/src/device.rs
@@ -1,4 +1,4 @@
-use std::process::Command;
+use std::{path::PathBuf, process::Command};
 
 use crate::IntoArgs;
 
@@ -7,6 +7,12 @@ pub enum QemuNic {
     VirtioPci { mac: Option<String> },
 }
 
+#[derive(Debug)]
+pub enum QemuDrive {
+    Nvme,
+    Sata,
+}
+
 #[derive(Debug)]
 pub enum QemuDevice {
     NetworkTap {
@@ -14,6 +20,11 @@ pub enum QemuDevice {
         script: Option<String>,
         ifname: Option<String>,
     },
+    Drive {
+        ty: QemuDrive,
+        file: PathBuf,
+        serial: Option<String>,
+    },
 }
 
 #[derive(Debug)]
@@ -61,6 +72,22 @@ impl IntoArgs for QemuDevice {
 
                 nic.add_args(command);
             }
+            Self::Drive { ty, file, serial } => {
+                command.arg("-drive");
+                command.arg(format!("file={},if=none,id=drive0", file.display()));
+
+                command.arg("-device");
+                let mut val = match ty {
+                    QemuDrive::Nvme => "nvme".to_owned(),
+                    _ => todo!(),
+                };
+                if let Some(serial) = serial {
+                    val.push_str(",serial=");
+                    val.push_str(serial);
+                }
+                val.push_str(",drive=drive0");
+                command.arg(val);
+            }
         }
     }
 }
diff --git a/xtask/src/main.rs b/xtask/src/main.rs
index 2f8e853c..7cc79f1a 100644
--- a/xtask/src/main.rs
+++ b/xtask/src/main.rs
@@ -74,6 +74,8 @@ enum SubArgs {
             help = "Override the default QEMU binary for the target"
         )]
         qemu: Option<PathBuf>,
+        #[clap(short, long, help = "Disk image to use for persistent data")]
+        disk: Option<PathBuf>,
         #[clap(help = "Extra arguments for QEMU")]
         extra_args: Vec<String>,
     },
@@ -122,7 +124,11 @@ fn run(args: Args) -> Result<(), Error> {
         SubArgs::Test => build::test_all(env),
         SubArgs::Clean { toolchain } => build::clean_all(&env, toolchain),
         // SubArgs::GitStatus => util::git_status_all(&env),
-        SubArgs::Qemu { qemu, extra_args } => qemu::run(env, qemu, extra_args),
+        SubArgs::Qemu {
+            qemu,
+            disk,
+            extra_args,
+        } => qemu::run(env, qemu, disk, extra_args),
         SubArgs::Toolchain { branch } => {
             let branch = branch.as_ref().unwrap_or(&env.config.toolchain.branch);
             build::build_toolchain(&env, branch)
diff --git a/xtask/src/qemu.rs b/xtask/src/qemu.rs
index f8f8eb0a..5b56d3e6 100644
--- a/xtask/src/qemu.rs
+++ b/xtask/src/qemu.rs
@@ -5,7 +5,7 @@ use std::{
 
 use qemu::{
     aarch64,
-    device::{QemuDevice, QemuNic, QemuSerialTarget},
+    device::{QemuDevice, QemuDrive, QemuNic, QemuSerialTarget},
     i386, x86_64, Qemu,
 };
 
@@ -162,9 +162,9 @@ fn run_x86_64(
         qemu.override_qemu(qemu_bin);
     }
     qemu.with_serial(QemuSerialTarget::MonStdio)
-        // .with_cpu(x86_64::Cpu::Host {
-        //     enable_kvm: config.machine.x86_64.enable_kvm,
-        // })
+        .with_cpu(x86_64::Cpu::Host {
+            enable_kvm: config.machine.x86_64.enable_kvm,
+        })
         .with_smp(config.machine.smp)
         .with_machine(x86_64::Machine::Q35)
         .with_boot_slot('a')
@@ -220,6 +220,7 @@ fn load_qemu_config<P: AsRef<Path>>(path: P) -> Result<QemuConfig, Error> {
 
 fn add_devices_from_config(
     devices: &mut Vec<QemuDevice>,
+    disk: Option<&PathBuf>,
     config: &QemuConfig,
 ) -> Result<(), Error> {
     if config.network.enable {
@@ -231,10 +232,22 @@ fn add_devices_from_config(
             ifname: Some(config.network.interface_name.clone()),
         });
     }
+    if let Some(disk) = disk {
+        devices.push(QemuDevice::Drive {
+            ty: QemuDrive::Nvme,
+            file: disk.clone(),
+            serial: Some("deadbeef".into()),
+        });
+    }
     Ok(())
 }
 
-pub fn run(env: BuildEnv, qemu: Option<PathBuf>, extra_args: Vec<String>) -> Result<(), Error> {
+pub fn run(
+    env: BuildEnv,
+    qemu: Option<PathBuf>,
+    disk: Option<PathBuf>,
+    extra_args: Vec<String>,
+) -> Result<(), Error> {
     let config = load_qemu_config(env.workspace_root.join("qemu.toml"))?;
 
     let kernel_output_dir = env.kernel_output_dir.clone();
@@ -243,7 +256,7 @@ pub fn run(env: BuildEnv, qemu: Option<PathBuf>, extra_args: Vec<String>) -> Res
     let built = build::build_all(env)?;
 
     let mut devices = vec![];
-    add_devices_from_config(&mut devices, &config)?;
+    add_devices_from_config(&mut devices, disk.as_ref(), &config)?;
 
     let mut command = match built {
         AllBuilt::AArch64(KernelProcessed(KernelBuilt(kernel)), InitrdGenerated(initrd)) => {