From fb79e75afcd82cfe2396d061c96fa6c2823136a7 Mon Sep 17 00:00:00 2001
From: Sergio Lopez <slp@redhat.com>
Date: Tue, 21 Jan 2020 12:22:09 +0100
Subject: [PATCH] vmm: device_manager: Add read-only support for virtio-blk

vhost_user_blk already has it, so it's only fair to give it to
virtio-blk too. Extend DiskConfig with a 'readonly' properly, and pass
it to vm_virtio::Block.

Signed-off-by: Sergio Lopez <slp@redhat.com>
---
 vmm/src/config.rs         | 6 ++++++
 vmm/src/device_manager.rs | 6 +++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/vmm/src/config.rs b/vmm/src/config.rs
index 4139ca5cd..6859e8b9a 100644
--- a/vmm/src/config.rs
+++ b/vmm/src/config.rs
@@ -338,6 +338,8 @@ impl CmdlineConfig {
 pub struct DiskConfig {
     pub path: PathBuf,
     #[serde(default)]
+    pub readonly: bool,
+    #[serde(default)]
     pub iommu: bool,
 }
 
@@ -347,11 +349,14 @@ impl DiskConfig {
         let params_list: Vec<&str> = disk.split(',').collect();
 
         let mut path_str: &str = "";
+        let mut readonly_str: &str = "";
         let mut iommu_str: &str = "";
 
         for param in params_list.iter() {
             if param.starts_with("path=") {
                 path_str = &param[5..];
+            } else if param.starts_with("readonly=") {
+                readonly_str = &param[9..];
             } else if param.starts_with("iommu=") {
                 iommu_str = &param[6..];
             }
@@ -359,6 +364,7 @@ impl DiskConfig {
 
         Ok(DiskConfig {
             path: PathBuf::from(path_str),
+            readonly: parse_on_off(readonly_str)?,
             iommu: parse_on_off(iommu_str)?,
         })
     }
diff --git a/vmm/src/device_manager.rs b/vmm/src/device_manager.rs
index 8a1ba8e2e..fc67500b8 100644
--- a/vmm/src/device_manager.rs
+++ b/vmm/src/device_manager.rs
@@ -938,7 +938,7 @@ impl DeviceManager {
                 // Open block device path
                 let image: File = OpenOptions::new()
                     .read(true)
-                    .write(true)
+                    .write(!disk_cfg.readonly)
                     .open(&disk_cfg.path)
                     .map_err(DeviceManagerError::Disk)?;
 
@@ -951,7 +951,7 @@ impl DeviceManager {
                         let dev = vm_virtio::Block::new(
                             raw_img,
                             disk_cfg.path.clone(),
-                            false,
+                            disk_cfg.readonly,
                             disk_cfg.iommu,
                         )
                         .map_err(DeviceManagerError::CreateVirtioBlock)?;
@@ -970,7 +970,7 @@ impl DeviceManager {
                         let dev = vm_virtio::Block::new(
                             qcow_img,
                             disk_cfg.path.clone(),
-                            false,
+                            disk_cfg.readonly,
                             disk_cfg.iommu,
                         )
                         .map_err(DeviceManagerError::CreateVirtioBlock)?;