From be4e1e871242a92bd67c7aced18784e6c04eab49 Mon Sep 17 00:00:00 2001
From: Sebastien Boeuf <sebastien.boeuf@intel.com>
Date: Tue, 7 Apr 2020 10:32:54 +0200
Subject: [PATCH] vmm: memory: Use fine grained mmap wrapper

In order to anticipate the need for special mmap flags when memory
mapping the guest RAM, we need to switch from from_file() wrapper to
build() wrapper.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
---
 vmm/src/memory_manager.rs | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/vmm/src/memory_manager.rs b/vmm/src/memory_manager.rs
index 6ab80cbec..fe91f4312 100644
--- a/vmm/src/memory_manager.rs
+++ b/vmm/src/memory_manager.rs
@@ -436,9 +436,15 @@ impl MemoryManager {
 
                 f.set_len(size as u64).map_err(Error::SharedFileSetLen)?;
 
+                let mmap_flags = libc::MAP_NORESERVE | libc::MAP_SHARED;
                 GuestRegionMmap::new(
-                    MmapRegion::from_file(FileOffset::new(f, 0), size)
-                        .map_err(Error::GuestMemoryRegion)?,
+                    MmapRegion::build(
+                        Some(FileOffset::new(f, 0)),
+                        size,
+                        libc::PROT_READ | libc::PROT_WRITE,
+                        mmap_flags,
+                    )
+                    .map_err(Error::GuestMemoryRegion)?,
                     start_addr,
                 )
                 .map_err(Error::GuestMemory)?