From 0f92f8e49f6ddd75447b3a3e10a88ca6c67f31d5 Mon Sep 17 00:00:00 2001
From: Bader Zaidan <bader.zaidan@rwth-aachen.de>
Date: Thu, 6 Jul 2023 16:00:39 +0200
Subject: [PATCH] Use vm_memory crate for guest allocation

---
 Cargo.lock         | 12 ++++++++++++
 Cargo.toml         |  1 +
 src/linux/uhyve.rs | 37 +++++++++++++++++++------------------
 3 files changed, 32 insertions(+), 18 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ade1d0e0..95ef8a61 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1462,6 +1462,7 @@ dependencies = [
  "tun-tap",
  "uhyve-interface",
  "virtio-bindings",
+ "vm-memory",
  "vmm-sys-util",
  "x86_64",
  "xhypervisor",
@@ -1511,6 +1512,17 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "878bcb1b2812a10c30d53b0ed054999de3d98f25ece91fc173973f9c57aaae86"
 
+[[package]]
+name = "vm-memory"
+version = "0.12.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9dc276f0d00c17b9aeb584da0f1e1c673df0d183cc2539e3636ec8cbc5eae99b"
+dependencies = [
+ "libc",
+ "thiserror",
+ "winapi",
+]
+
 [[package]]
 name = "vmm-sys-util"
 version = "0.12.1"
diff --git a/Cargo.toml b/Cargo.toml
index d5bf6814..1604d0e9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -65,6 +65,7 @@ mac_address = "1.1"
 nix = { version = "0.27", features = ["mman", "pthread", "signal"] }
 tun-tap = { version = "0.1", default-features = false }
 virtio-bindings = { version = "0.2", features = ["virtio-v4_14_0"] }
+vm-memory = { version = "0.12", features = ["backend-mmap"] }
 vmm-sys-util = "0.12"
 
 [target.'cfg(target_os = "macos")'.dependencies]
diff --git a/src/linux/uhyve.rs b/src/linux/uhyve.rs
index e636d639..f7fa9825 100755
--- a/src/linux/uhyve.rs
+++ b/src/linux/uhyve.rs
@@ -5,7 +5,7 @@ use std::{
 	cmp,
 	ffi::OsString,
 	fmt, mem,
-	os::{fd::BorrowedFd, raw::c_void},
+	os::raw::c_void,
 	path::{Path, PathBuf},
 	ptr,
 	sync::{Arc, Mutex},
@@ -17,6 +17,10 @@ use kvm_ioctls::VmFd;
 use log::debug;
 use nix::sys::mman::*;
 use vmm_sys_util::eventfd::EventFd;
+use vm_memory::{
+	GuestAddress, GuestMemoryMmap, GuestMemoryRegion, GuestRegionMmap, MemoryRegionAddress,
+	MmapRegion,
+};
 use x86_64::{
 	structures::paging::{Page, PageTable, PageTableFlags, Size2MiB},
 	PhysAddr,
@@ -302,6 +306,7 @@ struct MmapMemory {
 	memory_size: usize,
 	guest_address: usize,
 	host_address: usize,
+	pub mmap: vm_memory::GuestMemoryMmap,
 }
 
 impl MmapMemory {
@@ -312,37 +317,33 @@ impl MmapMemory {
 		huge_pages: bool,
 		mergeable: bool,
 	) -> MmapMemory {
-		let host_address = unsafe {
-			mmap::<BorrowedFd<'_>>(
-				None,
-				memory_size.try_into().unwrap(),
-				ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
-				MapFlags::MAP_PRIVATE | MapFlags::MAP_ANONYMOUS | MapFlags::MAP_NORESERVE,
-				None,
-				0,
-			)
-			.expect("mmap failed")
-		};
+		let regionmap = GuestRegionMmap::new(
+			MmapRegion::new(memory_size).unwrap(),
+			GuestAddress(guest_address),
+		)
+		.unwrap();
 
 		if mergeable {
 			debug!("Enable kernel feature to merge same pages");
-			unsafe {
-				madvise(host_address, memory_size, MmapAdvise::MADV_MERGEABLE).unwrap();
-			}
+			// TODO: implement flags
+			assert!(regionmap.flags() | MmapAdvise::MADV_MERGEABLE as i32 != 0);
 		}
 
 		if huge_pages {
 			debug!("Uhyve uses huge pages");
-			unsafe {
-				madvise(host_address, memory_size, MmapAdvise::MADV_HUGEPAGE).unwrap();
-			}
+			// TODO: implement flags
+			assert!(regionmap.flags() | MmapAdvise::MADV_HUGEPAGE as i32 != 0);
 		}
 
+		let host_address = regionmap.get_host_address(MemoryRegionAddress(0)).unwrap();
+		let mmap = GuestMemoryMmap::from_regions(vec![regionmap]).unwrap();
+
 		MmapMemory {
 			flags,
 			memory_size,
 			guest_address: guest_address as usize,
 			host_address: host_address as usize,
+			mmap,
 		}
 	}