fix memory initialization in boot setup

xencall/src/lib.rs

@@ -3,7 +3,8 @@ pub mod memory;
 pub mod sys;
 
 use crate::sys::{
-    Hypercall, MmapBatch, XenCapabilitiesInfo, HYPERVISOR_XEN_VERSION, XENVER_CAPABILITIES,
+    Hypercall, MmapBatch, MultiCallEntry, XenCapabilitiesInfo, HYPERVISOR_MULTICALL,
+    HYPERVISOR_XEN_VERSION, XENVER_CAPABILITIES,
 };
 use libc::{mmap, MAP_FAILED, MAP_SHARED, PROT_READ, PROT_WRITE};
 use nix::errno::Errno;
@@ -128,6 +129,15 @@ impl XenCall {
         self.hypercall(op, [arg1, arg2, arg3, arg4, 0])
     }
 
+    pub fn multicall(&self, calls: &mut [MultiCallEntry]) -> Result<(), XenCallError> {
+        self.hypercall2(
+            HYPERVISOR_MULTICALL,
+            calls.as_mut_ptr() as c_ulong,
+            calls.len() as c_ulong,
+        )?;
+        Ok(())
+    }
+
     pub fn hypercall5(
         &self,
         op: c_ulong,

xencall/src/memory.rs

@@ -1,8 +1,11 @@
-use crate::sys::{MemoryReservation, HYPERVISOR_MEMORY_OP, XEN_MEM_POPULATE_PHYSMAP};
+use crate::sys::{
+    MemoryReservation, MultiCallEntry, HYPERVISOR_MEMORY_OP, XEN_MEM_POPULATE_PHYSMAP,
+};
 use crate::{XenCall, XenCallError};
 
 use std::ffi::c_ulong;
 
+use libc::c_long;
 use std::ptr::addr_of_mut;
 
 pub struct MemoryControl<'a> {
@@ -30,12 +33,21 @@ impl MemoryControl<'_> {
             mem_flags,
             domid: domid as u16,
         };
-        let code = self.call.hypercall2(
-            HYPERVISOR_MEMORY_OP,
-            XEN_MEM_POPULATE_PHYSMAP as c_ulong,
-            addr_of_mut!(reservation) as c_ulong,
-        )?;
 
+        let calls = &mut [MultiCallEntry {
+            op: HYPERVISOR_MEMORY_OP,
+            result: 0,
+            args: [
+                XEN_MEM_POPULATE_PHYSMAP as c_ulong,
+                addr_of_mut!(reservation) as c_ulong,
+                0,
+                0,
+                0,
+                0,
+            ],
+        }];
+        self.call.multicall(calls)?;
+        let code = calls[0].result as c_long;
         if code < 0 {
             return Err(XenCallError::new("failed to populate physmap"));
         }

xencall/src/sys.rs

@@ -318,4 +318,12 @@ pub struct MemoryReservation {
     pub domid: u16,
 }
 
+#[repr(C)]
+#[derive(Copy, Clone, Debug)]
+pub struct MultiCallEntry {
+    pub op: c_ulong,
+    pub result: c_ulong,
+    pub args: [c_ulong; 6],
+}
+
 pub const XEN_MEM_POPULATE_PHYSMAP: u32 = 6;