minimal KVM abstraction + real mode guest example

1 files changed, 48 insertions, 0 deletions

diff --git a/examples/real_mode.rs b/examples/real_mode.rs
new file mode 100644
index 0000000..39d1796
--- /dev/null
+++ b/examples/real_mode.rs
@@ -0,0 +1,48 @@
+use kvm_rs::kvm::Kvm;
+use kvm_rs::vcpu::KvmExit;
+use kvm_rs::{PhysAddr, UserMem};
+
+fn main() -> std::io::Result<()> {
+    // Create VM & VCPU.
+    let vm = Kvm::new()?.create_vm()?;
+    let vcpu = vm.create_vpcu(0)?;
+
+    // Map memory for guest VM and initialize with guest image.
+    let mem = UserMem::with_init(0x1000, include_bytes!("../guest/guest16"))?;
+    unsafe {
+        vm.set_user_memory_region(PhysAddr(0x0), &mem)?;
+    }
+
+    // Initialize VPCU registers.
+    let mut regs = vcpu.get_regs()?;
+    regs.rip = 0;
+    regs.rflags.0 = 0x2;
+    vcpu.set_regs(regs)?;
+
+    // Initialize VPCU special registers.
+    let mut sregs = vcpu.get_sregs()?;
+    sregs.cs.base = 0;
+    sregs.cs.selector = 0;
+    vcpu.set_sregs(sregs)?;
+
+    // Run VCPU until `hlt` instruction.
+    while let Ok(exit) = vcpu.run() {
+        match exit {
+            KvmExit::Halt => break,
+            KvmExit::IoOut(_port, data) => {
+                let s = std::str::from_utf8(data).unwrap();
+                print!("{}", s);
+            }
+            KvmExit::MmioWrite(addr, data) => {
+                println!(
+                    "MMIO_WRITE: addr={:#x} len={} data={:#x?}",
+                    addr,
+                    data.len(),
+                    data
+                );
+            }
+        };
+    }
+
+    Ok(())
+}