pvh: Introduce EntryPoint struct

In order to properly initialize the kvm regs/sregs structs for
the guest, the load_kernel() return type must specify which
boot protocol to use with the entry point address it returns.

Make load_kernel() return an EntryPoint struct containing the
required information. This structure will later be used
in the vCPU configuration methods to setup the appropriate
initial conditions for the guest.

Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>

arch/src/lib.rs

@@ -77,4 +77,5 @@ pub mod x86_64;
 #[cfg(target_arch = "x86_64")]
 pub use x86_64::{
     arch_memory_regions, configure_system, layout, layout::CMDLINE_MAX_SIZE, layout::CMDLINE_START,
+    BootProtocol, EntryPoint,
 };

arch/src/x86_64/mod.rs

@@ -21,6 +21,32 @@ use vm_memory::{
     Address, ByteValued, Bytes, GuestAddress, GuestMemory, GuestMemoryMmap, GuestUsize,
 };
 
+#[derive(Debug, Copy, Clone)]
+pub enum BootProtocol {
+    LinuxBoot,
+    PvhBoot,
+}
+
+impl ::std::fmt::Display for BootProtocol {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        match self {
+            BootProtocol::LinuxBoot => write!(f, "Linux 64-bit boot protocol"),
+            BootProtocol::PvhBoot => write!(f, "PVH boot protocol"),
+        }
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+/// Specifies the entry point address where the guest must start
+/// executing code, as well as which of the supported boot protocols
+/// is to be used to configure the guest initial state.
+pub struct EntryPoint {
+    /// Address in guest memory where the guest must start execution
+    pub entry_addr: GuestAddress,
+    /// Specifies which boot protocol to use
+    pub protocol: BootProtocol,
+}
+
 const E820_RAM: u32 = 1;
 const E820_RESERVED: u32 = 2;
 

vmm/src/cpu.rs

@@ -1,3 +1,5 @@
+// Copyright © 2020, Oracle and/or its affiliates.
+//
 // Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 //
 // Portions Copyright 2017 The Chromium OS Authors. All rights reserved.
@@ -13,6 +15,7 @@ use crate::device_manager::DeviceManager;
 use acpi_tables::{aml, aml::Aml, sdt::SDT};
 #[cfg(feature = "acpi")]
 use arch::layout;
+use arch::EntryPoint;
 use devices::{ioapic, BusDevice};
 use kvm_bindings::CpuId;
 use kvm_ioctls::*;
@@ -271,11 +274,11 @@ impl Vcpu {
     /// # Arguments
     ///
     /// * `machine_config` - Specifies necessary info used for the CPUID configuration.
-    /// * `kernel_start_addr` - Offset from `guest_mem` at which the kernel starts.
+    /// * `kernel_entry_point` - Kernel entry point address in guest memory and boot protocol used.
     /// * `vm` - The virtual machine this vcpu will get attached to.
     pub fn configure(
         &mut self,
-        kernel_start_addr: Option<GuestAddress>,
+        kernel_entry_point: Option<EntryPoint>,
         vm_memory: &GuestMemoryAtomic<GuestMemoryMmap>,
         cpuid: CpuId,
     ) -> Result<()> {
@@ -286,11 +289,11 @@ impl Vcpu {
             .map_err(Error::SetSupportedCpusFailed)?;
 
         arch::x86_64::regs::setup_msrs(&self.fd).map_err(Error::MSRSConfiguration)?;
-        if let Some(kernel_start_addr) = kernel_start_addr {
+        if let Some(kernel_entry_point) = kernel_entry_point {
             // Safe to unwrap because this method is called after the VM is configured
             arch::x86_64::regs::setup_regs(
                 &self.fd,
-                kernel_start_addr.raw_value(),
+                kernel_entry_point.entry_addr.raw_value(),
                 arch::x86_64::layout::BOOT_STACK_POINTER.raw_value(),
                 arch::x86_64::layout::ZERO_PAGE_START.raw_value(),
             )
@@ -537,11 +540,7 @@ impl CpuManager {
         Ok(cpu_manager)
     }
 
-    fn activate_vcpus(
-        &mut self,
-        desired_vcpus: u8,
-        entry_addr: Option<GuestAddress>,
-    ) -> Result<()> {
+    fn activate_vcpus(&mut self, desired_vcpus: u8, entry_point: Option<EntryPoint>) -> Result<()> {
         if desired_vcpus > self.max_vcpus {
             return Err(Error::DesiredVCPUCountExceedsMax);
         }
@@ -586,7 +585,7 @@ impl CpuManager {
                         register_signal_handler(SIGRTMIN(), handle_signal)
                             .expect("Failed to register vcpu signal handler");
 
-                        vcpu.configure(entry_addr, &vm_memory, cpuid)
+                        vcpu.configure(entry_point, &vm_memory, cpuid)
                             .expect("Failed to configure vCPU");
 
                         // Block until all CPUs are ready.
@@ -628,10 +627,10 @@ impl CpuManager {
                     .map_err(Error::VcpuSpawn)?,
             );
 
-            // On hot plug calls into this function entry_addr is None. It is for
+            // On hot plug calls into this function entry_point is None. It is for
             // those hotplug CPU additions that we need to set the inserting flag.
             self.vcpu_states[usize::from(cpu_id)].handle = handle;
-            self.vcpu_states[usize::from(cpu_id)].inserting = entry_addr.is_none();
+            self.vcpu_states[usize::from(cpu_id)].inserting = entry_point.is_none();
         }
 
         // Unblock all CPU threads.
@@ -657,8 +656,8 @@ impl CpuManager {
     }
 
     // Starts all the vCPUs that the VM is booting with. Blocks until all vCPUs are running.
-    pub fn start_boot_vcpus(&mut self, entry_addr: GuestAddress) -> Result<()> {
-        self.activate_vcpus(self.boot_vcpus(), Some(entry_addr))
+    pub fn start_boot_vcpus(&mut self, entry_point: EntryPoint) -> Result<()> {
+        self.activate_vcpus(self.boot_vcpus(), Some(entry_point))
     }
 
     pub fn resize(&mut self, desired_vcpus: u8) -> Result<bool> {

vmm/src/vm.rs

@@ -1,3 +1,5 @@
+// Copyright © 2020, Oracle and/or its affiliates.
+//
 // Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 //
 // Portions Copyright 2017 The Chromium OS Authors. All rights reserved.
@@ -29,7 +31,7 @@ use crate::cpu;
 use crate::device_manager::{get_win_size, Console, DeviceManager, DeviceManagerError};
 use crate::memory_manager::{get_host_cpu_phys_bits, Error as MemoryManagerError, MemoryManager};
 use anyhow::anyhow;
-use arch::layout;
+use arch::{layout, BootProtocol, EntryPoint};
 use devices::{ioapic, HotPlugNotificationFlags};
 use kvm_bindings::{kvm_enable_cap, kvm_userspace_memory_region, KVM_CAP_SPLIT_IRQCHIP};
 use kvm_ioctls::*;
@@ -382,7 +384,7 @@ impl Vm {
         })
     }
 
-    fn load_kernel(&mut self) -> Result<GuestAddress> {
+    fn load_kernel(&mut self) -> Result<EntryPoint> {
         let mut cmdline = Cmdline::new(arch::CMDLINE_MAX_SIZE);
         cmdline
             .insert_str(self.config.lock().unwrap().cmdline.args.clone())
@@ -453,9 +455,24 @@ impl Vm {
                     .checked_add(KERNEL_64BIT_ENTRY_OFFSET)
                     .ok_or(Error::MemOverflow)?;
 
-                Ok(GuestAddress(load_addr))
+                Ok(EntryPoint {
+                    entry_addr: GuestAddress(load_addr),
+                    protocol: BootProtocol::LinuxBoot,
+                })
             }
             None => {
+                // Assume by default Linux boot protocol is used and not PVH
+                let mut entry_point_addr: GuestAddress = entry_addr.kernel_load;
+
+                let boot_prot = if cfg!(feature = "pvh_boot") && entry_addr.pvh_entry_addr.is_some()
+                {
+                    // entry_addr.pvh_entry_addr field is safe to unwrap here
+                    entry_point_addr = entry_addr.pvh_entry_addr.unwrap();
+                    BootProtocol::PvhBoot
+                } else {
+                    BootProtocol::LinuxBoot
+                };
+
                 arch::configure_system(
                     &mem,
                     arch::layout::CMDLINE_START,
@@ -466,7 +483,10 @@ impl Vm {
                 )
                 .map_err(Error::ConfigureSystem)?;
 
-                Ok(entry_addr.kernel_load)
+                Ok(EntryPoint {
+                    entry_addr: entry_point_addr,
+                    protocol: boot_prot,
+                })
             }
         }
     }