Merge "Native API fixes"
diff --git a/javalib/api/system-current.txt b/javalib/api/system-current.txt
index d14d83c..592a751 100644
--- a/javalib/api/system-current.txt
+++ b/javalib/api/system-current.txt
@@ -88,9 +88,6 @@
   }
 
   public class VirtualMachineException extends java.lang.Exception {
-    ctor public VirtualMachineException(@Nullable String);
-    ctor public VirtualMachineException(@Nullable String, @Nullable Throwable);
-    ctor public VirtualMachineException(@Nullable Throwable);
   }
 
   public class VirtualMachineManager {
diff --git a/javalib/src/android/system/virtualmachine/VirtualMachineException.java b/javalib/src/android/system/virtualmachine/VirtualMachineException.java
index 985eb70..9948fda 100644
--- a/javalib/src/android/system/virtualmachine/VirtualMachineException.java
+++ b/javalib/src/android/system/virtualmachine/VirtualMachineException.java
@@ -26,15 +26,15 @@
  */
 @SystemApi
 public class VirtualMachineException extends Exception {
-    public VirtualMachineException(@Nullable String message) {
+    VirtualMachineException(@Nullable String message) {
         super(message);
     }
 
-    public VirtualMachineException(@Nullable String message, @Nullable Throwable cause) {
+    VirtualMachineException(@Nullable String message, @Nullable Throwable cause) {
         super(message, cause);
     }
 
-    public VirtualMachineException(@Nullable Throwable cause) {
+    VirtualMachineException(@Nullable Throwable cause) {
         super(cause);
     }
 }
diff --git a/javalib/src/android/system/virtualmachine/VirtualMachineManager.java b/javalib/src/android/system/virtualmachine/VirtualMachineManager.java
index ea0a305..5b30617 100644
--- a/javalib/src/android/system/virtualmachine/VirtualMachineManager.java
+++ b/javalib/src/android/system/virtualmachine/VirtualMachineManager.java
@@ -150,6 +150,11 @@
      * Returns an existing {@link VirtualMachine} with the given name. Returns null if there is no
      * such virtual machine.
      *
+     * <p>There is at most one {@code VirtualMachine} object corresponding to a given virtual
+     * machine instance. Multiple calls to get() passing the same name will get the same object
+     * returned, until the virtual machine is deleted (via {@link #delete}) and then recreated.
+     *
+     * @see #getOrCreate
      * @throws VirtualMachineException if the virtual machine exists but could not be successfully
      *     retrieved.
      * @hide
diff --git a/pvmfw/src/hvc.rs b/pvmfw/src/hvc.rs
new file mode 100644
index 0000000..66f7977
--- /dev/null
+++ b/pvmfw/src/hvc.rs
@@ -0,0 +1,66 @@
+// Copyright 2022, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Wrappers around calls to the hypervisor.
+
+use crate::smccc::{self, checked_hvc64, checked_hvc64_expect_zero};
+use log::info;
+
+const VENDOR_HYP_KVM_MMIO_GUARD_INFO_FUNC_ID: u32 = 0xc6000005;
+const VENDOR_HYP_KVM_MMIO_GUARD_ENROLL_FUNC_ID: u32 = 0xc6000006;
+const VENDOR_HYP_KVM_MMIO_GUARD_MAP_FUNC_ID: u32 = 0xc6000007;
+const VENDOR_HYP_KVM_MMIO_GUARD_UNMAP_FUNC_ID: u32 = 0xc6000008;
+
+pub fn mmio_guard_info() -> smccc::Result<u64> {
+    let args = [0u64; 17];
+
+    checked_hvc64(VENDOR_HYP_KVM_MMIO_GUARD_INFO_FUNC_ID, args)
+}
+
+pub fn mmio_guard_enroll() -> smccc::Result<()> {
+    let args = [0u64; 17];
+
+    checked_hvc64_expect_zero(VENDOR_HYP_KVM_MMIO_GUARD_ENROLL_FUNC_ID, args)
+}
+
+pub fn mmio_guard_map(ipa: u64) -> smccc::Result<()> {
+    let mut args = [0u64; 17];
+    args[0] = ipa;
+
+    // TODO(b/253586500): pKVM currently returns a i32 instead of a i64.
+    let is_i32_error_code = |n| u32::try_from(n).ok().filter(|v| (*v as i32) < 0).is_some();
+    match checked_hvc64_expect_zero(VENDOR_HYP_KVM_MMIO_GUARD_MAP_FUNC_ID, args) {
+        Err(smccc::Error::Unexpected(e)) if is_i32_error_code(e) => {
+            info!("Handled a pKVM bug by interpreting the MMIO_GUARD_MAP return value as i32");
+            match e as u32 as i32 {
+                -1 => Err(smccc::Error::NotSupported),
+                -2 => Err(smccc::Error::NotRequired),
+                -3 => Err(smccc::Error::InvalidParameter),
+                ret => Err(smccc::Error::Unknown(ret as i64)),
+            }
+        }
+        res => res,
+    }
+}
+
+pub fn mmio_guard_unmap(ipa: u64) -> smccc::Result<()> {
+    let mut args = [0u64; 17];
+    args[0] = ipa;
+
+    // TODO(b/251426790): pKVM currently returns NOT_SUPPORTED for SUCCESS.
+    match checked_hvc64_expect_zero(VENDOR_HYP_KVM_MMIO_GUARD_UNMAP_FUNC_ID, args) {
+        Err(smccc::Error::NotSupported) | Ok(_) => Ok(()),
+        x => x,
+    }
+}
diff --git a/pvmfw/src/main.rs b/pvmfw/src/main.rs
index 79b6f57..2f1b42a 100644
--- a/pvmfw/src/main.rs
+++ b/pvmfw/src/main.rs
@@ -26,6 +26,7 @@
 mod fdt;
 mod heap;
 mod helpers;
+mod hvc;
 mod memory;
 mod mmio_guard;
 mod mmu;
diff --git a/pvmfw/src/mmio_guard.rs b/pvmfw/src/mmio_guard.rs
index 28f928f..e5f376e 100644
--- a/pvmfw/src/mmio_guard.rs
+++ b/pvmfw/src/mmio_guard.rs
@@ -15,9 +15,9 @@
 //! Safe MMIO_GUARD support.
 
 use crate::helpers;
+use crate::hvc::{mmio_guard_enroll, mmio_guard_info, mmio_guard_map, mmio_guard_unmap};
 use crate::smccc;
 use core::{fmt, result};
-use log::info;
 
 #[derive(Debug, Clone)]
 pub enum Error {
@@ -63,50 +63,3 @@
 pub fn unmap(addr: usize) -> Result<()> {
     mmio_guard_unmap(helpers::page_4kb_of(addr) as u64).map_err(Error::UnmapFailed)
 }
-
-fn mmio_guard_info() -> smccc::Result<u64> {
-    const VENDOR_HYP_KVM_MMIO_GUARD_INFO_FUNC_ID: u32 = 0xc6000005;
-    let args = [0u64; 17];
-
-    smccc::checked_hvc64(VENDOR_HYP_KVM_MMIO_GUARD_INFO_FUNC_ID, args)
-}
-
-fn mmio_guard_enroll() -> smccc::Result<()> {
-    const VENDOR_HYP_KVM_MMIO_GUARD_ENROLL_FUNC_ID: u32 = 0xc6000006;
-    let args = [0u64; 17];
-
-    smccc::checked_hvc64_expect_zero(VENDOR_HYP_KVM_MMIO_GUARD_ENROLL_FUNC_ID, args)
-}
-
-fn mmio_guard_map(ipa: u64) -> smccc::Result<()> {
-    const VENDOR_HYP_KVM_MMIO_GUARD_MAP_FUNC_ID: u32 = 0xc6000007;
-    let mut args = [0u64; 17];
-    args[0] = ipa;
-
-    // TODO(b/253586500): pKVM currently returns a i32 instead of a i64.
-    let is_i32_error_code = |n| u32::try_from(n).ok().filter(|v| (*v as i32) < 0).is_some();
-    match smccc::checked_hvc64_expect_zero(VENDOR_HYP_KVM_MMIO_GUARD_MAP_FUNC_ID, args) {
-        Err(smccc::Error::Unexpected(e)) if is_i32_error_code(e) => {
-            info!("Handled a pKVM bug by interpreting the MMIO_GUARD_MAP return value as i32");
-            match e as u32 as i32 {
-                -1 => Err(smccc::Error::NotSupported),
-                -2 => Err(smccc::Error::NotRequired),
-                -3 => Err(smccc::Error::InvalidParameter),
-                ret => Err(smccc::Error::Unknown(ret as i64)),
-            }
-        }
-        res => res,
-    }
-}
-
-fn mmio_guard_unmap(ipa: u64) -> smccc::Result<()> {
-    const VENDOR_HYP_KVM_MMIO_GUARD_UNMAP_FUNC_ID: u32 = 0xc6000008;
-    let mut args = [0u64; 17];
-    args[0] = ipa;
-
-    // TODO(b/251426790): pKVM currently returns NOT_SUPPORTED for SUCCESS.
-    match smccc::checked_hvc64_expect_zero(VENDOR_HYP_KVM_MMIO_GUARD_UNMAP_FUNC_ID, args) {
-        Err(smccc::Error::NotSupported) | Ok(_) => Ok(()),
-        x => x,
-    }
-}
diff --git a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
index 5f24c4b..eb756d8 100644
--- a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
+++ b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
@@ -258,14 +258,7 @@
         assertThrowsVmExceptionContaining(() -> vm.toDescriptor(), "deleted");
         // This is indistinguishable from the VM having never existed, so the message
         // is non-specific.
-        assertThrows(
-                VirtualMachineException.class, () -> getVirtualMachineManager().delete("test_vm"));
-    }
-
-    private void assertThrowsVmExceptionContaining(
-            ThrowingRunnable runnable, String expectedContents) {
-        Exception e = assertThrows(VirtualMachineException.class, runnable);
-        assertThat(e).hasMessageThat().contains(expectedContents);
+        assertThrowsVmException(() -> getVirtualMachineManager().delete("test_vm"));
     }
 
     @Test
@@ -423,6 +416,48 @@
 
     @Test
     @CddTest(requirements = {"9.17/C-1-1"})
+    public void vmmGetAndCreate() throws Exception {
+        assumeSupportedKernel();
+
+        VirtualMachineConfig config =
+                newVmConfigBuilder()
+                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setMemoryMib(minMemoryRequired())
+                        .setDebugLevel(DEBUG_LEVEL_FULL)
+                        .build();
+
+        VirtualMachineManager vmm = getVirtualMachineManager();
+        String vmName = "vmName";
+
+        // VM does not yet exist
+        assertThat(vmm.get(vmName)).isNull();
+
+        VirtualMachine vm1 = vmm.create(vmName, config);
+
+        // Now it does, and we should get the same instance back
+        assertThat(vmm.get(vmName)).isSameInstanceAs(vm1);
+        assertThat(vmm.getOrCreate(vmName, config)).isSameInstanceAs(vm1);
+
+        // Can't recreate it though
+        assertThrowsVmException(() -> vmm.create(vmName, config));
+
+        vmm.delete(vmName);
+        assertThat(vmm.get(vmName)).isNull();
+
+        // Now that we deleted the old one, this should create rather than get, and it should be a
+        // new instance.
+        VirtualMachine vm2 = vmm.getOrCreate(vmName, config);
+        assertThat(vm2).isNotSameInstanceAs(vm1);
+
+        // Subsequent gets should return this new one.
+        assertThat(vmm.get(vmName)).isSameInstanceAs(vm2);
+        assertThat(vmm.getOrCreate(vmName, config)).isSameInstanceAs(vm2);
+
+        vmm.delete(vmName);
+    }
+
+    @Test
+    @CddTest(requirements = {"9.17/C-1-1"})
     public void vmFilesStoredInDeDirWhenCreatedFromDEContext() throws Exception {
         final Context ctx = getContext().createDeviceProtectedStorageContext();
         final int userId = ctx.getUserId();
@@ -511,10 +546,10 @@
         assertThat(vmm.get("test_vm_delete")).isNull();
 
         // Can't start the VM even with an existing reference
-        assertThrows(VirtualMachineException.class, vm::run);
+        assertThrowsVmException(vm::run);
 
         // Can't delete the VM since it no longer exists
-        assertThrows(VirtualMachineException.class, () -> vmm.delete("test_vm_delete"));
+        assertThrowsVmException(() -> vmm.delete("test_vm_delete"));
     }
 
     @Test
@@ -1098,6 +1133,16 @@
         return filePath.toFile();
     }
 
+    private void assertThrowsVmException(ThrowingRunnable runnable) {
+        assertThrows(VirtualMachineException.class, runnable);
+    }
+
+    private void assertThrowsVmExceptionContaining(
+            ThrowingRunnable runnable, String expectedContents) {
+        Exception e = assertThrows(VirtualMachineException.class, runnable);
+        assertThat(e).hasMessageThat().contains(expectedContents);
+    }
+
     private int minMemoryRequired() {
         if (Build.SUPPORTED_ABIS.length > 0) {
             String primaryAbi = Build.SUPPORTED_ABIS[0];