Initial aarch64/KVM support

Justfile

@@ -24,9 +24,11 @@ export CROSS_CONTAINER_GID := if path_exists("/dev/kvm") == "true" { kvm-gid } e
 root := justfile_directory()
 
 default-target := "debug"
-simpleguest_source := "src/tests/rust_guests/simpleguest/target/x86_64-hyperlight-none"
-dummyguest_source := "src/tests/rust_guests/dummyguest/target/x86_64-hyperlight-none"
-witguest_source := "src/tests/rust_guests/witguest/target/x86_64-hyperlight-none"
+hyperlight-target-arch := env("HYPERLIGHT_TARGET", arch())
+hyperlight-target := if hyperlight-target-arch == "x86_64" { "x86_64-hyperlight-none" } else if hyperlight-target-arch == "aarch64" { "aarch64-hyperlight-none" } else { error("Unsupported architecture: " + arch()) }
+simpleguest_source := "src/tests/rust_guests/simpleguest/target/" + hyperlight-target
+dummyguest_source := "src/tests/rust_guests/dummyguest/target/" + hyperlight-target
+witguest_source := "src/tests/rust_guests/witguest/target/" + hyperlight-target
 rust_guests_bin_dir := "src/tests/rust_guests/bin"
 
 ################

c.just

@@ -1,8 +1,9 @@
 mkdir := if os() == "windows" { "mkdir -f -p" } else { "mkdir -p"} 
 
 # Elf options
+hyperlight-target-c := if hyperlight-target-arch == "x86_64" { "x86_64-unknown-linux-none" } else if hyperlight-target-arch == "aarch64" { "aarch64-unknown-linux-none" } else { error("Unsupported architecture: " + hyperlight-target-arch) }
 # We don't support stack protectors at the moment, but Arch Linux clang auto-enables them for -linux platforms, so explicitly disable them.
-c-compile-options-elf := '-nostdlibinc -H --target=x86_64-unknown-linux-none -fno-stack-protector -fstack-clash-protection -mstack-probe-size=4096 -fPIC'
+c-compile-options-elf := f'-nostdlibinc -H --target={{hyperlight-target-c}} -fno-stack-protector -fstack-clash-protection -mstack-probe-size=4096 -fPIC'
 c-include-flags-elf := "-I " + root / "src/hyperlight_guest_capi/include/"  + " -I " + root / "src/hyperlight_libc/third_party/picolibc/libc/include/" + " -I " + root / "src/hyperlight_libc/third_party/picolibc/libc/stdio/" + " -I " + root / "src/hyperlight_libc/include/"
 c-linker-options-elf := '--entry "entrypoint" --nostdlib -pie --no-dynamic-linker'
 c-flags-debug-elf := '-O0'
@@ -19,7 +20,7 @@ compile-c-guest target=default-target:
 
 link-c-guest target=default-target:
     # elf
-    cd src/tests/c_guests/c_simpleguest && ld.lld -o out/{{target}}/simpleguest {{c-linker-options-elf}} out/{{target}}/main.o -l hyperlight_guest_capi -L "{{justfile_directory()}}/target/x86_64-hyperlight-none/{{target}}"
+    cd src/tests/c_guests/c_simpleguest && ld.lld -o out/{{target}}/simpleguest {{c-linker-options-elf}} out/{{target}}/main.o -l hyperlight_guest_capi -L "{{justfile_directory()}}/target/{{hyperlight-target}}/{{target}}"
 
 move-c-guests target=default-target:
     # elf

docs/paging-development-notes.md

@@ -172,3 +172,9 @@ below the exception stack within the scratch region.
 
 Hyperlight unconditionally uses 48-bit virtual addresses (4-level
 paging) and enables PAE.  The guest is always entered in long mode.
+
+## aarch64
+
+Hyperlight unconditionally uses 48-bit virtual addresses. Hyperlight
+presently only uses addresses in the lower (ttbr0) half of the address range.
+

flake.nix

@@ -51,7 +51,7 @@
               toolchainVersionAttrs = args;
             };
           })) // {
-            targetPlatforms = [ "x86_64-linux" ];
+            targetPlatforms = [ "aarch64-linux" "x86_64-linux" ];
             badTargetPlatforms = [ ];
           };
           overrideRustPkg = pkg: self.lib.makeOverridable (origArgs:
@@ -68,21 +68,21 @@
               args = [ "-c" "declare > $out" ];
             });
         in {
-          shells.default = gcrootForShell devShells.x86_64-linux.default;
+          shells.x86_64-linux.default = gcrootForShell devShells.x86_64-linux.default;
+          shells.aarch64-linux.default = gcrootForShell devShells.aarch64-linux.default;
         };
-      devShells.x86_64-linux.default =
-        let pkgs = import nixpkgs {
-              system = "x86_64-linux";
-              overlays = [ (import (nixpkgs-mozilla + "/rust-overlay.nix")) overlays.fix-rust ];
-            };
-        in with pkgs; let
+      devShells = nixpkgs.lib.genAttrs nixpkgs.lib.systems.flakeExposed (system: {
+        default = let pkgs = import nixpkgs {
+          inherit system;
+          overlays = [ (import (nixpkgs-mozilla + "/rust-overlay.nix")) overlays.fix-rust ];
+        }; in with pkgs; let
           customisedRustChannelOf = args:
             lib.flip builtins.mapAttrs (rustChannelOf args) (_: pkg: pkg.override {
               targets = [
                 "x86_64-unknown-linux-gnu"
                 "x86_64-pc-windows-msvc" "x86_64-unknown-none"
                 "wasm32-wasip1" "wasm32-wasip2" "wasm32-unknown-unknown"
-                "i686-unknown-linux-gnu"
+                "i686-unknown-linux-gnu" "aarch64-unknown-none"
               ];
               extensions = [ "rust-src" ] ++ (if args.channel == "nightly" then [ "miri-preview" ] else []);
             });
@@ -227,10 +227,11 @@
             src = fetchFromGitHub {
               owner = "hyperlight-dev";
               repo = "cargo-hyperlight";
-              tag = "v${version}";
-              hash = "sha256-xq4/c69N0wG/I8WOYVloo0J0JqoSIKiWWtECdSKrsxo=";
+              rev = "28ac7b57e8e7b83f80bd601f1fab334aa3ae6d4a";
+              hash = "sha256-a/mvPEDJycrCbmd826SmFdasE8BFtMkCsefCNR5JnkM=";
             };
-            cargoHash = "sha256-muiMVrK1TydQiMitihfo7xYidqUIIQ+Hw3BIeo5rLFw=";
+            cargoHash = "sha256-wLapaao8qcB/toltV/xjQ7SXXcfh2J19nw6jWljmb2s=";
+            doCheck = false;
           };
         in (buildRustPackageClang (mkDerivationAttrs: {
           pname = "hyperlight";
@@ -280,5 +281,6 @@
         })).overrideAttrs(oA: {
           hardeningDisable = [ "all" ];
         });
+      });
     };
 }

src/hyperlight_common/src/arch/aarch64/layout.rs

@@ -14,12 +14,21 @@ See the License for the specific language governing permissions and
 limitations under the License.
  */
 
-// TODO(aarch64): change these, they are only provided in order to compile
-pub const MAX_GVA: usize = 0xffff_ffff_ffff_efff;
-pub const SNAPSHOT_PT_GVA_MIN: usize = 0xffff_8000_0000_0000;
-pub const SNAPSHOT_PT_GVA_MAX: usize = 0xffff_80ff_ffff_ffff;
-pub const MAX_GPA: usize = 0x0000_000f_ffff_ffff;
+// TODO: consider using the upper half, like we do on x86;
+// this would require enabling ttbr1
+pub const SCRATCH_TOP_GVA: usize = 0x0000_ffff_ffff_dfff;
+pub const SNAPSHOT_PT_GVA_MIN: usize = 0x0000_8000_0000_0000;
+pub const SNAPSHOT_PT_GVA_MAX: usize = 0x0000_80ff_ffff_ffff;
+pub const SCRATCH_TOP_GPA: usize = 0x0000_000f_ffff_efff;
 
-pub fn min_scratch_size(_input_data_size: usize, _output_data_size: usize) -> usize {
-    unimplemented!("min_scratch_size")
+pub const IO_PAGE_GVA: u64 = 0x0000_ffff_ffff_e000;
+pub const IO_PAGE_GPA: u64 = 0x0000_000f_ffff_f000;
+
+pub const fn io_page() -> Option<(crate::vmem::PhysAddr, crate::vmem::VirtAddr)> {
+    Some((IO_PAGE_GPA, IO_PAGE_GVA))
+}
+
+pub fn min_scratch_size(input_data_size: usize, output_data_size: usize) -> usize {
+    (input_data_size + output_data_size).next_multiple_of(crate::vmem::PAGE_SIZE)
+        + 12 * crate::vmem::PAGE_SIZE
 }