Add support for PVH boot protocol; FreeBSD VM tests

.github/workflows/integration_tests.yml

@@ -11,9 +11,50 @@ jobs:
       - name: Setup build environment
         uses: ./.github/actions/setup-build-env
 
+      - name: Install cross-compilation dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends lld
+
       - name: Add musl target
         run: rustup target add x86_64-unknown-linux-musl
 
+      - name: Add FreeBSD x86_64 target
+        run: rustup target add x86_64-unknown-freebsd
+
+      - name: Install FreeBSD test prerequisites
+        run: sudo apt-get install -y --no-install-recommends libarchive-tools
+
+      - name: Build FreeBSD sysroot and init
+        run: make BUILD_BSD_INIT=1 -- init/init-freebsd
+
+      - name: Install Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: 'stable'
+
+      - name: Build and cache gvproxy (x86_64)
+        uses: actions/cache@v4
+        id: gvproxy-cache
+        with:
+          path: /tmp/gvproxy-bin/
+          key: gvproxy-x86_64-c09fb7d
+
+      - name: Build gvproxy
+        if: steps.gvproxy-cache.outputs.cache-hit != 'true'
+        run: |
+          GVPROXY_BUILD_DIR=$(mktemp -d)
+          git clone https://github.com/containers/gvisor-tap-vsock.git "$GVPROXY_BUILD_DIR"
+          cd "$GVPROXY_BUILD_DIR"
+          git checkout c09fb7d0a9e08260d238066c3c4311498d15311e
+          mkdir -p /tmp/gvproxy-bin
+          make
+          cp bin/gvproxy /tmp/gvproxy-bin/gvproxy-x86_64
+
+      - name: Install gvproxy to PATH
+        run: |
+          sudo cp /tmp/gvproxy-bin/gvproxy-x86_64 /usr/local/bin/gvproxy
+
       - name: Build and install libkrun to test prefix
         run: make test-prefix NET=1
 
@@ -80,9 +121,50 @@ jobs:
       - name: Setup build environment
         uses: ./.github/actions/setup-build-env
 
+      - name: Install cross-compilation dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends clang lld
+
       - name: Add musl target
         run: rustup target add aarch64-unknown-linux-musl
 
+      - name: Install nightly toolchain with rust-src for FreeBSD aarch64
+        run: rustup +nightly-2026-01-25 component add rust-src
+
+      - name: Install FreeBSD test prerequisites
+        run: sudo apt-get install -y --no-install-recommends libarchive-tools
+
+      - name: Build FreeBSD sysroot and init
+        run: make BUILD_BSD_INIT=1 -- init/init-freebsd
+
+      - name: Install Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: 'stable'
+
+      - name: Build and cache gvproxy (aarch64)
+        uses: actions/cache@v4
+        id: gvproxy-cache
+        with:
+          path: /tmp/gvproxy-bin/
+          key: gvproxy-aarch64-c09fb7d
+
+      - name: Build gvproxy
+        if: steps.gvproxy-cache.outputs.cache-hit != 'true'
+        run: |
+          GVPROXY_BUILD_DIR=$(mktemp -d)
+          git clone https://github.com/containers/gvisor-tap-vsock.git "$GVPROXY_BUILD_DIR"
+          cd "$GVPROXY_BUILD_DIR"
+          git checkout c09fb7d0a9e08260d238066c3c4311498d15311e
+          mkdir -p /tmp/gvproxy-bin
+          make
+          cp bin/gvproxy /tmp/gvproxy-bin/gvproxy-aarch64
+
+      - name: Install gvproxy to PATH
+        run: |
+          sudo cp /tmp/gvproxy-bin/gvproxy-aarch64 /usr/local/bin/gvproxy
+
       - name: Build and install libkrun to test prefix
         run: make test-prefix NET=1
 

Makefile

@@ -33,6 +33,19 @@ endif
 ifeq ($(VIRGL_RESOURCE_MAP2),1)
 	FEATURE_FLAGS += --features virgl_resource_map2
 endif
+# Test targets require the block device (BLK) feature for FreeBSD disk tests
+# and the NET feature for gvproxy-based network tests.
+# Enable automatically unless the user explicitly set them to a value.
+ifeq ($(BLK),)
+    ifneq ($(filter test test-prefix,$(MAKECMDGOALS)),)
+        BLK := 1
+    endif
+endif
+ifeq ($(NET),)
+    ifneq ($(filter test test-prefix,$(MAKECMDGOALS)),)
+        NET := 1
+    endif
+endif
 ifeq ($(BLK),1)
     FEATURE_FLAGS += --features blk
 endif

src/arch/Cargo.toml

@@ -26,5 +26,8 @@ kvm-bindings = { version = "0.12", features = ["fam-wrappers"] }
 kvm-ioctls = "0.22"
 tdx = { version = "0.1.0", optional = true }
 
+[target.'cfg(target_arch = "x86_64")'.dependencies]
+linux-loader = { version = "0.13.2", features = ["elf"] }
+
 [dev-dependencies]
 utils = { package = "krun-utils", version = "=0.1.0-1.18.0", path = "../utils" }

src/arch/src/x86_64/gdt.rs

@@ -25,7 +25,14 @@ fn get_base(entry: u64) -> u64 {
 }
 
 fn get_limit(entry: u64) -> u32 {
-    ((((entry) & 0x000F_0000_0000_0000) >> 32) | ((entry) & 0x0000_0000_0000_FFFF)) as u32
+    let limit =
+        ((((entry) & 0x000F_0000_0000_0000) >> 32) | ((entry) & 0x0000_0000_0000_FFFF)) as u32;
+
+    if get_g(entry) == 1 {
+        (limit << 12) | 0xFFF
+    } else {
+        limit
+    }
 }
 
 fn get_g(entry: u64) -> u8 {
@@ -109,7 +116,7 @@ mod tests {
         assert_eq!(0xB, seg.type_);
         // base and limit
         assert_eq!(0x10_0000, seg.base);
-        assert_eq!(0xfffff, seg.limit);
+        assert_eq!(0xffffffff, seg.limit);
         assert_eq!(0x0, seg.unusable);
     }
 }

src/arch/src/x86_64/layout.rs

@@ -31,6 +31,21 @@ pub const IRQ_MAX: u32 = 15;
 /// Address for the TSS setup.
 pub const KVM_TSS_ADDRESS: u64 = 0xfffb_d000;
 
+/// Address of the hvm_start_info struct used in PVH boot.
+/// Mutually exclusive with SNP_CPUID_START (TEE only).
+pub const PVH_INFO_START: u64 = 0x6000;
+
+/// Starting address of array of modules of hvm_modlist_entry type.
+/// Used to enable initrd support using the PVH boot ABI.
+pub const MODLIST_START: u64 = 0x6040;
+
+/// Address of memory map table used in PVH boot. Can overlap
+/// with the zero page address since they are mutually exclusive.
+pub const MEMMAP_START: u64 = 0x7000;
+
+/// Location of RSDP pointer in x86 machines.
+pub const RSDP_ADDR: u64 = 0x000e_0000;
+
 /// The 'zero page', a.k.a linux kernel bootparams.
 pub const ZERO_PAGE_START: u64 = 0x7000;