sample of sigill in rustc

Author: durin42

igvm/src/lib.rs

@@ -949,6 +949,46 @@ pub enum BinaryHeaderError {
     UnsupportedAArch64Register(#[from] registers::UnsupportedRegister<HvArm64RegisterName>),
 }
 
+#[inline(never)]
+fn write_snp_vp_context_header(
+    header: &IgvmDirectiveHeader,
+    variable_headers: &mut Vec<u8>,
+    file_data: &mut FileDataSerializer,
+) -> Result<(), BinaryHeaderError> {
+    let IgvmDirectiveHeader::SnpVpContext { gpa, compatibility_mask, vp_index, vmsa } = header
+    else {
+        panic!("Not vp context")
+    };
+    // GPA must be 4k aligned.
+    assert_eq!(gpa % PAGE_SIZE_4K, 0);
+
+    // Pad file data to 4K.
+    let align_up_iter =
+        std::iter::repeat(&0u8).take(PAGE_SIZE_4K as usize - vmsa.as_bytes().len());
+    let data: Vec<u8> = vmsa.as_bytes().iter().chain(align_up_iter).copied().collect();
+    let file_offset = file_data.write_file_data(&data);
+
+    let info = IGVM_VHS_VP_CONTEXT {
+        gpa: u64_le::new(*gpa),
+        compatibility_mask: *compatibility_mask,
+        file_offset,
+        vp_index: *vp_index,
+        reserved: 0,
+    };
+
+    append_header(&info, IgvmVariableHeaderType::IGVM_VHT_VP_CONTEXT, variable_headers);
+
+    Ok(())
+}
+
+#[test]
+fn test_write_snp_vp_context_header() {
+    let header = IgvmDirectiveHeader::SnpVpContext { gpa: 0x4000, compatibility_mask: 0x1, vp_index: 4, vmsa: SevVmsa::new_box_zeroed().unwrap() };
+    let mut variable_headers = vec![];
+    let mut file_data = FileDataSerializer::new(10000);
+    write_snp_vp_context_header(&header, &mut variable_headers, &mut file_data);
+}
+
 impl IgvmDirectiveHeader {
     /// Get the binary variable header size of the given type.
     fn header_size(&self) -> usize {