add igvmfile read/write to vmgstool

Cargo.lock

@@ -9317,6 +9317,7 @@ dependencies = [
  "uefi_specs",
  "vmgs",
  "vmgs_format",
+ "winapi",
 ]
 
 [[package]]

Guide/src/dev_guide/dev_tools/vmgstool.md

@@ -63,6 +63,14 @@ variables without parsers:
 
 `vmgstool.exe uefi-nvram dump --filepath <vmgs file path> --keypath <key file path> --truncate`
 
+### Read DLL File to Write IGVMfile to VMGS
+
+Additionally, the VmgsTool contains a tool to read the IGVMfile from a DLL (passed in as a data file)
+and write it to VMGS FileId 8 (GUEST_FIRMWARE). To do this pass one of three resource codes
+(nonconfidential, snp, tdx, snp_no_hcl, tdx_no_hcl) into the cmdline tool:
+
+`vmgstool.exe copy-igvmfile --filepath <vmgs file path> --keypath <key file path> --datapath <dll path> --resource-code <code>`
+
 ### Delete Boot Variables to Recover a VM that Fails to Boot
 
 A VM may fail to boot if the disk configuration changes and

vm/vmgs/vmgstool/Cargo.toml

@@ -39,6 +39,13 @@ serde_json = { workspace = true, features = ["std"] }
 thiserror.workspace = true
 ucs2.workspace = true
 
+[target.'cfg(windows)'.dependencies.winapi]
+features = [
+  "libloaderapi",
+  "errhandlingapi",
+]
+workspace = true
+
 [dev-dependencies]
 tempfile.workspace = true
 

vm/vmgs/vmgstool/build.rs

@@ -9,4 +9,5 @@ fn main() {
     if cfg!(feature = "encryption_ossl") || cfg!(feature = "encryption_win") {
         println!("cargo:rustc-cfg=with_encryption")
     }
+    println!("cargo:rustc-check-cfg=cfg(guest_arch, values(\"x86_64\"))");
 }