hypervisor: mshv: retrieve MSRs list correctly

The MSR enumeration logic in MSHV does not accurately
account for the capabilities of the underlying
hardware and hypervisor. Previously, integration tests
passed because only the default MSRs—universally supported
across platforms—were involved. However, recent feature
additions in MSHV have introduced MSRs that are not
supported on Intel hardware, causing failures.

This patch retrieves the MSRs from the VM specific
API call that filters out the unsupported MSRs.

Signed-off-by: Muminul Islam <muislam@microsoft.com>

hypervisor/src/vm.rs

@@ -257,6 +257,12 @@ pub enum HypervisorVmError {
     ///
     #[error("Failed to initialize VM")]
     InitializeVm(#[source] anyhow::Error),
+    #[cfg(all(target_arch = "x86_64", feature = "mshv"))]
+    ///
+    /// Failed to retrieve list of MSRs.
+    ///
+    #[error("Failed to get the list of supported MSRs")]
+    GetMsrList(#[source] anyhow::Error),
 }
 ///
 /// Result type for returning from a function