vmm/linux/tee: Handle KVM_EXIT_MEMORY_FAULT exits

Like KVM_EXIT_HYPERCALL, KVM_EXIT_MEMORY_FAULT is used by SEV-SNP guests
to set memory regions to private or shared. Allow vCPUs encountering a
KVM_EXIT_MEMORY_FAULT to re-use the shared/private memory handler used
by KVM_EXIT_HYPERCALL to set regions to private or shared.

Signed-off-by: Tyler Fanelli <tfanelli@redhat.com>

Author: tylerfanelli

src/vmm/src/linux/vstate.rs

@@ -1240,6 +1240,16 @@ impl Vcpu {
                     self.io_bus.write(0, u64::from(addr), data);
                     Ok(VcpuEmulation::Handled)
                 }
+                VcpuExit::MemoryFault { gpa, size, flags } => {
+                    let private = (flags & (1 << 3)/* KVM_EXIT_MEMORY_FAULT */) != 0;
+
+                    let mem_properties = MemoryProperties { gpa, size, private };
+
+                    self.pm_sender.0.send(mem_properties).unwrap();
+                    let _ = self.pm_sender.1.read().unwrap();
+
+                    Ok(VcpuEmulation::Handled)
+                }
                 VcpuExit::MmioRead(addr, data) => {
                     if let Some(ref mmio_bus) = self.mmio_bus {
                         mmio_bus.read(0, addr, data);