runtime-rs: Add Discard Capability in each vmm driver

Add the BlockDeviceDiscardSupport cap in the qemu/clh/dragonball
drivers.

Signed-off-by: Alex Lyn <alex.lyn@antgroup.com>

src/runtime-rs/crates/hypervisor/src/ch/inner.rs

@@ -88,6 +88,7 @@ impl CloudHypervisorInner {
         capabilities.set(
             CapabilityBits::BlockDeviceSupport
                 | CapabilityBits::BlockDeviceHotplugSupport
+                | CapabilityBits::BlockDeviceDiscardSupport
                 | CapabilityBits::FsSharingSupport
                 | CapabilityBits::HybridVsockSupport,
         );

src/runtime-rs/crates/hypervisor/src/ch/inner_hypervisor.rs

@@ -807,10 +807,12 @@ impl CloudHypervisorInner {
             // TDX does not permit the use of virtio-fs.
             CapabilityBits::BlockDeviceSupport
                 | CapabilityBits::BlockDeviceHotplugSupport
+                | CapabilityBits::BlockDeviceDiscardSupport
                 | CapabilityBits::HybridVsockSupport
         } else {
             CapabilityBits::BlockDeviceSupport
                 | CapabilityBits::BlockDeviceHotplugSupport
+                | CapabilityBits::BlockDeviceDiscardSupport
                 | CapabilityBits::FsSharingSupport
                 | CapabilityBits::HybridVsockSupport
         };

src/runtime-rs/crates/hypervisor/src/dragonball/inner.rs

@@ -97,6 +97,7 @@ impl DragonballInner {
         capabilities.set(
             CapabilityBits::BlockDeviceSupport
                 | CapabilityBits::BlockDeviceHotplugSupport
+                | CapabilityBits::BlockDeviceDiscardSupport
                 | CapabilityBits::FsSharingSupport
                 | CapabilityBits::HybridVsockSupport
                 | CapabilityBits::GuestMemoryProbe,

src/runtime-rs/crates/hypervisor/src/qemu/inner.rs

@@ -763,10 +763,13 @@ impl QemuInner {
         let flags = if self.hypervisor_config().security_info.confidential_guest
             || self.hypervisor_config().shared_fs.shared_fs.is_none()
         {
-            CapabilityBits::BlockDeviceSupport | CapabilityBits::BlockDeviceHotplugSupport
+            CapabilityBits::BlockDeviceSupport
+                | CapabilityBits::BlockDeviceHotplugSupport
+                | CapabilityBits::BlockDeviceDiscardSupport
         } else {
             CapabilityBits::BlockDeviceSupport
                 | CapabilityBits::BlockDeviceHotplugSupport
+                | CapabilityBits::BlockDeviceDiscardSupport
                 | CapabilityBits::FsSharingSupport
         };
         caps.set(flags);