9p: Add hypervisor configuration for 9p msize

This allows msize option for 9p to be configured and tuned.

Fixes #206

Signed-off-by: Archana Shinde <archana.m.shinde@intel.com>

virtcontainers/api_test.go

@@ -913,6 +913,7 @@ func TestStatusSandboxSuccessfulStateReady(t *testing.T) {
 		DefaultBridges:    defaultBridges,
 		BlockDeviceDriver: defaultBlockDriver,
 		DefaultMaxVCPUs:   defaultMaxQemuVCPUs,
+		Msize9p:           defaultMsize9p,
 	}
 
 	expectedStatus := SandboxStatus{
@@ -969,6 +970,7 @@ func TestStatusSandboxSuccessfulStateRunning(t *testing.T) {
 		DefaultBridges:    defaultBridges,
 		BlockDeviceDriver: defaultBlockDriver,
 		DefaultMaxVCPUs:   defaultMaxQemuVCPUs,
+		Msize9p:           defaultMsize9p,
 	}
 
 	expectedStatus := SandboxStatus{

virtcontainers/hypervisor.go

@@ -226,6 +226,9 @@ type HypervisorConfig struct {
 	// DisableNestingChecks is used to override customizations performed
 	// when running on top of another VMM.
 	DisableNestingChecks bool
+
+	// Msize9p is used as the msize for 9p shares
+	Msize9p uint32
 }
 
 func (conf *HypervisorConfig) valid() (bool, error) {
@@ -257,6 +260,10 @@ func (conf *HypervisorConfig) valid() (bool, error) {
 		conf.DefaultMaxVCPUs = defaultMaxQemuVCPUs
 	}
 
+	if conf.Msize9p == 0 {
+		conf.Msize9p = defaultMsize9p
+	}
+
 	return true, nil
 }
 

virtcontainers/hypervisor_test.go

@@ -182,7 +182,9 @@ func TestHypervisorConfigDefaults(t *testing.T) {
 		DefaultBridges:    defaultBridges,
 		BlockDeviceDriver: defaultBlockDriver,
 		DefaultMaxVCPUs:   defaultMaxQemuVCPUs,
+		Msize9p:           defaultMsize9p,
 	}
+
 	if reflect.DeepEqual(hypervisorConfig, hypervisorConfigDefaultsExpected) == false {
 		t.Fatal()
 	}

virtcontainers/kata_agent.go

@@ -485,6 +485,8 @@ func (k *kataAgent) startSandbox(sandbox Sandbox) error {
 		}
 	}
 
+	sharedDir9pOptions = append(sharedDir9pOptions, fmt.Sprintf("msize=%d", sandbox.config.HypervisorConfig.Msize9p))
+
 	// We mount the shared directory in a predefined location
 	// in the guest.
 	// This is where at least some of the host config files

virtcontainers/qemu_arch_base.go

@@ -108,6 +108,7 @@ const (
 	defaultCPUModel         = "host"
 	defaultBridgeBus        = "pcie.0"
 	maxDevIDSize            = 31
+	defaultMsize9p          = 8192
 )
 
 const (

virtcontainers/qemu_test.go

@@ -39,6 +39,7 @@ func newQemuConfig() HypervisorConfig {
 		DefaultBridges:    defaultBridges,
 		BlockDeviceDriver: defaultBlockDriver,
 		DefaultMaxVCPUs:   defaultMaxQemuVCPUs,
+		Msize9p:           defaultMsize9p,
 	}
 }