Revert "qemu: tdx: Adapt command line" (partially)

This reverts commit b7cccfa019.

The `private=on` bit has never made its way upstream, and was removed
from the latest iteration that we're using.  With that in mind, let's
revert its usage in the code.

Signed-off-by: Fabiano Fidêncio <fabiano.fidencio@intel.com>

src/runtime/pkg/govmm/qemu/qemu.go

@@ -3028,9 +3028,6 @@ func (config *Config) appendMemoryKnobs() {
 		numaMemParam = "node,memdev=" + dimmName
 	}
 
-	if config.Knobs.Private {
-		objMemParam += ",private=on"
-	}
 	if config.Knobs.MemShared {
 		objMemParam += ",share=on"
 	}

src/runtime/pkg/govmm/qemu/qemu_test.go

@@ -586,7 +586,6 @@ func TestAppendMemoryFileBackedMem(t *testing.T) {
 	knobs := Knobs{
 		FileBackedMem: true,
 		MemShared:     false,
-		Private:       false,
 	}
 	objMemString := "-object memory-backend-file,id=dimm1,size=1G,mem-path=foobar"
 	numaMemString := "-numa node,memdev=dimm1"
@@ -600,36 +599,6 @@ func TestAppendMemoryFileBackedMem(t *testing.T) {
 	}
 
 	testConfigAppend(conf, knobs, memString+" "+knobsString, t)
-
-	// Reset the conf and memString values
-	conf = &Config{
-		Memory: Memory{
-			Size:   "1G",
-			Slots:  8,
-			MaxMem: "3G",
-			Path:   "foobar",
-		},
-	}
-	memString = "-m 1G,slots=8,maxmem=3G"
-	testConfigAppend(conf, conf.Memory, memString, t)
-
-	knobs = Knobs{
-		FileBackedMem: true,
-		MemShared:     false,
-		Private:       true,
-	}
-	objMemString = "-object memory-backend-file,id=dimm1,size=1G,mem-path=foobar,private=on"
-	numaMemString = "-numa node,memdev=dimm1"
-	memBackendString = "-machine memory-backend=dimm1"
-
-	knobsString = objMemString + " "
-	if isDimmSupported(nil) {
-		knobsString += numaMemString
-	} else {
-		knobsString += memBackendString
-	}
-
-	testConfigAppend(conf, knobs, memString+" "+knobsString, t)
 }
 
 func TestAppendMemoryFileBackedMemPrealloc(t *testing.T) {

src/runtime/virtcontainers/qemu.go

@@ -615,17 +615,6 @@ func (q *qemu) CreateVM(ctx context.Context, id string, network Network, hypervi
 		return err
 	}
 
-	if q.config.ConfidentialGuest {
-		// At this point we're safe to just check for the protection field
-		// on the hypervisor specific code, as availableGuestProtection()
-		// has been called earlier and we know we have the value stored.
-		if q.arch.getProtection() == tdxProtection {
-
-			// TDX relies on ",private=on" passed to the memory object.
-			knobs.Private = true
-		}
-	}
-
 	kernelPath, err := q.config.KernelAssetPath()
 	if err != nil {
 		return err