kola/qemu: add support for simulating 512e disks

It's come up a few times now that we need to dig into 512e-specific
behaviours (most recently in OCPBUGS-35410). Let's add a knob for this
in the qemu platform just like the one we have for 4Kn.

Author: jlebon

docs/cosa/run.md

@@ -87,6 +87,7 @@ Additional disks CLI arguments support optional flags using the `--add-disk
 
 - `mpath`: enables multipathing for the disk (see below for details).
 - `4k`: sets the disk as 4Kn (4096 physical sector size)
+- `512e`: sets the disk as 512e (4096 physical sector size, 512 logical sector size)
 - `channel=CHANNEL`: set the channel type (e.g. `virtio`, `nvme`, `scsi`)
 - `serial=NAME`: sets the disk serial; this can then be used to customize the
   default `diskN` naming documented above (e.g. `serial=foobar` will make the

mantle/cmd/kola/options.go

@@ -157,6 +157,7 @@ func init() {
 	bv(&kola.QEMUOptions.NbdDisk, "qemu-nbd-socket", false, "Present the disks over NBD socket to qemu")
 	bv(&kola.QEMUOptions.MultiPathDisk, "qemu-multipath", false, "Enable multiple paths for the main disk")
 	bv(&kola.QEMUOptions.Native4k, "qemu-native-4k", false, "Force 4k sectors for main disk")
+	bv(&kola.QEMUOptions.Disk512e, "qemu-512e", false, "Force 512e layout for main disk")
 	bv(&kola.QEMUOptions.Nvme, "qemu-nvme", false, "Use NVMe for main disk")
 	bv(&kola.QEMUOptions.Swtpm, "qemu-swtpm", true, "Create temporary software TPM")
 	ssv(&kola.QEMUOptions.BindRO, "qemu-bind-ro", nil, "Inject a host directory; this does not automatically mount in the guest")

mantle/cmd/kola/qemuexec.go

@@ -139,8 +139,12 @@ func buildDiskFromOptions() *platform.Disk {
 		channel = "nvme"
 	}
 	sectorSize := 0
+	logicalSectorSize := 0
 	if kola.QEMUOptions.Native4k {
 		sectorSize = 4096
+	} else if kola.QEMUOptions.Disk512e {
+		sectorSize = 4096
+		logicalSectorSize = 512
 	}
 	options := []string{}
 	if kola.QEMUOptions.DriveOpts != "" {
@@ -155,13 +159,14 @@ func buildDiskFromOptions() *platform.Disk {
 	// Build the disk definition. Note that if kola.QEMUOptions.DiskImage is
 	// "" we'll just end up with a blank disk image, which is what we want.
 	disk := &platform.Disk{
-		BackingFile:   kola.QEMUOptions.DiskImage,
-		Channel:       channel,
-		Size:          size,
-		SectorSize:    sectorSize,
-		DriveOpts:     options,
-		MultiPathDisk: kola.QEMUOptions.MultiPathDisk,
-		NbdDisk:       kola.QEMUOptions.NbdDisk,
+		BackingFile:       kola.QEMUOptions.DiskImage,
+		Channel:           channel,
+		Size:              size,
+		SectorSize:        sectorSize,
+		LogicalSectorSize: logicalSectorSize,
+		DriveOpts:         options,
+		MultiPathDisk:     kola.QEMUOptions.MultiPathDisk,
+		NbdDisk:           kola.QEMUOptions.NbdDisk,
 	}
 	return disk
 }

mantle/platform/machine/qemu/cluster.go

@@ -145,8 +145,12 @@ func (qc *Cluster) NewMachineWithQemuOptions(userdata *conf.UserData, options pl
 		channel = "nvme"
 	}
 	sectorSize := 0
+	logicalSectorSize := 0
 	if qc.flight.opts.Native4k {
 		sectorSize = 4096
+	} else if qc.flight.opts.Disk512e {
+		sectorSize = 4096
+		logicalSectorSize = 512
 	}
 	multiPathDisk := options.MultiPathDisk || qc.flight.opts.MultiPathDisk
 	var diskSize string
@@ -156,11 +160,12 @@ func (qc *Cluster) NewMachineWithQemuOptions(userdata *conf.UserData, options pl
 		diskSize = qc.flight.opts.DiskSize
 	}
 	primaryDisk := platform.Disk{
-		BackingFile:   qc.flight.opts.DiskImage,
-		Channel:       channel,
-		Size:          diskSize,
-		SectorSize:    sectorSize,
-		MultiPathDisk: multiPathDisk,
+		BackingFile:       qc.flight.opts.DiskImage,
+		Channel:           channel,
+		Size:              diskSize,
+		SectorSize:        sectorSize,
+		LogicalSectorSize: logicalSectorSize,
+		MultiPathDisk:     multiPathDisk,
 	}
 
 	if options.OverrideBackingFile != "" {

mantle/platform/machine/qemu/flight.go

@@ -41,6 +41,7 @@ type Options struct {
 	NbdDisk       bool
 	MultiPathDisk bool
 	Native4k      bool
+	Disk512e      bool
 	Nvme          bool
 
 	//Option to create a temporary software TPM - true by default

mantle/platform/qemu.go

@@ -89,16 +89,17 @@ type QEMUMachine interface {
 
 // Disk holds the details of a virtual disk.
 type Disk struct {
-	Size          string   // disk image size in bytes, optional suffixes "K", "M", "G", "T" allowed.
-	BackingFile   string   // raw disk image to use.
-	BackingFormat string   // qcow2, raw, etc.  If unspecified will be autodetected.
-	Channel       string   // virtio (default), nvme, scsi
-	DeviceOpts    []string // extra options to pass to qemu -device. "serial=XXXX" makes disks show up as /dev/disk/by-id/virtio-<serial>
-	DriveOpts     []string // extra options to pass to -drive
-	SectorSize    int      // if not 0, override disk sector size
-	NbdDisk       bool     // if true, the disks should be presented over nbd:unix socket
-	MultiPathDisk bool     // if true, present multiple paths
-	Wwn           uint64   // Optional World wide name for the SCSI disk. If not set or set to 0, a random one will be generated. Used only with "channel=scsi". Must be an integer
+	Size              string   // disk image size in bytes, optional suffixes "K", "M", "G", "T" allowed.
+	BackingFile       string   // raw disk image to use.
+	BackingFormat     string   // qcow2, raw, etc.  If unspecified will be autodetected.
+	Channel           string   // virtio (default), nvme, scsi
+	DeviceOpts        []string // extra options to pass to qemu -device. "serial=XXXX" makes disks show up as /dev/disk/by-id/virtio-<serial>
+	DriveOpts         []string // extra options to pass to -drive
+	SectorSize        int      // if not 0, override disk sector size
+	LogicalSectorSize int      // if not 0, override disk sector size
+	NbdDisk           bool     // if true, the disks should be presented over nbd:unix socket
+	MultiPathDisk     bool     // if true, present multiple paths
+	Wwn               uint64   // Optional World wide name for the SCSI disk. If not set or set to 0, a random one will be generated. Used only with "channel=scsi". Must be an integer
 
 	attachEndPoint string   // qemuPath to attach to
 	dstFileName    string   // the prepared file
@@ -108,6 +109,7 @@ type Disk struct {
 func ParseDisk(spec string) (*Disk, error) {
 	var channel string
 	sectorSize := 0
+	logicalSectorSize := 0
 	serialOpt := []string{}
 	multipathed := false
 	var wwn uint64
@@ -123,6 +125,9 @@ func ParseDisk(spec string) (*Disk, error) {
 			channel = value
 		case "4k":
 			sectorSize = 4096
+		case "512e":
+			sectorSize = 4096
+			logicalSectorSize = 512
 		case "mpath":
 			multipathed = true
 		case "serial":
@@ -139,12 +144,13 @@ func ParseDisk(spec string) (*Disk, error) {
 	}
 
 	return &Disk{
-		Size:          fmt.Sprintf("%dG", size),
-		Channel:       channel,
-		DeviceOpts:    serialOpt,
-		SectorSize:    sectorSize,
-		MultiPathDisk: multipathed,
-		Wwn:           wwn,
+		Size:              fmt.Sprintf("%dG", size),
+		Channel:           channel,
+		DeviceOpts:        serialOpt,
+		SectorSize:        sectorSize,
+		LogicalSectorSize: logicalSectorSize,
+		MultiPathDisk:     multipathed,
+		Wwn:               wwn,
 	}, nil
 }
 
@@ -1171,7 +1177,11 @@ func (builder *QemuBuilder) addDiskImpl(disk *Disk, primary bool) error {
 		channel = "virtio"
 	}
 	if disk.SectorSize != 0 {
-		diskOpts = append(diskOpts, fmt.Sprintf("physical_block_size=%[1]d,logical_block_size=%[1]d", disk.SectorSize))
+		logical := disk.LogicalSectorSize
+		if logical == 0 {
+			logical = disk.SectorSize
+		}
+		diskOpts = append(diskOpts, fmt.Sprintf("physical_block_size=%d,logical_block_size=%d", disk.SectorSize, logical))
 	}
 	// Primary disk gets bootindex 1, all other disks have unspecified
 	// bootindex, which means lower priority.