[Xen-devel] [PATCH v3 8/8] RFC: Sketch constructors, DomainCreateNew

From: George Dunlap <george.dunlap@citrix.com>
To: <xen-devel@lists.xenproject.org>
Cc: Nick Rosbrook <rosbrookn@ainfosec.com>,
	George Dunlap <george.dunlap@citrix.com>
Subject: [Xen-devel] [PATCH v3 8/8] RFC: Sketch constructors, DomainCreateNew
Date: Fri, 17 Jan 2020 15:57:34 +0000	[thread overview]
Message-ID: <20200117155734.1067550-8-george.dunlap@citrix.com> (raw)
In-Reply-To: <20200117155734.1067550-1-george.dunlap@citrix.com>

This is a sketch of functionality suitable for creating a basic
domain, with a disk and a vif.  DomainConfig, DeviceDisk, and
DeviceNic types are all created using constructor functions, which
initialize them with libxl's defaults.

DomainCreateNew takes the config and calls without any updates.

Obviously some of these will need to be changed it we switch to
passing references to .toC() rather than passing back by value.

The main purpose of this is to allow testing of creating a hard-coded
domain.

Creating a domain would look like this:

	// type = "pv"
	dconf, err := xl.NewDomainConfig(xl.DomainTypePv)
	if err != nil {
		fmt.Printf("NewDomainConfig: %v\n", err)
		return
	}
	dconf.CInfo.Type = xl.DomainTypePv
	// name = "c6-01"
	dconf.CInfo.Name = "c6-01"
	// vcpus=4
	dconf.BInfo.MaxVcpus = 4
	// memory = "2048"
	dconf.BInfo.MaxMemkb = 2048 * 1024
	dconf.BInfo.TargetMemkb = 2048 * 1024
	// on_crash = 'destroy'
	dconf.OnCrash = xl.ActionOnShutdownDestroy
	// bootloader = "pygrub"
	dconf.BInfo.Bootloader = "pygrub"
	// disk = [ 'vdev=hda,format=raw,target=/images/c6-01.raw']
	{
		disk, err := xl.NewDeviceDisk()
		if err != nil {
			fmt.Printf("NewDeviceDisk: %v\n", err)
			return
		}
		disk.Vdev = "hda"
		//disk.DiskBackend = xl.DiskBackendPhy
		disk.Format = xl.DiskFormatRaw
		disk.Readwrite = 1
		disk.PdevPath = "/images/c6-01.raw"
		dconf.Disks = append(dconf.Disks, *disk)
	}
	// vif = [ 'mac=5a:5b:d6:f1:d6:b4' ]
	{
		vif, err := xl.NewDeviceNic()
		if err != nil {
			fmt.Printf("NewDeviceNic: %v\n", err)
			return
		}
		vif.Mac = xl.Mac{ 0x5a, 0x5b, 0xd6, 0x31, 0xd6, 0xb4 }
		dconf.Nics = append(dconf.Nics, *vif)
	}
	// serial='pty' # HVM only

	did, err := ctx.DomainCreateNew(dconf)

	if err != nil {
		fmt.Printf("Creating domain: %v\n", err)
		return
	}

	fmt.Printf("Domain %s(%d) created successfully", dconf.CInfo.Name, did)


Signed-off-by: George Dunlap <george.dunlap@citrix.com>
---
CC: Nick Rosbrook <rosbrookn@ainfosec.com>
---
 tools/golang/xenlight/xenlight.go | 66 +++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

diff --git a/tools/golang/xenlight/xenlight.go b/tools/golang/xenlight/xenlight.go
index c462e4bb42..5a21a2b9b8 100644
--- a/tools/golang/xenlight/xenlight.go
+++ b/tools/golang/xenlight/xenlight.go
@@ -1113,3 +1113,69 @@ func (Ctx *Context) PrimaryConsoleGetTty(domid uint32) (path string, err error)
 	path = C.GoString(cpath)
 	return
 }
+
+func NewDomainConfig(t DomainType) (*DomainConfig, error) {
+	var cconfig C.libxl_domain_config
+
+	C.libxl_domain_config_init(&cconfig)
+	C.libxl_domain_build_info_init_type(&cconfig.b_info, C.libxl_domain_type(t))
+
+	gconfig := &DomainConfig{}
+	err := gconfig.fromC(&cconfig)
+	if err != nil {
+		return nil, err
+	}
+
+	return gconfig, nil
+}
+
+func NewDeviceDisk() (*DeviceDisk, error) {
+	var ctype C.libxl_device_disk
+
+	C.libxl_device_disk_init(&ctype)
+
+	gtype := &DeviceDisk{}
+	err := gtype.fromC(&ctype)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return gtype, nil
+}
+
+func NewDeviceNic() (*DeviceNic, error) {
+	var ctype C.libxl_device_nic
+
+	C.libxl_device_nic_init(&ctype)
+
+	gtype := &DeviceNic{}
+	err := gtype.fromC(&ctype)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return gtype, nil
+}
+
+// int libxl_domain_create_new(libxl_ctx *ctx, libxl_domain_config *d_config,
+//                             uint32_t *domid,
+//                             const libxl_asyncop_how *ao_how,
+//                             const libxl_asyncprogress_how *aop_console_how)
+func (Ctx *Context) DomainCreateNew(config *DomainConfig) (Domid, error) {
+	var cdomid C.uint32_t
+	var cconfig C.libxl_domain_config
+	err := config.toC(&cconfig)
+	if err != nil {
+		return Domid(0), fmt.Errorf("converting domain config to C: %v", err)
+	}
+	defer C.libxl_domain_config_dispose(&cconfig)
+
+	ret := C.libxl_domain_create_new(Ctx.ctx, &cconfig, &cdomid, nil, nil)
+	if ret != 0 {
+		return Domid(0), Error(ret)
+	}
+
+	return Domid(cdomid), nil
+}
-- 
2.24.1


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