The Design and Implementation of the Anykernel and Rump Kernels

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186 SLOC 8000 7000 6000 5000 4000 3000 2000 base threading and synchronization host sockets base misc emulation interrupts and clock synchronization vm remote system calls memory allocation file descriptors misc async i/o time device glue authentication kernel mib atomic ops syscall stubs vm glue tap interface shm interface sockets networking syscalls network buffers routing misc if framework raw networking arp ip ipv6 ipv6 subroutines neighbour disco icmp tcp udp unix domain 1000 0 user kern net SLOC 8000 7000 6000 5000 4000 3000 2000 virtual block device vm glue rump rootfs basic interfaces vfs caches namei fs syscalls buffer priorities vfs subr generic journalling generic file system code vnode pager vm vnode routines FAT tmpfs cd9660 efs (r/o) glue wlan−at−usb autoconf glue rnd attachment raidframe attachment /dev/smb attachment cgd (cryptodisk) attachment scsi−at−umass autoconf glue rump usb host controller device autoconf 802.11 crypto 802.11 input/output 802.11 ioctl 802.11 misc scsi midlayer scsi disk usb umass rnd raidframe1 raidframe2 raidframe3 raidframe4 /dev/smb cgd (cryptodisk) 1000 0 vfs dev implemented extracted Figure 4.1: Source Lines Of Code in rump kernel and selected drivers. The amount of code usable without modification is vastly greater than the amount of support code necessary. A majority of the drivers tested to work in rump kernels is not included in the figure due to the limited space available for presentation. The size difference between rump kernel specific support code and drivers is evident.
187 50 40 kLoC 30 20 10 0 rump Xen UML Alpha AMD64 i386 kLoC Figure 4.2: Lines of code for platform support. All listed platforms with the exception of User Mode Linux (UML) are NetBSD platforms. The figure for UML was measured from the Linux kernel sources. To get another perspective on the amount of code, the total number of lines for code and headers under sys/rump is 16k. This directory not only contains the code implemented for the rump kernel base and factions, but also the drivers implemented for a rump kernel (e.g. the if virt networking interface which was described in Section 3.9.1). Out of the code in sys/rump, 6k lines are autogenerated (system call wrappers alone are 4.5k lines of autogenerated code), leaving 10k lines as implemented code. From the remaining 10k lines, a fifth (2k lines) consists of the rump root file system (Section 3.7) and the USB ugen host controller (Section 3.10). For comparison, we present the amount of code for full kernel support in Figure 4.2. Given that architecture support is commonly developed with the copy-and-modify approach, looking purely at the figure for lines of code does not give a full estimate of implementation effort. For example, normal architectures include the standard MI VM and interface it to the platform with the pmap module. In contrast, in a rump kernel we provide a partial rewrite for the MI VM interfaces. However, these comparisons give us a rough idea of how much code is required.
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Department of Computer Science and
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9 Preface Meet the new boss Same as
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11 Then there is my dear Xi, who, s
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14 2.3.3 InterruptsandPreemption...
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16 4.1.1 Implementation Effort ....
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18 Appendix C Patches to the 5.99.4
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20 ISA LGPL LRU LWP MD MI MMU NIC O
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23 List of Figures 2.1 Rumpkernelhi
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25 4.14 Time to execute 5M system c
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29 1 Introduction In its classic ro
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31 and application-level drivers. T
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33 We define an anykernel to be an
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35 Our implementation supports rump
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37 The project was done in small in
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39 2 The Anykernel and Rump Kernels
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41 building on top of the entities
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43 Drivers in a rump kernel remain
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45 Figure 2.1: Rump k
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47 in Section 3.2.3. Whenever discu
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49 int rumpns_bpfopen(dev_t, int, i
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51 Figure 2.4:
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53 while the application logic stil
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55 We must solve the lack of a rump
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57 2.3.1 Kernel threads Up until no
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59 void * pool_cache_get_paddr(pool
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61 2.3.4 An Example We present an e
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63 Figure 2.6: Prov
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65 The straightforward use of exist
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68 We identified three obstacles fo
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70 for loadable kernel modules (dis
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72 e.g. the routine for mapping a p
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74 3.2.1 C Symbol Namespaces In the
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76 the double underscore namespace
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78 since the representation might n
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80 The following rumpuser interface
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82 The entry point rump_schedule()
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84 3.3.1 CPU Scheduling Recall from
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86 The fastpath is taken in cases w
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88 Releasing a CPU requires the fol
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90 10 8 seconds 6 4 2 0 1CPU 2CPU n
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92 Hardware interrupt handlers are
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94 Due to the design choice that a
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96 in. Therefore, we should critica
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98 Pager window create+access time
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100 A rump kernel can be configured
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102 Since all pages managed by the
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104 not in control of thread schedu
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106 synchronization part of the alg
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108 /* * Run a cross call to cycle
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110 kernel needs to do is make sure
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112 The kernel with uniprocessor lo
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114 the header file while open() c
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116 The same wrapper works both for
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118 5. Some calling conventions (e.
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120 int rump_pub_lwproc_rfork(int a
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122 By convention, file system devi
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124 ule directory tree from /stand
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126 After these steps have been per
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128 Host Dynamic Linker Using the h
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130 for (i = 0; i < SYS_NSYSENT; i+
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132 into a rump kernel and the driv
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134 sys/arch/x86/include/cpu.h: #de
Page 138 and 139: 136 3.8.4 Rump Component Init Routi
Page 140 and 141: 138 RUMP_COMPONENT(RUMP_COMPONENT_N
Page 142 and 143: 140 We have three distinct cases we
Page 144 and 145: 142 # ifconfig tap0 create # ifconf
Page 146 and 147: 144 Unprivileged use of host’s ne
Page 148 and 149: 146 DOMAIN_DEFINE(sockindomain); co
Page 150 and 151: 148 issue another write before the
Page 152 and 153: 150 using an interface called USBDI
Page 154 and 155: 152 The kernel device configuration
Page 156 and 157: 154 # $NetBSD: UMASS.ioconf,v 1.4 2
Page 158 and 159: 156 USB Host Controller Hub0 (root)
Page 160 and 161: 158 Figure 3.30: File s
Page 162 and 163: 160 in-kernel mount: /dev/sd0e /m/u
Page 164 and 165: 162 structure being created by rump
Page 166 and 167: 164 3.12.1 Client-Kernel Locators B
Page 168 and 169: 166 A tmpfs server listening on INA
Page 170 and 171: 168 Request Arguments Response Desc
Page 172 and 173: 170 Host syscall rump syscall 1. op
Page 174 and 175: 172 A client’s initial connection
Page 176 and 177: 174 their system calls to a rump ke
Page 178 and 179: 176 stdin/stdout, the new file desc
Page 180 and 181: 178 Supporting fork() Recall, the f
Page 182 and 183: 180 As with fork, most of the kerne
Page 184 and 185: 182 Anecdotal analysis For several
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Page 190 and 191: 188 Total commits to the kernel 9,6
Page 192 and 193: 190 120 build time (minutes) 100 80
Page 194 and 195: 192 4.2.2 makefs For a source tree
Page 196 and 197: 194 not include later debugging [76
Page 198 and 199: 196 the necessary tools such as mak
Page 200 and 201: 198 proach of supplying alternate c
Page 202 and 203: 200 are not out-of-the-box compatib
Page 204 and 205: 202 golem> mount -t msdos -o rump /
Page 206 and 207: 204 Full OS By a full OS we mean a
Page 208 and 209: 206 • Rapid prototyping: One of t
Page 210 and 211: 208 4.5.3 Testing: Case Studies We
Page 212 and 213: 210 static void scsitest_request(st
Page 214 and 215: 212 waits for the timeout and check
Page 216 and 217: 214 • We noticed that even in sup
Page 218 and 219: 216 which were discovered during wr
Page 220 and 221: 218 version swap no swap NetBSD 5.1
Page 222 and 223: 220 It needs to be stressed that Ta
Page 224 and 225: 222 Network clusters Bootstrapping
Page 226 and 227: 224 8 7 Standard components Self-co
Page 228 and 229: 226 Rump kernel calls, as expected,
Page 230 and 231: 228 Traditional FFS We measure the
Page 232 and 233: 230 80 70 60 seconds 50 40 30 20 10
Page 234 and 235: 232 The results are presented in Fi
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236
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238 Rialto [29] is an operating sys
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240 One argument for partitioned op
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242 View OS The View OS [37] approa
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244 OSKit Instead of making system
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246 discussing the type incompatibi
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248 difference to the abovementione
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250 At runtime, a rump kernel can a
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252 For testing and development we
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254
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256 Art of Virtualization. In: Proc
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258 [30] Adam Dunkels. 2001. Design
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260 [47] Galen C. Hunt and James R.
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262 [67] Steven McCanne and Van Jac
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264 [87] NetBSD Project. URL http:/
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266 of the 6th Workshop on Programm
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268
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A-2 RUMP.DHCPCLIENT(1) NetBSD Gener
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A-4 RUMP.HALT(1) NetBSD General Com
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A-6 RUMP_SERVER(1) NetBSD General C
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A-8 RUMP_SERVER(1) NetBSD General C
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A-10 SHMIF_DUMPBUS(1) NetBSD Genera
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A-12 P2K(3) NetBSD Library Function
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A-14 P2K(3) NetBSD Library Function
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A-16 RUMP(3) NetBSD Library Functio
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A-18 RUMP(3) NetBSD Library Functio
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A-20 RUMP_ETFS(3) NetBSD Library Fu
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A-22 RUMP_ETFS(3) NetBSD Library Fu
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A-24 RUMP_LWPROC(3) NetBSD Library
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A-26 RUMP_LWPROC(3) NetBSD Library
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A-28 RUMPCLIENT(3) NetBSD Library F
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A-30 RUMPCLIENT(3) NetBSD Library F
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A-32 RUMPHIJACK(3) NetBSD Library F
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A-38 UKFS(3) NetBSD Library Functio
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A-48 SHMIF(4) NetBSD Kernel Interfa
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A-50 RUMP_SP(7) NetBSD Miscellaneou
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A-52 RUMP_SP(7) NetBSD Miscellaneou
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B-2 TCP connections use standard TC
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B-4 rump clients. This means that j
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B-6 ponents. That can be done simpl
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B-8 Our goal is to add another part
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B-10 golem> export RUMP_SERVER=unix
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B-12 golem> rump.dd if=/dev/rcgd0d
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B-14 demogorgon# cgdconfig cgd0 /de
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B-16 rump_server -lrumpnet -lrumpne
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B-18 golem> rump.ifconfig virt0 cre
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B-20 Congratulations, that’s it.
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B-22 purely in userspace, it does n
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B-24 We then proceed to create a mo
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B-26 Then, the only thing left is t
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B-28 -d key=/dk,hostpath=${NFSX}/ff
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B-30 configuration. golem> sh rumpn
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B-32
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C-2 This is a quick fix for making
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C-4 This fixes the conditionally co
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Aalto-DD 171/2012 9HSTFMG*aejbgi+ I
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