Xen
: ad
van
tag
es
- sm
all
su
rfa
ce
of atta
ck
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ola
tio
n
- re
sili
en
ce
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ecia
lized
alg
orith
ms (
sch
ed
ule
r)
Xe
n a
nd
th
e L
inu
x k
ern
el
Xen
wa
s in
itia
lly a
un
ivers
ity r
esea
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pro
ject
invasiv
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ha
ng
es to th
e k
ern
el to
ru
n L
inu
x a
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P
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ue
st
eve
n m
ore
ch
ang
es to
ru
n L
inux a
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om
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Xe
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nd
th
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inu
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up
po
rt in
th
e L
inu
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ern
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ot u
pstr
ea
m
Gre
at m
ain
tance
effo
rt o
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Ris
k o
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ibutio
ns d
rop
pin
g X
en
su
ppo
rt
Xe
n a
nd
th
e L
inu
x k
ern
el
- P
V s
up
po
rt w
en
t in
Lin
ux 2
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6
- b
asic
Do
m0
su
pp
ort
wen
t in
Lin
ux 2
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7
- N
etb
ack w
en
t in
Lin
ux 2
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9
- B
lkba
ck w
en
t in
Lin
ux 3
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A s
ing
le 3
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Lin
ux k
ern
el im
ag
e b
oo
ts o
n n
ative,
on
Xe
n a
s d
om
U, a
s d
om
0 a
nd P
V o
n H
VM
gue
st
Xe
n a
nd
Lin
ux d
istr
ibu
tio
ns
2010
- F
ed
ora
an
d U
bun
tu d
rop
pe
d X
en
sup
po
rt fro
m
th
eir L
inux k
ern
els
- D
eb
ian
, S
use
, G
ento
o s
till
pro
vid
e X
en
kern
els
- X
en
Se
rver
we
nt O
pe
n S
ou
rce w
ith
XC
P
Pre
sent
- F
ed
ora
an
d U
bun
tu a
re a
dd
ing
Xe
n s
up
port
b
ack in
ke
rne
l in
the
ne
xt re
lea
se
s
Xen
an
d Q
em
u
- in
itia
lly fo
rked
in
20
05
- u
pd
ate
d o
nce
eve
ry fe
w r
ele
ases
- X
en
su
pp
ort
we
nt in
up
str
ea
m Q
em
u a
t th
e
b
eg
inn
ing
of 2
011
- U
pstr
ea
m Q
em
u is g
oin
g to b
e u
se
d a
s d
evic
e
m
ode
l w
ith
Xe
n 4
.2
Ne
w d
ev
elo
pm
en
ts:
Lib
xen
lig
ht
Mu
ltip
le to
ols
tacks:
- X
en
d, X
api, X
en
VM
, Lib
Virt, …
- co
de
dup
licatio
ns, in
effic
ien
cie
s, b
ug
s, w
aste
d
effo
rts
Xen
d:
- d
ifficu
lt to
un
de
rsta
nd
, m
od
ify a
nd e
xte
nd
- sig
nific
an
t m
em
ory
fo
otp
rint
Lib
xen
lig
ht
Wh
at is
Lib
xe
nlig
ht:
- a
sm
all
low
er
leve
l lib
rary
in C
- sim
ple
to u
nd
ers
tan
d
- e
asy to m
od
ify a
nd
exte
nd
Goa
ls:
- p
rovid
e a
sim
ple
an
d r
obu
st A
PI fo
r to
ols
tacks
- cre
ate
a c
om
mon
cod
eb
ase
to
do
Xe
n
o
pera
tio
ns
XL
- th
e u
nit te
stin
g to
ol fo
r lib
xen
ligh
t
- fe
atu
re c
om
ple
te
- a
min
ima
l to
ols
tack
- co
mp
atib
le w
ith
xm
Do
mo
re w
ith
le
ss!
XL
: d
esig
n p
rin
cip
les
- sm
alle
st p
ossib
le to
ols
tack o
n to
p o
f lib
xe
nlig
ht
- sta
tele
ss C
LI →
XL
→ lib
xe
nlig
ht →
EX
IT
XL
vs. X
en
d
XL: p
ros
- ve
ry s
ma
ll a
nd e
asy to
re
ad
- w
ell
teste
d
- co
mp
atib
le w
ith
xm
Xen
d: p
ros
- p
rovid
e X
ML
RP
C in
terf
ace
- p
rovid
e ”
ma
nag
ed
do
ma
ins”
Lin
ux a
s a
gu
ests
: p
rob
lem
s
Lin
ux P
V g
ue
sts
ha
ve
lim
itatio
ns:
- d
ifficu
lt “
diffe
rent”
to
in
sta
ll
- lim
ite
d s
et of virtu
al h
ard
wa
re
Lin
ux H
VM
gu
ests
:
- in
sta
ll th
e s
am
e w
ay a
s n
ative
- ve
ry s
low
Lin
ux
PV
on
HV
M:
the s
olu
tio
n
- in
sta
ll th
e s
am
e w
ay a
s n
ative
- P
C-lik
e h
ard
wa
re
- a
ccess to fa
st p
ara
virtu
aliz
ed
de
vic
es
- e
xp
loit n
este
d p
ag
ing
Lin
ux P
V o
n H
VM
: in
itia
l fe
ats
Initia
l ve
rsio
n in
Lin
ux 2
.6.3
6:
- in
trod
uce th
e x
en
pla
tform
de
vic
e d
rive
r
- a
dd
su
pp
ort
fo
r H
VM
hyp
erc
alls
, xe
nb
us a
nd
g
ran
t ta
ble
- e
na
ble
s b
lkfr
on
t, n
etf
ron
t an
d P
V t
ime
rs
- a
dd
su
pp
ort
to
PV
su
spe
nd
/re
su
me
- th
e v
ec
tor
callb
ack
me
ch
anis
m
Rec
eiv
ing
an
in
terr
up
t
do_
IRQ ha
nd
le_
faste
oi_
irq
ha
nd
le_irq
_e
ve
nt
xe
n_
evtc
hn
_d
o_
up
ca
ll
ac
k_
ap
ic_
leve
l←
>=
3 V
ME
XIT
Lin
ux
PV
on
HV
M:
new
er
feats
Late
r e
nh
ance
me
nts
(2
.6.3
7+
):
- b
allo
on
ing
- P
V s
pin
locks
- P
V IP
Is
- In
terr
up
t re
ma
pp
ing
onto
even
t ch
an
nels
- M
SI re
ma
ppin
g o
nto
eve
nt ch
an
ne
ls
PV
sp
ectr
um
HV
M g
uests
Cla
ssic
PV
on H
VM
Enhanced
PV
on H
VM
Hybrid P
V
on H
VM
P
V g
uests
Bo
ot
se
quen
ce
em
ula
ted
em
ula
ted
em
ula
ted
para
virtu
aliz
ed
Mem
ory
hard
ware
hard
ware
hard
ware
para
virtu
aliz
ed
Inte
rrupts
em
ula
ted
em
ula
ted
para
virtu
aliz
ed
para
virtu
aliz
ed
Tim
ers
em
ula
ted
em
ula
ted
para
virtu
aliz
ed
para
virtu
aliz
ed
Sp
inlo
cks
em
ula
ted
em
ula
ted
para
virtu
aliz
ed
para
virtu
aliz
ed
Dis
kem
ula
ted
para
virtu
aliz
ed
para
virtu
aliz
ed
para
virtu
aliz
ed
Netw
ork
em
ula
ted
para
virtu
aliz
ed
para
virtu
aliz
ed
para
virtu
aliz
ed
Privile
ged
opera
tio
ns
hard
ware
hard
ware
hard
ware
para
virtu
aliz
ed
Be
nch
mark
s:
the s
etu
p
Ha
rdw
are
se
tup
:
Dell
Pow
erE
dg
e R
710
CP
U: du
al In
tel X
eon E
5520 q
uad
core
CP
Us @
2.2
7G
Hz
RA
M: 22G
B
So
ftw
are
se
tup:
Xen
4.1
, 64 b
itD
om
0 L
inux 2
.6.3
2,
64 b
itD
om
U L
inux 3
.0 r
c4, 8
GB
of m
em
ory
, 8
vcpus
PC
I p
as
sth
rou
gh
: b
en
ch
mark
PC
I p
assth
roug
h o
f a
n I
nte
l G
igab
it N
ICC
PU
usa
ge
: th
e lo
we
r th
e b
ette
r:
inte
rru
pt re
ma
pp
ing
no
in
terr
up
t re
ma
pp
ing
0
20
40
60
80
10
0
12
0
14
0
16
0
18
0
20
0
CP
U u
sa
ge
do
mU
CP
U u
sa
ge
do
m0
Kern
ben
ch
Results:
perc
enta
ge
of n
ative, th
e low
er
the
bett
er
PV
on
HV
M 6
4 b
itP
V o
n H
VM
32
bit
HV
M 6
4 b
itH
VM
32
bit
PV
64
bit
PV
32
bit
90
95
10
0
10
5
11
0
11
5
12
0
12
5
13
0
13
5
14
0
PB
ZIP
2
Resu
lts: pe
rce
nta
ge
of n
ative
, th
e lo
we
r th
e b
ette
r
PV
on
HV
M 6
4 b
itP
V 6
4 b
itP
V o
n H
VM
32
bit
PV
32
bit
10
0
11
0
12
0
13
0
14
0
15
0
16
0
SP
EC
jbb
2005
PV
64
bit
PV
on
HV
M 6
4 b
it0
10
20
30
40
50
60
70
80
90
10
0Re
sults:
perc
enta
ge o
f n
ative,
the
hig
he
r th
e b
ett
er
Iperf
tcp
Resu
lts: gb
it/s
ec,
the h
ighe
r th
e b
ett
er
PV
64
bit
PV
on
HV
M 6
4 b
itP
V o
n H
VM
32
bit
PV
32
bit
HV
M 6
4 b
itH
VM
32
bit
012345678
Co
nclu
sio
ns
PV
on
HV
M g
ue
sts
are
ve
ry c
lose
to
PV
gu
ests
in
be
nch
ma
rks th
at fa
vo
r P
V M
MU
s
PV
on
HV
M g
ue
sts
are
fa
r ah
ea
d o
f P
V g
ue
sts
in
be
nch
ma
rks th
at fa
vo
r n
este
d p
ag
ing