kernel_optimize_test/drivers
Avi Kivity 6aa8b732ca [PATCH] kvm: userspace interface
web site: http://kvm.sourceforge.net

mailing list: kvm-devel@lists.sourceforge.net
  (http://lists.sourceforge.net/lists/listinfo/kvm-devel)

The following patchset adds a driver for Intel's hardware virtualization
extensions to the x86 architecture.  The driver adds a character device
(/dev/kvm) that exposes the virtualization capabilities to userspace.  Using
this driver, a process can run a virtual machine (a "guest") in a fully
virtualized PC containing its own virtual hard disks, network adapters, and
display.

Using this driver, one can start multiple virtual machines on a host.

Each virtual machine is a process on the host; a virtual cpu is a thread in
that process.  kill(1), nice(1), top(1) work as expected.  In effect, the
driver adds a third execution mode to the existing two: we now have kernel
mode, user mode, and guest mode.  Guest mode has its own address space mapping
guest physical memory (which is accessible to user mode by mmap()ing
/dev/kvm).  Guest mode has no access to any I/O devices; any such access is
intercepted and directed to user mode for emulation.

The driver supports i386 and x86_64 hosts and guests.  All combinations are
allowed except x86_64 guest on i386 host.  For i386 guests and hosts, both pae
and non-pae paging modes are supported.

SMP hosts and UP guests are supported.  At the moment only Intel
hardware is supported, but AMD virtualization support is being worked on.

Performance currently is non-stellar due to the naive implementation of the
mmu virtualization, which throws away most of the shadow page table entries
every context switch.  We plan to address this in two ways:

- cache shadow page tables across tlb flushes
- wait until AMD and Intel release processors with nested page tables

Currently a virtual desktop is responsive but consumes a lot of CPU.  Under
Windows I tried playing pinball and watching a few flash movies; with a recent
CPU one can hardly feel the virtualization.  Linux/X is slower, probably due
to X being in a separate process.

In addition to the driver, you need a slightly modified qemu to provide I/O
device emulation and the BIOS.

Caveats (akpm: might no longer be true):

- The Windows install currently bluescreens due to a problem with the
  virtual APIC.  We are working on a fix.  A temporary workaround is to
  use an existing image or install through qemu
- Windows 64-bit does not work.  That's also true for qemu, so it's
  probably a problem with the device model.

[bero@arklinux.org: build fix]
[simon.kagstrom@bth.se: build fix, other fixes]
[uril@qumranet.com: KVM: Expose interrupt bitmap]
[akpm@osdl.org: i386 build fix]
[mingo@elte.hu: i386 fixes]
[rdreier@cisco.com: add log levels to all printks]
[randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings]
[anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support]
Signed-off-by: Yaniv Kamay <yaniv@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Simon Kagstrom <simon.kagstrom@bth.se>
Cc: Bernhard Rosenkraenzer <bero@arklinux.org>
Signed-off-by: Uri Lublin <uril@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Anthony Liguori <anthony@codemonkey.ws>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:57:22 -08:00
..
acorn
acpi
amba
ata [PATCH] libata: Incorrect timing computation for PIO5/6 2006-12-07 07:37:07 -05:00
atm [PATCH] atm/ambassador: use bitrev8 2006-12-08 08:28:40 -08:00
base Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6 2006-12-07 08:59:11 -08:00
block [PATCH] struct path: convert nbd 2006-12-08 08:28:47 -08:00
bluetooth [PATCH] lockdep: annotate bcsp driver 2006-12-07 08:39:34 -08:00
cdrom [PATCH] drivers/cdrom/*: trivial vsnprintf() conversion 2006-12-07 08:39:35 -08:00
char [PATCH] sysctl: remove unused "context" param 2006-12-10 09:55:41 -08:00
clocksource [PATCH] clocksource: small cleanup 2006-12-10 09:57:22 -08:00
connector
cpufreq [PATCH] hotplug CPU: clean up hotcpu_notifier() use 2006-12-07 08:39:39 -08:00
crypto [PATCH] geode crypto is PCI device 2006-12-10 09:55:40 -08:00
dio
dma [PATCH] slab: remove SLAB_KERNEL 2006-12-07 08:39:24 -08:00
edac [PATCH] Add include/linux/freezer.h and move definitions from sched.h 2006-12-07 08:39:27 -08:00
eisa
fc4
firmware
hid [PATCH] Generic HID layer - build 2006-12-08 10:43:20 -08:00
hwmon
i2c [PATCH] struct path: convert i2c-drivers 2006-12-08 08:28:45 -08:00
ide [PATCH] ide-cd: Handle strange interrupt on the Intel ESB2 2006-12-10 09:57:20 -08:00
ieee1394 [PATCH] struct path: convert ieee1394 2006-12-08 08:28:46 -08:00
infiniband [PATCH] LOG2: Implement a general integer log2 facility in the kernel 2006-12-08 08:28:51 -08:00
input [PATCH] ucb1400_ts depends SND_AC97_BUS 2006-12-10 09:55:39 -08:00
isdn [PATCH] Don't build some broken ISDN drivers on big endian MIPS 2006-12-10 09:55:42 -08:00
kvm [PATCH] kvm: userspace interface 2006-12-10 09:57:22 -08:00
leds [PATCH] PCEngines WRAP LED Support 2006-12-07 08:39:36 -08:00
macintosh Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 2006-12-08 01:07:56 -05:00
mca
md [PATCH] md: assorted md and raid1 one-liners 2006-12-10 09:57:21 -08:00
media [PATCH] struct path: convert v4l 2006-12-08 08:28:50 -08:00
message [PATCH] kernel-doc: fix fusion and i2o docs 2006-12-07 08:39:40 -08:00
mfd [PATCH] Add include/linux/freezer.h and move definitions from sched.h 2006-12-07 08:39:27 -08:00
misc [PATCH] tifm: fix NULL ptr and style 2006-12-07 08:39:33 -08:00
mmc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc 2006-12-08 08:47:07 -08:00
mtd [PATCH] slab: remove SLAB_KERNEL 2006-12-07 08:39:24 -08:00
net [PATCH] Amiga PCMCIA NE2000 Ethernet dev->irq init 2006-12-09 09:41:18 -08:00
nubus
oprofile [PATCH] struct path: convert oprofile 2006-12-08 08:28:48 -08:00
parisc
parport [PATCH] Kconfig refactoring for better menu nesting 2006-12-10 09:55:39 -08:00
pci [PATCH] Kconfig refactoring for better menu nesting 2006-12-10 09:55:39 -08:00
pcmcia [PATCH] struct path: convert pcmcia 2006-12-08 08:28:48 -08:00
pnp [PATCH] struct path: convert isapnp 2006-12-08 08:28:46 -08:00
ps3
rapidio
rtc [PATCH] AT91RM9200 RTC 2006-12-10 09:55:40 -08:00
s390 Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6 2006-12-08 11:21:55 -08:00
sbus [PATCH] struct path: convert sbus 2006-12-08 08:28:49 -08:00
scsi [PATCH] Sun3 SCSI: Make sun3 scsi drivers compile/work again 2006-12-09 09:41:18 -08:00
serial [PATCH] Kconfig refactoring for better menu nesting 2006-12-10 09:55:39 -08:00
sh
sn
spi [PATCH] spi: stabilize PIO mode transfers on PXA2xx systems 2006-12-10 09:55:40 -08:00
tc [PATCH] tty: switch to ktermios 2006-12-08 08:28:57 -08:00
telephony [PATCH] struct path: convert ixj 2006-12-08 08:28:46 -08:00
usb [PATCH] Generic HID layer - build 2006-12-08 10:43:20 -08:00
video [PATCH] Fbdev driver for IBM GXT4500P videocards 2006-12-10 09:57:20 -08:00
w1 [PATCH] better CONFIG_W1_SLAVE_DS2433_CRC handling 2006-12-07 08:39:43 -08:00
zorro [PATCH] struct path: convert zorro 2006-12-08 08:28:50 -08:00
Kconfig [PATCH] kvm: userspace interface 2006-12-10 09:57:22 -08:00
Makefile [PATCH] kvm: userspace interface 2006-12-10 09:57:22 -08:00