Commit 0d681009 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest 

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest: (45 commits)
  Use "struct boot_params" in example launcher
  Loading bzImage directly.
  Revert lguest magic and use hook in head.S
  Update lguest documentation to reflect the new virtual block device name.
  generalize lgread_u32/lgwrite_u32.
  Example launcher handle guests not being ready for input
  Update example launcher for virtio
  Lguest support for Virtio
  Remove old lguest I/O infrrasructure.
  Remove old lguest bus and drivers.
  Virtio helper routines for a descriptor ringbuffer implementation
  Module autoprobing support for virtio drivers.
  Virtio console driver
  Block driver using virtio.
  Net driver using virtio
  Virtio interface
  Boot with virtual == physical to get closer to native Linux.
  Allow guest to specify syscall vector to use.
  Rename "cr3" to "gpgdir" to avoid x86-specific naming.
  Pagetables to use normal kernel types
  ...
parents a98ce5c6 43d33b21

Documentation/lguest/Makefile

+3 −23
Original line number Original line Diff line number Diff line 
# This creates the demonstration utility "lguest" which runs a Linux guest.

# This creates the demonstration utility "lguest" which runs a Linux guest.



CFLAGS:=-Wall -Wmissing-declarations -Wmissing-prototypes -O3 -I../../include

# For those people that have a separate object dir, look there for .config

KBUILD_OUTPUT := ../..

ifdef O

  ifeq ("$(origin O)", "command line")

    KBUILD_OUTPUT := $(O)

  endif

endif

# We rely on CONFIG_PAGE_OFFSET to know where to put lguest binary.

include $(KBUILD_OUTPUT)/.config

LGUEST_GUEST_TOP := ($(CONFIG_PAGE_OFFSET) - 0x08000000)



CFLAGS:=-Wall -Wmissing-declarations -Wmissing-prototypes -O3 -Wl,-T,lguest.lds

LDLIBS:=-lz

LDLIBS:=-lz

# Removing this works for some versions of ld.so (eg. Ubuntu Feisty) and

# not others (eg. FC7).

LDFLAGS+=-static

all: lguest.lds lguest





# The linker script on x86 is so complex the only way of creating one

all: lguest

# which will link our binary in the right place is to mangle the

# default one.

lguest.lds:

	$(LD) --verbose | awk '/^==========/ { PRINT=1; next; } /SIZEOF_HEADERS/ { gsub(/0x[0-9A-F]*/, "$(LGUEST_GUEST_TOP)") } { if (PRINT) print $$0; }' > $@





clean:

clean:

	rm -f lguest.lds lguest
 
	rm -f lguest

Documentation/lguest/lguest.c

+882 −747

File changed.

Preview size limit exceeded, changes collapsed.

Documentation/lguest/lguest.txt

+31 −41
Original line number Original line Diff line number Diff line
@@ -6,7 +6,7 @@ Lguest is designed to be a minimal hypervisor for the Linux kernel, for 
Linux developers and users to experiment with virtualization with the

Linux developers and users to experiment with virtualization with the

minimum of complexity.  Nonetheless, it should have sufficient

minimum of complexity.  Nonetheless, it should have sufficient

features to make it useful for specific tasks, and, of course, you are

features to make it useful for specific tasks, and, of course, you are

encouraged to fork and enhance it.

encouraged to fork and enhance it (see drivers/lguest/README).





Features:

Features:
@@ -23,19 +23,30 @@ Developer features: 




Running Lguest:

Running Lguest:





- Lguest runs the same kernel as guest and host.  You can configure

- The easiest way to run lguest is to use same kernel as guest and host.

  them differently, but usually it's easiest not to.

  You can configure them differently, but usually it's easiest not to.





  You will need to configure your kernel with the following options:

  You will need to configure your kernel with the following options:





  CONFIG_HIGHMEM64G=n ("High Memory Support" "64GB")[1]

  "General setup":

  CONFIG_TUN=y/m ("Universal TUN/TAP device driver support")

     "Prompt for development and/or incomplete code/drivers" = Y

  CONFIG_EXPERIMENTAL=y ("Prompt for development and/or incomplete code/drivers")

        (CONFIG_EXPERIMENTAL=y)

  CONFIG_PARAVIRT=y ("Paravirtualization support (EXPERIMENTAL)")



  CONFIG_LGUEST=y/m ("Linux hypervisor example code")

  "Processor type and features":



     "Paravirtualized guest support" = Y

  and I recommend:

        "Lguest guest support" = Y

  CONFIG_HZ=100 ("Timer frequency")[2]

     "High Memory Support" = off/4GB

     "Alignment value to which kernel should be aligned" = 0x100000

        (CONFIG_PARAVIRT=y, CONFIG_LGUEST_GUEST=y, CONFIG_HIGHMEM64G=n and

         CONFIG_PHYSICAL_ALIGN=0x100000)



  "Device Drivers":

     "Network device support"

        "Universal TUN/TAP device driver support" = M/Y

           (CONFIG_TUN=m)

     "Virtualization"

        "Linux hypervisor example code" = M/Y

           (CONFIG_LGUEST=m)





- A tool called "lguest" is available in this directory: type "make"

- A tool called "lguest" is available in this directory: type "make"

  to build it.  If you didn't build your kernel in-tree, use "make

  to build it.  If you didn't build your kernel in-tree, use "make
@@ -51,14 +62,17 @@ Running Lguest: 
	  dd if=/dev/zero of=rootfile bs=1M count=2048

	  dd if=/dev/zero of=rootfile bs=1M count=2048

	  qemu -cdrom image.iso -hda rootfile -net user -net nic -boot d

	  qemu -cdrom image.iso -hda rootfile -net user -net nic -boot d





  Make sure that you install a getty on /dev/hvc0 if you want to log in on the

  console!



- "modprobe lg" if you built it as a module.

- "modprobe lg" if you built it as a module.





- Run an lguest as root:

- Run an lguest as root:





      Documentation/lguest/lguest 64m vmlinux --tunnet=192.168.19.1 --block=rootfile root=/dev/lgba

      Documentation/lguest/lguest 64 vmlinux --tunnet=192.168.19.1 --block=rootfile root=/dev/vda





   Explanation:

   Explanation:

    64m: the amount of memory to use.

    64: the amount of memory to use, in MB.





    vmlinux: the kernel image found in the top of your build directory.  You

    vmlinux: the kernel image found in the top of your build directory.  You

       can also use a standard bzImage.

       can also use a standard bzImage.
@@ -66,10 +80,10 @@ Running Lguest: 
    --tunnet=192.168.19.1: configures a "tap" device for networking with this

    --tunnet=192.168.19.1: configures a "tap" device for networking with this

       IP address.

       IP address.





    --block=rootfile: a file or block device which becomes /dev/lgba

    --block=rootfile: a file or block device which becomes /dev/vda

       inside the guest.

       inside the guest.





    root=/dev/lgba: this (and anything else on the command line) are

    root=/dev/vda: this (and anything else on the command line) are

       kernel boot parameters.

       kernel boot parameters.





- Configuring networking.  I usually have the host masquerade, using

- Configuring networking.  I usually have the host masquerade, using
@@ -99,31 +113,7 @@ Running Lguest: 
  "--sharenet=<filename>": any two guests using the same file are on

  "--sharenet=<filename>": any two guests using the same file are on

  the same network.  This file is created if it does not exist.

  the same network.  This file is created if it does not exist.





Lguest I/O model:

There is a helpful mailing list at http://ozlabs.org/mailman/listinfo/lguest



Lguest uses a simplified DMA model plus shared memory for I/O.  Guests

can communicate with each other if they share underlying memory

(usually by the lguest program mmaping the same file), but they can

use any non-shared memory to communicate with the lguest process.



Guests can register DMA buffers at any key (must be a valid physical

address) using the LHCALL_BIND_DMA(key, dmabufs, num<<8|irq)

hypercall.  "dmabufs" is the physical address of an array of "num"

"struct lguest_dma": each contains a used_len, and an array of

physical addresses and lengths.  When a transfer occurs, the

"used_len" field of one of the buffers which has used_len 0 will be

set to the length transferred and the irq will fire.





Using an irq value of 0 unbinds the dma buffers.

Good luck!



To send DMA, the LHCALL_SEND_DMA(key, dma_physaddr) hypercall is used,

and the bytes used is written to the used_len field.  This can be 0 if

noone else has bound a DMA buffer to that key or some other error.

DMA buffers bound by the same guest are ignored.



Cheers!

Rusty Russell rusty@rustcorp.com.au.
 
Rusty Russell rusty@rustcorp.com.au.
 


[1] These are on various places on the TODO list, waiting for you to

    get annoyed enough at the limitation to fix it.

[2] Lguest is not yet tickless when idle.  See [1].

arch/i386/Kconfig

+22 −10
Original line number Original line Diff line number Diff line
@@ -227,28 +227,40 @@ config SCHED_NO_NO_OMIT_FRAME_POINTER 
	  If in doubt, say "Y".

	  If in doubt, say "Y".





config PARAVIRT

config PARAVIRT

	bool "Paravirtualization support (EXPERIMENTAL)"

	bool

	depends on EXPERIMENTAL

	depends on !(X86_VISWS || X86_VOYAGER)

	depends on !(X86_VISWS || X86_VOYAGER)

	help

	help

	  Paravirtualization is a way of running multiple instances of

	  This changes the kernel so it can modify itself when it is run

	  Linux on the same machine, under a hypervisor.  This option

	  under a hypervisor, potentially improving performance significantly

	  changes the kernel so it can modify itself when it is run

	  over full virtualization.  However, when run without a hypervisor

	  under a hypervisor, improving performance significantly.

	  the kernel is theoretically slower and slightly larger.

	  However, when run without a hypervisor the kernel is



	  theoretically slower.  If in doubt, say N.

menuconfig PARAVIRT_GUEST

	bool "Paravirtualized guest support"

	help

	  Say Y here to get to see options related to running Linux under

	  various hypervisors.  This option alone does not add any kernel code.



	  If you say N, all options in this submenu will be skipped and disabled.



if PARAVIRT_GUEST





source "arch/x86/xen/Kconfig"

source "arch/x86/xen/Kconfig"





config VMI

config VMI

	bool "VMI Paravirt-ops support"

	bool "VMI Guest support"

	depends on PARAVIRT

	select PARAVIRT

	depends on !(X86_VISWS || X86_VOYAGER)

	help

	help

	  VMI provides a paravirtualized interface to the VMware ESX server

	  VMI provides a paravirtualized interface to the VMware ESX server

	  (it could be used by other hypervisors in theory too, but is not

	  (it could be used by other hypervisors in theory too, but is not

	  at the moment), by linking the kernel to a GPL-ed ROM module

	  at the moment), by linking the kernel to a GPL-ed ROM module

	  provided by the hypervisor.

	  provided by the hypervisor.





source "arch/x86/lguest/Kconfig"



endif



config ACPI_SRAT

config ACPI_SRAT

	bool

	bool

	default y

	default y

arch/i386/Makefile

+3 −0
Original line number Original line Diff line number Diff line
@@ -99,6 +99,9 @@ core-$(CONFIG_X86_ES7000) := arch/x86/mach-es7000/ 
# Xen paravirtualization support

# Xen paravirtualization support

core-$(CONFIG_XEN)		+= arch/x86/xen/

core-$(CONFIG_XEN)		+= arch/x86/xen/





# lguest paravirtualization support

core-$(CONFIG_LGUEST_GUEST)	+= arch/x86/lguest/



# default subarch .h files

# default subarch .h files

mflags-y += -Iinclude/asm-x86/mach-default

mflags-y += -Iinclude/asm-x86/mach-default