Commit Graph

40 Commits

Author SHA1 Message Date
Michal Hocko 0acf00014b lguest: move process freezing before pending signals check
run_guest tries to freeze the current process after it has handled
pending interrupts and before it calls lguest_arch_run_guest.
This doesn't work nicely if the task has been killed while being frozen
and when we want to handle that signal as soon as possible.
Let's move try_to_freeze before we check for pending signal so that we
can get out of the loop as soon as possible.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-10-27 10:56:18 +10:30
Rusty Russell b56e3215d4 lguest: Allow running under paravirt-enabled KVM.
We actually can run under KVM, as it doesn't paravirtualize anything we
need to use; reduce the check to checking we are the normal ringlevel.

Reported-by: Stefanos Geraggelos <sgerag@cslab.ece.ntua.gr>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au># HG changeset patch
2011-10-27 10:56:17 +10:30
Rusty Russell 9f54288def lguest: update comments
Also removes a long-unused #define and an extraneous semicolon.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-22 14:39:50 +09:30
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Xiao Guangrong 6c189d8312 lguest: cleanup for map_switcher()
We can use alloc_page() instead of get_zeroed_page() and virt_to_page()

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-23 22:26:47 +09:30
Rusty Russell a91d74a3c4 lguest: update commentry
Every so often, after code shuffles, I need to go through and unbitrot
the Lguest Journey (see drivers/lguest/README).  Since we now use RCU in
a simple form in one place I took the opportunity to expand that explanation.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
2009-07-30 16:03:46 +09:30
Rusty Russell 2e04ef7691 lguest: fix comment style
I don't really notice it (except to begrudge the extra vertical
space), but Ingo does.  And he pointed out that one excuse of lguest
is as a teaching tool, it should set a good example.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
2009-07-30 16:03:45 +09:30
Rusty Russell 5dac051bc6 lguest: remove obsolete LHREQ_BREAK call
We no longer need an efficient mechanism to force the Guest back into
host userspace, as each device is serviced without bothering the main
Guest process (aka. the Launcher).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:11 +09:30
Rusty Russell df60aeef4f lguest: use eventfds for device notification
Currently, when a Guest wants to perform I/O it calls LHCALL_NOTIFY with
an address: the main Launcher process returns with this address, and figures
out what device to run.

A far nicer model is to let processes bind an eventfd to an address: if we
find one, we simply signal the eventfd.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Davide Libenzi <davidel@xmailserver.org>
2009-06-12 22:27:10 +09:30
Matias Zabaljauregui ed1dc77810 lguest: map switcher with executable page table entries
Map switcher with executable page table entries.
(This bug didn't matter before PAE and hence NX support -- RR)

Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:06 +09:30
Rusty Russell a32a8813d0 lguest: improve interrupt handling, speed up stream networking
lguest never checked for pending interrupts when enabling interrupts, and
things still worked.  However, it makes a significant difference to TCP
performance, so it's time we fixed it by introducing a pending_irq flag
and checking it on irq_restore and irq_enable.

These two routines are now too big to patch into the 8/10 bytes
patch space, so we drop that code.

Note: The high latency on interrupt delivery had a very curious
effect: once everything else was optimized, networking without GSO was
faster than networking with GSO, since more interrupts were sent and
hence a greater chance of one getting through to the Guest!

Note2: (Almost) Closing the same loophole for iret doesn't have any
measurable effect, so I'm leaving that patch for the moment.

Before:
	1GB tcpblast Guest->Host:		30.7 seconds
	1GB tcpblast Guest->Host (no GSO):	76.0 seconds

After:
	1GB tcpblast Guest->Host:		6.8 seconds
	1GB tcpblast Guest->Host (no GSO):	27.8 seconds

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:03 +09:30
Rusty Russell abd41f037e lguest: fix race in halt code
When the Guest does the LHCALL_HALT hypercall, we go to sleep, expecting
that a timer or the Waker will wake_up_process() us.

But we do it in a stupid way, leaving a classic missing wakeup race.

So split maybe_do_interrupt() into interrupt_pending() and
try_deliver_interrupt(), and check maybe_do_interrupt() and the
"break_out" flag before calling schedule.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:02 +09:30
Matias Zabaljauregui df1693abc4 lguest: use bool instead of int
Impact: clean up

Rusty told me, some time ago, that he had become a fan of "bool".
So, here are some replacements.

Signed-off-by: Matias Zabaljauregui <zabaljauregui at gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-30 21:55:25 +10:30
Atsushi SAKAI 72410af921 lguest: typos fix
3 points

lguest_asm.S => i386_head.S
LHCALL_BREAK => LHREQ_BREAK
perferred    => preferred

Signed-off-by: Atsushi SAKAI <sakaia@jp.fujitsu.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-01-30 11:34:10 +10:30
Johannes Weiner 0a707210aa lguest: fix switcher_page leak on unload
map_switcher allocates the array, unmap_switcher has to free it
accordingly.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29 09:58:32 +10:00
Rusty Russell a6bd8e1303 lguest: comment documentation update.
Took some cycles to re-read the Lguest Journey end-to-end, fix some
rot and tighten some phrases.

Only comments change.  No new jokes, but a couple of recycled old jokes.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-03-28 11:05:54 +11:00
Rusty Russell f14ae652ba lguest: fix __get_vm_area usage.
Robert Bragg's 5dc3318528 tightened
(ie. fixed) the checking in __get_vm_area, and it broke lguest.

lguest should pass the exact "end" it wants, not some random constant
(it was possible previously that it would actually get an address
different from SWITCHER_ADDR).

Also, Fabio Checconi pointed out that we should make sure we're not
hitting the fixmap area.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Robert Bragg <robert@sixbynine.org>
2008-03-11 09:35:56 +11:00
Glauber de Oliveira Costa 382ac6b3fb lguest: get rid of lg variable assignments
We can save some lines of code by getting rid of
*lg = cpu... lines of code spread everywhere by now.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30 22:50:18 +11:00
Glauber de Oliveira Costa 5e232f4f42 lguest: make pending notifications per-vcpu
this patch makes the pending_notify field, used to control
pending notifications, per-vcpu, instead of per-guest

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30 22:50:13 +11:00
Glauber de Oliveira Costa 66686c2ab0 lguest: per-vcpu lguest task management
lguest uses tasks to control its running behaviour (like sending
breaks, controlling halted state, etc). In a per-vcpu environment,
each vcpu will have its own underlying task. So this patch
makes the infrastructure for that possible

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30 22:50:12 +11:00
Glauber de Oliveira Costa 177e449dc5 lguest: per-vcpu interrupt processing.
This patch adapts interrupt processing for using the vcpu struct.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30 22:50:09 +11:00
Glauber de Oliveira Costa 73044f05a4 lguest: make hypercalls use the vcpu struct
this patch changes do_hcall() and do_async_hcall() interfaces (and obviously their
callers) to get a vcpu struct. Again, a vcpu services the hypercall, not the whole
guest

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30 22:50:08 +11:00
Glauber de Oliveira Costa d0953d42c3 lguest: per-cpu run guest
This patch makes the run_guest() routine use the lg_cpu struct.
This is required since in a smp guest environment, there's no
more the notion of "running the guest", but rather, it is "running the vcpu"

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30 22:50:06 +11:00
Balaji Rao ec04b13f67 lguest: Reboot support
Reboot Implemented

(Prevent fd leak, fix style and fix documentation --RR)

Signed-off-by: Balaji Rao <balajirrao@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30 22:50:04 +11:00
Glauber de Oliveira Costa 5c55841d16 lguest: remove pv_info dependency
Currently, lguest module can't be compiled without the PARAVIRT flag being
on. This is a fake dependency, since the module itself shouldn't need any
paravirt override. Reason for that is the reference to pv_info structure
in initial loading tests.

This patch removes it in favour of a more generic error message.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30 22:50:03 +11:00
Rusty Russell e1e72965ec lguest: documentation update
Went through the documentation doing typo and content fixes.  This
patch contains only comment and whitespace changes.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-25 15:02:50 +10:00
Rusty Russell 2d37f94a28 generalize lgread_u32/lgwrite_u32.
Jes complains that page table code still uses lgread_u32 even though
it now uses general kernel pte types.  The best thing to do is to
generalize lgread_u32 and lgwrite_u32.

This means we lose the efficiency of getuser().  We could potentially
regain it if we used __copy_from_user instead of copy_from_user, but
I'm not certain that our range check is equivalent to access_ok() on
all platforms.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Jes Sorensen <jes@sgi.com>
2007-10-23 15:49:56 +10:00
Rusty Russell 15045275c3 Remove old lguest I/O infrrasructure.
This patch gets rid of the old lguest host I/O infrastructure and
replaces it with a single hypercall "LHCALL_NOTIFY" which takes an
address.

The main change is the removal of io.c: that mainly did inter-guest
I/O, which virtio doesn't yet support.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23 15:49:55 +10:00
Rusty Russell c18acd73ff Allow guest to specify syscall vector to use.
(Based on Ron Minnich's LGUEST_PLAN9_SYSCALL patch).

This patch allows Guests to specify what system call vector they want,
and we try to reserve it.  We only allow one non-Linux system call
vector, to try to avoid DoS on the Host.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23 15:49:53 +10:00
Rusty Russell cc6d4fbcef Introduce "hcall" pointer to indicate pending hypercall.
Currently we look at the "trapnum" to see if the Guest wants a
hypercall.  But once the hypercall is done we have to reset trapnum to
a bogus value, otherwise if we exit to userspace and return, we'd run
the same hypercall twice (that was a nasty bug to find!).

This has two main effects:

1) When Jes's patch changes the hypercall args to be a generic "struct
   hcall_args" we simply change the type of "lg->hcall".  It's set by
   arch code, so if it has to copy args or something it can do so, and
   point "hcall" into lg->arch somewhere.

2) Async hypercalls only get run when an actual hypercall is pending.
   This simplfies the code a little and is a more logical semantic.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23 15:49:52 +10:00
Jes Sorensen 625efab1cd Move i386 part of core.c to x86/core.c.
Separate i386 architecture specific from core.c and move it to
x86/core.c and add x86/lguest.h header file to match.

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23 15:49:51 +10:00
Rusty Russell 48245cc070 Remove fixed limit on number of guests, and lguests array.
Back when we had all the Guest state in the switcher, we had a fixed
array of them.  This is no longer necessary.

If we switch the network code to using random_ether_addr (46 bits is
enough to avoid clashes), we can get rid of the concept of "guest id"
altogether.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23 15:49:51 +10:00
Rusty Russell 3c6b5bfa3c Introduce guest mem offset, static link example launcher
In order to avoid problematic special linking of the Launcher, we give
the Host an offset: this means we can use any memory region in the
Launcher as Guest memory rather than insisting on mmap() at 0.

The result is quite pleasing: a number of casts are replaced with
simple additions.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23 15:49:50 +10:00
Jeremy Fitzhardinge 93b1eab3d2 paravirt: refactor struct paravirt_ops into smaller pv_*_ops
This patch refactors the paravirt_ops structure into groups of
functionally related ops:

pv_info - random info, rather than function entrypoints
pv_init_ops - functions used at boot time (some for module_init too)
pv_misc_ops - lazy mode, which didn't fit well anywhere else
pv_time_ops - time-related functions
pv_cpu_ops - various privileged instruction ops
pv_irq_ops - operations for managing interrupt state
pv_apic_ops - APIC operations
pv_mmu_ops - operations for managing pagetables

There are several motivations for this:

1. Some of these ops will be general to all x86, and some will be
   i386/x86-64 specific.  This makes it easier to share common stuff
   while allowing separate implementations where needed.

2. At the moment we must export all of paravirt_ops, but modules only
   need selected parts of it.  This allows us to export on a case by case
   basis (and also choose which export license we want to apply).

3. Functional groupings make things a bit more readable.

Struct paravirt_ops is now only used as a template to generate
patch-site identifiers, and to extract function pointers for inserting
into jmp/calls when patching.  It is only instantiated when needed.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Cc: Zach Amsden <zach@vmware.com>
Cc: Avi Kivity <avi@qumranet.com>
Cc: Anthony Liguory <aliguori@us.ibm.com>
Cc: "Glauber de Oliveira Costa" <glommer@gmail.com>
Cc: Jun Nakajima <jun.nakajima@intel.com>
2007-10-16 11:51:29 -07:00
Rusty Russell 0d027c01cd lguest: Fix Malicious Guest GDT Host Crash
If a Guest makes hypercall which sets a GDT entry to not present, we
currently set any segment registers using that GDT entry to 0.
Unfortunately, this is not sufficient: there are other ways of
altering GDT entries which will cause a fault.

The correct solution to do what Linux does: let them set any GDT value
they want and handle the #GP when popping causes a fault.  This has
the added benefit of making our Switcher slightly more robust in the
case of any other bugs which cause it to fault.

We kill the Guest if it causes a fault in the Switcher: it's the
Guest's responsibility to make sure it's not using segments when it
changes them.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-09 08:14:56 -07:00
Rusty Russell f8f0fdcd40 lguest: documentation VI: Switcher
Documentation: The Switcher

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26 11:35:17 -07:00
Rusty Russell bff672e630 lguest: documentation V: Host
Documentation: The Host

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26 11:35:17 -07:00
Rusty Russell dde797899a lguest: documentation IV: Launcher
Documentation: The Launcher

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26 11:35:17 -07:00
Rusty Russell f938d2c892 lguest: documentation I: Preparation
The netfilter code had very good documentation: the Netfilter Hacking HOWTO.
Noone ever read it.

So this time I'm trying something different, using a bit of Knuthiness.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26 11:35:16 -07:00
Rusty Russell d7e28ffe6c lguest: the host code
This is the code for the "lg.ko" module, which allows lguest guests to
be launched.

[akpm@linux-foundation.org: update for futex-new-private-futexes]
[akpm@linux-foundation.org: build fix]
[jmorris@namei.org: lguest: use hrtimers]
[akpm@linux-foundation.org: x86_64 build fix]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:52 -07:00