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2007-09-25fix modules oopsing in lguest guestsRusty Russell
The assembly templates for lguest guest patching are in the .init.text section. This means that modules get patched with "cc cc cc cc" or similar junk. 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>
2007-09-12lguest: Fix guest crash when CONFIG_X86_USE_3DNOW=yRusty Russell
One of the very first things lguest_init() does is a memcpy. On Athlon/Duron/K7 or CyrixIII/VIA-C3 or Geode GX/LX, this tries to use MMX. memcpy -> _mmx_memcpy -> kernel_fpu_begin -> clts -> paravirt_ops.clts But we haven't set paravirt_ops.clts yet, so we do the native version and crash. The simplest solution is to use __memcpy. Thanks to Michael Rasenberger for the bug report. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-30Fix lguest page-pinning logic ("lguest: bad stack page 0xc057a000")Rusty Russell
If the stack pointer is 0xc057a000, then the first stack page is at 0xc0579000 (the stack pointer is decremented before use). Not calculating this correctly caused guests with CONFIG_DEBUG_PAGEALLOC=y to be killed with a "bad stack page" message: the initial kernel stack was just proceeding the .smp_locks section which CONFIG_DEBUG_PAGEALLOC marks read-only when freeing. Thanks to Frederik Deweerdt for the bug report! Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-23lguest should depend on CONFIG_FUTEXAlexey Dobriyan
It uses get_futex_key(). Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-11i386: Make patching more robust, fix paravirt issueAndi Kleen
Commit 19d36ccdc34f5ed444f8a6af0cbfdb6790eb1177 "x86: Fix alternatives and kprobes to remap write-protected kernel text" uses code which is being patched for patching. In particular, paravirt_ops does patching in two stages: first it calls paravirt_ops.patch, then it fills any remaining instructions with nop_out(). nop_out calls text_poke() which calls lookup_address() which calls pgd_val() (aka paravirt_ops.pgd_val): that call site is one of the places we patch. If we always do patching as one single call to text_poke(), we only need make sure we're not patching the memcpy in text_poke itself. This means the prototype to paravirt_ops.patch needs to change, to marshal the new code into a buffer rather than patching in place as it does now. It also means all patching goes through text_poke(), which is known to be safe (apply_alternatives is also changed to make a single patch). AK: fix compilation on x86-64 (bad rusty!) AK: fix boot on x86-64 (sigh) AK: merged with other patches Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-11lguest files should explicitly include asm/paravirt.hJes Sorensen
Files using bits from paravirt.h should explicitly include it rather than relying on it being pulled in by something else. Signed-off-by: Jes Sorensen <jes@sgi.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-09lguest: Fix Malicious Guest GDT Host CrashRusty Russell
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>
2007-08-09Fix non-TSC guest clocksource lockupRusty Russell
lguest uses a host-supplied wallclock-based clocksource when the TSC is not reliable. As this is already in nanoseconds, I naively used a multiplier of 1 and a shift of 0. But update_wall_time() in its infinite wisdom decides to adjust the clock a little (where does it think it's getting a more accurate time from?) It will happily tweak the multiplier... to 0, then -1. So the "fix" is to use a shift of 22 like everyone else, and a multiplier of 1 << 22. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-06Enable lguest drivers in KconfigRusty Russell
Lguest drivers need to default to "Y" otherwise they're never selected for new builds. (We don't bother prompting, because they're less than 4k combined, and implied by selecting lguest support). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-29Make lguest compile with CONFIG_BLOCK=n and CONFIG_NET=nRusty Russell
Gabriel C reports lguest doesn't compile with CONFIG_BLOCK=n. Fix this by introducing a config var for the block device, which depends on LGUEST && BLOCK. Do the same for the net driver, rather then depending gratuitously on CONFIG_NET. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Gabriel C <nix.or.die@googlemail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-28Provide timespec to guests rather than jiffies clock.Rusty Russell
A non-periodic clock_event_device and the "jiffies" clock don't mix well: tick_handle_periodic() can go into an infinite loop. Currently lguest guests use the jiffies clock when the TSC is unusable. Instead, make the Host write the current time into the lguest page on every interrupt. This doesn't cost much but is more precise and at least as accurate as the jiffies clock. It also gets rid of the GET_WALLCLOCK hypercall. Also, delay setting sched_clock until our clock is set up, otherwise the early printk timestamps can go backwards (not harmful, just ugly). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-28Fix lguest bzImage loading with CONFIG_RELOCATABLE=yRusty Russell
Jason Yeh sent his crashing .config: bzImages made with CONFIG_RELOCATABLE=y put the relocs where the BSS is expected, and we crash with unusual results such as: lguest: unhandled trap 14 at 0xc0122ae1 (0xa9) Relying on BSS being zero was merely laziness on my part, and unfortunately, lguest doesn't go through the normal startup path (which does this in asm). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26lguest: documentation VII: FIXMEsRusty Russell
Documentation: The FIXMEs 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>
2007-07-26lguest: documentation VI: SwitcherRusty Russell
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>
2007-07-26lguest: documentation V: HostRusty Russell
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>
2007-07-26lguest: documentation IV: LauncherRusty Russell
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>
2007-07-26lguest: documentation III: DriversRusty Russell
Documentation: The Drivers 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>
2007-07-26lguest: documentation II: GuestRusty Russell
Documentation: The Guest 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>
2007-07-26lguest: documentation I: PreparationRusty Russell
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>
2007-07-21clockevents: fix resume logicThomas Gleixner
We need to make sure, that the clockevent devices are resumed, before the tick is resumed. The current resume logic does not guarantee this. Add CLOCK_EVT_MODE_RESUME and call the set mode functions of the clock event devices before resuming the tick / oneshot functionality. Fixup the existing users. Thanks to Nigel Cunningham for tracking down a long standing thinko, which affected the jinxed VAIO. [akpm@linux-foundation.org: xen build fix] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20lguest: override sched_clockRusty Russell
Guests currently use the default scheduler clock: this means they always use jiffies even if TSC is actually available. It doesn't make any noticeable difference here, but it's a better thing to do. Also remove commented-out asm/sched-clock.h from -mm tree. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20lguest: trivial: We now have asm/processor-flags.h, so use it.Rusty Russell
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20lguest: fix sense if IF flag on interrupt injectionRusty Russell
The sense of the IF bit is backwards in the host interrupt handling. This means we always save "IF=1" on the stack when injecting an interrupt. It turns out this is almost always correct (unless the guest is taking a page fault in an interrupt due to an unpopulated vmalloc mapping), so went unnoticed. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20Fix lguest misannotationAl Viro
It's void __user *, not void * __user... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19lguest: the Makefile and KconfigRusty Russell
This is the Kconfig and Makefile to allow lguest to actually be compiled. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19lguest: the host codeRusty Russell
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>
2007-07-19lguest: the guest codeRusty Russell
lguest is a simple hypervisor for Linux on Linux. Unlike kvm it doesn't need VT/SVM hardware. Unlike Xen it's simply "modprobe and go". Unlike both, it's 5000 lines and self-contained. Performance is ok, but not great (-30% on kernel compile). But given its hackability, I expect this to improve, along with the paravirt_ops code which it supplies a complete example for. There's also a 64-bit version being worked on and other craziness. But most of all, lguest is awesome fun! Too much of the kernel is a big ball of hair. lguest is simple enough to dive into and hack, plus has some warts which scream "fork me!". This patch: This is the code and headers required to make an i386 kernel an lguest guest. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>