1) This allows us to get alot closer to booting bzImages.
2) It means we don't have to know page_offset.
3) The Guest needs to modify the boot pagetables to create the
PAGE_OFFSET mapping before jumping to C code.
4) guest_pa() walks the page tables rather than using page_offset.
5) We don't use page_offset to figure out whether to emulate: it was
always kinda quesationable, and won't work for instructions done
before remapping (bzImage unpacking in particular).
6) We still want the kernel address for tlb flushing: have the initial
hypercall give us that, too.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
(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>
This is my first step in the migration of page_tables.c to the kernel
types and functions/macros (2.6.23-rc3). Seems to be working OK.
Signed-off-by: Matias Zabaljauregui <matias.zabaljauregui@cern.ch>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Move setup_regs() to lguest_arch_setup_regs() in i386_core.c given
that this is very architecture specific.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Clean up the hypercall code to make the code in hypercalls.c
architecture independent. First process the common hypercalls and
then call lguest_arch_do_hcall() if the call hasn't been handled.
Rename struct hcall_ring to hcall_args.
This patch requires the previous patch which reorganize the layout of
struct lguest_regs on i386 so they match the layout of struct
hcall_args.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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>
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>
This simplifies the code a little, in preparation for allowing
alternate system call vectors in guests (Plan 9 uses 0x40).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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>
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>
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>
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>
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>
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>
