Commit Graph

11 Commits

Author SHA1 Message Date
Jeremy Fitzhardinge 6aaf5d633b xen: use iret for return from 64b kernel to 32b usermode
If Xen wants to return to a 32b usermode with sysret it must use the
right form.  When using VCGF_in_syscall to trigger this, it looks at
the code segment and does a 32b sysret if it is FLAT_USER_CS32.
However, this is different from __USER32_CS, so it fails to return
properly if we use the normal Linux segment.

So avoid the whole mess by dropping VCGF_in_syscall and simply use
plain iret to return to usermode.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Jan Beulich <jbeulich@novell.com>
Cc: Stable Kernel <stable@kernel.org>
2009-12-03 11:14:54 -08:00
Tejun Heo 130ace11a9 x86: style cleanups for xen assemblies
Make the following style cleanups:

* drop unnecessary //#include from xen-asm_32.S
* compulsive adding of space after comma
* reformat multiline comments

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-05 20:25:41 +01:00
Jeremy Fitzhardinge 5393744b71 xen: make direct versions of irq_enable/disable/save/restore to common code
Now that x86-64 has directly accessible percpu variables, it can also
implement the direct versions of these operations, which operate on a
vcpu_info structure directly embedded in the percpu area.

In fact, the 64-bit versions are more or less identical, and so can be
shared.  The only two differences are:
 1. xen_restore_fl_direct takes its argument in eax on 32-bit, and rdi on 64-bit.
    Unfortunately it isn't possible to directly refer to the 2nd lsb of rdi directly
    (as you can with %ah), so the code isn't quite as dense.
 2. check_events needs to variants to save different registers.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-02-04 16:59:04 -08:00
Brian Gerst 3d1e42a7cf x86-64: Move oldrsp from PDA to per-cpu.
tj: * in asm-offsets_64.c, pda.h inclusion shouldn't be removed as pda
      is still referenced in the file
    * s/oldrsp/old_rsp/

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-19 00:38:58 +09:00
Brian Gerst 9af45651f1 x86-64: Move kernelstack from PDA to per-cpu.
Also clean up PER_CPU_VAR usage in xen-asm_64.S

tj: * remove now unused stack_thread_info()
    * s/kernelstack/kernel_stack/
    * added FIXME comment in xen-asm_64.S

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-19 00:38:58 +09:00
Jeremy Fitzhardinge db053b86f4 xen: clean up x86-64 warnings
There are a couple of Xen features which rely on directly accessing
per-cpu data via a segment register, which is not yet available on
x86-64.  In the meantime, just disable direct access to the vcpu info
structure; this leaves some of the code as dead, but it will come to
life in time, and the warnings are suppressed.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-03 10:04:10 +02:00
Jeremy Fitzhardinge 0d1edf46ba xen: compile irq functions without -pg for ftrace
For some reason I managed to miss a bunch of irq-related functions
which also need to be compiled without -pg when using ftrace.  This
patch moves them into their own file, and starts a cleanup process
I've been meaning to do anyway.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: "Alex Nixon (Intern)" <Alex.Nixon@eu.citrix.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-31 12:39:39 +02:00
Jeremy Fitzhardinge 2dc1697eb3 xen: don't use sysret for sysexit32
When implementing sysexit32, don't let Xen use sysret to return to
userspace.  That results in usermode register state being trashed.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-24 12:28:12 +02:00
Jeremy Fitzhardinge 6fcac6d305 xen64: set up syscall and sysenter entrypoints for 64-bit
We set up entrypoints for syscall and sysenter.  sysenter is only used
for 32-bit compat processes, whereas syscall can be used in by both 32
and 64-bit processes.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 11:05:52 +02:00
Jeremy Fitzhardinge 997409d3d0 xen64: deal with extra words Xen pushes onto exception frames
Xen pushes two extra words containing the values of rcx and r11.  This
pvop hook copies the words back into their appropriate registers, and
cleans them off the stack.  This leaves the stack in native form, so
the normal handler can run unchanged.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 11:02:31 +02:00
Jeremy Fitzhardinge cdacc1278b xen64: add 64-bit assembler
Split xen-asm into 32- and 64-bit files, and implement the 64-bit
variants.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 10:59:09 +02:00