If an E820 region is entirely beyond mem_end, don't attempt to truncate
it and add the truncated pages to extra_pages, as they will be negative.
Also, make sure the extra memory region starts after all BIOS provided
E820 regions (and in the case of RAM regions, post-clipping).
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Keep xen_max_p2m_pfn up to date with the end of the extra memory
we're adding. It is possible that it will be too high since memory
may be truncated by a "mem=" option on the kernel command line, but
that won't matter.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
If extra memory is very much larger than the base memory size
then all of the base memory can be filled with structures reserved to
describe the extra memory, leaving no space for anything else.
Even at the maximum ratio there will be little space for anything else,
but this change is intended to at least allow the system to boot rather
than crash mysteriously.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
If an entire E820 RAM region is beyond mem_end, still add its
pages to the extra area so that space can be used by the kernel.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
If Xen gives us non-RAM E820 entries (dom0 only, typically), then
make sure the extra RAM region is beyond them. It's OK for
the extra space to grow into E820 regions, however.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
When using the e820 map to get the initial pseudo-physical address space,
look for either Xen-provided memory which doesn't lie within an E820
region, or an E820 RAM region which extends beyond the Xen-provided
memory range.
Count these pages, and add them to a new "extra memory" range. This range
has an E820 RAM range to describe it - so the kernel will allocate page
structures for it - but it is also marked reserved so that the kernel
will not attempt to use it.
The balloon driver can then add this range as a set of currently
ballooned-out pages, which can be used to extend the domain beyond its
original size.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Rather than simply using a flat memory map from Xen, use its provided
E820 map. This allows the domain builder to tell the domain to reserve
space for more pages than those initially provided at domain-build time.
It also allows the host to specify holes in the address space (for
PCI-passthrough, for example).
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Register a panic notifier so that when the guest crashes it can shut
down the domain and indicate it was a crash to the host.
Signed-off-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Scan the set of pages we're freeing and make sure they're actually
owned by the domain before freeing. This generally won't happen on a
domU (since Xen gives us contigious memory), but it could happen if
there are some hardware mappings passed through.
We only bother going up to the highest page Xen actually claimed to
give us, since there's definitely nothing of ours above that.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Scan an e820 table and release any memory which lies between e820 entries,
as it won't be used and would just be wasted. At present this is just to
release any memory beyond the end of the e820 map, but it will also deal
with holes being punched in the map.
Derived from patch by Miroslav Rezanina <mrezanin@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Use reserve_early rather than e820 reservations for Xen start info and mfn->pfn
table, so that the memory use is a bit more self-documenting.
[ Impact: cleanup ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4A032EF1.6070708@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
PFN_PHYS() can truncate large addresses unless its passed a suitable
large type. This is fixed more generally in the patch series
introducing phys_addr_t, but we need a short-term fix to solve a
Xen regression reported by Roberto De Ioris.
Reported-by: Roberto De Ioris <roberto@unbit.it>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now that the vdso32 code can cope with both syscall and sysenter
missing for 32-bit compat processes, just disable the features without
disabling vdso altogether.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
AMD only supports "syscall" from 32-bit compat usermode.
Intel and Centaur(?) only support "sysenter" from 32-bit compat usermode.
Set the X86 feature bits accordingly, and set up the vdso in
accordance with those bits. On the offchance we run on in a 64-bit
environment which supports neither syscall nor sysenter from 32-bit
mode, then fall back to the int $0x80 vdso.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
fix:
arch/x86/xen/built-in.o: In function `xen_enable_syscall':
(.cpuinit.text+0xdb): undefined reference to `sysctl_vsyscall32'
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Old versions of Xen (3.1 and before) don't support sysenter or syscall
from 32-bit compat userspaces. If we can't set the appropriate
syscall callback, then disable the corresponding feature bit, which
will cause the vdso32 setup to fall back appropriately.
Linux assumes that syscall is always available to 32-bit userspace,
and installs it by default if sysenter isn't available. In that case,
we just disable vdso altogether, forcing userspace libc to fall back
to int $0x80.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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>
Use callback_op hypercall to register callbacks in a 32/64-bit
independent way (64-bit doesn't need a code segment, but that detail
is hidden in XEN_CALLBACK).
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>
A number of random changes to make xen/smp.c compile in 64-bit mode.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>a
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>
[ TODO: release the underlying memory back to Xen. ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: the arch/x86 maintainers <x86@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
rename update_memory_range to e820_update_range
rename add_memory_region to e820_add_region
to make it more clear that they are about e820 map operations.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add a config option to set the max size of a Xen domain. This is used
to scale the size of the physical-to-machine array; it ends up using
around 1 page/GByte, so there's no reason to be very restrictive.
For a 32-bit guest, the default value of 8GB is probably sufficient;
there's not much point in giving a 32-bit machine much more memory
than that.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We now support the use of memory hotplug, so the physical to machine
page mapping structure must be dynamic. This is implemented as a
two-level radix tree structure, which allows us to efficiently
incrementally allocate memory for the p2m table as new pages are
added.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
64-bit Xen supports sysenter for 32-bit guests, so support its
use. (sysenter is faster than int $0x80 in 32-on-64.)
sysexit is still not supported, so we fake it up using iret.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Construct Xen guest e820 map with a hole between 640K-1M.
It's pure luck that Xen kernels have gotten away with it in the past.
The patch below seems like the right thing to do. It certainly boots in
a domU without the DMI problem (without any of the other related patches
such as Alexander's).
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Tested-by: Mark McLoughlin <markmc@redhat.com>
Acked-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
additional section for .init.text appending a number.
A side effect of this was a section mismatch warning because modpost did
not recognize a .init.text section named .init.text.1: WARNING:
vmlinux.o(.text.head+0x247): Section mismatch: reference to
.init.text.1:start_kernel (between 'is386' and 'check_x87')
Fix this by hardcoding the "ax" in the pushsection. Thanks to Torlaf for
reporting this.
Alan Modra provided the hint that made me able to locate the root cause of
this warning. And Mike Frysinger told me how to properly fix it using
__INIT/__FINIT.
Fix following Section mismatch warning in addition:
WARNING: vmlinux.o(.text+0x14c8): Section mismatch: reference to .init.data:vsyscall_int80_start (between 'fiddle_vdso' and 'xen_setup_features')
fiddle_vdso was only used from a __init function - so declare it __init.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This makes x86_64's ia32 emulation support share the sources used in the
32-bit kernel for the 32-bit vDSO and much of its setup code.
The 32-bit vDSO mapping now behaves the same on x86_64 as on native 32-bit.
The abi.syscall32 sysctl on x86_64 now takes the same values that
vm.vdso_enabled takes on the 32-bit kernel. That is, 1 means a randomized
vDSO location, 2 means the fixed old address. The CONFIG_COMPAT_VDSO
option is now available to make this the default setting, the same meaning
it has for the 32-bit kernel. (This does not affect the 64-bit vDSO.)
The argument vdso32=[012] can be used on both 32-bit and 64-bit kernels to
set this paramter at boot time. The vdso=[012] argument still does this
same thing on the 32-bit kernel.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This makes the i386 kernel use the new vDSO build in arch/x86/vdso/vdso32/
to replace the old one from arch/x86/kernel/.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
