Other than sanity check and debug message, the x86 specific version of
memblock reserve/free functions are simple wrappers around the generic
versions - memblock_reserve/free().

This patch adds debug messages with caller identification to the
generic versions and replaces x86 specific ones and kills them.
arch/x86/include/asm/memblock.h and arch/x86/mm/memblock.c are empty
after this change and removed.
Signed-off-by: NTejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310462166-31469-14-git-send-email-tj@kernel.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The earlier attempts (24bdb0b6)
at fixing this problem caused other problems to surface (PV guests
with no PCI passthrough would have SWIOTLB turned on - which meant
64MB of precious contingous DMA32 memory being eaten up per guest).
The problem was: "on xen we add an extra memory region at the end of
the e820, and on this particular machine this extra memory region
would start below 4g and cross over the 4g boundary:

[0xfee01000-0x192655000)

Unfortunately e820_end_of_low_ram_pfn does not expect an
e820 layout like that so it returns 4g, therefore initial_memory_mapping
will map [0 - 0x100000000), that is a memory range that includes some
reserved memory regions."

The memory range was the IOAPIC regions, and with the 1-1 mapping
turned on, it would map them as RAM, not as MMIO regions. This caused
the hypervisor to complain. Fortunately this is experienced only under
the initial domain so we guard for it.
Acked-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Cleanup code/data sections definitions
accordingly to include/linux/init.h.
Signed-off-by: NDaniel Kiper <dkiper@net-space.pl>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

git commit 24bdb0b6 (xen: do not create
the extra e820 region at an addr lower than 4G) does not take into
account that ifdef CONFIG_X86_32 instead of e820_end_of_low_ram_pfn()
find_low_pfn_range() is called (both calls are from arch/x86/kernel/setup.c).
find_low_pfn_range() behaves correctly and does not require change in
xen_extra_mem_start initialization. Additionally, if xen_extra_mem_start
is initialized in the same way as ifdef CONFIG_X86_64 then memory hotplug
support for Xen balloon driver (under development) is broken.
Signed-off-by: NDaniel Kiper <dkiper@net-space.pl>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

When we parse the raw E820, the Xen hypervisor can set "E820_RAM"
to "E820_UNUSABLE" if the mem=X argument is used. As such we
should _not_ consider the E820_UNUSABLE as an 1-1 identity
mapping, but instead use the same case as for E820_RAM.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Do not add the extra e820 region at a physical address lower than 4G
because it breaks e820_end_of_low_ram_pfn().

It is OK for us to move the xen_extra_mem_start up and down because this
is the index of the memory that can be ballooned in/out - it is memory
not available to the kernel during bootup.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

We walk the E820 region and start at 0 (for PV guests we start
at ISA_END_ADDRESS) and skip any E820 RAM regions. For all other
regions and as well the gaps we set them to be identity mappings.

The reasons we do not want to set the identity mapping from 0->
ISA_END_ADDRESS when running as PV is b/c that the kernel would
try to read DMI information and fail (no permissions to read that).
There is a lot of gnarly code to deal with that weird region so
we won't try to do a cleanup in this patch.

This code ends up calling 'set_phys_to_identity' with the start
and end PFN of the the E820 that are non-RAM or have gaps.
On 99% of machines that means one big region right underneath the
4GB mark. Usually starts at 0xc0000 (or 0x80000) and goes to
0x100000.

[v2: Fix for E820 crossing 1MB region and clamp the start]
[v3: Squshed in code that does this over ranges]
[v4: Moved the comment to the correct spot]
[v5: Use the "raw" E820 from the hypervisor]
[v6: Added Review-by tag]
Reviewed-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

If we have a guest that asked for:

memory=1024
maxmem=2048

Which means we want 1GB now, and create pagetables so that we can expand
up to 2GB, we would have this E820 layout:

[    0.000000] BIOS-provided physical RAM map:
[    0.000000]  Xen: 0000000000000000 - 00000000000a0000 (usable)
[    0.000000]  Xen: 00000000000a0000 - 0000000000100000 (reserved)
[    0.000000]  Xen: 0000000000100000 - 0000000080800000 (usable)

Due to patch: "xen/setup: Inhibit resource API from using System RAM E820 gaps as PCI mem gaps."
we would mark the memory past the 1GB mark as unusuable resulting in:

[    0.000000] BIOS-provided physical RAM map:
[    0.000000]  Xen: 0000000000000000 - 00000000000a0000 (usable)
[    0.000000]  Xen: 00000000000a0000 - 0000000000100000 (reserved)
[    0.000000]  Xen: 0000000000100000 - 0000000040000000 (usable)
[    0.000000]  Xen: 0000000040000000 - 0000000080800000 (unusable)

which meant that we could not balloon up anymore. We could
balloon the guest down. The fix is to run the code introduced
by the above mentioned patch only for the initial domain.

We will have to revisit this once we start introducing a modified
E820 for PCI passthrough so that we can utilize the P2M identity code.

We also fix an overflow by having UL instead of ULL on 32-bit machines.

[v2: Ian pointed to the overflow issue]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

With this patch, we diligently set regions that will be used by the
balloon driver to be INVALID_P2M_ENTRY and under the ownership
of the balloon driver. We are OK using the __set_phys_to_machine
as we do not expect to be allocating any P2M middle or entries pages.
The set_phys_to_machine has the side-effect of potentially allocating
new pages and we do not want that at this stage.

We can do this because xen_build_mfn_list_list will have already
allocated all such pages up to xen_max_p2m_pfn.

We also move the check for auto translated physmap down the
stack so it is present in __set_phys_to_machine.

[v2: Rebased with mmu->p2m code split]
Reviewed-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

With the hypervisor argument of dom0_mem=X we iterate over the physical
(only for the initial domain) E820 and subtract the the size from each
E820_RAM region the delta so that the cumulative size of all E820_RAM regions
is equal to 'X'. This sometimes ends up with E820_RAM regions with zero size
(which are removed by e820_sanitize) and E820_RAM that are smaller
than physically.

Later on the PCI API looks at the E820 and attempts to set up an
resource region for the "PCI mem". The E820 (assume dom0_mem=1GB is
set) compared to the physical looks as so:

 [    0.000000] BIOS-provided physical RAM map:
 [    0.000000]  Xen: 0000000000000000 - 0000000000097c00 (usable)
 [    0.000000]  Xen: 0000000000097c00 - 0000000000100000 (reserved)
-[    0.000000]  Xen: 0000000000100000 - 00000000defafe00 (usable)
+[    0.000000]  Xen: 0000000000100000 - 0000000040000000 (usable)
 [    0.000000]  Xen: 00000000defafe00 - 00000000defb1ea0 (ACPI NVS)
 [    0.000000]  Xen: 00000000defb1ea0 - 00000000e0000000 (reserved)
 [    0.000000]  Xen: 00000000f4000000 - 00000000f8000000 (reserved)
..
And we get
[    0.000000] Allocating PCI resources starting at 40000000 (gap: 40000000:9efafe00)

while it should have started at e0000000 (a nice big gap up to
f4000000 exists). The "Allocating PCI" is part of the resource API.

The users that end up using those PCI I/O regions usually supply their
own BARs when calling the resource API (request_resource, or allocate_resource),
but there are exceptions which provide an empty 'struct resource' and
expect the API to provide the 'struct resource' to be populated with valid values.
The one that triggered this bug was the intel AGP driver that requested
a region for the flush page (intel_i9xx_setup_flush).

Before this patch, when running under Xen hypervisor, the 'struct resource'
returned could have (depending on the dom0_mem size) physical ranges of a 'System RAM'
instead of 'I/O' regions. This ended up with the Hypervisor failing a request
to populate PTE's with those PFNs as the domain did not have access to those
'System RAM' regions (rightly so).

After this patch, the left-over E820_RAM region from the truncation, will be
labeled as E820_UNUSABLE. The E820 will look as so:

 [    0.000000] BIOS-provided physical RAM map:
 [    0.000000]  Xen: 0000000000000000 - 0000000000097c00 (usable)
 [    0.000000]  Xen: 0000000000097c00 - 0000000000100000 (reserved)
-[    0.000000]  Xen: 0000000000100000 - 00000000defafe00 (usable)
+[    0.000000]  Xen: 0000000000100000 - 0000000040000000 (usable)
+[    0.000000]  Xen: 0000000040000000 - 00000000defafe00 (unusable)
 [    0.000000]  Xen: 00000000defafe00 - 00000000defb1ea0 (ACPI NVS)
 [    0.000000]  Xen: 00000000defb1ea0 - 00000000e0000000 (reserved)
 [    0.000000]  Xen: 00000000f4000000 - 00000000f8000000 (reserved)

For more information:
http://mid.gmane.org/1A42CE6F5F474C41B63392A5F80372B2335E978C@shsmsx501.ccr.corp.intel.com

BugLink: http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=1726Signed-off-by: NFengzhe Zhang <fengzhe.zhang@intel.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

With this patch, the cpuidle driver does not load and
does not issue the mwait operations. Instead the hypervisor
is doing them (b/c we call the safe_halt pvops call).

This fixes quite a lot of bootup issues wherein the user had
to force interrupts for the continuation of the bootup.

Details are discussed in:

http://lists.xensource.com/archives/html/xen-devel/2011-01/msg00535.html

[v2: Wrote the commit description]
Reported-by: NDaniel De Graaf <dgdegra@tycho.nsa.gov>
Tested-by: NDaniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Under Dell Inspiron 1525, and Intel SandyBridge SDP's the
BIOS e820 RAM is not page-aligned:

[   0.000000]  Xen: 0000000000100000 - 00000000df66d800 (usable)

We were not handling that and ended up setting up a pagetable
that included up to df66e000 with the disastrous effect that when

        memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));

tried to clear the page it would crash at the 2K mark.

Initially reported by Michael Young @
http://lists.xensource.com/archives/html/xen-devel/2011-01/msg00108.html

The fix is to page-align the size and also take into consideration
the start of the E820 (in case that is not page-aligned either). This
fixes the bootup failure on those affected machines.

This patch is a rework of the Micheal A Young initial patch and
considers the case if the start is not page-aligned.
Reported-by: NMichael A Young <m.a.young@durham.ac.uk>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NMichael A Young <m.a.young@durham.ac.uk>

Remove duplicated #include('s) in
  arch/x86/xen/setup.c
Signed-off-by: NHuang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

We just need the idle loop to drop into safe_halt, which default_idle()
is perfectly capable of doing.  There's no need to duplicate it.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Make sure that extra_pages is added for all E820_RAM regions beyond
mem_end - completely excluded regions as well as the remains of partially
included regions.

Also makes sure the extra region is not unnecessarily high, and simplifies
the logic to decide which regions should be added.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

This patch is based off "xen dom0: Set up basic IO permissions for dom0."
by Juan Quintela <quintela@redhat.com>.

On AMD machines when we boot the kernel as Domain 0 we get this nasty:

mapping kernel into physical memory
Xen: setup ISA identity maps
about to get started...
(XEN) traps.c:475:d0 Unhandled general protection fault fault/trap [#13] on VCPU 0 [ec=0000]
(XEN) domain_crash_sync called from entry.S
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
(XEN) ----[ Xen-4.1-101116  x86_64  debug=y  Not tainted ]----
(XEN) CPU:    0
(XEN) RIP:    e033:[<ffffffff8130271b>]
(XEN) RFLAGS: 0000000000000282   EM: 1   CONTEXT: pv guest
(XEN) rax: 000000008000c068   rbx: ffffffff8186c680   rcx: 0000000000000068
(XEN) rdx: 0000000000000cf8   rsi: 000000000000c000   rdi: 0000000000000000
(XEN) rbp: ffffffff81801e98   rsp: ffffffff81801e50   r8:  ffffffff81801eac
(XEN) r9:  ffffffff81801ea8   r10: ffffffff81801eb4   r11: 00000000ffffffff
(XEN) r12: ffffffff8186c694   r13: ffffffff81801f90   r14: ffffffffffffffff
(XEN) r15: 0000000000000000   cr0: 000000008005003b   cr4: 00000000000006f0
(XEN) cr3: 0000000221803000   cr2: 0000000000000000
(XEN) ds: 0000   es: 0000   fs: 0000   gs: 0000   ss: e02b   cs: e033
(XEN) Guest stack trace from rsp=ffffffff81801e50:

RIP points to read_pci_config() function.

The issue is that we don't set IO permissions for the Linux kernel early enough.

The call sequence used to be:

    xen_start_kernel()
	x86_init.oem.arch_setup = xen_setup_arch;
        setup_arch:
           - early_cpu_init
               - early_init_amd
                  - read_pci_config
           - x86_init.oem.arch_setup [ xen_arch_setup ]
               - set IO permissions.

We need to set the IO permissions earlier on, which this patch does.
Acked-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Now that the balloon driver doesn't stumble over non-RAM pages, we
can enable the extra space for ballooning.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

We already deliberately setup a 1-1 P2M for the region up to 1M in
order to allow code which assumes this region is already mapped to
work without having to convert everything to ioremap.

Domain 0 should not return any apparently unused memory regions
(reserved or otherwise) in this region to Xen since the e820 may not
accurately reflect what the BIOS has stashed in this region.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

          CC      arch/x86/xen/setup.o
        arch/x86/xen/setup.c: In function 'xen_memory_setup':
        arch/x86/xen/setup.c:161: error: implicit declaration of function 'xen_initial_domain'
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

add the direct mapping area for ISA bus access when running as initial
domain
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

When running as initial domain, get the real physical memory map from
xen using the XENMEM_machine_memory_map hypercall and use it to setup
the e820 regions.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NJeremy 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: NJeremy 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: NJeremy 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: NJeremy 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: NJeremy 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: NJeremy 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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

If a guest domain wants to access PCI devices through the frontend
driver (coming later in the patch series), it will need access to the
I/O space.

[ Impact: Allow for domU IO access, preparing for pci passthrough ]
Signed-off-by: NAlex Nixon <alex.nixon@citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1.include linux/memblock.h directly. so later could reduce e820.h reference.
2 this patch is done by sed scripts mainly

-v2: use MEMBLOCK_ERROR instead of -1ULL or -1UL
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.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: NDonald Dutile <ddutile@redhat.com>
Signed-off-by: NJeremy 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: NJeremy 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: NJeremy 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: NJeremy 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: NIngo Molnar <mingo@elte.hu>

Impact: cleanup
Signed-off-by: NTej <bewith.tej@gmail.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo 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: NRoberto De Ioris <roberto@unbit.it>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo 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: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NH. 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: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NH. 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: NIngo 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: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>