linux-toradex.git/include/xen/page.h, branch v4.9.31

xen: Fix page <-> pfn conversion on 32 bit systems

2016-04-06T10:18:17+00:00

Commit 1084b1988d22dc165c9dbbc2b0e057f9248ac4db (xen: Add Xen specific
page definition) caused a regression in 4.4.

The xen functions to convert between pages and pfns fail due to an
overflow on systems where a physical address may not fit in an
unsigned long (e.g. x86 32 bit PAE systems). Rework the conversion to
avoid overflow. This should also result in simpler object code.

This bug manifested itself as disk corruption with Linux 4.4 when
using blkfront in a Xen HVM x86 32 bit guest with more than 4 GiB of
memory.

Signed-off-by: Ross Lagerwall 
Cc:  # 4.4+
Signed-off-by: David Vrabel

xen: Add Xen specific page definition

2015-10-23T13:20:33+00:00

The Xen hypercall interface is always using 4K page granularity on ARM
and x86 architecture.

With the incoming support of 64K page granularity for ARM64 guest, it
won't be possible to re-use the Linux page definition in Xen drivers.

Introduce Xen page definition helpers based on the Linux page
definition. They have exactly the same name but prefixed with
XEN_/xen_ prefix.

Also modify xen_page_to_gfn to use new Xen page definition.

Signed-off-by: Julien Grall 
Reviewed-by: Stefano Stabellini 
Signed-off-by: David Vrabel

xen: Use correctly the Xen memory terminologies

2015-09-08T17:03:49+00:00

Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN
is meant, I suspect this is because the first support for Xen was for
PV. This resulted in some misimplementation of helpers on ARM and
confused developers about the expected behavior.

For instance, with pfn_to_mfn, we expect to get an MFN based on the name.
Although, if we look at the implementation on x86, it's returning a GFN.

For clarity and avoid new confusion, replace any reference to mfn with
gfn in any helpers used by PV drivers. The x86 code will still keep some
reference of pfn_to_mfn which may be used by all kind of guests
No changes as been made in the hypercall field, even
though they may be invalid, in order to keep the same as the defintion
in xen repo.

Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a
name to close to the KVM function gfn_to_page.

Take also the opportunity to simplify simple construction such
as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up
will come in follow-up patches.

[1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cb

Signed-off-by: Julien Grall 
Reviewed-by: Stefano Stabellini 
Acked-by: Dmitry Torokhov 
Acked-by: Wei Liu 
Signed-off-by: David Vrabel

xen: switch extra memory accounting to use pfns

2015-09-08T15:28:06+00:00

Instead of using physical addresses for accounting of extra memory
areas available for ballooning switch to pfns as this is much less
error prone regarding partial pages.

Reported-by: Roger Pau Monné 
Tested-by: Roger Pau Monné 
Signed-off-by: Juergen Gross 
Signed-off-by: David Vrabel

xen: add page_to_mfn()

2015-01-14T05:22:00+00:00

pfn_to_mfn(page_to_pfn(p)) is a common use case so add a generic
helper for it.

Signed-off-by: David Vrabel 
Signed-off-by: David S. Miller

xen: allow balloon driver to use more than one memory region

2011-09-29T15:12:10+00:00

Allow the xen balloon driver to populate its list of extra pages from
more than one region of memory.  This will allow platforms to provide
(for example) a region of low memory and a region of high memory.

The maximum possible number of extra regions is 128 (== E820MAX) which
is quite large so xen_extra_mem is placed in __initdata.  This is safe
as both xen_memory_setup() and balloon_init() are in __init.

The balloon regions themselves are not altered (i.e., there is still
only the one region).

Signed-off-by: David Vrabel 
Signed-off-by: Konrad Rzeszutek Wilk

xen/balloon: account for pages released during memory setup

2011-09-29T15:12:09+00:00

In xen_memory_setup() pages that occur in gaps in the memory map are
released back to Xen.  This reduces the domain's current page count in
the hypervisor.  The Xen balloon driver does not correctly decrease
its initial current_pages count to reflect this.  If 'delta' pages are
released and the target is adjusted the resulting reservation is
always 'delta' less than the requested target.

This affects dom0 if the initial allocation of pages overlaps the PCI
memory region but won't affect most domU guests that have been setup
with pseudo-physical memory maps that don't have gaps.

Fix this by accouting for the released pages when starting the balloon
driver.

If the domain's targets are managed by xapi, the domain may eventually
run out of memory and die because xapi currently gets its target
calculations wrong and whenever it is restarted it always reduces the
target by 'delta'.

Signed-off-by: David Vrabel 
Signed-off-by: Konrad Rzeszutek Wilk

xen: add extra pages to balloon

2010-11-20T06:15:59+00:00

Add extra pages in the pseudo-physical address space to the balloon
so we can extend into them later.

Signed-off-by: Jeremy Fitzhardinge

xen: make include/xen/page.h portable moving those definitions under asm dir

2008-04-24T21:57:32+00:00

The definitions in include/asm/xen/page.h are arch specific.
ia64/xen wants to define its own version. So move them to arch specific
directory and keep include/xen/page.h in order not to break compilation.

Signed-off-by: Isaku Yamahata 
Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

xen: unify pte operations on machine frames

2008-04-24T21:57:31+00:00

Xen's pte operations on mfns can be unified like the kernel's pfn operations.

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner