Commit Graph
38649 Commits
Author SHA1 Message Date
Jan Beulich a67ce55a3e tmem: default to off
As a short term alternative to deleting the code, default its building
to off (overridable in EXPERT mode only). Additionally make sure other
related baggage (LZO code) won't be carried when the option is off (with
TMEM scheduled to be deleted anyway, I didn't want to introduce a
separate Kconfig option to control the LZO compression code, and hence
CONFIG_TMEM is used directly there). Similarly I couldn't be bothered to
add actual content to the command line option doc for the two affected
options.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
2019-01-11 12:30:29 +01:00
Razvan Cojocaru 2bad3829a5 x86/p2m: fix p2m_finish_type_change()
finish_type_change() returns a negative int on error, but the
current code checks if ( !rc ). We also need to treat
finish_type_change()'s return codes cumulatively in the
success case (don't overwrite a 1 returned while processing
the hostp2m if processing an altp2m returns 0).

The breakage was introduced by commit 0fb4b58c8b
("x86/altp2m: fix display frozen when switching to a new view
early").

Properly indent the out: label while at it.

Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
2019-01-11 12:28:49 +01:00
Juergen Gross 808cff4c2a sched/credit2: remove stale comment
With being the default scheduler now the comment in sched_credit2
stating it being experimental should be removed.

While at it remove the "TODO" comments already addressed.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Dario Faggioli <dfaggioli@suse.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
2019-01-09 15:46:05 +01:00
Sergey Dyasli 5ac2dddb17 mm/page_alloc: fix MEMF_no_dma allocations for single NUMA
Currently dma_bitsize is zero by default on single NUMA node machines.
This makes all alloc_domheap_pages() calls with MEMF_no_dma return NULL.

There is only 1 user of MEMF_no_dma: dom0_memflags, which are used
during memory allocation for Dom0. Failing allocation with default
dom0_memflags is especially severe for the PV Dom0 case: it makes
alloc_chunk() to use suboptimal 2MB allocation algorithm with a search
for higher memory addresses.

This can lead to the NMI watchdog timeout during PV Dom0 construction
on some machines, which can be worked around by specifying "dma_bits"
in Xen's cmdline manually.

Fix the issue by ignoring MEMF_no_dma in cases when dma_bitsize is zero,
which means there is no DMA zone. This shouldn't cause any issues for
Dom0 because alloc_heap_pages() will first use higher memory addresses
for satisfying memory allocation requests.

Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2019-01-09 15:45:14 +01:00
Wei Liu b16281870e tools/firmware: update OVMF Makefile
OVMF has become dependent on OpenSSL, which is included as a
submodule.  Initialise submodules before building.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2019-01-09 14:35:50 +00:00
Anthony PERARD f35a59452d docs: Fix output of man/xen-vbd-interface
In pandoc's markdown, a code block needs at least 4 spaces to be
recognize as such. This patch fix the rendering of description of the
encoding in the VBD interface so that [1] can be readable.

[1] https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
[ wei: rebase on top of staging ]
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
2019-01-09 11:08:04 +00:00
Stefano Stabellini 1292f9a059 xen/iommu: fix dev assignment on ARM after 91d4eca7
Fix device assignment on ARM after 91d4eca7 "mm / iommu: split
need_iommu() into has_iommu_pt() and need_iommu_pt_sync()".

arch_iommu_populate_page_table returns -ENOSYS which causes
iommu_construct to return early, although it is not an error.

hd->status needs to be set to IOMMU_STATUS_initializing before calling
iommu_use_hap_pt, otherwise iommu_use_hap_pt will return the wrong
value.

Signed-off-by: Stefano Stabellini <stefanos@xilinx.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2019-01-08 10:47:19 -08:00
Roger Pau Monné 525ef6584f x86/dom0: add verbose mode and print memory allocation stats
Add a verbose option to the dom0 command line, so that dom0 builder
can print extra debug information when required.

Use this new verbose mode to print statistics about memory allocations
when populating dom0 p2m.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2019-01-08 10:08:48 +01:00
Roger Pau Monné 2de4a8b263 x86/shim: only mark special pages as RAM in pvshim mode
When running Xen as a guest it's not necessary to mark such pages as
RAM because they won't be assigned to the initial domain memory map.

While there move the functions to the PV shim specific file and rename
them accordingly.

No functional change expected.

Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2019-01-08 10:03:45 +01:00
Paul Durrant a5b0eb3636 x86/mm/p2m: stop checking for IOMMU shared page tables in mmio_order()
Now that the iommu_map() and iommu_unmap() operations take an order
parameter and elide flushing there's no strong reason why modifying MMIO
ranges in the p2m should be restricted to a 4k granularity simply because
the IOMMU is enabled but shared page tables are not in operation.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2019-01-03 10:36:06 +00:00
Paul Durrant e8afe1124c iommu: elide flushing for higher order map/unmap operations
This patch removes any implicit flushing that occurs in the implementation
of map and unmap operations and adds new iommu_map/unmap() wrapper
functions. To maintain semantics of the iommu_legacy_map/unmap() wrapper
functions, these are modified to call the new wrapper functions and then
perform an explicit flush operation.

Because VT-d currently performs two different types of flush dependent upon
whether a PTE is being modified versus merely added (i.e. replacing a non-
present PTE) 'iommu flush flags' are defined by this patch and the
iommu_ops map_page() and unmap_page() methods are modified to OR the type
of flush necessary for the PTE that has been populated or depopulated into
an accumulated flags value. The accumulated value can then be passed into
the explicit flush operation.

The ARM SMMU implementations of map_page() and unmap_page() currently
perform no implicit flushing and therefore the modified methods do not
adjust the flush flags.

NOTE: The per-cpu 'iommu_dont_flush_iotlb' is respected by the
      iommu_legacy_map/unmap() wrapper functions and therefore this now
      applies to all IOMMU implementations rather than just VT-d.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Julien Grall <julien.grall@arm.com>
Acked-by: Brian Woods <brian.woods@amd.com>
2019-01-03 10:36:06 +00:00
Paul Durrant d40029c844 iommu: rename wrapper functions
A subsequent patch will add semantically different versions of
iommu_map/unmap() so, in advance of that change, this patch renames the
existing functions to iommu_legacy_map/unmap() and modifies all call-sites.
It also adjusts a comment that refers to iommu_map_page(), which was re-
named by a previous patch.

This patch is purely cosmetic. No functional change.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
2019-01-03 10:36:06 +00:00
Paul Durrant cbe21fd047 amd-iommu: add flush iommu_ops
The iommu_ops structure contains two methods for flushing: 'iotlb_flush' and
'iotlb_flush_all'. This patch adds implementations of these for AMD IOMMUs.

The iotlb_flush method takes a base DFN and a (4k) page count, but the
flush needs to be done by page order (i.e. 0, 9 or 18). Because a flush
operation is fairly expensive to perform, the code calculates the minimum
order single flush that will cover the specified page range rather than
performing multiple flushes.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Brian Woods <brian.woods@amd.com>
2019-01-03 10:36:06 +00:00
Andrew Cooper d68de0d6cb docs: Fix ./configure following c/s d661611
The misc/xen-command-line.markdown reference in configure.ac should have been
updated in the same changeset.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
2019-01-02 20:20:05 +00:00
Andrew Cooper a2783e97fb docs: Remove Markdown from configure.ac and the build instructions
Now that all use of markdown as been replaced with pandoc, drop it from
configure.ac and from the docs/ Makefile.

Instead of just deleting the markdown reference from README, adjust the line
to mention the other optional packages required for documentation.

Drop markdown from travis, but leave it in the docker containers as they get
used for stable branches as well.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2019-01-02 17:50:36 +00:00
Andrew Cooper 8410fcb54a docs/man: Fix/simplify generation of manpages
The original intent of this patch was to rename xen-vbd-interface.markdown.7
to xen-vbd-interface.pandoc.7 to remove the final markdown file from the docs/
tree.

The DOC_MANx lists are broken.  They contain MANxSRC-y twice, the first half
with a partial %.pod substituation, and the second half with a partial
%.markdown substitution.  This is also the root cause behind the filtering
activity in the uninstall-man$(i)-pages rule.

Furthermore, the logic for generating the manpage targets is unnecesserily
repetative, owing to the layout of source files in the man/ directory.

Therefore, tackle the problem by renaming all of our manpage source files from
"$FORMAT.$SECTION" to "$SECTION.$FORMAT".  For the two xl.cfg.5 and xl.1 which
are preprocessed by autoconf to contain path information, this requires
updating configure.ac and .gitignore.  The markdown to pandoc conversion is
performed as well, as it is also a straight rename.

An ancillary benefit of this renaming is that text editors stand a chance of
being able to work out the correct mode to use.

As for the makefile:

1) Break the MAN_SECTIONS list out of the GENERATE_MANPAGE_RULES loop, as we
   are going to use it a second time.
2) Do away with the individaul MANxSRC-y variables.  Use a single list,
   derived from all *.pod and *.pandoc files, with their format suffixes
   removed.
3) Use a $(foreach ...) to generate the DOC_MANx lists, filling them with the
   correct content.
4) The DOC_HTML and DOC_TXT can now include all manpages with a single
   substitution, as they don't need to separate the manpages by
   section-numbered-directory.
5) Fix up the filenames in the manpage metarule to match the renaming.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2019-01-02 17:50:36 +00:00
Andrew Cooper d661611d08 docs/markdown: Switch to using pandoc, and fix underscore escaping
c/s a3a99df44 "docs/cmdline: Rewrite the cpuid_mask_* section" completely
forgot about how markdown gets rendered to HTML (as opposed to PDF), because
we use different translators depending on the destination format.

markdown and pandoc are very similar markup languages, but a couple of details
about pandoc cause it to have far more user-friendly inline markup.

Switch all markdown documents to be pandoc (so we are using a single
translator, and therefore a single flavour of markdown), which fixes the
rendered docs on xenbits.xen.org/docs.

While changing the format, fix the remainder of the escaped underscores in the
same mannor as the previous patch.  The two problem cases here are __LINE__
and __FILE__ where the first underscore still needs escaping.

In addition, dmop.markdown and dom0less.markdown didn't used to get processed,
as only .markdown files in the misc/ directory got considered.
dom0less.pandoc gets picked up automatically now, due to being in the
features/ directory, but designs/ needs adding to the pandoc directory list
for dmop.pandoc to get processed.

While edting in appropriate areas, take the opportunity to fix some markup to
the surrounding style, and drop trailing whitespace.

No change in content - only formatting.  This results in the text being easier
to read and grep.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2019-01-02 17:50:36 +00:00
Andrew Cooper 5020c170e2 docs/pandoc: Don't escape underscores in the middle of text
Pandoc deliberately (and contrary to markdown) doesn't treat underscores in
the middle of normal text as emphasis markers, as this is almost always the
unhelpful interpretation.

For text which is emphasised using _, an underscore in the middle is
interpreted, but the emphasis marker can be switched to * instead.

One problem case is where we use {} globbing with identifier names, as it
counts as a word break.  Therefore, we do need to retain the escaped
underscore immediately following a closing brace.

No change in content - only formatting.  This results in the text being easier
to read and grep.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2019-01-02 17:50:36 +00:00
Roger Pau Monne e5268a3ce3 x86/mm-locks: apply a bias to lock levels for control domain
paging_log_dirty_op function takes mm locks from a subject domain and
then attempts to perform copy to operations against the caller domain
in order to copy the result of the hypercall into the caller provided
buffer.

This works fine when the caller is a non-paging domain, but triggers a
lock order panic when the caller is a paging domain due to the fact
that at the point where the copy to operation is performed the subject
domain paging lock is locked, and the copy operation requires
locking the caller p2m lock which has a lower level.

Fix this limitation by adding a bias to the level of control domain mm
locks, so that the lower control domain mm lock always has a level
greater than the higher unprivileged domain lock level. This allows
locking the subject domain mm locks and then locking the control
domain mm locks, while keeping the same lock ordering and the changes
mostly confined to mm-locks.h.

Note that so far only this flow (locking a subject domain locks and
then the control domain ones) has been identified, but not all
possible code paths have been inspected. Hence this solution attempts
to be a non-intrusive fix for the problem at hand, without discarding
further changes in the future if other valid code paths are found that
require more complex lock level ordering.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
2019-01-02 14:20:48 +00:00
Razvan Cojocaru 98fb4adf8f libxc/altp2m: clean up TABs
Replace all the TABs with spaces.

Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
2019-01-02 14:20:17 +00:00
Lars Kurth f258c90eef CONTRIBUTING: Clarifications on how to handle license deviations
This patch makes a few clarifications which were discussed on
IRC recently.

Specifically:
- Highlight the principle that license deviations
  should be brought to the attention of maintainers
- Add a requirement for GPLv2 compatibility
- Restructure the document to highlight use-cases for
  "New components" and "Importing code" clearer
- Add conventions and instructions for "New files"

Signed-off-by: Lars Kurth <lars.kurth@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Julien Grall <julien.grall@arm.com>
2019-01-02 14:17:45 +00:00
Anthony PERARD 3fa1afc57e libxl_create: Re-order callbacks of initiate_domain_create
Callbacks should be in the order that there are going to be executed.
This patch fixes the initiate_domain_create callbacks, and also
reorders the callbacks prototypes. That way, it's easier to follow the
flow.

This patch:
- move libxl__colo_restore_setup_done after domcreate_bootloader_done.
- move domcreate_attach_devices after domcreate_devmodel_started.

No functional change.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
2019-01-02 14:16:52 +00:00
Razvan Cojocaru 9b97818c3d x86/altp2m: add altp2m_vcpu_disable_notify
Allow altp2m users to disable #VE/VMFUNC alone. Currently it is
only possible to disable this functionality when we disable altp2m
completely; #VE/VMFUNC can only be enabled once per altp2m session.

In addition to making things complete, disabling #VE is also a
workaround for CFW116 ("When Virtualization Exceptions are Enabled,
EPT Violations May Generate Erroneous Virtualization Exceptions")
on Xeon E-2100 CPUs.

Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
2019-01-02 12:20:42 +00:00
Andrew Cooper 7b6e05c50f x86/emul: Make POPF emulation easier to follow
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2018-12-31 12:09:46 +00:00
Roger Pau Monne ae7fc10d2c x86/dom0: take alignment into account when populating p2m in PVH mode
Current code that allocates memory and populates the p2m for PVH Dom0
doesn't take the address alignment into account, this can lead to high
order allocations that start on a non-aligned address to be broken
down into lower order entries on the p2m page tables.

Fix this by taking into account the p2m page sizes and alignment
requirements when allocating the memory and populating the p2m.

Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>
2018-12-28 14:32:57 +00:00
Roger Pau Monne 626c9bde57 x86/dom0: propagate guest_physmap_add_page error code
No functional change.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2018-12-27 19:47:33 +00:00
Roger Pau Monne b61c9acdea x86/dom0: add missing flag to printf format for PVH
No functional change.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2018-12-27 19:47:13 +00:00
Roger Pau Monne 667e916fca x86/dom0: allow stealing RAM from a region that starts in the low 1MB
As long as the memory stolen is always above 1MB. This allows the PVH
Dom0 builder to be used on a memory map that only has a single RAM
region starting at 0.

Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>
2018-12-27 19:46:46 +00:00
Roger Pau Monne d4ac876ec8 x86/dom0: fix wording of PVH Dom0 error message
No functional change.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2018-12-27 19:46:18 +00:00
Andrew Cooper 3136dee9cf x86/vtx: Improvements to ept= command line handling
Switch parse_ept_param() to use the parse_boolean() infrastructure for more
consistency with related command line parameters.  Rename opt_pml_enabled to
opt_ept_pml for consistency with opt_ept_ad, and switch it to being bool

Drop the leading comment for parse_ept_param().  It is stale, and just repeats
the command line documentation.

For the command line documentation, rewrite it largely from scratch, updating
to the latest metadata style.  Document A/D first, including a note about
AVR41, and modify PML to note its dependency on A/D.

No practical changes to behaviour.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
2018-12-27 10:20:03 +00:00
Razvan Cojocaru 7f28661f6a p2m: change_type_range: Only invalidate mapped gfns
change_type_range() invalidates gfn ranges to lazily change the type
of a range of gfns, and also modifies the logdirty rangesets of that
p2m. At the moment, it clips both down by the hostp2m.

While this will result in correct behavior, it's not entirely efficient,
since invalidated entries outside that range will, on fault, simply be
modified back to "empty" before faulting normally again.

Separate out the calculation of the two ranges. Keep using the
hostp2m's max_mapped_pfn to clip the logdirty ranges, but use the
current p2m's max_mapped_pfn to further clip the invalidation range
for alternate p2ms.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Tamas K Lengyel <tamas@tklengyel.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
2018-12-22 09:43:52 +00:00
Razvan Cojocaru b5acd075aa p2m: Always use hostp2m when clipping rangesets
The logdirty rangesets of the altp2ms need to be kept in sync with the
hostp2m. This means when iterating through the altp2ms, we need to
use the host p2m to clip the rangeset, not the indiviual altp2m's
value.

This change also:

- Documents that the end is non-inclusive

- Calculates an "inclusive" value for the end once, rather than
  open-coding the modification, and (worse) back-modifying updates so
  that the calculation ends up correct

- Clarifies the logic deciding whether to call
  change_entry_type_global() or change_entry_type_range()

- Handles the case where start >= hostp2m->max_mapped_pfn

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Tested-by: Tamas K Lengyel <tamas@tklengyel.com>
2018-12-22 09:43:52 +00:00
Razvan Cojocaru 0fb4b58c8b x86/altp2m: fix display frozen when switching to a new view early
When an new altp2m view is created very early on guest boot, the
display will freeze (although the guest will run normally). This
may also happen on resizing the display. The reason is the way
Xen currently (mis)handles logdirty VGA: it intentionally
misconfigures VGA pages so that they will fault.

The problem is that it only does this in the host p2m. Once we
switch to a new altp2m, the misconfigured entries will no longer
fault, so the display will not be updated.

This patch:
* updates ept_handle_misconfig() to use the active altp2m instead
  of the hostp2m;
* modifies p2m_change_entry_type_global(),
  p2m_memory_type_changed(), p2m_change_type_range() and
  p2m_finish_type_change() to propagate their changes to all
  valid altp2ms.

With the introduction of altp2m fields in p2m_memory_type_changed()
the whole function has been put under CONFIG_HVM.

Suggested-by: George Dunlap <george.dunlap@citrix.com>
Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Tested-by: Tamas K Lengyel <tamas@tklengyel.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
2018-12-22 09:43:51 +00:00
Razvan Cojocaru 6e23f46ea9 x86/p2m: refactor p2m_reset_altp2m()
Refactor p2m_reset_altp2m() so that it can be used to remove
redundant codepaths, fixing the locking while we're at it.

The previous code now replaced by p2m_reset_altp2m(d, i,
ALTP2M_DEACTIVATE) calls did not set p2m->min_remapped_gfn
and p2m->max_remapped_gfn because in those cases the altp2m
idx was disabled; so before getting used again,
p2m_init_altp2m_ept() would get called, which resets them.
Always setting them in p2m_reset_altp2m(), while redundant,
is preferable to an extra conditional.

Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Tested-by: Tamas K Lengyel <tamas@tklengyel.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
2018-12-22 09:43:50 +00:00
Razvan Cojocaru 95ba8404d4 x86/p2m: allocate logdirty_ranges for altp2ms
For now, only do allocation/deallocation; keeping them in sync
will be done in subsequent patches.

Logdirty synchronization will only be done for active altp2ms;
so allocate logdirty rangesets (copying the host logdirty
rangeset) when an altp2m is activated, and free it when
deactivated.

Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Tested-by: Tamas K Lengyel <tamas@tklengyel.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
2018-12-22 09:43:49 +00:00
George Dunlap 82c62c8734 libxl/dm_depriv: Fix non-debug build
Apparently older versions of gcc, when building with debug=n, the
uninitialized variable logic gets confused.  Distros on which a
non-debug build will fail include:
- Centos 7
- Debian Jessie
- Ubuntu Trusty

It seems to be one particular path confusing the logic; so just set it
on that path to keep the compiler happy, while still catching other
potential paths where it might be unset.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
2018-12-22 08:59:48 +00:00
George Dunlap 9d357cbaf7 libxl/dm_depriv: Fix build
Build tests noticed a path where we weren't setting rc.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
2018-12-21 19:35:04 +00:00
George Dunlap c820787c6e dm_depriv: Mark UID cleanup as completed
Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2018-12-21 18:42:01 +00:00
George Dunlap f45e7d333f libxl: Introduce specific username to be used as a reaper
Untrusted device models must be killed by uid rather than by pid for
safety.  To do this reliably, we need another uid, not used for any
other purpose, from which to make the kill system call.

When using xen-qemuuser-range-base, we can repurpose
xen-qemuuser-range-base itself as a UID from which to kill other
devicemodel uids (since domain ID 0 should never have a device model
associated with it).

However, we'd like people to be able to use the device_model_user
feature without also defining xen-qemuuser-range-base (which requires
the ability to 'reserve' 32k+ user IDs).

To that end, introduce the xen-qemuuser-reaper id.  When killing by
UID, first look for and use that ID if available; then fall back to
xen-qemuuser-range-base.

Document the new call in docs/features/qemu-deprivilege.pandoc.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2018-12-21 18:42:00 +00:00
George Dunlap 87f9458e34 libxl: Kill QEMU with "reaper" ruid
Using kill(-1) to killing an untrusted dm process with the real uid
equal to the dm_uid isn't guaranteed to succeed: the process in
question may be able to kill the reaper process after the setresuid()
and before the kill().

Instead, set the real uid to the QEMU user for domain 0
(QEMU_USER_RANGE_BASE + 0).  The reaper process will still be able to
kill the dm process, but not vice versa.

This, in turn, requires locking to make sure that only one reaper
process is using that uid at a time; otherwise one reaper process may
kill the other reaper process.

Create a lockfile in RUNDIR/dm-reaper-lock, and grab the lock before
executing kill.

In the event that we can't get the lock for some reason, go ahead with
the kill using dm_uid for both real and effective UIDs.  This isn't
guaranteed to work, but it's no worse than not trying to kill the
process at all.

NB that this effectively requires admins using device_model_user to
also define xen_qemuuser_range_base; this will be addressed in
subsequent patches.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2018-12-21 18:41:59 +00:00
George Dunlap 0c653574d3 libxl: Kill QEMU by uid when possible
The privcmd fd that a dm_restrict'ed QEMU has gives it permission to
one specific domain ID.  This domain ID will probably eventually be
used again.  It is therefore necessary to make absolutely sure that a
rogue QEMU process cannot hang around after its domain has exited.

Killing QEMU by pid is insufficient in this situation, because QEMU
may be able to fork() to escape killing.  It is surprisingly tricky to
kill a process which can call fork() without races; the only reliable
way is to use kill(-1) to kill all processes with a given uid.

We can use this method only when we're sure that there's only one QEMU
instance per uid.  Add a dm_uid into the domain_build_state struct,
and set it in libxl__domain_get_device_model_uid() when it's safe to
kill by UID.  Store this in xenstore next to device-model-pid.

On domain destroy, check to see if device-model-uid is present in
xenstore.  If so, fork off a reaper process, setuid to that uid, and
do kill(-9) to kill all uids of that type.  Otherwise, carry on
destroying by pid.

While we're here, make libxl__destroy_device_model() consistently:
 1. Return an error when anything fails
 2. But continue to do as much clean-up as possible

NOTE that this is not yet completely safe: with ruid == dm_uid, the
device model may be able to kill(-9) the 'reaper' process before the
reaper process can kill it.  Further patches will address this.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2018-12-21 18:41:57 +00:00
George Dunlap 6a05c1a9b6 libxl: Make killing of device model asynchronous
Or at least, give it an asynchronous interface so that we can make it
actually asynchronous in subsequent patches.

Create state structures and callback function signatures.  Add the
state structure to libxl__destroy_domid_state.  Break
libxl__destroy_domid down into two functions.

No functional change intended.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2018-12-21 18:41:56 +00:00
George Dunlap a233781cd6 libxl: Move qmp cleanup into devicemodel destroy function
Removing the qmp connection is logically part of the device model
destruction; having the caller destroy it is a mild layering
violation.

Move libxl__qmp_cleanup() into libxl__destroy_device_model().  This
will make it easier when we make devicemodel destruction asynchronous.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2018-12-21 18:41:55 +00:00
George Dunlap 436bf83bf1 libxl: Do root checks once in libxl__domain_get_device_model_uid
At the moment, we check for equivalence to literal "root" before
deciding whether to add the `runas` command-line option to QEMU.  This
is unsatisfactory for several reasons.

First, just because the string doesn't match "root" doesn't mean the
final uid won't end up being zero; in particular, the range_base
calculations may end up producing "0:NNN", which would be root in any
case.

Secondly, it's almost certainly a configuration error if the resulting
uid ends up to be zero; rather than silently do what was specified but
probably not intended, throw an error.

To fix this, check for root once in
libxl__domain_get_device_model_uid.  If the result is root, return an
error; if appropriate, set `runas`.

After that, assume that the presence of state->dm_runas implies that a
`runas` argument should be constructed.

One side effect of this is to check whether device_model_user exists
before passing it to qemu, resulting in better error reporting.

While we're here:
- Refactor the function to use the "goto out" idiom
- Use 'rc' rather than 'ret', in line with CODING_STYLE

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2018-12-21 18:41:53 +00:00
George Dunlap 53bf85de47 dm_depriv: Describe expected usage of device_model_user parameter
A number of subsequent patches rely on as-yet undefined behavior for
what the `device_model_user` parameter does.  Rather than implement it
incorrectly (or randomly), or remove the feature, describe an expected
usage for the feature.  Further patches will make decisions based on
this expected usage.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2018-12-21 18:41:52 +00:00
George Dunlap 6572b66578 libxl: Clean up userlookup_helper_getpw* helper
Bring conventions more in line with libxl__xs_read_checked():
- If found, return 0 and set pointer to non-NULL
- If not found, return 0 and set pointer to NULL
- On error, return libxl-style error number.

Update documentation to match.

Use CODING_STYLE compliant `r` rather than `ret`.

On error, log the error code before returning instead of discarding
it.

Now that it only returns 0 or errno, update caller error checks to be
`if (ret)` rather than `if (ret < 0)`.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2018-12-21 18:41:51 +00:00
George Dunlap 28b5856b02 libxl: Get rid of support for QEMU_USER_BASE (xen-qemuuser-domidNN)
QEMU_USER_BASE allows a user to specify the UID to use when running
the devicemodel for a specific domain number.  Unfortunately, this is
not really practical: It requires nearly 32,000 entries in
/etc/passwd.  QEMU_USER_RANGE_BASE is much more practical.

Remove support for QEMU_USER_BASE.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2018-12-21 18:41:50 +00:00
George Dunlap 0fa6c9b344 libxl: Move dm user determination logic into a helper function
To reliably kill an untrusted devicemodel, we need to know not only
its pid, but its uid.  In preparation for this, move the userid
determination logic into a helper function.

Create a new field, `dm_runas`, in libxl__domain_build_state to store
the value during domain creation.

This change also removes unnecessary duplication of the argument
construction code.

While here, clean up some minor CODING_STYLE infractions (space
between * and variable name).

No functional change intended.

While here, delete some trailing whitespace.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2018-12-21 18:41:48 +00:00
Benjamin Sanda d3ce6380c1 xenalyze: Build for Both ARM and x86 Platforms
Modified to provide building of the xenalyze binary for both ARM and
x86 platforms. The xenalyze binary is now built as part of the BIN
list for both platforms.

Signed-off-by: Benjamin Sanda <ben.sanda@dornerworks.com>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2018-12-21 09:45:11 -08:00
Benjamin Sanda 4e191a854d xen/arm: Initialize trace buffer
Now that we allow a privileged domain to map tracing buffer, initialize
them so a user can effectively trace Xen.

Signed-off-by: Benjamin Sanda <ben.sanda@dornerworks.com>
[julien: rework commit message]
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Andrii Anisov <andrii_anisov@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2018-12-21 09:44:55 -08:00