Commit Graph
320 Commits
Author SHA1 Message Date
Jan Beulich 1ecb0d46d3 x86: Make "spec-ctrl=no" a global disable of all mitigations
In order to have a simple and easy to remember means to suppress all the
more or less recent workarounds for hardware vulnerabilities, force
settings not controlled by "spec-ctrl=" also to their original defaults,
unless they've been forced to specific values already by earlier command
line options.

This is part of XSA-273.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit d8800a82c3)
2018-08-14 17:39:57 +01:00
Andrew Cooper 4b12b44b21 x86/spec-ctrl: Introduce an option to control L1D_FLUSH for HVM HAP guests
This mitigation requires up-to-date microcode, and is enabled by default on
affected hardware if available, and is used for HVM guests

The default for SMT/Hyperthreading is far more complicated to reason about,
not least because we don't know if the user is going to want to run any HVM
guests to begin with.  If a explicit default isn't given, nag the user to
perform a risk assessment and choose an explicit default, and leave other
configuration to the toolstack.

This is part of XSA-273 / CVE-2018-3620.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 3bd36952da)
2018-08-14 17:39:57 +01:00
Andrew Cooper b2449f57ae x86/spec-ctrl: CPUID/MSR definitions for L1D_FLUSH
This is part of XSA-273 / CVE-2018-3646.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 3563fc2b27)
2018-08-14 17:39:57 +01:00
Andrew Cooper 2b1e6a4868 x86/spec-ctrl: Introduce an option to control L1TF mitigation for PV guests
Shadowing a PV guest is only available when shadow paging is compiled in.
When shadow paging isn't available, guests can be crashed instead as
mitigation from Xen's point of view.

Ideally, dom0 would also be potentially-shadowed-by-default, but dom0 has
never been shadowed before, and there are some stability issues under
investigation.

This is part of XSA-273 / CVE-2018-3620.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 66a4e98681)
2018-08-14 17:39:56 +01:00
Stefano Stabellini 45f6a2777c ARM: disable grant table v2
It was never expected to work, the implementation is incomplete.

As a side effect, it also prevents guests from triggering a
"BUG_ON(page_get_owner(pg) != d)" in gnttab_unpopulate_status_frames().

This is XSA-268.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 9a5c16a3e7)
2018-08-14 17:39:56 +01:00
Andrew Cooper 4c8d9f87bd common/gnttab: Introduce command line feature controls
This patch was originally released as part of XSA-226.  It retains the same
command line syntax (as various downstreams are mitigating XSA-226 using this
mechanism) but the defaults have been updated due to the revised XSA-226
patched, after which transitive grants are believed to functioning
properly.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit dc96c65ed6)
2018-08-14 17:39:56 +01:00
Jan Beulich e0981f6087 x86: command line option to avoid use of secondary hyper-threads
Shared resources (L1 cache and TLB in particular) present a risk of
information leak via side channels. Provide a means to avoid use of
hyperthreads in such cases.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: d8f974f1a6
master date: 2018-07-19 13:43:33 +0100
2018-07-30 14:21:07 +02:00
Andrew Cooper 542f711567 x86/spec-ctrl: Mitigations for LazyFPU
Intel Core processors since at least Nehalem speculate past #NM, which is the
mechanism by which lazy FPU context switching is implemented.

On affected processors, Xen must use fully eager FPU context switching to
prevent guests from being able to read FPU state (SSE/AVX/etc) from previously
scheduled vcpus.

This is part of XSA-267 / CVE-2018-3665

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 243435bf67)
2018-06-13 22:01:37 +01:00
Juergen Gross 365ecffbb6 xen/x86: use PCID feature
Avoid flushing the complete TLB when switching %cr3 for mitigation of
Meltdown by using the PCID feature if available.

We are using 4 PCID values for a 64 bit pv domain subject to XPTI and
2 values for the non-XPTI case:

- guest active and in kernel mode
- guest active and in user mode
- hypervisor active and guest in user mode (XPTI only)
- hypervisor active and guest in kernel mode (XPTI only)

We use PCID only if PCID _and_ INVPCID are supported. With PCID in use
we disable global pages in cr4. A command line parameter controls in
which cases PCID is being used.

As the non-XPTI case has shown not to perform better with PCID at least
on some machines the default is to use PCID only for domains subject to
XPTI.

With PCID enabled we always disable global pages. This avoids having to
either flush the complete TLB or do a cycle through all PCID values
when invalidating a single global page.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2018-05-29 11:31:34 +02:00
Juergen Gross cb0230a637 xen/x86: use invpcid for flushing the TLB
If possible use the INVPCID instruction for flushing the TLB instead of
toggling cr4.pge for that purpose.

While at it remove the dependency on cr4.pge being required for mtrr
loading, as this will be required later anyway.

Add a command line option "invpcid" for controlling the use of
INVPCID (default to true).

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2018-05-29 11:28:53 +02:00
Juergen Gross 4336ffad91 xen/x86: support per-domain flag for xpti
Instead of switching XPTI globally on or off add a per-domain flag for
that purpose. This allows to modify the xpti boot parameter to support
running dom0 without Meltdown mitigations. Using "xpti=no-dom0" as boot
parameter will achieve that.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2018-05-29 11:28:24 +02:00
Andrew Cooper bfe8f3e884 x86/Intel: Mitigations for GPZ SP4 - Speculative Store Bypass
To combat GPZ SP4 "Speculative Store Bypass", Intel have extended their
speculative sidechannel mitigations specification as follows:

 * A feature bit to indicate that Speculative Store Bypass Disable is
   supported.
 * A new bit in MSR_SPEC_CTRL which, when set, disables memory disambiguation
   in the pipeline.
 * A new bit in MSR_ARCH_CAPABILITIES, which will be set in future hardware,
   indicating that the hardware is not susceptible to Speculative Store Bypass
   sidechannels.

For contemporary processors, this interface will be implemented via a
microcode update.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 9df52a25e0
master date: 2018-05-21 14:20:06 +0100
2018-05-29 11:08:34 +02:00
Andrew Cooper 4f0509d9bf x86/AMD: Mitigations for GPZ SP4 - Speculative Store Bypass
AMD processors will execute loads and stores with the same base register in
program order, which is typically how a compiler emits code.

Therefore, by default no mitigating actions are taken, despite there being
corner cases which are vulnerable to the issue.

For performance testing, or for users with particularly sensitive workloads,
the `spec-ctrl=ssbd` command line option is available to force Xen to disable
Memory Disambiguation on applicable hardware.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 8c0e338086
master date: 2018-05-21 14:20:06 +0100
2018-05-29 11:08:10 +02:00
Andrew Cooper 2f99d683f8 x86/spec_ctrl: Introduce a new spec-ctrl= command line argument to replace bti=
In hindsight, the options for `bti=` aren't as flexible or useful as expected
(including several options which don't appear to behave as intended).
Changing the behaviour of an existing option is problematic for compatibility,
so introduce a new `spec-ctrl=` in the hopes that we can do better.

One common way of deploying Xen is with a single PV dom0 and all domUs being
HVM domains.  In such a setup, an administrator who has weighed up the risks
may wish to forgo protection against malicious PV domains, to reduce the
overall performance hit.  To cater for this usecase, `spec-ctrl=no-pv` will
disable all speculative protection for PV domains, while leaving all
speculative protection for HVM domains intact.

For coding clarity as much as anything else, the suboptions are grouped by
logical area; those which affect the alternatives blocks, and those which
affect Xen's in-hypervisor settings.  See the xen-command-line.markdown for
full details of the new options.

While changing the command line options, take the time to change how the data
is reported to the user.  The three DEBUG printks are upgraded to unilateral,
as they are all relevant pieces of information, and the old "mitigations:"
line is split in the two logical areas described above.

Sample output from booting with `spec-ctrl=no-pv` looks like:

  (XEN) Speculative mitigation facilities:
  (XEN)   Hardware features: IBRS/IBPB STIBP IBPB
  (XEN)   Compiled-in support: INDIRECT_THUNK
  (XEN)   Xen settings: BTI-Thunk RETPOLINE, SPEC_CTRL: IBRS-, Other: IBPB
  (XEN)   Support for VMs: PV: None, HVM: MSR_SPEC_CTRL RSB
  (XEN)   XPTI (64-bit PV only): Dom0 enabled, DomU enabled

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 3352afc26c
master date: 2018-05-16 12:19:10 +0100
2018-05-29 11:07:29 +02:00
Andrew Cooper 8994cf3cf7 x86/ctxt: Issue a speculation barrier between vcpu contexts
Issuing an IBPB command flushes the Branch Target Buffer, so that any poison
left by one vcpu won't remain when beginning to execute the next.

The cost of IBPB is substantial, and skipped on transition to idle, as Xen's
idle code is robust already.  All transitions into vcpu context are fully
serialising in practice (and under consideration for being retroactively
declared architecturally serialising), so a cunning attacker cannot use SP1 to
try and skip the flush.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: a2ed643ed7
master date: 2018-01-26 14:10:21 +0000
2018-02-14 13:44:01 +01:00
Andrew Cooper 642c6037bb x86/boot: Calculate the most appropriate BTI mitigation to use
See the logic and comments in init_speculation_mitigations() for further
details.

There are two controls for RSB overwriting, because in principle there are
cases where it might be safe to forego rsb_native (Off the top of my head,
SMEP active, no 32bit PV guests at all, no use of vmevent/paging subsystems
for HVM guests, but I make no guarantees that this list of restrictions is
exhaustive).

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

x86/spec_ctrl: Fix determination of when to use IBRS

The original version of this logic was:

    /*
     * On Intel hardware, we'd like to use retpoline in preference to
     * IBRS, but only if it is safe on this hardware.
     */
    else if ( boot_cpu_has(X86_FEATURE_IBRSB) )
    {
        if ( retpoline_safe() )
            thunk = THUNK_RETPOLINE;
        else
            ibrs = true;
    }

but it was changed by a request during review.  Sadly, the result is buggy as
it breaks the later fallback logic by allowing IBRS to appear as available
when in fact it isn't.

This in practice means that on repoline-unsafe hardware without IBRS, we
select THUNK_JUMP despite intending to select THUNK_RETPOLINE.

Reported-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 2713715305
master date: 2018-01-26 14:10:21 +0000
master commit: 30cbd0c83e
master date: 2018-02-06 18:32:58 +0000
2018-02-14 13:43:36 +01:00
Andrew Cooper 4d2154914e x86/cmdline: Introduce a command line option to disable IBRS/IBPB, STIBP and IBPB
Instead of gaining yet another top level boolean, introduce a more generic
cpuid= option.  Also introduce a helper function to parse a generic boolean
value.

This is part of XSA-254.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

xen/cmdline: Fix parse_boolean() for unadorned values

A command line such as "cpuid=no-ibrsb,no-stibp" tickles a bug in
parse_boolean() because the separating comma fails the NUL case.

Instead, check for slen == nlen which accounts for the boundary (if any)
passed via the 'e' parameter.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 7850b1c007
master date: 2018-01-16 17:45:50 +0000
master commit: ac37ec1dde
master date: 2018-01-31 10:47:12 +0000
2018-02-14 12:44:17 +01:00
Andrew Cooper 2613a1bc70 x86: Introduce alternative indirect thunks
Depending on hardware and microcode availability, we will want to replace
IND_THUNK_REPOLINE with other implementations.

For AMD hardware, choose IND_THUNK_LFENCE in preference to retpoline if lfence
is known to be (or was successfully made) dispatch serialising.

This is part of XSA-254.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 858cba0d4c
master date: 2018-01-16 17:45:50 +0000
2018-02-14 12:43:05 +01:00
Jan Beulich 44ad7f6895 x86: allow Meltdown band-aid to be disabled
First of all we don't need it on AMD systems. Additionally allow its use
to be controlled by command line option. For best backportability, this
intentionally doesn't use alternative instruction patching to achieve
the intended effect - while we likely want it, this will be later
follow-up.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: e871e80c38
master date: 2018-01-16 17:50:59 +0100
2018-01-17 17:32:03 +01:00
George Dunlap be63d665b8 x86/mm: Make PV linear pagetables optional
Allowing pagetables to point to other pagetables of the same level
(often called 'linear pagetables') has been included in Xen since its
inception; but recently it has been the source of a number of subtle
reference-counting bugs.

It is not used by Linux or MiniOS; but it is used by NetBSD and Novell
Netware.  There are significant numbers of people who are never going
to use the feature, along with significant numbers who need the
feature.

Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2017-11-16 12:13:11 +01:00
Jan Beulich f974d3211e gnttab: split maptrack lock to make it fulfill its purpose again
The way the lock is currently being used in get_maptrack_handle(), it
protects only the maptrack limit: The function acts on current's list
only, so races on list accesses are impossible even without the lock.

Otoh list access races are possible between __get_maptrack_handle() and
put_maptrack_handle(), due to the invocation of the former for other
than current from steal_maptrack_handle(). Introduce a per-vCPU lock
for list accesses to become race free again. This lock will be
uncontended except when it becomes necessary to take the steal path,
i.e. in the common case there should be no meaningful performance
impact.

When in get_maptrack_handle adds a stolen entry to a fresh, empty,
freelist, we think that there is probably no concurrency.  However,
this is not a fast path and adding the locking there makes the code
clearly correct.

Also, while we are here: the stolen maptrack_entry's tail pointer was
not properly set.  Set it.

This is CVE-2017-12136 / XSA-228.

Reported-by: Ian Jackson <ian.jackson@eu.citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
master commit: 02cbeeb620
master date: 2017-08-15 15:07:25 +0200
2017-08-15 15:30:26 +02:00
Stefano Stabellini 82fde4fa36 xen/arm: introduce vwfi parameter
Introduce new Xen command line parameter called "vwfi", which stands for
virtual wfi. The default is "trap": Xen traps guest wfi and wfe
instructions. In the case of wfi, Xen calls vcpu_block on the guest
vcpu; in the case of guest wfe, Xen calls vcpu_yield on the guest vcpu.
The behavior can be changed by setting vwfi to "native", in that case
Xen doesn't trap neither wfi nor wfe, running them in guest context.

The result is strong reduction in irq latency (from 5000ns to 2000ns,
measured using https://github.com/edgarigl/tbm, the physical timer, and
1 pcpu dedicated to 1 vcpu). The downside is that the scheduler thinks
that the guest is busy when actually is sleeping, leading to suboptimal
scheduling decisions.

Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Dario Faggioli <dario.faggioli@citrix.com>
Reviewed-by: Julien Grall <julien.grall@arm.com>
2017-03-07 11:26:58 -08:00
Ian Jackson 44d8545ba6 libxl: Document ~/serial/ correctly
xenstore-paths.markdown talked about ~/device/serial/, but that's not
used.

(It is very wrong for this value, which contains a driver domain
filesystem path, to be in the guest's area of xenstore.  However, it
is only ever created by libxl and ready by xenconsoled.  When it is
created, it inherits the read-only permissions of /local/domain/DOMID.
So there is no security bug.)

This is a followup to XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-06 15:08:59 +01:00
Ian Jackson 866bea560b libxl: Make copy of every xs backend in /libxl in _generic_add
We want to stop libxl trustingly reading information from the backend
directory (since this is, of course, writeable by the backend, which
might be a semi-trusted driver domain).

In principle it is wrong in current libxl for anything to try to
divine virtual device configuration from xenstore: the JSON domain
config ought to supply that, and xenstore should only tell us which
devices actually exist.

However:

Firstly, there are several existing places where configuration
information is retrieved from xenstore rather than JSON.  We do not
want to reen gineer this in a security patch.

Secondly, we want to make a security patch which can be backported to
versions of libxl without the JSON configuration machinery.

So we take the expedient approach of keeping a copy of the
configuration somewhere we trust, namely /libxl.  This is obviously
fairly low-risk, although it does write significantly more keys in
xenstore.

In this patch we make this change in libxl__device_generic_add.  This
is responsible for actually writing the vast majority of device
information to xenstore.  There are a few loose ends which will be
dealt with in a moment.

Likewise, changes to readers to use the new location will appear in
further patches.

This is part of XSA-178.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-06 14:47:35 +01:00
Ian Jackson 71bdf79ede libxl: Record backend/frontend paths in /libxl/$DOMID
This gives us a record of all the backends we have set up for a
domain, which is separate from the frontends in
  /local/domain/$DOMID/device.

In particular:

1. A guest has write permission for the frontend path:
  /local/domain/$DOMID/device/$KIND/$DEVID
which means that the guest can completely delete the frontend.
(They can't recreate it because they don't have write permission
on the containing directory.)

2. A guest has write permission for the backend path recorded in the
frontend, ie, it can write to
  /local/domain/$DOMID/device/$KIND/$DEVID/backend
which means that the guest can break the association between
frontend and backend.

So we can't rely on iterating over the frontends to find all the
backends, or examining a frontend to discover how a device is
configured.

So, have libxl__device_generic_add record the frontend and backend
paths in /libxl/$DOMID/device, and have libxl__device_destroy remove
them again.

Create the containing directory /libxl/GUEST/device in
libxl__domain_make.  The already existing xs_rm in devices_destroy_cb
will take care of removing it.

This is part of XSA-175.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
2016-06-06 13:56:33 +01:00
Jan Beulich 6d03c9e4f2 x86: enforce consistent cachability of MMIO mappings
We've been told by Intel that inconsistent cachability between
multiple mappings of the same page can affect system stability only
when the affected page is an MMIO one. Since the stale data issue is
of no relevance to the hypervisor (since all guest memory accesses go
through proper accessors and validation), handling of RAM pages
remains unchanged here. Any MMIO mapped by domains however needs to be
done consistently (all cachable mappings or all uncachable ones), in
order to avoid Machine Check exceptions. Since converting existing
cachable mappings to uncachable (at the time an uncachable mapping
gets established) would in the PV case require tracking all mappings,
allow MMIO to only get mapped uncachable (UC, UC-, or WC).

This also implies that in the PV case we mustn't use the L1 PTE update
fast path when cachability flags get altered.

Since in the HVM case at least for now we want to continue honoring
pinned cachability attributes for pages not mapped by the hypervisor,
special case handling of r/o MMIO pages (forcing UC) gets added there.
Arguably the counterpart change to p2m-pt.c may not be necessary, since
UC- (which already gets enforced there) is probably strict enough.

Note that the shadow code changes include fixing the write protection
of r/o MMIO ranges: shadow_l1e_remove_flags() and its siblings, other
than l1e_remove_flags() and alike, return the new PTE (and hence
ignoring their return values makes them no-ops).

This is CVE-2016-2270 / XSA-154.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: c61a6f74f8
master date: 2016-02-17 16:16:53 +0100
2016-02-17 16:31:16 +01:00
Ian Campbell 5929e25d98 docs: correct descriptions of gnttab_max_{, maptrack}_frames
gnttab_max_frames incorrectly referred to numbers of grant tab
operations and gnttab_max_maptrack_frames was confusingly worded.

Add the default for gnttab_max_frames while here (it's currently the
same on all arches since no arch uses the available arch override) and
adjust the default for gnttab_max_maptrack_frames to match the normal
form.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: ef17887d84
master date: 2016-01-19 16:24:44 +0000
2016-01-20 13:59:02 +01:00
Jan Beulich 499886c800 x86/vPMU: document as unsupported
This is XSA-163.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
master commit: c03480cf5c
master date: 2015-11-24 18:32:20 +0100
2015-12-15 15:22:58 +01:00
Jan Beulich 2ce580f21f memory: split and tighten maximum order permitted in memops
Introduce and enforce separate limits for ordinary DomU, DomU with
pass-through device(s), control domain, and hardware domain.

The DomU defaults were determined based on what so far was allowed by
multipage_allocation_permitted().

The x86 hwdom default was chosen based on linux-2.6.18-xen.hg c/s
1102:82782f1361a9 indicating 2Mb is not enough, plus some slack.

The ARM hwdom default was chosen to allow 2Mb (order-9) mappings, plus
a little bit of slack.

This is CVE-2015-8338 / XSA-158.

Reported-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
master commit: 4a578b316e
master date: 2015-12-08 14:00:33 +0100
2015-12-08 14:05:20 +01:00
Ross Lagerwall 9204673fc6 x86/EPT: work around hardware erratum setting A bit
Since commit 191b3f3344 ("p2m/ept: enable PML in p2m-ept for
log-dirty"), the A and D bits of EPT paging entries are set
unconditionally, regardless of whether PML is enabled or not. This
causes a regression in Xen 4.6 on some processors due to Intel Errata
AVR41 -- HVM guests get severe memory corruption when the A bit is set
due to incorrect TLB flushing on mov to cr3. The erratum affects the
Atom C2000 family (Avoton).

To fix, do not set the A bit on this processor family.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>

Move feature suppression to feature detection code. Add command line
override.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
master commit: 33b55dc103
master date: 2015-10-02 13:39:12 +0200
2015-10-02 13:53:27 +02:00
Chao Peng 41c46dd10b docs: make xl-psr.markdown more precise
Drop the chapter number as it can be confusing when it gets changed in
the referred document.

Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Reviewed-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
[ ijc -- dropped hunk changing URL to specific revision, this is not
         needed now that the references do not include a specific
         chapter number ]

(cherry picked from commit 7f732ffa2b)
2015-09-29 10:59:54 +01:00
Andrew Cooper c85d3d1d98 docs: Move misc README's into docs/misc/
To live with the other documentation.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
2015-08-27 19:14:17 +01:00
Ting-Wei Lan 146341187a VT-d: add iommu=igfx option to workaround graphics issues
When using Linux >= 3.19 (commit 47591df) as dom0 on some Intel Ironlake
devices, It is possible to encounter graphics issues that make screen
unreadable or crash the system. It was reported in freedesktop bugzilla:

https://bugs.freedesktop.org/show_bug.cgi?id=90037

As we still cannot find a proper fix for this problem, this patch adds
iommu=igfx option to control whether Intel graphics IOMMU is enabled.
Running Xen with iommu=no-igfx is similar to running Linux with
intel_iommu=igfx_off, which disables IOMMU for Intel GPU. This can be
used by users to manually workaround the problem before a fix is
available for i915 driver.

Signed-off-by: Ting-Wei Lan <lantw44@gmail.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
2015-08-06 10:03:53 +01:00
Ed White fce42d9ad7 x86/HVM: hardware alternate p2m support detection
As implemented here, only supported on platforms with VMX HAP.

By default this functionality is force-disabled, it can be enabled
by specifying altp2m=1 on the Xen command line.

Signed-off-by: Ed White <edmund.h.white@intel.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
2015-07-24 13:26:02 +02:00
Chris (Christopher) Brand a7da1081d1 xen: arm: Document xenheap_megabytes limitation
In setup_mm(), the value passed as xenheap_megabytes gets
converted to pages and passed to setup_xenheap_mappings(),
which in turn passes it to create_32mb_mappings(), which
contains an ASSERT that the value passed is a multiple of
32MB. So specifying any value that is not an integer multiple
of 32 will cause Xen to hit this assert and fail to boot.

Signed-off-by: Chris Brand <chris.brand@broadcom.com>
Reviewed-by: Julien Grall <julien.grall@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-07-24 11:16:11 +01:00
Tiejun Chen 63bc1398ad tools: introduce some new parameters to set rdm policy
This patch introduces user configurable parameters to specify RDM
resource and according policies,

Global RDM parameter:
    rdm = "strategy=host,policy=strict/relaxed"
Per-device RDM parameter:
    pci = [ 'sbdf, rdm_policy=strict/relaxed' ]

Global RDM parameter, "strategy", allows user to specify reserved regions
explicitly, Currently, using 'host' to include all reserved regions reported
on this platform which is good to handle hotplug scenario. In the future
this parameter may be further extended to allow specifying random regions,
e.g. even those belonging to another platform as a preparation for live
migration with passthrough devices. By default this isn't set so we don't
check all rdms. Instead, we just check rdm specific to a given device if
you're assigning this kind of device. Note this option is not recommended
unless you can make sure any conflict does exist.

'strict/relaxed' policy decides how to handle conflict when reserving RDM
regions in pfn space. If conflict exists, 'strict' means an immediate error
so VM can't keep running, while 'relaxed' allows moving forward with a
warning message thrown out.

Default per-device RDM policy is same as default global RDM policy as being
'relaxed'. And the per-device policy would override the global policy like
others.

CC: Ian Jackson <ian.jackson@eu.citrix.com>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: Ian Campbell <ian.campbell@citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Checked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2015-07-23 13:45:25 +01:00
Fabio Fantoni 05d428addd libxl: Add AHCI support for upstream qemu
Usage:
hdtype=ide|ahci (default=ide)

If hdtype=ahci adds ich9 disk controller in ahci mode and uses it with
upstream qemu to emulate disks instead of ide.
It doesn't support cdroms which still using ide (cdroms will use
"-device ide-cd" as new qemu parameter)
Ahci requires new qemu parameter but for now other emulated disks cases
remains with old ones (I did it in other patch, not needed by this one)
I did it as libxl parameter disabled by default to avoid possible
problems:
- with save/restore/migration (restoring with ahci a domU that was with
ide instead)
- windows < 8 without pv drivers (a registry key change is needed for
AHCI<->IDE change FWIK to avoid possible blue screen)
- windows XP or older that many not support ahci by default.
Setting AHCI with libxl parameter and default to disabled seems the best
solution.
AHCI increase hvm domUs boot performance. On linux hvm domU I saw up to
only 20% of the previous total boot time, whereas boot time decrease a
lot on W7 domUs for most of boots I have done. Small difference in boot
time compared to ide mode on W8 and newer (probably other xen
improvements or fixes are needed not ahci related)

Signed-off-by: Fabio Fantoni <fabio.fantoni@m2r.biz>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- adjust name of LIBXL_HAVE #define as discussed on list,
         fixup pod syntax in xl.cfg.pod.5 ]
2015-07-09 12:15:16 +01:00
Chao Peng 5bedb5b7c6 docs: add xl-psr.markdown
Add document to introduce basic concepts and terms in PSR family
technologies and the xl interfaces.

Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-07-09 10:07:38 +01:00
Dario Faggioli 0e8c53915e docs: get rid of the SEDF scheduler
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-07-08 14:37:43 +01:00
Dario Faggioli bd2f866bc3 xen: get rid of the SEDF scheduler
more specifically, of all the symbols and references
to it.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2015-07-08 14:37:43 +01:00
Chao Peng 65a399acae x86: detect and initialize Intel CAT feature
Detect Intel Cache Allocation Technology(CAT) feature and store the
cpuid information for later use. Currently only L3 cache allocation is
supported. The L3 CAT features may vary among sockets so per-socket
feature information is stored. The initialization can happen either at
boot time or when CPU(s) is hot plugged after booting.

Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>

Use -1 as notifier priority. Fix typos.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
2015-07-07 15:43:33 +02:00
David Vrabel 40de9fffb4 gnttab: make the grant table lock a read-write lock
In combination with the per-active entry locks, the grant table lock
can be made a read-write lock since the majority of cases only the
read lock is required. The grant table read lock protects against
changes to the table version or size (which are done with the write
lock held).

The write lock is also required when two active entries must be
acquired.

The double lock is still required when updating IOMMU page tables.

With the lock contention being only on the maptrack lock (unless IOMMU
updates are required), performance and scalability is improved.

Based on a patch originally by Matt Wilson <msw@amazon.com>.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2015-06-15 13:25:20 +02:00
David Vrabel 5a9899ddc4 gnttab: introduce maptrack lock
Split grant table lock into two separate locks. One to protect
maptrack free list (maptrack_lock) and one for everything else (lock).

Based on a patch originally by Matt Wilson <msw@amazon.com>.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2015-06-15 13:23:34 +02:00
David Vrabel b4650e9a96 gnttab: per-active entry locking
Introduce a per-active entry spin lock to protect active entry state
The grant table lock must be locked before acquiring (locking) an
active entry.

This is a step in reducing contention on the grant table lock, but
will only do so once the grant table lock is turned into a read-write
lock.

Based on a patch originally by Matt Wilson <msw@amazon.com>.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2015-06-15 13:22:07 +02:00
Konrad Rzeszutek Wilk 74cdad5dae EFI: support default attributes to map Runtime service areas with none given
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

For example on Dell machines we see:

(XEN)  00000fed18000-00000fed19fff type=11 attr=8000000000000000
(XEN) Unknown cachability for MFNs 0xfed18-0xfed19

Let's allow them to be mapped as UC.

We also alter the 'efi-rs' to be 'efi=rs' or 'efi=no-rs'.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-06-10 12:04:07 +02:00
Daniel De Graaf 926158e2a1 flask/policy: add initial SIDs for domU/domDM
Add default security contexts to the XSM policy for use by the toolstack
when a domain is created without specifying an explicit security label.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-05-21 15:25:53 +01:00
Wei Liu 9d5eaa6e4c docs: remove qemu-upstream_howto_use_it.markdown
QEMU upstream has been the default for several releases. The only
setting described in that document is no longer required.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Keir Fraser <keir@xen.org>
Cc: Tim Deegan <tim@xen.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-05-21 15:21:34 +01:00
Julien Grall 0b24160656 docs/misc: arm: Add documentation about Device Tree passthrough
Note that the example is done on Midway whose SMMU driver is not
supported on Xen upstream.

Currently, I don't have other platform where I can test Device Tree
passthrough.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-05-21 15:12:09 +01:00
Kai Huang b83bf83c12 vmx: add new boot parameter to control PML enabling
A top level EPT parameter "ept=<options>" and a sub boolean "opt_pml_enabled"
are added to control PML. Other booleans can be further added for any other EPT
related features.

The document description for the new parameter is also added.

Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Kevin Tian <kevin.tian@intel.com>
2015-05-04 12:09:03 +02:00
Ian Campbell 2c2666aa8f docs: efi: given some hint about the dom0 command line
Suggested-by: Carlos Gustavo Ramirez Rodriguez <carlosgrr@gmail.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-04-14 15:00:28 +02:00