Nick Rosbrook [Sat, 4 Jan 2020 21:00:52 +0000 (16:00 -0500)]
golang/xenlight: implement keyed union Go to C marshaling
Since the C union cannot be directly populated, populate the fields of the
corresponding C struct defined in the cgo preamble, and then copy that
struct as bytes into the byte slice that Go uses as the union.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com> Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Roger Pau Monne [Tue, 24 Dec 2019 10:18:10 +0000 (11:18 +0100)]
x86/hvm: always expose x2APIC feature in max HVM cpuid policy
On hardware without x2APIC support Xen emulated local APIC will
provide such mode, and hence the feature should be set in the maximum
HVM cpuid policy.
Not exposing it in the maximum policy results in HVM domains not
getting such feature exposed unless it's also supported by the
underlying hardware.
This was regressed by c/s 3e0c8272f20 which caused x2APIC not to be enabled
unilaterally for HVM guests.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Andrew Cooper [Thu, 19 Dec 2019 21:19:35 +0000 (21:19 +0000)]
libxc/migration: Adjust layout of struct xc_sr_context
We are shortly going to want to introduce some common x86 fields, so having
x86_pv and x86_hvm as the top level objects is a problem. Insert a
surrounding struct x86 and drop the x86 prefix from the pv/hvm objects.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Andrew Cooper [Thu, 5 Dec 2019 15:57:13 +0000 (15:57 +0000)]
tools/migration: Formatting and style cleanup
The code has devating from the prevailing style in many ways. Adjust spacing,
indentation, position of operators, layout of multiline comments, removal of
superfluous comments, constness, trailing commas, and use of unqualified
'unsigned'.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Andrew Cooper [Wed, 15 Jan 2020 18:44:18 +0000 (18:44 +0000)]
xen/vcpu: Improve sanity checks in vcpu_create()
The BUG_ON() is confusing to follow. The (!is_idle_domain(d) || vcpu_id) part
is a vestigial remnant of architectures poisioning idle_vcpu[0] with non-NULL
pointers.
Now that idle_vcpu[0] is NULL on all architectures, and d->max_vcpus specified
before vcpu_create() is called, we can properly range check the requested
vcpu_id.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Acked-by: Julien Grall <julien@xen.org>
Andrew Cooper [Wed, 15 Jan 2020 18:43:58 +0000 (18:43 +0000)]
ARM/boot: Don't poison 'current' during early boot
This logic was inherited from x86 (which was updated several times since).
Unlike x86 (at the time) however, while NULL isn't mapped in ARM, 0xfffff000
is, making this actively dangerous.
Drop the logic entirely, and leave 'current' as NULL during early boot.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Julien Grall <julien@xen.org>
xen/arm: during efi boot, improve the check for usable memory
When booting via EFI, the EFI memory map has information about memory
regions and their type. Improve the check for the type and attribute of
each memory region to figure out whether it is usable memory or not.
This patch brings the check on par with Linux v5.5-rc6 and makes more
memory reusable as normal memory by Xen (except that Linux also reuses
EFI_PERSISTENT_MEMORY, which we do not).
Specifically, this patch also reuses memory marked as
EfiLoaderCode/Data, and it uses both Attribute and Type for the check
(Attribute needs to be EFI_MEMORY_WB).
Tamas K Lengyel [Fri, 10 Jan 2020 02:30:52 +0000 (19:30 -0700)]
Remove undocumented and unmaintained tools/memshr library
The library has been largely untouched for over a decade at this point, it is
undocumented and it's unclear what it was originally used for. Remove it from
tree, if anyone needs it in the future it can be carved out from git history.
Signed-off-by: Tamas K Lengyel <tamas@tklengyel.com> Acked-by: Wei Liu <wl@xen.org>
Andrew Cooper [Fri, 10 Jan 2020 16:06:08 +0000 (16:06 +0000)]
x86/boot: Rename l?_identmap to l?_directmap
Since c/s faa85d4fb3 "x86/boot: Don't map 0 during boot", l1_identmap no
longer has an alias mapped at 0, meaning that none of the l?_identmap[]
pagetables are actually an identity map.
Rename them to l?_directmap, which avoids any kind of implication that they
might be mapped at 0.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Jan Beulich <jbeulich@suse.com>
Andrew Cooper [Fri, 20 Dec 2019 16:34:16 +0000 (16:34 +0000)]
libxc/migration: Rationalise the 'checkpointed' field to 'stream_type'
Originally, 'checkpointed' was a boolean signalling the difference between a
plain and a Remus stream. COLO was added later, but several bits of code
retained boolean-style logic. While correct, it is confusing to follow.
Additionally, XC_MIG_STREAM_NONE means "no checkpoints" but reads as "no
stream".
Consolidate all the logic on the term 'stream_type', and rename STREAM_NONE
to STREAM_PLAIN. Re-position the stream_type variable so it isn't
duplicated in both the save and restore unions.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Andrew Cooper [Wed, 18 Dec 2019 19:01:57 +0000 (19:01 +0000)]
libxc/restore: Introduce functionality to simplify blob handling
During migration, we buffer several blobs of data which ultimately need
handing back to Xen at an appropriate time.
Currently, this is all handled in an ad-hoc manner, but more blobs are soon
going to be added. Introduce xc_sr_blob to encapsulate a ptr/size pair, and
update_blob() to handle the memory management aspects.
Switch the HVM_CONTEXT and the four PV_VCPU_* blobs over to this new
infrastructure. No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
"IRQ: u16 is too narrow for an event channel number" introduced a use of
evetchn_port_t, but its typedef apparently surfaces indirectly here only
on x86.
Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Julien Grall [Thu, 19 Dec 2019 08:12:21 +0000 (08:12 +0000)]
xen/arm: Place a speculation barrier sequence following an eret instruction
Some CPUs can speculate past an ERET instruction and potentially perform
speculative accesses to memory before processing the exception return.
Since the register state is often controlled by lower privilege level
at the point of an ERET, this could potentially be used as part of a
side-channel attack.
Newer CPUs may implement a new SB barrier instruction which acts
as an architected speculation barrier. For current CPUs, the sequence
DSB; ISB is known to prevent speculation.
The latter sequence is heavier than SB but it would never be executed
(this is speculation after all!).
Introduce a new macro 'sb' that could be used when a speculation barrier
is required. For now it is using dsb; isb but this could easily be
updated to cater SB in the future.
Julien Grall [Sat, 11 Jan 2020 00:03:44 +0000 (00:03 +0000)]
docs/misc: pvcalls: Verbatim block should be indented with 4 spaces
At the moment, the diagram is only indented with 2 spaces. So pandoc
will try to badly interpret it and not display it correctly.
Fix it by indenting all the block by 4 spaces (i.e an extra 2 spaces).
Fixes: d661611d08 ("docs/markdown: Switch to using pandoc, and fix underscore escaping") Signed-off-by: Julien Grall <julien@xen.org> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Paul Durrant [Thu, 9 Jan 2020 11:15:05 +0000 (11:15 +0000)]
tools/Rules.mk: fix distclean
Running 'make distclean' under tools will currently result in:
tools/Rules.mk:245: *** You have to run ./configure before building or installing the tools. Stop.
This patch adds 'distclean', 'subdir-distclean%' and 'subdir-clean%' to
no-configure-targets, which allows 'make distclean' to run to completion.
Fixes: 00691c6c (tools: Allow to make *-dir-force-update without ./configure) Signed-off-by: Paul Durrant <pdurrant@amazon.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Wei Liu <wl@xen.org>
Jan Beulich [Tue, 14 Jan 2020 11:03:47 +0000 (12:03 +0100)]
IRQ: u16 is too narrow for an event channel number
FIFO event channels allow ports up to 2^17, so we need to use a wider
field in struct pirq. Move "masked" such that it may share the 8-byte
slot with struct arch_pirq on 64-bit arches, rather than leaving a
7-byte hole in all cases.
Take the opportunity and also add a comment regarding "arch" placement
within the structure.
Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
George Dunlap [Mon, 9 Dec 2019 11:12:07 +0000 (11:12 +0000)]
CODING_STYLE: Document how to handle unexpected conditions
It's not always clear what the best way is to handle unexpected
conditions: whether with ASSERT(), domain_crash(), BUG_ON(), or some
other method. All methods have a risk of introducing security
vulnerabilities and unnecessary instabilities to production systems.
Provide guidelines for different options and when to use them.
Signed-off-by: George Dunlap <george.dunlap@citrix.com> Acked-by: Jan Beulich <jbeulich@suse.com> Acked-by: Julien Grall <julien@xen.org>
Andrew Cooper [Sat, 28 Dec 2019 15:01:00 +0000 (15:01 +0000)]
x86/boot: Drop INVALID_VCPU
Now that NULL will fault at boot, there is no need for a special constant to
signify "current not set up yet".
Since c/s fae249d23413 "x86/boot: Rationalise stack handling during early
boot", the BSP cpu_info block is now consistently zero, so drop the adjacent
re-zeroing.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Andrew Cooper [Mon, 6 Jan 2020 13:37:41 +0000 (13:37 +0000)]
x86/boot: Don't map 0 during boot
In particular, it causes accidental NULL pointer dereferences to go unnoticed.
The majority of the early operation takes place either in Real mode, or
Protected Unpaged mode. The only bit which requires pagetable mappings is the
trampoline transition into Long mode and jump to the higher mappings, so there
is no need for the whole bottom 2M to be mapped.
Introduce a new l1_bootmap in .init.data, and use it instead of l1_identmap.
The EFI boot path doesn't pass through the trampoline, so doesn't need any
adjustment.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Andrew Cooper [Mon, 6 Jan 2020 13:37:54 +0000 (13:37 +0000)]
x86/boot: Clean up l?_bootmap[] construction
The need for Xen to be identity mapped into the bootmap is not obvious, and
differs between the MB and EFI boot paths.
The EFI side is further complicated by an attempt to cope with with l2_bootmap
only being 4k long. This is undocumented, confusing, only works if Xen is the
single object wanting mapping.
The pageables are common to both the MB and EFI builds, so simplify the EFI
bootmap construction code to make exactly one identity-map of Xen, which now
makes the two paths consistent. Comment both pieces of logic, explaining what
the mappings are needed for.
Finally, leave a linker assert covering the fact that plenty of code blindly
assumes that Xen is less that 16M. This wants fixing in due course.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Andrew Cooper [Sat, 28 Dec 2019 14:20:59 +0000 (14:20 +0000)]
x86/boot: Remove the preconstructed low 16M superpage mappings
These are left over from c/s b2804422 "x86: make Xen early boot code
relocatable", which made it possible for Xen not to be in the bottom 16M.
Nothing using the mappings any more. Build them in the directmap when walking
the E820 table along with everything else.
Furthermore, it is undefined to have superpages and MTRRs disagree on
cacheability boundaries, and nothing actually checks. While we don't fix this
explicitly, we do at least honour the E820 now if it says there are boundaries
in this range.
As a consequence, there are now no _PAGE_PRESENT entries between
__page_tables_{start,end} which need to skip relocation. This simplifies the
MB1/2 entry path logic to remove the l2_identmap[] special case.
The low 2M (using 4k pages) is retained for now. Amongst other things, it
matters for console logging while the legacy VGA hole is in use.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Andrew Cooper [Wed, 8 Jan 2020 13:36:42 +0000 (13:36 +0000)]
x86/boot: Rationalise stack handling during early boot
The top (numerically higher addresses) of cpu0_stack[] contains the BSP's
cpu_info block. Logic in Xen expects this to be initialised to 0, but this
area of stack is also used during early boot.
Update the head.S code to avoid using the cpu_info block. Additionally,
update the stack_start variable to match, which avoids __high_start() and
efi_arch_post_exit_boot() needing to make the adjustment manually.
Finally, leave a big warning by the BIOS BSS initialisation, because it is by
no means obvious that the stack doesn't survive the REP STOS.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Jan Beulich [Thu, 9 Jan 2020 10:09:02 +0000 (11:09 +0100)]
x86/MCE: correct struct mcinfo_extended for compat guests
The use of any kind of pointers in the public interface is wrong,
including dimensioning arrays based on the size of pointers. The least
bad option of addressing the issue looks to be to pin down the number
that the (64-bit) hypervisor has used anyway (even when passing
information to compat but privileged guests). There aren't actual
instantiations of the structure apart from ones allocated dynamically
out of struct mc_info's mi_data[], which is entirely controlled by the
hypervisor.
Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Jan Beulich [Thu, 9 Jan 2020 10:08:29 +0000 (11:08 +0100)]
x86/MCE: avoid leaking stack data
While HYPERVISOR_mca is a privileged operation, we still shouldn't leak
stack contents (the tail of every array entry's mc_msrvalues[] of
XEN_MC_physcpuinfo output). Simply use a zeroing allocation here.
Take the occasion and also restrict the involved local variable's scope.
Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Juergen Gross [Thu, 9 Jan 2020 10:07:38 +0000 (11:07 +0100)]
x86: clear per cpu stub page information in cpu_smpboot_free()
cpu_smpboot_free() removes the stubs for the cpu going offline, but it
isn't clearing the related percpu variables. This will result in
crashes when a stub page is released due to all related cpus gone
offline and one of those cpus going online later.
Fix that by clearing stubs.addr and stubs.mfn in order to allocate a
new stub page when needed, irrespective of whether the CPU gets parked
or removed.
Fixes: 2e6c8f182c9c50 ("x86: distinguish CPU offlining from CPU removal") Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Wei Liu <wl@xen.org> Reviewed-by: Jan Beulich <jbeulich@suse.com> Tested-by: Tao Xu <tao3.xu@intel.com>
Andrew Cooper [Wed, 8 Jan 2020 13:11:13 +0000 (13:11 +0000)]
x86/boot: Simplify BSS zeroing
There is no need to load a non-flat %es to zero the BSS. Use sym_esi()
instead, which is easier to follow, faster (avoids two segment loads) and
doesn't require use of the stack.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Andrew Cooper [Mon, 6 Jan 2020 13:36:30 +0000 (13:36 +0000)]
x86/boot: Map the trampoline as read-only
c/s ec92fcd1d08, which caused the trampoline GDT Access bits to be set,
removed the final writes which occurred between enabling paging and switching
to the high mappings. There don't plausibly need to be any memory writes in
few instructions is takes to perform this transition.
As a consequence, we can remove the RWX mapping of the trampoline. It is RX
via its identity mapping below 1M, and RW via the directmap.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Juergen Gross [Wed, 8 Jan 2020 16:57:16 +0000 (17:57 +0100)]
MAINTAINERS: fix malformed entry
MAINTAINERS entries tagged with "L:" should have a pure mail address
as the second word. Fix a malformed entry. Otherwise add_maintainers.pl
will produce an empty "Cc:" line.
Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Jan Beulich <jbeulich@suse.com>
Juergen Gross [Wed, 8 Jan 2020 10:43:24 +0000 (11:43 +0100)]
xen/spinlock: disable spinlock debugging in console_force_unlock()
console_force_unlock() might result in subsequent ASSERT() triggering
when CONFIG_DEBUG_LOCKS was active. Avoid that by calling
spin_debug_disable() in console_force_unlock() and make the spinlock
debug assertions trigger only if spin_debug was active.
Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
mem_sharing.c:361:13: error: 'rmap_has_entries' defined but not used [-Werror=unused-function]
static bool rmap_has_entries(const struct page_info *page)
^
cc1: all warnings being treated as errors
This happens in a release build (disables MEM_SHARING_AUDIT) when
CONFIG_MEM_SHARING is enabled.
Expand both trivial helpers into their single callsite.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tamas K Lengyel <tamas@tklengyel.com>
Wei Liu [Tue, 7 Jan 2020 17:17:03 +0000 (17:17 +0000)]
x86/hyperv: drop all __packed from hyperv-tlfs.h
All structures are already naturally aligned. Linux added those
attributes out of paranoia.
In Xen we've had instance we had to drop pointless __packed to placate
gcc 9 (see ca9310b24e "x86/IO-APIC: fix build with gcc9"), it is better
to drop those attributes in hyperv-tlfs.h as well.
Requested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Wei Liu <liuwe@microsoft.com> Acked-by: Jan Beulich <jbeulich@suse.com>
Jan Beulich [Wed, 8 Jan 2020 14:04:36 +0000 (15:04 +0100)]
libxl: don't needlessly report "highmem" in use
Due to the unconditional updating of dom->highmem_end in
libxl__domain_device_construct_rdm() I've observed on a 2Gb HVM guest
with a passed through device (without overly large BARs, and with no RDM
ranges at all)
Jan Beulich [Wed, 8 Jan 2020 14:03:19 +0000 (15:03 +0100)]
x86/mm: rename and tidy create_pae_xen_mappings()
After dad74b0f9e ("i386: fix handling of Xen entries in final L2 page
table") and the removal of 32-bit support the function doesn't modify
state anymore, and hence its name has been misleading. Change its name,
constify parameters and a local variable, and make it return bool.
Also drop the call to it from mod_l3_entry(): The function explicitly
disallows 32-bit domains to modify slot 3. This way we also won't
re-check slot 3 when a slot other than slot 3 changes. Doing so has
needlessly disallowed making some L2 table recursively link back to an
L2 used in some L3's 3rd slot, as we check for the type ref count to be
1. (Note that allowing dynamic changes of L3 entries in the way we do is
bogus anyway, as that's not how L3s behave in the native and EPT cases:
They get re-evaluated only upon CR3 reloads. NPT is different in this
regard.)
As a result of this we no longer need to play games to get at the start
of the L3 table.
Additionally move the single remaining call site, allowing to drop one
is_pv_32bit_domain() invocation and a _PAGE_PRESENT check (in the
function itself) as well as to exit the loop early (remaining entries
have all been set to empty just ahead of this loop).
Further move a BUG_ON() such that in the common case its condition
wouldn't need evaluating.
Finally, since we're at it, move init_xen_pae_l2_slots() next to the
renamed function, as they really belong together (in fact
init_xen_pae_l2_slots() was [indirectly] broken out of this function).
Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Jan Beulich [Wed, 8 Jan 2020 14:02:26 +0000 (15:02 +0100)]
x86/mm: mod_l<N>_entry() have no need to use __copy_from_user()
mod_l1_entry()'s need to do so went away with commit 2d0557c5cb ("x86:
Fold page_info lock into type_info"), and the other three never had such
a need, at least going back as far as 3.2.0. Replace the uses by
l<N>e_read_atomic().
Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Juergen Gross [Wed, 8 Jan 2020 13:59:25 +0000 (14:59 +0100)]
sched: fix resuming from S3 with smt=0
When resuming from S3 and smt=0 or maxcpus= are specified we must not
do anything in cpu_schedule_callback(). This is not true today for
taking down a cpu during resume.
If anything goes wrong during resume all the scheduler related error
handling is in cpupool.c, so we can just bail out early from
cpu_schedule_callback() when suspending or resuming.
This fixes commit 0763cd2687897b55e7 ("xen/sched: don't disable
scheduler on cpus during suspend").
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: George Dunlap <george.dunlap@citrix.com>
Wei Liu [Tue, 7 Jan 2020 12:06:49 +0000 (12:06 +0000)]
x86/mm: change pl*e to l*t in virt_to_xen_l*e
We will need to have a variable named pl*e when we rewrite
virt_to_xen_l*e. Change pl*e to l*t to reflect better its purpose.
This will make reviewing later patch easier.
No functional change.
Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: Hongyan Xia <hongyxia@amazon.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Wei Liu [Tue, 7 Jan 2020 12:06:46 +0000 (12:06 +0000)]
x86/mm: introduce l{1,2}t local variables to modify_xen_mappings
The pl2e and pl1e variables are heavily (ab)used in that function. It
is fine at the moment because all page tables are always mapped so
there is no need to track the life time of each variable.
We will soon have the requirement to map and unmap page tables. We
need to track the life time of each variable to avoid leakage.
Introduce some l{1,2}t variables with limited scope so that we can
track life time of pointers to xen page tables more easily.
No functional change.
Signed-off-by: Wei Liu <wei.liu2@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Wei Liu [Tue, 7 Jan 2020 12:06:45 +0000 (12:06 +0000)]
x86/mm: introduce l{1,2}t local variables to map_pages_to_xen
The pl2e and pl1e variables are heavily (ab)used in that function. It
is fine at the moment because all page tables are always mapped so
there is no need to track the life time of each variable.
We will soon have the requirement to map and unmap page tables. We
need to track the life time of each variable to avoid leakage.
Introduce some l{1,2}t variables with limited scope so that we can
track life time of pointers to xen page tables more easily.
No functional change.
Signed-off-by: Wei Liu <wei.liu2@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Andrew Cooper [Tue, 17 Dec 2019 18:20:33 +0000 (18:20 +0000)]
tools/dombuilder: Don't allocate dom->p2m_host[] for translated domains
xc_dom_p2m() and dom->p2m_host[] implement a linear transform for translated
domains, but waste a substantial chunk of RAM doing so.
ARM literally never reads dom->p2m_host[] (because of the xc_dom_translated()
short circuit in xc_dom_p2m()). Drop it all.
x86 HVM does use dom->p2m_host[] for xc_domain_populate_physmap_exact() calls
when populating 4k pages. Reuse the same tactic from 2M/1G ranges and use an
on-stack array instead. Drop the memory allocation.
x86 PV guests do use dom->p2m_host[] as a non-identity transform. Rename the
field to pv_p2m to make it clear it is PV-only.
No change in the constructed guests.
Reported-by: Varad Gautam <vrd@amazon.de> Reported-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Wei Liu <wl@xen.org>
Andrew Cooper [Tue, 17 Dec 2019 17:41:36 +0000 (17:41 +0000)]
tools/dombuilder: Remove p2m_guest from the common interface
In-guest p2m's are a concept specific to x86 PV guests. alloc_p2m_list() is
the only hook which initialises dom->p2m_guest, making
xc_dom_update_guest_p2m() a nop for non-PV guests.
Move p2m_guest into xc_dom_image_x86 and adjust alloc_p2m_list() to match.
Drop xc_dom_update_guest_p2m() entirely.
One caller, move_l3_below_4G(), only uses it to modify a single entry, so
rewriting the whole guest p2m is wasteful - opencode the single update
instead. The other caller is common code. Instead, move the logic into the
setup_pgtables() hooks, which know their own sizeof_pfn and can do away with
the switch statement.
No change in the constructed guests.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Wei Liu <wl@xen.org>
Andrew Cooper [Tue, 17 Dec 2019 17:08:22 +0000 (17:08 +0000)]
tools/dombuilder: Remove PV-only, mandatory hooks
Currently, the setup_pgtable() hook is optional, but alloc_pgtable() hook is
not. Both are specific to x86 PV guests, and stubbed in various ways by the
dombuilders for translated guests (x86 HVM, ARM).
Make alloc_pgtables() optional, and drop all the stubs for translated guest
types.
No change in the constructed guests.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Wei Liu <wl@xen.org> Acked-by: Julien Grall <julien@xen.org>
Andrew Cooper [Tue, 17 Dec 2019 17:03:17 +0000 (17:03 +0000)]
tools/dombuilder: xc_dom_x86 cleanup
The two xc_dom_params structures for PV pagetables are never modified and can
live in .rodata. Reduce their scope to the alloc_pgtable_*() functions which
construct xc_dom_image_x86 appropriately.
Rename {alloc,setup}_pgtables() to {alloc,setup}_pgtables_pv() to highlight
that they are PV only, and drop some _x86() suffixes from static helpers.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Wei Liu <wl@xen.org>
And the following reduced to stubs:
arch_iommu_hwdom_init 852 2 -850
p2m_add_foreign 880 16 -864
This patch also has the unintended but useful consequence of stopping
hardware_dom= functionality from being usable (in at least PV_SHIM_EXCLUSIVE
builds).
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Wei Liu <wl@xen.org> Tested-by: Sergey Dyasli <sergey.dyasli@citrix.com>
Andrew Cooper [Fri, 3 Jan 2020 18:31:46 +0000 (18:31 +0000)]
tools/save: Drop unused parameters from xc_domain_save()
XCFLAGS_CHECKPOINT_COMPRESS has been unused since c/s b15bc4345 (2015),
XCFLAGS_HVM since c/s 9e8672f1c (2013), and XCFLAGS_STDVGA since c/s 087d43326 (2007). Drop the constants, and code which sets them.
The separate hvm parameter (appeared in c/s d11bec8a1, 2007 and ultimately
redundant with XCFLAGS_HVM), is used for sanity checking and debug printing,
then discarded and replaced with Xen's idea of whether the domain is PV or
HVM.
Rearrange the logic in xc_domain_save() to ask Xen sightly earlier, and use a
consistent idea of 'hvm' throughout. Removing this parameter removes the
final user of libxl's dss->hvm, so drop that field as well.
Update the doxygen comment to be accurate.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Jackson <Ian.Jackson@citrix.com>
livepatch: use proper rc variable in livepatch_do_action()
Fix c&p bug in the livepatch_do_action() code of
LIVEPATCH_ACTION_REPLACE case.
The correct variable handling return code of revert action is
other->rc in this case.
Coverity-ID: 1457467 Fixes: 6047104c3c ("livepatch: Add per-function applied/reverted state tracking marker") Reported-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Pawel Wieczorkiewicz <wipawel@amazon.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Andrew Cooper [Mon, 6 Jan 2020 13:26:28 +0000 (13:26 +0000)]
Coverity: Improve model for {,un}map_domain_page()
The first attempt resulted in several "Free of address-of
expression (BAD_FREE)" issues, because of code which relies on the fact that
any pointer in the same page is ok to pass to unmap_domain_page()
Model this property to remove the issues.
Coverity IDs: 1135356 113536{0,1} 1401300 141809{0,1} 1438864 Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Jan Beulich <jbeulich@suse.com>
Roger Pau Monne [Fri, 3 Jan 2020 17:29:35 +0000 (18:29 +0100)]
tools/libxc: disable x2APIC when using nested virtualization
There are issues as reported by osstest when Xen is running nested on
itself and the L1 Xen is using x2APIC. While those are being
investigated, disable announcing the x2APIC feature in CPUID when nested
HVM mode is enabled.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Wei Liu <wl@xen.org>
Juergen Gross [Thu, 19 Dec 2019 07:42:08 +0000 (08:42 +0100)]
xen: put more code under CONFIG_CRASH_DEBUG
debugger_trap_entry() is not needed without CONFIG_CRASH_DEBUG, so only
include it if CONFIG_CRASH_DEBUG is defined.
While at it remove CONFIG_HAS_GDBSX as it can easily be replaced by
CONFIG_CRASH_DEBUG.
Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: George Dunlap <george.dunlap@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Andrew Cooper [Fri, 3 Jan 2020 17:06:51 +0000 (17:06 +0000)]
tools/restore: Drop unused parameters from xc_domain_restore()
The hvm and pae parameters are a remnant of legacy migration. They have 0
passed in from libxl_stream_read.c's process_record(), and are discarded in
xc_domain_restore().
While dropping these, update the doxygen comment to be accurate, and simplify
the other hvm vs pv handling in xc_domain_restore().
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Andrew Cooper [Thu, 2 Jan 2020 14:38:32 +0000 (14:38 +0000)]
x86/boot: Clean up the trampoline transition into Long mode
The jmp after setting %cr0 is redundant with the following ljmp.
The CPUID to protect the jump to higher mappings was inserted due to an
abundance of caution/paranoia before Spectre was public. It doesn't usefully
protect against an attack, which is able to leak memory with one single
instruction's worth of onward speculation.
Only CPU Hotplug (if used at all) will use this path while guests are
executing. An attacker would have to be running and primed on an adjacent
thread while a hotplug event occurred, to gain one single data sample, and
have some other way of inferring that a hotplug event has occurred, which it
won't know directly.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Jan Beulich <jbeulich@suse.com>
Andrew Cooper [Thu, 2 Jan 2020 13:52:23 +0000 (13:52 +0000)]
xen/efi: Drop infinite loops and use unreachable()/noreturn
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Wei Liu <wl@xen.org> Acked-by: Jan Beulich <jbeulich@suse.com> Acked-by: Julien Grall <julien@xen.org>
Paul Durrant [Fri, 3 Jan 2020 16:06:57 +0000 (17:06 +0100)]
domctl: return EEXIST from XEN_DOMCTL_createdomain...
...if a specified domid is already in use.
XEN_DOMCTL_createdomain allows a domid to be specified by its caller and
will correctly fail if that domid is already in use. However the errno
returned in this case will be EINVAL, making it indistinguishable from
several other failures. Also a value of EINVAL does not seem appropriate
as the specified domid is valid [1] but just not (transiently) available.
[1] any invalid value passed in is ignored and causes Xen to choose an
unused and valid value.
Signed-off-by: Paul Durrant <pdurrant@amazon.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Paul Durrant [Fri, 3 Jan 2020 16:06:03 +0000 (17:06 +0100)]
x86/save: reserve HVM save record numbers that have been consumed...
...for patches not (yet) upstream.
This patch is simply adding a comment to reserve save record number space
to avoid the risk of clashes between existent downstream changes made by
Amazon and future upstream changes which may be incompatible.
Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: Wei Liu <wl@xen.org> Acked-by: Jan Beulich <jbeulich@suse.com>
Jan Beulich [Fri, 3 Jan 2020 16:04:41 +0000 (17:04 +0100)]
x86/HVM: use single (atomic) MOV for aligned emulated writes
Using memcpy() may result in multiple individual byte accesses
(dependening how memcpy() is implemented and how the resulting insns,
e.g. REP MOVSB, get carried out in hardware), which isn't what we
want/need for carrying out guest insns as correctly as possible. Fall
back to memcpy() only for accesses not 2, 4, or 8 bytes in size.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Ian Jackson [Fri, 13 Dec 2019 17:01:44 +0000 (17:01 +0000)]
docs/process/branching-checklist: Fix a broken rune
cr-daily-branch ought to be called via cr-for-branches so that we take
the lock. Otherwise strange things can occur if cron runs
cr-daily-branch in the same directory - in particular, it will be
likely to update the osstest revision, breaking everything.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Andrew Cooper [Fri, 26 Apr 2019 15:53:27 +0000 (16:53 +0100)]
xen/tasklet: Switch data parameter from unsigned long to void *.
Most users pass a vcpu pointer, and only stopmachine_action() takes an integer
parameter. Switch to using void * to substantially reduce the number of
explicit casts.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Julien Grall <julien@xen.org> Acked-by: Jan Beulich <jbeulich@suse.com>
Andrew Cooper [Thu, 11 Apr 2019 12:54:36 +0000 (13:54 +0100)]
xen/tasklet: Fix return value truncation on arm64
The use of return_reg() assumes ARM's 32bit ABI. Therefore, a failure such as
-EINVAL will appear as a large positive number near 4 billion to a 64bit ARM
guest which happens to use continue_hypercall_on_cpu().
Introduce a new arch_hypercall_tasklet_result() hook which is implemented by
both architectures, and drop the return_reg() macros. This logic will be
extended in a later change to make continuations out of the tasklet work.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Julien Grall <julien@xen.org>
Andrew Cooper [Thu, 31 May 2018 17:50:50 +0000 (18:50 +0100)]
x86/debug: Plumb pending_dbg through the monitor and devicemodel interfaces
Like %cr2 for pagefaults, %dr6 contains ancillary information for debug
exceptions, and needs similar handling.
For xendevicemodel_inject_event(), no ABI change is needed (although an API
one would be ideal). Switch from 'cr2' to 'extra' in variable names which
don't constitute an API change, and update the documentation to match.
For the monitor interface, vm_event_debug needs extending with a pending_dbg
field. This shall behave like the VT-x PENDING_DBG control. Extend
hvm_monitor_debug() and for now, always pass in 0 - this will be fixed
eventually, when other hypervisor bugfixes are complete.
While modifying hvm_monitor_debug(), take the opportunity to correct trap type
and instruction length from unsigned long to unsigned int, as they are both
tiny values.
Finally, adjust xen-access.c to the new expectations. Introspection tools
intercepting debug exceptions should mirror the new pending_dbg field into
xendevicemodel_inject_event() for %dr6 to be processed correctly for the
guest.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Tamas K Lengyel <tamas@tklengyel.com> Acked-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Petre Pircalabu <ppircalabu@bitdefender.com>
Andrew Cooper [Fri, 20 Dec 2019 15:26:00 +0000 (15:26 +0000)]
tools/libxc: Fix HVM_PARAM_PAE_ENABLED handling in xc_cpuid_apply_policy()
Despite as suggested in c/s 685e922d6f3, not all HVM_PARAMs are handled
in the same way. HVM_PARAM_PAE_ENABLED is a toolstack-only value, and
the xc_cpuid_apply_policy() used to be the only consumer.
Reinstate the old behaviour (mad as it is) to avoid regressions.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Jan Beulich <jbeulich@suse.com>
Andrew Cooper [Mon, 19 Aug 2019 13:16:53 +0000 (14:16 +0100)]
x86/boot: Reposition trampoline data
... to separate code from data. In particular, trampoline_realmode_entry's
write to trampoline_cpu_started clobbers the I-cache line containing
trampoline_protmode_entry, which won't be great for AP startup performance.
Reformat the comments for trampoline_gdt to reduce their volume.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Jan Beulich <jbeulich@suse.com>
Jan Beulich [Fri, 27 Dec 2019 09:01:43 +0000 (10:01 +0100)]
x86/mm: avoid IOMMU operations in more cases in _get_page_type()
All that really matters is whether writability of a page changes; in
particular e.g. page table -> page table (but different levels)
transitions do not require unmapping the page from the IOMMU again.
Note that the XSA-288 fix did arrange for PGT_none pages not needing
special consideration here.
Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Jan Beulich [Fri, 27 Dec 2019 08:57:05 +0000 (09:57 +0100)]
x86: move vgc_flags to struct pv_vcpu
There's been effectively no use of the field for HVM.
Also shrink the field to unsigned int, even if this doesn't immediately
yield any space benefit for the structure itself. The resulting 32-bit
padding slot can eventually be used for some other field. The change in
size makes accesses slightly more efficient though, as no REX.W prefix
is going to be needed anymore on the respective insns.
Mirror the HVM side change here (dropping of setting the field to
VGCF_online) also to Arm, on the assumption that it was cloned like
this originally. VGCF_online really should simply and consistently be
the guest view of the inverse of VPF_down, and hence needs representing
only in the get/set vCPU context interfaces.
Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Jan Beulich [Fri, 27 Dec 2019 08:56:04 +0000 (09:56 +0100)]
x86: move and rename NR_VECTORS
This is an architectural definition, so move it to x86-defns.h and add
an X86_ prefix. This in particular allows removing the inclusion of
irq_vectors.h by virtually every source file, due to irq.h and
hvm/vmx/vmcs.h having needed to include it: Changes to IRQ vector usage
shouldn't really trigger full rebuilds.
Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Jan Beulich [Fri, 27 Dec 2019 08:54:59 +0000 (09:54 +0100)]
x86/IRQ: re-use legacy vector ranges on APs
The legacy vectors have been actively used on CPU 0 only. CPUs not
sharing vector space with CPU 0 can easily re-use them, slightly
increasing the relatively scarce resource of total vectors available in
the system. As a result the legacy vector range simply becomes a
sub-range of the dynamic one, with an extra check performed in
_assign_irq_vector() (we can't rely on the
"per_cpu(vector_irq, new_cpu)[vector] >= 0" check in the subsequent
loop, as we need to also exclude vectors of disabled legacy IRQs).
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Jan Beulich [Fri, 27 Dec 2019 08:54:19 +0000 (09:54 +0100)]
x86/IRQ: flip legacy and dynamic vector ranges
There's no reason to have the PIC vectors (which are typically entirely
unused on 64-bit systems anyway) right below the high priority ones. Put
them in the lowest possible range, and shift the dynamic vector range up
accordingly. This is to reduce the priority of PIC vectors in the LAPIC
vs all other ones.
Note that irq_move_cleanup_interrupt(), despite using
FIRST_DYNAMIC_VECTOR, does not get touched, as PIC interrupts aren't
movable.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Jan Beulich [Fri, 27 Dec 2019 08:53:35 +0000 (09:53 +0100)]
x86/IRQ: simplify pending EOI stack logic for internally used IRQs
In 5655ce8b1ec2 ("x86/IRQ: make internally used IRQs also honor the
pending EOI stack") it was mentioned that both the check_eoi_deferral
per-CPU variable and the cpu_has_pending_apic_eoi() were added just to
have as little impact on existing behavior as possible, to reduce the
risk of a last minute regression in 4.13.
Upon closer inspection, dropping the variable is an option only if all
callers of ->end() would assume the responsibility of also calling
flush_ready_eoi(). Therefore only drop the cpu_has_pending_apic_eoi()
guard now.
Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Jan Beulich [Fri, 27 Dec 2019 08:52:41 +0000 (09:52 +0100)]
x86/IRQ: move and rename __do_IRQ_guest()
This is for it to be next to do_IRQ(). Beyond the actual code movement
this
- drops the leading underscores,
- passes in desc and vector, rather than irq,
- flips the order of two ASSERT()s,
- changes i and sp to unsigned int,
- restricts the scope of d and sp,
- corrects style.
Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Jan Beulich [Fri, 27 Dec 2019 08:51:52 +0000 (09:51 +0100)]
x86/IRQ: move do_IRQ()
This is to avoid forward declarations of static functions. Beyond the
actual code movement this does
- u8 -> uint8_t,
- convert to Xen style,
- drop unnecessary parentheses and alike,
- strip trailing white space.
Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Paul Durrant [Fri, 27 Dec 2019 08:50:31 +0000 (09:50 +0100)]
x86/hvm/rtc: preserved guest RTC offset during suspend/resume/migrate
The emulated RTC is synchronized with the PV wallclock; any write to the
RTC will update struct domain's 'time_offset_seconds' field and call
update_domain_wallclock().
However, the value of 'time_offset_seconds' is not preserved in any save
record and indeed, when the RTC save record is loaded, the CMOS values
will be updated based on an offset value which may or may not have been
set by the toolstack [1]. This may result in making bogus values available
to the guest and messing up any calculations done in the call to
alarm_timer_update() at the end of rtc_load().
This patch extends the RTC save record to contain an offset value, which
will be zero filled on load of an older record. The 'time_offset_secoonds'
field in struct domain is also modified into a 'time_offset' struct,
containing a 'seconds' field and a boolean 'set' field.
The code in rtc_load() then uses the new value in the save record to
update the value of struct domain's 'time_offset.seconds' unless
'time_offset.set' is true, which will only be the case if the toolstack has
already performed a XEN_DOMCTL_settimeoffset.
[1] There is currently no way for a toolstack to read the value of
'time_offset_seconds' from struct domain. In the past, any hope of
preservation of the value across a guest life-cycle operation was based
on relying on qemu-dm to write a value into xenstore whenever the RTC
was updated, in response to an IOREQ with type IOREQ_TYPE_TIMEOFFSET
being sent by Xen; see:
but this behaviour was never forward-ported into upstream QEMU, which
completely ignores that IOREQ type.
In either case, nothing in xl or libxl ever samples the value of
RTC offset from xenstore so any offset adjustment to a non-zero value
performed by the guest (which in the case of Windows is highly likely
as it normally writes RTC in local time, whereas Xen maintains time in
UTC) is completely lost with the de-facto toolstack, and always has
been. Instead, PV drivers are relied upon to paper over this gaping
hole.
Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Acked-by: Julien Grall <julien@xen.org>
Roger Pau Monne [Tue, 24 Dec 2019 15:32:47 +0000 (16:32 +0100)]
x86/vvmx: virtualize x2APIC mode and APIC accesses can't both be enabled
According to the Intel SDM, "virtualize x2APIC mode" and "virtualize
APIC accesses" can't be enabled at the same time, or else a
vm{launch/entry} failure will happen. This was seen when running Xen
nested and with x2APIC enabled:
(XEN) d3v0 VMLAUNCH error: 0x7
[...]
(XEN) *** Control State ***
(XEN) PinBased=0000003f CPUBased=b6a075fe SecondaryExec=000014fb
[...]
Fix this by making sure nvmx_update_secondary_exec_control clears the
incompatible bits from the host vmcs before merging it with the nested
vmcs.
This fixes a regression reported by osstest in the
test-amd64-amd64-qemuu-nested-intel job.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Andrew Cooper [Tue, 17 Dec 2019 17:49:47 +0000 (17:49 +0000)]
libxc/migration: Drop unimplemented domain types
x86 PVH is completely obsolete - it was intended for legacy PVH before that
idea was abandoned. There was an RFC series for ARM in 2015, but there is
plenty of outstanding work which hasn't been done yet.
No functional change. New types can be (re)introduced with the code which
actually implements them.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Julien Grall <julien@xen.org> Acked-by: Wei Liu <wl@xen.org> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Andrew Cooper [Wed, 18 Dec 2019 19:43:18 +0000 (19:43 +0000)]
libxc/restore: Don't duplicate state in process_vcpu_basic()
vcpu_guest_context_any_t is currently allocated on the stack, and copied from
a mutable buffer which is freed immediately after its use here. Mutate the
buffer in place instead of duplicating it.
The code is as it is due to how it was developed. Originally,
process_vcpu_basic() operated on a const pointer from the X86_VCPU_BASIC
record, but during upstreaming, the addition of Remus support required
buffering of X86_VCPU_BASIC records each checkpoint.
By the time process_vcpu_basic() runs, we are commited to completing state
restoration and unpausing the guest.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Nick Rosbrook [Mon, 23 Dec 2019 15:17:06 +0000 (10:17 -0500)]
golang/xenlight: revise use of Context type
Remove the exported global context variable, 'Ctx.' Generally, it is
better to not export global variables for use through a Go package.
However, there are some exceptions that can be found in the standard
library.
Add a NewContext function instead, and remove the Open, IsOpen, and
CheckOpen functions as a result.
Also, comment-out an ineffectual assignment to 'err' inside the function
Context.CpupoolInfo so that compilation does not fail.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com> Reviewed-by: George Dunlap <george.dunlap@citrix.com>
projects / people / dwmw2 / xen.git / log