-LONG_MIN cannot be represented in a long and hence is UB, for being one
larger than LONG_MAX.
The caller passing an unsigned long and the 1st param also being (array
of) unsigned long, change the 2nd param accordingly while adding the
sole necessary cast. This was the original form of the function anyway.
Fixes: 5644ce0142 ("x86emul: relax asm() constraints")
Oss-fuzz: 70923
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
For widening and narrowing moves, operand (vector) size is calculated
from a table. This calculation, for the AVX512 cases, lives ahead of
validation of EVEX.L'L (which cannot be 3 without raising #UD). Account
for the later checking by adjusting the constants in the expression such
that even EVEX.L'L == 3 will yield a non-UB shift (read: shift count
reliably >= 0).
Fixes: 3988beb08 ("x86emul: support AVX512{F,BW} zero- and sign-extending moves")
Oss-fuzz: 70914
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Being able to recognize that "par" is reliably initialized on the 1st
loop iteration requires not overly old compilers.
Fixes: 7809132b1a ("tools/xen-9pfsd: add 9pfs response generation support")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Do as was decided in Lisbon. Reportedly Xen hasn't been working very
well on those processors anyway.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Therefore with SHADOW_PAGING=n this is better compiled out, to avoid
leaving around unreachable/dead code.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
No other arch-*.h does so, and arch-x86/xen.h really just takes the role
of arch-x86_32.h and arch-x86_64.h (by those two forwarding there). With
xen.h itself including the per-arch headers, doing so is also kind of
backwards anyway, and just calling for problems. There's exactly one
place where arch-x86/xen.h is included when really xen.h is meant (for
wanting XEN_GUEST_HANDLE_64() to be made available, the default
definition of which lives in the common xen.h).
This then addresses a violation of Misra C:2012 Directive 4.10
("Precautions shall be taken in order to prevent the contents of a
header file being included more than once").
Reported-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
There's no use of them anymore except in the definitions of the non-
underscore-prefixed aliases.
On Arm convert the (renamed) inline function to a macro.
On x86 rename the inline functions, adjust the virt_to_maddr() #define,
and purge the maddr_to_virt() one, thus eliminating a bogus cast which
would have allowed the passing of a pointer type variable into
maddr_to_virt() to go silently.
No functional change intended.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Julien Grall <jgrall@amazon.com>
At least in pure address calculation use the intended basic construct
instead of opend-coded left-shifting by PAGE_SHIFT. Leave alone page
table entry calculations for now, as those aren't really calculating
addresses.
No functional change.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
This really is gfn_to_gaddr() in disguise; no need to have two variants
of the same logic.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
While we didn't copy the full Linux commentary, Linux commit
7180d4fb8308 ("x86_64: Fix 64bit FXSAVE encoding") is quite explicit
about gas 2.16 supporting FXSAVEQ / FXRSTORQ. As that's presently our
minimal required version, we can drop the workaround that was needed for
yet older gas.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Let the subtree fall under general x86 maintainership instead, then also
properly reflecting Roger's role there.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Forever since its introduction the main loop in the function dealing
with multi-vector MSI had error exit points ("break") with different
properties: In one case no IRQ descriptor lock is being held.
Nevertheless the subsequent error cleanup path assumed such a lock would
uniformly need releasing. Identify the case by setting "desc" to NULL,
thus allowing the unlock to be skipped as necessary.
This is CVE-2024-31143 / XSA-458.
Coverity ID: 1605298
Fixes: d1b6d0a024 ("x86: enable multi-vector MSI")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
PVH in particular has no (externally visible) notion of pIRQ-s. Mention
that in the description of the respective command line option and have
arch_hwdom_irqs() also reflect this (thus suppressing the log message
there as well, as being pretty meaningless in this case anyway).
Suggested-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Much like noted in 43d5c5d5f7 ("xen: avoid UB in guest handle
arithmetic"), address calculations involved in accessing a struct field
can overflow, too. Cast respective pointers to "unsigned long" and
convert type checking accordingly. Remaining arithmetic is, despite
there possibly being mathematical overflow, okay as per the C99 spec:
"A computation involving unsigned operands can never overflow, because a
result that cannot be represented by the resulting unsigned integer type
is reduced modulo the number that is one greater than the largest value
that can be represented by the resulting type." The overflow that we
need to guard against is checked for in array_access_ok().
While there add the missing (see {,__}copy_to_guest_offset()) is-not-
const checks to {,__}copy_field_to_guest().
Typically, but not always, no change to generated code; code generation
(register allocation) is different for at least common/grant_table.c.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
While doing so is intentional when invoking the actual callback, to
mimic a hard-coded SYCALL_MASK / FMASK MSR, the same should not be done
when no handler is available and hence #UD is raised.
Fixes: ca6fcf4321 ("x86/pv: Inject #UD for missing SYSCALL callbacks")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
PHYSDEVOP_pirq_eoi_gmfn_v<N> accepting just a single GFN implies that no
more than 32k pIRQ-s can be used by a domain on x86. Document this upper
bound.
To also enforce the limit, (ab)use both arch_hwdom_irqs() (changing its
parameter type) and setup_system_domains(). This is primarily to avoid
exposing the two static variables or introducing yet further arch hooks.
While touching arch_hwdom_irqs() also mark it hwdom-init.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Its original introduction had two issues: For one the "common" part of
the checks (carried out in the macro) was inverted. And then after
removal from the radix tree the structure wasn't scheduled for freeing.
(All structures still left in the radix tree would be freed upon domain
destruction, though.)
For the freeing to be safe even if it didn't use RCU (i.e. to avoid use-
after-free), re-arrange checks/operations in evtchn_close(), such that
the pointer wouldn't be used anymore after calling pirq_cleanup_check()
(noting that unmap_domain_pirq_emuirq() itself calls the function in the
success case).
Fixes: c24536b636 ("replace d->nr_pirqs sized arrays with radix tree")
Fixes: 79858fee30 ("xen: fix hvm_domain_use_pirq's behavior")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
The odd DEFINE_XEN_GUEST_HANDLE(), inconsistent with all other similar
constructs, should have caught my attention. Turns out it was needed for
the build to succeed merely because the corresponding #ifndef had a
typo. That typo in turn broke compat mode guests, by having query-size
requests of theirs wire into the domain_crash() at the bottom of the
switch().
Fixes: 8c3bb4d8ce ("xen/gnttab: Perform compat/native gnttab_query_size check")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <Oleksii.kurochko@gmail.com>
When re-working them to avoid UB on guest address calculations, I failed
to add explicit type checks in exchange for the implicit ones that until
then had happened in assignments that were there anyway.
Fixes: 43d5c5d5f7 ("xen: avoid UB in guest handle arithmetic")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
The emulation_count field is set only conditionally right now. Convert
all field setting to an initializer, thus guaranteeing that field to be
set to 0 (default initialized) when GUEST_PAGING_LEVELS != 3.
Rework trace_shadow_emulate() to be consistent with the other trace helpers.
Coverity-ID: 1598430
Fixes: 9a86ac1aa3 ("xentrace 5/7: Additional tracing for the shadow code")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
When the left shift amount is up to 31, the shifted quantity wants to be
of unsigned int (or wider) type.
While there also adjust types: get doesn't alter the array and returns a
boolean, while both don't really accept negative "nr". Drop a stray
blank each as well.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
As was made noticeable by the last of the commits referenced below,
using a fixed-size type for such purposes is not only against
./CODING_STYLE, but can lead to actual issues. Switch to using size_t
instead, thus also allowing calculations to be lighter-weight in 32-bit
builds.
No functional change for 64-bit builds.
Link: https://gitlab.com/xen-project/xen/-/jobs/7136417308
Fixes: b145b4a39c ("livepatch: Handle arbitrary size names with the list operation")
Fixes: 5083e0ff93 ("livepatch: Add metadata runtime retrieval mechanism")
Fixes: 43d5c5d5f7 ("xen: avoid UB in guest handle arithmetic")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
At least XENMEM_memory_exchange can have huge values passed in the
nr_extents and nr_exchanged fields. Adding such values to pointers can
overflow, resulting in UB. Cast respective pointers to "unsigned long"
while at the same time making the necessary multiplication explicit.
Remaining arithmetic is, despite there possibly being mathematical
overflow, okay as per the C99 spec: "A computation involving unsigned
operands can never overflow, because a result that cannot be represented
by the resulting unsigned integer type is reduced modulo the number that
is one greater than the largest value that can be represented by the
resulting type." The overflow that we need to guard against is checked
for in array_access_ok().
Note that in / down from array_access_ok() the address value is only
ever cast to "unsigned long" anyway, which is why in the invocation from
guest_handle_subrange_okay() the value doesn't need casting back to
pointer type.
In compat grant table code change two guest_handle_add_offset() to avoid
passing in negative offsets.
Since {,__}clear_guest_offset() need touching anyway, also deal with
another (latent) issue there: They were losing the handle type, i.e. the
size of the individual objects accessed. Luckily the few users we
presently have all pass char or uint8 handles.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Intel CPUs have a MSR bit to limit CPUID enumeration to leaf two. If
this bit is set by the BIOS then CPUID evaluation does not work when
data from any leaf greater than two is needed; early_cpu_init() in
particular wants to collect leaf 7 data.
Cure this by unlocking CPUID right before evaluating anything which
depends on the maximum CPUID leaf being greater than two.
Inspired by (and description cloned from) Linux commit 0c2f6d04619e
("x86/topology/intel: Unlock CPUID before evaluating anything").
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
mfn_valid() is RAM-focused; it will often return false for MMIO. Yet
access to actual MMIO space should not generally be restricted to UC
only; especially video frame buffer accesses are unduly affected by such
a restriction.
Since, as of 777c71d313 ("x86/EPT: avoid marking non-present entries
for re-configuring"), the function won't be called with INVALID_MFN or,
worse, truncated forms thereof anymore, we call fully drop that check.
Fixes: 81fd0d3ca4 ("x86/hvm: simplify 'mmio_direct' check in epte_get_entry_emt()")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
For non-present entries EMT, like most other fields, is meaningless to
hardware. Make the logic in ept_set_entry() setting the field (and iPAT)
conditional upon dealing with a present entry, leaving the value at 0
otherwise. This has two effects for epte_get_entry_emt() which we'll
want to leverage subsequently:
1) The call moved here now won't be issued with INVALID_MFN anymore (a
respective BUG_ON() is being added).
2) Neither of the other two calls could now be issued with a truncated
form of INVALID_MFN anymore (as long as there's no bug anywhere
marking an entry present when that was populated using INVALID_MFN).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
mfn_valid() granularity is (currently) 256Mb. Therefore the start of a
1Gb page passing the test doesn't necessarily mean all parts of such a
range would also pass. Yet using the result of mfn_to_page() on an MFN
which doesn't pass mfn_valid() checking is liable to result in a crash
(the invocation of mfn_to_page() alone is presumably "just" UB in such a
case).
Fixes: ca24b2ffdb ("x86/hvm: set 'ipat' in EPT for special pages")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
It's hardly ever correct to check for just DOMID_SELF, as guests have
ways to figure out their domain IDs and hence could instead use those as
inputs to respective hypercalls. Note, however, that for ordinary DomU-s
the adjustment is relaxing things rather than tightening them, since
- as a result of XSA-237 - the respective XSM checks would have rejected
self (un)mapping attempts for other than the control domain.
Since in physdev_map_pirq() handling overall is a little easier this
way, move obtaining of the domain pointer into the caller. Doing the
same for physdev_unmap_pirq() is just to keep both consistent in this
regard.
Fixes: 0b469cd687 ("Interrupt remapping to PIRQs in HVM guests")
Fixes: 9e1a3415b7 ("x86: fixes after emuirq changes")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
To get past the recurring friction on the approach to take wrt
workarounds needed for various firmware flaws, I'm stepping down as the
maintainer of our code interfacing with EFI firmware. Two new
maintainers are being introduced in my place.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Marek Marczykowski <marmarek@invisiblethingslab.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
... in order to also deny Dom0 access through the alias ports (commonly
observed on Intel chipsets). Without this it is only giving the
impression of denying access to PIT. Unlike for CMOS/RTC, do detection
pretty early, to avoid disturbing normal operation later on (even if
typically we won't use much of the PIT).
Like for CMOS/RTC a fundamental assumption of the probing is that reads
from the probed alias port won't have side effects (beyond such that PIT
reads have anyway) in case it does not alias the PIT's.
As to the port 0x61 accesses: Unlike other accesses we do, this masks
off the top four bits (in addition to the bottom two ones), following
Intel chipset documentation saying that these (read-only) bits should
only be written with zero.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
Help reading of code programming the PIT by introducing constants for
control word, read back and latch commands, as well as status.
Requested-by: Jason Andryuk <jason.andryuk@amd.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
... in order to also deny Dom0 access through the alias ports (commonly
observed on Intel chipsets). Without this it is only giving the
impression of denying access to both PICs. Unlike for CMOS/RTC, do
detection very early, to avoid disturbing normal operation later on.
Like for CMOS/RTC a fundamental assumption of the probing is that reads
from the probed alias port won't have side effects in case it does not
alias the respective PIC's one.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
By default there's already no use for this when we run in shim mode.
Plus there may also be a need to suppress the probing in case of issues
with it. Before introducing further port alias probing, introduce a
command line option allowing to bypass it, default it to on when in shim
mode, and gate RTC/CMOS port alias probing on it.
Requested-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
The function itself properly handles and hands onwards failure from
create_perdomain_mapping(). Therefore its caller should respect possible
failure, too.
Fixes: 4b28bf6ae9 ("x86: re-introduce map_domain_page() et al")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
While decompression errors are likely going to be fatal to Xen's boot
process anyway, the latest with the goal of doing multiple decompressor
runs it is likely better to avoid leaks even on error paths. All the
more when this way code size actually shrinks a tiny bit.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
A stray 'p' was there, rendering the #undef ineffectual.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
The same set of conditions is used in three places, requiring to be kept
in sync. Introduce a helper to centralize these checks.
To allow all parameters of the new helper be pointer-to-const,
iommu_has_cap() also needs its 1st parameter to be constified. Beyond
that further "modernize" that function.
Requested-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
This is a prereq to us, in particular, respecting the "ATC required"
flag.
Note that ACPI_SATC_ATC_REQUIRED has its #define put in dmar.h, as we
try to keep actbl*.h in sync what Linux (who in turn inherit from ACPI
CA) has.
Note further that some perhaps sub-optimal style aspects are mainly the
way they are in order to stay consistent with other pre-existing code.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
It's acpi_parse_one_rmrr() where the allocation is coming from (by way
of invoking acpi_parse_dev_scope()), or in add_one_user_rmrr()'s case
allocation is even open-coded there, so freeing would better also happen
there. Care needs to be taken to preserve acpi_parse_one_rmrr()'s
ultimate return value.
While fiddling with callers also move scope_devices_free() to .init and
have it use XFREE() instead of open-coding it. To avoid making the
situation worse for register_one_rmrr(), mark that __init right here as
well.
In register_one_rmrr() also have the "ignore" path take the main
function return path.
Suggested-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Spec version 4.1 says
"The ATSR structures identifies PCI Express Root-Ports supporting
Address Translation Services (ATS) transactions. Software must enable
ATS on endpoint devices behind a Root Port only if the Root Port is
reported as supporting ATS transactions."
Clearly root complex integrated devices aren't "behind root ports",
matching my observation on a SapphireRapids system having an ATS-
capable root complex integrated device. Hence for such devices we
shouldn't try to locate a corresponding ATSR.
Since both pci_find_ext_capability() and pci_find_cap_offset() return
"unsigned int", change "pos" to that type at the same time.
Fixes: 903b93211f ("[VTD] laying the ground work for ATS")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
This reverts commit c40bc0576d.
That change aimed at eliminating an open-coded lock-like construct,
which really isn't all that similar to, in particular, get_page(). The
function always succeeds. Any remaining concern would want taking care
of by placing block_lock_speculation() at the end of the function.
Since the function is called only during page (de)validation, any
possible performance concerns over such extra serialization could
likely be addressed by pre-validating (e.g. via pinning) page tables.
The fundamental issue with the change being reverted is that it detects
bad state only after already having caused possible corruption. While
the system is going to be halted in such an event, there is a time
window during which the resulting incorrect state could be leveraged by
a clever (in particular: fast enough) attacker.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Much like was recently done for setting entry vector, and along the
lines of what we already had in handle_exception_saved, avoid 32-bit
immediates where 8-bit ones do. Reduces .text.entry size by 16 bytes in
my non-CET reference build, while in my CET reference build section size
doesn't change (there and in .text only padding space increases).
Inspired by other long->byte conversion work.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Neither X86_SEG_AR_DPL nor MASK_EXTR() should really be avoided here,
using literal number instead.
No difference in generated code (with gcc13 at least).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
As of the commit referenced below the update_paging_modes() hook is per-
domain and hence also set (already) during domain construction.
Fixes: d0816a9085 ("x86/paging: move update_paging_modes() hook")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
... thanks to paging_vcpu_init() being part of vCPU creation. Further
if paging is enabled on a domain, it's also guaranteed to be either HAP
or shadow. Drop respective unnecessary (parts of) conditionals.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Hypercalls in particular can be the subject of continuations, and logic
there checks updated state against incoming register values. If the
guest manufactured a suitable argument register with a non-zero upper
half before entering compatibility mode and issuing a hypercall from
there, checks in hypercall_xlat_continuation() might trip.
Since for HVM we want to also be sure to not hit a corner case in the
emulator, initiate the clipping right from the top of
{svm,vmx}_vmexit_handler(). Also rename the invoked function, as it no
longer does only invalidation of fields.
Note that architecturally the upper halves of registers are undefined
after a switch between compatibility and 64-bit mode (either direction).
Hence once having entered compatibility mode, the guest can't assume
the upper half of any register to retain its value.
This is part of XSA-454 / CVE-2023-46842.
Fixes: b8a7efe852 ("Enable compatibility mode operation for HYPERVISOR_memory_op")
Reported-by: Manuel Andreas <manuel.andreas@tum.de>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
With a02174c6c8 ("amd/iommu: clean up unused guest iommu related
functions") having removed the sole place where d->g_iommu would be set
to non-NULL, guest_iommu_add_ppr_log() will unconditionally bail the
latest from its 2nd if(). With it dropped, all other stuff in the file
is unused, too. Delete iommu_guest.c altogether.
Further delete struct guest{_buffer,_dev_table,_iommu{,_msi}} as well as
struct mmio_reg for being unused with the unused g_iommu also dropped
from struct arch_iommu.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
When not holding the PoD lock across the entire region covering P2M
update and stats update, the entry count - if to be incorrect at all -
should indicate too large a value in preference to a too small one, to
avoid functions bailing early when they find the count is zero. However,
instead of moving the increment ahead (and adjust back upon failure),
extend the PoD-locked region.
Fixes: 99af3cd40b ("x86/mm: Rework locking in the PoD layer")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: George Dunlap <george.dunlap@cloud.com>
I can only guess that using block_speculation() there was a leftover
from, earlier on, SPECULATIVE_HARDEN_LOCK depending on
SPECULATIVE_HARDEN_BRANCH.
Fixes: 197ecd838a ("locking: attempt to ensure lock wrappers are always inline")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
We'd like to thank Kevin, so far the VT-d maintainer, for his past
contributions, while at the same time we'd like to reflect reality as it
has been for quite some time. Have VT-d maintainership (and for symmetry
also AMD IOMMU's) fall back to the maintainers of general x86. This also
brings things in sync with how they are for Arm.
While touching the X86 section also append two so far missing slashes.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
... by way of a new arch-selectable Kconfig control.
Note that some smaller pieces of code are left without #ifdef, to keep
things better readable. Hence items like ECS_PIRQ, nr_static_irqs, or
domain_pirq_to_irq() remain uniformly.
As to XEN_DOMCTL_irq_permission - this, despite having a uniformly
available wrapper in libxc, is unused on Arm: libxl bypasses those
calls, and the Python and OCamL bindings have no users at all.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
We'd like to thank the VT-x maintainers for their past contributions,
while at the same time we'd like to reflect reality as it has been for
quite some time. Have VT-x maintainership (and for symmetry also AMD
SVM's) fall back to general x86.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
In light of recent observations with how macros are handled by gas,
let's play by what we informally set for ourselves as a guideline: Use
commas to separate parameters/arguments.
Requested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
In light of recent observations with how macros are handled by gas,
let's play by what we informally set for ourselves as a guideline: Use
commas to separate parameters/arguments.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
As of 732571959f ("xen/build: use new $(c_flags) and $(a_flags)
instead of $(CFLAGS)") -M options aren't part of CFLAGS anymore, and
c_flags isn't supposed to be passed to this macro. Drop the now dead
part of filtering.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Passing in $(CFLAGS) means also requesting inclusion of certain headers
(via -include command line options). That's particularly xen/config.h,
which in turn requires generated/autoconf.h. This has not caused any
problems so far only because arch.mk is processed twice, and the missing
header on the 1st pass would be there on the 2nd. Having added an
inclusion of asm/asm-macros.h to x86'es asm/config.h, the 2nd pass then
also fails on an initial, pristine build.
As per dd40177c1b ("x86-64/EFI: add CFLAGS to check compile") dropping
the use of $(CFLAGS) altogether isn't an option, though. Hence remove
the problematic options only.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Neither pread() / pwrite() nor O_DIRECTORY are available from glibc
2.11.3 headers without defining (e.g.) _GNU_SOURCE. Supplying the
definition unconditionally shouldn't be a problem, seeing that various
other tools/ components do so, too.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
BARs of size 2Gb and up can't possibly fit below 4Gb: Both the bottom of
the lower 2Gb range and the top of the higher 2Gb range have special
purpose. Don't even have them influence whether to (perhaps) relocate
low RAM.
Reported-by: Neowutran <xen@neowutran.ovh>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
find_ring_mfn() already holds a page reference when trying to obtain a
writable type reference. We shouldn't make assumptions on the general
reference count limit being effectively "infinity". Obtain merely a type
ref, re-using the general ref by only dropping the previously acquired
one in the case of an error.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
At the time they were introduced, there were no asm/nospec.h yet, so
they were placed in system.h. Move them to nospec.h and drop
xen/nospec.h's including of asm/system.h; there's one unrelated #include
that needs adding in exchange, on x86.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
The usage of a cmpxchg loop in get_next_handle() is unnecessary, as the same
can be achieved with an atomic increment, which is both simpler to read, and
avoid any need for a loop.
The cmpxchg usage is likely a remnant of 32bit support, which didn't have an
instruction to do an atomic 64bit add, and instead a cmpxchg had to be used.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-of-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>
On the BSP, shadow stacks are enabled only relatively late in the
booting process. They in particular aren't active yet when initcalls are
run. Keep the testing there, but invoke that testing a 2nd time when
shadow stacks are active, to make sure we won't regress that case after
addressing XSA-451.
While touching this code, switch the guard from NDEBUG to CONFIG_DEBUG,
such that IS_ENABLED() can validly be used at the new call site.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Dealing with exceptions raised from within emulation stubs involves
discarding return address (replaced by exception related information).
Such discarding of course also requires removing the corresponding entry
from the shadow stack.
Also amend the comment in fixup_exception_return(), to further clarify
why use of ptr[1] can't be an out-of-bounds access.
While touching do_invalid_op() also add a missing fall-through
annotation.
This is CVE-2023-46841 / XSA-451.
Fixes: 209fb9919b ("x86/extable: Adjust extable handling to be shadow stack compatible")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
elf_load_binary() isn't the primary source of brokenness being
indicated. Therefore make the respective PVH log message there
conditional (much like PV has it), and add another instance when
elf_xen_parse() failed (again matching behavior in the PV case).
Make the PV side match the (new) use of %pd here.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Avoid logging all-identical messages for every vCPU, but make sure to
log unusual events like the vector differing from vCPU 0's (note that
the respective condition also makes sure vCPU 0 itself will have the
vector setting logged), or it changing after it was once set. (Arguably
a downside is that some vCPU not having its vector set would no longer
be recognizable from the logs. But I think that's tolerable as
sufficiently unlikely outside of people actively fiddling with related
code.)
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
The usage of a cmpxchg loop in hpet_get_channel() is unnecessary, as the same
can be achieved with an atomic increment, which is both simpler to read, and
avoid any need for a loop.
Note there can be a small divergence in the channel returned if next_channel
overflows, but returned channel will always be in the [0, num_hpets_used)
range, and that's fine for the purpose of balancing HPET channels across CPUs.
Signed-of-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The type not being used in do_bug_frame() is suspicious. Apparently
that's solely because the type uses a pointer-to-const parameter,
when so far run_in_exception_handler() wanted functions taking pointer-
to-non-const. Expand use of const, in turn requiring common code's
do_bug_frame() as well as [gs]et_irq_regs() to also gain const. This
then brings the former function also closer to the common one, with
Arm's use of vaddr_t remaining as a difference.
While there also replace the bogus use of hard tabs in [gs]et_irq_regs()
(I clearly didn't mean to put it in like this).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
The only place it was needed is in the spurious handler, and there we
can use get_irq_regs() instead.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
It's not needed anymore. This is in preparation of dropping the register
parameters from IRQ handler functions.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
In preparation for further removal of regs parameters, drop it here. In
the two places where it's actually needed, retrieve IRQ context if
available, or else guest context.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
In preparation of dropping the register parameters from
serial_[rt]x_interrupt() and in turn from IRQ handler functions,
register state needs making available another way for the few key
handlers which need it. Fake IRQ-like state.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
When re-working library call wrapping the sed invocation didn't account
for all sources living in the parent directory when building the 32-bit
harness binary.
Fixes: 6fba45ca3b ("x86emul: rework wrapping of libc functions in test and fuzzing harnesses")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
EVEX.R' is not ignored in 64-bit code when encoding a GPR or mask
register. While for mask registers suitable checks are in place (there
also covering EVEX.R), they were missing for the few cases where in
EVEX-encoded instructions ModR/M.reg encodes a GPR. While for VPEXTRW
the bit is replaced before an emulation stub is invoked, for
VCVT{,T}{S,D,H}2{,U}SI this actually would have led to #UD from inside
an emulation stub, in turn raising #UD to the guest, but accompanied by
log messages indicating something's wrong in Xen nevertheless.
Fixes: 001bd91ad8 ("x86emul: support AVX512{F,BW,DQ} extract insns")
Fixes: baf4a376f5 ("x86emul: support AVX512F legacy-equivalent scalar int/FP conversion insns")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Because of using "-include", failure to (re)build auto.conf (with
auto.conf.cmd produced as a secondary target) won't stop make from
continuing the build. Arrange for it being possible to drop the - from
Rules.mk, requiring that the include be skipped for tools-only targets.
Note that relying on the inclusion in those cases wouldn't be correct
anyway, as it might be a stale file (yet to be rebuilt) which would be
included, while during initial build, the file would be absent
altogether.
Fixes: 8d4c17a90b ("xen/build: silence make warnings about missing auto.conf*")
Reported-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Along the line with observations in the context of XSA-448, no field in
struct gnttab_copy_ptr is relevant when no data is to be copied, much
like e.g. the pointers passed to memcpy() are irrelevant (and would
never be "validated") when the passed length is zero.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Holding a valid struct page_info * in hands already means the referenced
MFN is valid; there's no need to check that again. Convert the checking
logic to a switch(), to help keeping the extra (and questionable) x86-
only check in somewhat tidy shape.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Christopher Clark <christopher.w.clark@gmail.com>
While in the vast majority of cases failure of the function will not
be followed by re-invocation with the same emulation context, a few
very specific insns - involving multiple independent writes, e.g. ENTER
and PUSHA - exist where this can happen. Since failure of the function
only signals to the caller that it ought to try an MMIO write instead,
such failure also cannot be assumed to result in wholesale failure of
emulation of the current insn. Instead we have to maintain internal
state such that another invocation of the function with the same
emulation context remains possible. To achieve that we need to reset MFN
slots after putting page references on the error path.
Note that all of this affects debugging code only, in causing an
assertion to trigger (higher up in the function). There's otherwise no
misbehavior - such a "leftover" slot would simply be overwritten by new
contents in a release build.
Also extend the related unmap() assertion, to further check for MFN 0.
Fixes: 8cbd4fb0b7 ("x86/hvm: implement hvmemul_write() using real mappings")
Reported-by: Manuel Andreas <manuel.andreas@tum.de>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Paul Durrant <paul@xen.org>
The 'fast' path of p2m_get_page_from_gfn handles three cases: normal ram,
foreign p2m entries, and grant map entries. For normal ram and grant table
entries, get_page() is called, but for foreign entries,
page_get_owner_and_reference() is called, since the current domain is
expected not to be the owner.
Unfortunately, grant maps are *also* generally expected to be owned by
foreign domains; so this function will fail for any p2m entry containing a
grant map that doesn't happen to be local.
Have grant maps take the same path as foreign entries. Since grants may
actually be either foreign or local, adjust the assertion to allow for this.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: George Dunlap <george.dunlap@cloud.com>
Reviewed-by: George Dunlap <george.dunlap@cloud.com>
While the PAE-extended-CR3 VM assist is a 32-bit only concept, it still
applies to guests also when run on a 64-bit hypervisor: The "extended
CR3" format has to be used there as well, to fit the address in the only
32-bit wide register there. As a result it was a mistake that the check
was never enabled for that case, and was then mistakenly deleted in the
course of removal of 32-bit-Xen code (218adf199e ["x86: We can assume
CONFIG_PAGING_LEVELS==4"]).
Similarly during Dom0 construction kernel awareness needs to be taken
into account, and respective code was again mistakenly never enabled for
32-bit Dom0 when running on 64-bit Xen (and thus wrongly deleted by
5d1181a5ea ["xen: Remove x86_32 build target"]).
At the same time restrict enabling of the assist for Dom0 to just the
32-bit case. Furthermore there's no need for an atomic update there.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
This is a prereq to enabling e.g. the MSRLIST feature.
Note that the PROCBASED_CTLS3 MSR is different from other VMX feature
reporting MSRs, in that all 64 bits report allowed 1-settings.
vVMX code is left alone, though, for the time being.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
While not performance critical, these hook invocations still want
converting: This way all pre-filled struct cpu_dev instances can become
__initconst_cf_clobber, thus allowing to eliminate further 8 ENDBR
during the 2nd phase of alternatives patching (besides moving previously
resident data to .init.*).
Since all use sites need touching anyway, take the opportunity and also
address a Misra C:2012 Rule 5.5 violation: Rename the this_cpu static
variable.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
While .setup() and .e820_fixup() don't need fiddling with for being run
only very early, both .ap_setup() and .resume() want converting too:
This way both pre-filled struct hypervisor_ops instances can become
__initconst_cf_clobber, thus allowing to eliminate up to 5 more ENDBR
(configuration dependent) during the 2nd phase of alternatives patching.
While fiddling with section annotations here, also move "ops" itself to
.data.ro_after_init.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Paul Durrant <paul@xen.org>
While altcall is already used for them, the functions want announcing in
.init.rodata.cf_clobber, even if the resulting static variables aren't
otherwise used.
While doing this also move ctxt_switch_masking to .data.ro_after_init.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
There's no use for IOMMU code in the shim. Disable at least the vendor-
specific code, until eventually IOMMU code can be disabled altogether.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Allow the compiler a little more room on DCE by moving the compile-time-
constant condition into the predicate (from the one place where it was
added in an open-coded fashion for XSA-450).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Avoid recurring MFN -> page or page -> MFN translations. Drop the pretty
pointless local variable "p". Make sure the MFN logged in a debugging
error message is actually the offending one. Return negative errno
values rather than -1 (presently no caller really cares, but imo this
should change). Adjust style.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: George Dunlap <george.dunlap@cloud.com>
Even going back to 3.2 source code, I can't spot how this watchdog mode
could ever have been enabled in Xen. The only effect its presence had
for all the years was the retaining of a dead string literal.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Jan Beulich