Commit Graph
46845 Commits
Author SHA1 Message Date
Andrew Cooper 0e7ea8ca5f x86/Kconfig: Introduce CONFIG_{AMD,INTEL} and conditionalise ucode
We eventually want to be able to build a stripped down Xen for a single
platform.  Make a start with CONFIG_{AMD,INTEL} (hidden behind EXPERT, but
available to randconfig), and adjust the microcode logic.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-04-10 18:41:28 +01:00
Andrew Cooper 2eea952b70 x86/ucode: Move vendor specifics back out of early_microcode_init()
I know it was me who dropped microcode_init_{intel,amd}() in c/s
dd5f07997f ("x86/ucode: Rationalise startup and family/model checks"), but
times have moved on.  We've gained new conditional support, and a wish to
compile-time specialise Xen to single platform.

(Re)introduce ucode_probe_{amd,intel}() and move the recent vendor specific
additions back out.  Encode the conditional support state in the NULL-ness of
hooks as it's already done on other paths.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-10 18:34:46 +01:00
Stefano Stabellini f48299cad5 docs/misra: document the expected sizes of integer types
Xen makes assumptions about the size of integer types on the various
architectures. Document these assumptions.

Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Bertrand Marquis <bertrand.marquis@arm.com>
2024-04-09 14:28:59 -07:00
John Ernberg dfc9455b80 MAINTAINERS: Become a reviewer of iMX8Q{M,XP} related patches
I have experience with the IMX8QXP, and the supported parts of the IMX8QM
are identical.

Help review patches touching these areas.

Signed-off-by: John Ernberg <john.ernberg@actia.se>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Peng Fan <peng.fan@nxp.com>
2024-04-09 14:28:07 -07:00
John Ernberg 2f85a6d9f5 xen/drivers: imx-lpuart: Replace iMX8QM compatible with iMX8QXP
Allow the uart to probe also with iMX8QXP. The ip-block is the same as in
the QM.

Since the fsl,imx8qm-lpuart compatible in Linux exists in name only and is
not used in the driver any iMX8QM device tree that can boot Linux must set
fsl,imx8qxp-lpuart compatible as well as the QM one.

Thus we replace the compatible rather than adding just another one.

Signed-off-by: John Ernberg <john.ernberg@actia.se>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
2024-04-09 14:27:52 -07:00
John Ernberg 71d4356544 xen/arm: Add imx8q{m,x} platform glue
When using Linux for dom0 there are a bunch of drivers that need to do SMC
SIP calls into the firmware to enable certain hardware bits like the
watchdog.

Provide a basic platform glue that implements the needed SMC forwarding.

The format of these calls are as follows:
 - reg 0: function ID
 - reg 1: subfunction ID (when there's a subfunction)
 remaining regs: args

For now we only allow Dom0 to make these calls as they are all managing
hardware. There is no specification for these SIP calls, the IDs and names
have been extracted from the upstream linux kernel and the vendor kernel.

We can reject CPUFREQ because Dom0 cannot make an informed decision
regarding CPU frequency scaling, WAKEUP_SRC is to wake up from suspend,
which Xen doesn't support at this time.

This leaves the TIME SIP, OTP SIPs which for now are allowed to Dom0.

NOTE: This code is based on code found in NXP Xen tree located here:
https://github.com/nxp-imx/imx-xen/blob/lf-5.10.y_4.13/xen/arch/arm/platforms/imx8qm.c

Signed-off-by: Peng Fan <peng.fan@nxp.com>
[jernberg: Add SIP call filtering]
Signed-off-by: John Ernberg <john.ernberg@actia.se>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
[stefano: commit message improvement]
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
2024-04-09 14:27:35 -07:00
Andrew Cooper a9fa825008 x86/entry: Fix build with older toolchains
Binutils older than 2.29 doesn't know INCSSPD.

Fixes: 8e186f98ce ("x86: Use indirect calls in reset-stack infrastructure")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-04-09 14:25:01 -07:00
Andrew Cooper d5887c0dec x86/spec-ctrl: Support the "long" BHB loop sequence
Out of an abudnance of caution, implement the long loop too, and allowing for
it to be opted in to.

This is part of XSA-456 / CVE-2024-2201.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 689ad48ce9 x86/spec-ctrl: Wire up the Native-BHI software sequences
In the absence of BHI_DIS_S, mitigating Native-BHI requires the use of a
software sequence.

Introduce a new bhb-seq= option to select between avaialble sequences and
bhb-entry= to control the per-PV/HVM actions like we have for other blocks.

Activate the short sequence by default for PV and HVM guests on affected
hardware if BHI_DIS_S isn't present.

This is part of XSA-456 / CVE-2024-2201.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 954c983abc x86/spec-ctrl: Software BHB-clearing sequences
Implement clear_bhb_{tsx,loops}() as per the BHI guidance.  The loops variant
is set up as the "short" sequence.

Introduce SCF_entry_bhb and extend SPEC_CTRL_ENTRY_* with a conditional call
to selected clearing routine.

Note that due to a limitation in the ALTERNATIVE capability, the TEST/JZ can't
be included alongside a CALL in a single alternative block.  This is going to
require further work to untangle.

The BHB sequences (if used) must be after the restoration of Xen's
MSR_SPEC_CTRL value, which must be accounted for when judging whether it is
safe to skip the safety LFENCEs.

This is part of XSA-456 / CVE-2024-2201.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 62a1106415 x86/spec-ctrl: Support BHI_DIS_S in order to mitigate BHI
Introduce a "bhi-dis-s" boolean to match the other options we have for
MSR_SPEC_CTRL values.  Also introduce bhi_calculations().

Use BHI_DIS_S whenever possible.

Guests which are levelled to be migration compatible with older CPUs can't see
BHI_DIS_S, and Xen must fill in the difference to make the guest safe.  Use
the virt MSR_SPEC_CTRL infrastructure to force BHI_DIS_S behind the guest's
back.

This is part of XSA-456 / CVE-2024-2201.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper c94e210592 x86/tsx: Expose RTM_ALWAYS_ABORT to guests
A TSX Abort is one option mitigate Native-BHI, but a guest kernel doesn't get
to see this if Xen has turned RTM off using MSR_TSX_{CTRL,FORCE_ABORT}.

Therefore, the meaning of RTM_ALWAYS_ABORT has been adjusted to "XBEGIN won't
fault", and it should be exposed to guests so they can make a better decision.

Expose it in the max policy for any RTM-capable system.  Offer it by default
only if RTM has been disabled.

Update test-tsx to account for this new meaning.  While adjusting the logic in
test_guest_policies(), take the opportunity to use feature names (now they're
available) to make the logic easier to follow.

This is part of XSA-456 / CVE-2024-2201.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 0b66d7ce3c x86: Drop INDIRECT_JMP
Indirect JMPs which are not tailcalls can lead to an unwelcome form of
speculative type confusion, and we've removed the uses of INDIRECT_JMP to
compensate.  Remove the temptation to reintroduce new instances.

This is part of XSA-456 / CVE-2024-2201.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 8e186f98ce x86: Use indirect calls in reset-stack infrastructure
Mixing up JMP and CALL indirect targets leads a very fun form of speculative
type confusion.  A target which is expecting to be called CALLed needs a
return address on the stack, and an indirect JMP doesn't place one there.

An indirect JMP which predicts to a target intending to be CALLed can end up
with a RET speculatively executing with a value from the JMPers stack frame.

There are several ways get indirect JMPs in Xen.

 * From tailcall optimisations.  These are safe because the compiler has
   arranged the stack to point at the callee's return address.

 * From jump tables.  These are unsafe, but Xen is built with -fno-jump-tables
   to work around several compiler issues.

 * From reset_stack_and_jump_ind(), which is particularly unsafe.  Because of
   the additional stack adjustment made, the value picked up off the stack is
   regs->r15 of the next vCPU to run.

In order to mitigate this type confusion, we want to make all indirect targets
be CALL targets, and remove the use of indirect JMP except via tailcall
optimisation.

Luckily due to XSA-348, all C target functions of reset_stack_and_jump_ind()
are noreturn.  {svm,vmx}_do_resume() exits via reset_stack_and_jump(); a
direct JMP with entirely different prediction properties.  idle_loop() is an
infinite loop which eventually exits via reset_stack_and_jump_ind() from a new
schedule.  i.e. These paths are all fine having one extra return address on
the stack.

This leaves continue_pv_domain(), which is expecting to be a JMP target.
Alter it to strip the return address off the stack, which is safe because
there isn't actually a RET expecting to return to its caller.

This allows us change reset_stack_and_jump_ind() to reset_stack_and_call_ind()
in order to mitigate the speculative type confusion.

This is part of XSA-456 / CVE-2024-2201.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 45dac88e78 x86/spec-ctrl: Widen the {xen,last,default}_spec_ctrl fields
Right now, they're all bytes, but MSR_SPEC_CTRL has been steadily gaining new
features.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-09 16:37:30 +01:00
Roger Pau Monne 97c5b8b657 x86/vmx: Add support for virtualize SPEC_CTRL
The feature is defined in the tertiary exec control, and is available starting
from Sapphire Rapids and Alder Lake CPUs.

When enabled, two extra VMCS fields are used: SPEC_CTRL mask and shadow.  Bits
set in mask are not allowed to be toggled by the guest (either set or clear)
and the value in the shadow field is the value the guest expects to be in the
SPEC_CTRL register.

By using it the hypervisor can force the value of SPEC_CTRL bits behind the
guest back without having to trap all accesses to SPEC_CTRL, note that no bits
are forced into the guest as part of this patch.  It also allows getting rid of
SPEC_CTRL in the guest MSR load list, since the value in the shadow field will
be loaded by the hardware on vmentry.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 40dea83b75 x86/spec-ctrl: Detail the safety properties in SPEC_CTRL_ENTRY_*
The complexity is getting out of hand.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 2378d16a93 x86/spec-ctrl: Simplify DO_COND_IBPB
With the prior refactoring, SPEC_CTRL_ENTRY_{PV,INTR} both load SCF into %ebx,
and handle the conditional safety including skipping if interrupting Xen.

Therefore, we can drop the maybexen parameter and the conditional safety.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 9607aeb660 x86/spec_ctrl: Hold SCF in %ebx across SPEC_CTRL_ENTRY_{PV,INTR}
... as we do in the exit paths too.  This will allow simplification to the
sub-blocks.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 22390697bf x86/entry: Arrange for %r14 to be STACK_END across SPEC_CTRL_ENTRY_FROM_PV
Other SPEC_CTRL_* paths already use %r14 like this, and it will allow for
simplifications.

All instances of SPEC_CTRL_ENTRY_FROM_PV are followed by a GET_STACK_END()
invocation, so this change is only really logic and register shuffling.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 94896de1a9 x86/spec-ctrl: Rework conditional safety for SPEC_CTRL_ENTRY_*
Right now, we have a mix of safety strategies in different blocks, making the
logic fragile and hard to follow.

Start addressing this by having a safety LFENCE at the end of the blocks,
which can be patched out if other safety criteria are met.  This will allow us
to simplify the sub-blocks.  For SPEC_CTRL_ENTRY_FROM_IST, simply leave an
LFENCE unconditionally at the end; the IST path is not a fast-path by any
stretch of the imagination.

For SPEC_CTRL_ENTRY_FROM_INTR, the existing description was incorrect.  The
IRET #GP path is non-fatal but can occur with the guest's choice of
MSR_SPEC_CTRL.  It is safe to skip the flush/barrier-like protections when
interrupting Xen, but we must run DO_SPEC_CTRL_ENTRY irrespective.

This will skip RSB stuffing which was previously unconditional even when
interrupting Xen.

AFAICT, this is a missing cleanup from commit 3fffaf9c13 ("x86/entry: Avoid
using alternatives in NMI/#MC paths") where we split the IST entry path out of
the main INTR entry path.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper c62673c433 x86/spec-ctrl: Rename spec_ctrl_flags to scf
XSA-455 was ultimately caused by having fields with too-similar names.

Both {xen,last}_spec_ctrl are fields containing an architectural MSR_SPEC_CTRL
value.  The spec_ctrl_flags field contains Xen-internal flags.

To more-obviously distinguish the two, rename spec_ctrl_flags to scf, which is
also the prefix of the constants used by the fields.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 489d93cd0f x86/spec-ctrl: Fix BTC/SRSO mitigations
We were looking for SCF_entry_ibpb in the wrong variable in the top-of-stack
block, and xen_spec_ctrl won't have had bit 5 set because Xen doesn't
understand SPEC_CTRL_RRSBA_DIS_U yet.

This is XSA-455 / CVE-2024-31142.

Fixes: 53a570b285 ("x86/spec-ctrl: Support IBPB-on-entry")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-09 16:37:30 +01:00
Andrew Cooper 4b3da946ad x86/cpuid: Don't expose {IPRED,RRSBA,BHI}_CTRL to PV guests
All of these are prediction-mode (i.e. CPL) based.  They don't operate as
advertised in PV context.

Fixes: 4dd6760706 ("x86/spec-ctrl: Expose IPRED_CTRL to guests")
Fixes: 478e4787fa ("x86/spec-ctrl: Expose RRSBA_CTRL to guests")
Fixes: 583f1d0950 ("x86/spec-ctrl: Expose BHI_CTRL to guests")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2024-04-09 15:26:27 +01:00
Roger Pau Monné 4be1fef1e6 x86/alternatives: fix .init section reference in _apply_alternatives()
The code in _apply_alternatives() will unconditionally attempt to read
__initdata_cf_clobber_{start,end} when called as part of applying alternatives
to a livepatch payload when Xen is using IBT.

That leads to a page-fault as __initdata_cf_clobber_{start,end} living in
.init section will have been unmapped by the time a livepatch gets loaded.

Fix by adding a check that limits the clobbering of endbr64 instructions to
boot time only.

Fixes: 37ed5da851 ('x86/altcall: Optimise away endbr64 instruction where possible')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2024-04-09 14:05:59 +01:00
Bjoern Doebel 9926e692c4 hypercall_xlat_continuation: Replace BUG_ON with domain_crash
Instead of crashing the host in case of unexpected hypercall parameters,
resort to only crashing the calling domain.

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: Bjoern Doebel <doebel@amazon.de>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
2024-04-09 12:49:40 +01:00
Jan Beulich 6a98383b08 x86/HVM: clear upper halves of GPRs upon entry from 32-bit code
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>
2024-04-09 12:49:40 +01:00
Vaishnav Achath 672b26b66e drivers: char: Enable OMAP UART driver for TI K3 devices
TI K3 devices (J721E, J721S2, AM62X .etc) have the same variant
of UART as OMAP4. Add the compatible used in Linux device tree,
"ti,am654-uart" to the OMAP UART dt_match so that the driver can
be used with these devices. Also, enable the driver for ARM64
platforms.

Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-04-08 17:18:26 -07:00
Nicola Vetrini c079823df6 xen/compiler: address violation of MISRA C Rule 20.9
The rule states:
"All identifiers used in the controlling expression of #if or #elif
preprocessing directives shall be #define'd before evaluation".
In this case, using defined(identifier) is a MISRA-compliant
way to achieve the same effect.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-04-08 09:23:15 +02:00
Jason Andryuk dfc9fab003 x86/PVH: Support relocatable dom0 kernels
Xen tries to load a PVH dom0 kernel at the fixed guest physical address
from the elf headers.  For Linux, this defaults to 0x1000000 (16MB), but
it can be configured.

Unfortunately there exist firmwares that have reserved regions at this
address, so Xen fails to load the dom0 kernel since it's not RAM.

The PVH entry code is not relocatable - it loads from absolute
addresses, which fail when the kernel is loaded at a different address.
With a suitably modified kernel, a reloctable entry point is possible.

Add XEN_ELFNOTE_PHYS32_RELOC which specifies optional alignment,
minimum, and maximum addresses needed for the kernel.  The presence of
the NOTE indicates the kernel supports a relocatable entry path.

Change the loading to check for an acceptable load address.  If the
kernel is relocatable, support finding an alternate load address.

The primary motivation for an explicit align field is that Linux has a
configurable CONFIG_PHYSICAL_ALIGN field.  This value is present in the
bzImage setup header, but not the ELF program headers p_align, which
report 2MB even when CONFIG_PHYSICAL_ALIGN is greater.  Since a kernel
is only considered relocatable if the PHYS32_RELOC elf note is present,
the alignment contraints can just be specified within the note instead
of searching for an alignment value via a heuristic.

Load alignment uses the PHYS32_RELOC note value if specified.
Otherwise, the maxmum ELF PHDR p_align value is selected if greater than
or equal to PAGE_SIZE.  Finally, the fallback default is 2MB.

libelf-private.h includes common-macros.h to satisfy the fuzzer build.

Link: https://gitlab.com/xen-project/xen/-/issues/180
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-08 09:22:56 +02:00
Jason Andryuk 4d3b8669d8 libelf: Store maximum PHDR p_align
While parsing the PHDRs, store the maximum p_align value.  This may be
consulted for moving a PVH image's load address.

Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-04-08 09:22:28 +02:00
Juergen Gross 77b219f915 xen/rwlock: raise the number of possible cpus
The rwlock handling is limiting the number of cpus to 4095 today. The
main reason is the use of the atomic_t data type for the main lock
handling, which needs 2 bits for the locking state (writer waiting or
write locked), 12 bits for the id of a possible writer, and a 12 bit
counter for readers. The limit isn't 4096 due to an off by one sanity
check.

The atomic_t data type is 32 bits wide, so in theory 15 bits for the
writer's cpu id and 15 bits for the reader count seem to be fine, but
via read_trylock() more readers than cpus are possible.

This means that it is possible to raise the number of cpus to 16384
without changing the rwlock_t data structure. In order to avoid the
reader count wrapping to zero, don't let read_trylock() succeed in case
the highest bit of the reader's count is set already. This leaves enough
headroom for non-recursive readers to enter without risking a wrap.

While at it calculate _QW_CPUMASK and _QR_SHIFT from _QW_SHIFT and
add a sanity check for not overflowing the atomic_t data type.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-08 09:21:41 +02:00
Juergen Gross c286bb93d2 xen/spinlock: support higher number of cpus
Allow 16 bits per cpu number, which is the limit imposed by
spinlock_tickets_t.

This will allow up to 65535 cpus, while increasing only the size of
recursive spinlocks in debug builds from 8 to 12 bytes.

The current Xen limit of 4095 cpus is imposed by SPINLOCK_CPU_BITS
being 12. There are machines available with more cpus than the current
Xen limit, so it makes sense to have the possibility to use more cpus.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-08 09:21:13 +02:00
Juergen Gross 0b09531d21 xen/spinlock: let all is_locked and trylock variants return bool
Switch the remaining trylock and is_locked variants to return bool.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-08 09:20:24 +02:00
Juergen Gross bfbec024b8 xen/spinlock: split recursive spinlocks from normal ones
Recursive and normal spinlocks are sharing the same data structure for
representation of the lock. This has two major disadvantages:

- it is not clear from the definition of a lock, whether it is intended
  to be used recursive or not, while a mixture of both usage variants
  needs to be

- in production builds (builds without CONFIG_DEBUG_LOCKS) the needed
  data size of an ordinary spinlock is 8 bytes instead of 4, due to the
  additional recursion data needed (associated with that the rwlock
  data is using 12 instead of only 8 bytes)

Fix that by introducing a struct spinlock_recursive for recursive
spinlocks only, and switch recursive spinlock functions to require
pointers to this new struct.

This allows to check the correct usage at build time.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-08 09:19:34 +02:00
Juergen Gross 31be78285c xen/spinlock: add missing rspin_is_locked() and rspin_barrier()
Add rspin_is_locked() and rspin_barrier() in order to prepare differing
spinlock_t and rspinlock_t types.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-08 09:18:40 +02:00
Juergen Gross ee1e133125 xen/spinlock: add another function level
Add another function level in spinlock.c hiding the spinlock_t layout
from the low level locking code.

This is done in preparation of introducing rspinlock_t for recursive
locks without having to duplicate all of the locking code.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-08 09:17:47 +02:00
Juergen Gross 3696a9f27d xen/spinlock: add explicit non-recursive locking functions
In order to prepare a type-safe recursive spinlock structure, add
explicitly non-recursive locking functions to be used for non-recursive
locking of spinlocks, which are used recursively, too.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Michal Orzel <michal.orzel@amd.com>
2024-04-08 09:16:23 +02:00
Simone Ballarin 402c2d3e66 MISRA C Rule 17.1 states: "The features of `<stdarg.h>' shall not be used"
The Xen community wants to avoid using variadic functions except for
specific circumstances where it feels appropriate by strict code review.

Functions hypercall_create_continuation and hypercall_xlat_continuation
are internal helper functions made to break long running hypercalls into
multiple calls. They take a variable number of arguments depending on the
original hypercall they are trying to continue.

Add SAF deviations for the aforementioned functions.

Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-04-05 11:15:47 -07:00
Simone Ballarin ea33a6e1e3 MISRA C:2012 Rule 17.1 states: The features of `<stdarg.h>' shall not be used
The Xen community wants to avoid using variadic functions except for
specific circumstances where it feels appropriate by strict code review.

Add deviation for printf()-like functions.

Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-04-05 11:15:47 -07:00
Nicola Vetrini 80d28865e1 automation/eclair: add deviations for Rule 20.7
These deviations deal with the following cases:
- macro arguments used directly as initializer list arguments;
- uses of the __config_enabled macro, that can't be brought
  into compliance without breaking its functionality;
- exclude files that are out of scope (efi headers and cpu_idle);
- uses of alternative_{call,vcall}[0-9] macros.

The existing configuration for R20.7 is reordered so that it matches the
cases listed in its documentation comment.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-04-05 11:15:47 -07:00
Nicola Vetrini 6bdb67d19e arm/public: address violations of MISRA C Rule 20.7
MISRA C Rule 20.7 states: "Expressions resulting from the expansion
of macro parameters shall be enclosed in parentheses". Therefore, some
macro definitions should gain additional parentheses to ensure that all
current and future users will be safe with respect to expansions that
can possibly alter the semantics of the passed-in macro parameter.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-04-05 11:15:47 -07:00
Andrew Cooper e9b0f8b690 x86: Address MISRA Rule 13.6
MISRA Rule 13.6 doesn't like having an expression in a sizeof() which
potentially has side effects, including function calls.

Address several violations by pulling the expression out into a local
variable.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-05 14:54:53 +01:00
Andrew Cooper b33f191e3c x86/tsx: Cope with RTM_ALWAYS_ABORT vs RTM mismatch
It turns out there is something wonky on some but not all CPUs with
MSR_TSX_FORCE_ABORT.  The presence of RTM_ALWAYS_ABORT causes Xen to think
it's safe to offer HLE/RTM to guests, but in this case, XBEGIN instructions
genuinely #UD.

Spot this case and try to back out as cleanly as we can.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-04-05 14:53:59 +01:00
Michal Orzel 270588b9b2 char: lpuart: Drop useless variables from UART structure
These variables are useless. They are being assigned a value which is
never used since UART is expected to be pre-configured.

No functional change.

Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-04-04 16:36:25 -07:00
Michal Orzel 4932163b35 drivers: char: Drop useless suspend/resume stubs in Arm drivers
On Arm we don't use console_{suspend,resume} and the corresponding
stubs in serial drivers are being redundantly copied whenever a new
driver is added. Drop them as well as useless .endboot = NULL assignment.

Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2024-04-04 16:35:58 -07:00
Federico Serafini 6eeb3e86bd vsprintf: address violations of MISRA C:2012 Rule 16.3
MISRA C:2012 Rule 16.3 states: "An unconditional `break' statement
shall terminate every switch-clause".

In order to meet the requirements to deviate the rule:
1) refactor the for loop to make the switch-clause ending with a
   return statement (note that adding a break at the end of the
   switch-clause would result in a violation of Rule 2.1
   "A project shall not contain unreachable code");
2) add pseudo-keyword fallthrough.

No functional change.

Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-04-04 12:01:50 +02:00
Federico Serafini 226bdb155b xen/sched: address violations of MISRA C:2012 Rule 16.3
Add break statement to address a violation of MISRA C:2012 Rule 16.3
("An unconditional `break' statement shall terminate every
switch-clause").
Replace deprecated comment /* FALLTHRU */ with pseudo-keyword
fallthrough to meet the requirements to deviate the rule.

No functional change.

Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: George Dunlap <george.dunlap@cloud.com>
2024-04-04 12:01:27 +02:00
Jason Andryuk 21e0c8fc0e tools: Move MB/GB() to common-macros.h
Consolidate to a single set of common macros for tools.

MB() will gain another use in libelf, so this movement makes it
available.

Requested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2024-04-04 12:01:13 +02:00
Jason Andryuk 4c41749852 tools/init-xenstore-domain: Replace variable MB() usage
The local MB() & GB() macros will be replaced with a common
implementation, but those only work with numeric values.  Introduce a
static inline mb_to_bytes() in place of the MB() macro to convert the
variable values, at the same time addressing the lack of
parenthesization of the prior macro's parameter.

Fixes: 134d53f577 ("tools/init-xenstore-domain: fix memory map for PVH stubdom")
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2024-04-04 12:00:59 +02:00