Commit Graph
41883 Commits
Author SHA1 Message Date
Andrew Cooper 297fce96e1 Update Xen to version 4.14.6
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
RELEASE-4.14.6
2023-08-07 13:11:14 +01:00
Andrew Cooper 050abf9e97 x86/spec-ctrl: Mitigate Gather Data Sampling
This is part of XSA-435 / CVE-2022-40982

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 56d690efd3)
2023-08-03 19:14:19 +01:00
Andrew Cooper e138318362 x86/spec-ctrl: Enumerations for Gather Data Sampling
GDS_CTRL is introduced by the August 2023 microcode.  GDS_NO is for current
and future processors not susceptible to GDS.

This is part of XSA-435 / CVE-2022-40982

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 9f585f59d9)
2023-08-03 19:14:19 +01:00
Andrew Cooper 5792b92fd9 x86/cpu-policy: Hide CLWB by default on SKX/CLX/CPX
The August 2023 microcode for GDS has an impact on the CLWB instruction.  See
code comments for full details.

This is part of XSA-435 / CVE-2022-40982

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 2dd06b4ea1)
2023-08-03 19:14:19 +01:00
Andrew Cooper e8db771a17 x86/spec-ctrl: Mitigate Speculative Return Stack Overflow
On native, synthesise the SRSO bits by probing various hardware properties as
given by AMD.

Extend the IBPB-on-entry mitigations to Zen3/4 CPUs.  There is a microcode
prerequisite to make this an effective mitigation.

This is part of XSA-434 / CVE-2023-20569

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 220c06e6fe)
2023-08-03 19:14:19 +01:00
Andrew Cooper 6a2df62a98 x86/spec-ctrl: Enumerations for Speculative Return Stack Overflow
AMD have specified new CPUID bits relating to SRSO.

 * SRSO_NO indicates that hardware is no longer vulnerable to SRSO.
 * IBPB_BRTYPE indicates that IBPB flushes branch type information too.
 * SBPB indicates support for a relaxed form of IBPB that does not flush
   branch type information.

Current CPUs (Zen4 and older) are not expected to enumerate these bits.
Native software is expected to synthesise them for guests using model and
microcode revision checks.

Two are just status bits, and SBPB is trivial to support for guests by
tweaking the reserved bit calculation in guest_wrmsr() and feature
dependencies.  Expose all by default to guests, so they start showing up when
Xen synthesises them.

While adding feature dependenies for IBPB, fix up an overlooked issue from
XSA-422.  It's inappropriate to advertise that IBPB flushes RET predictions if
IBPB is unavailable itself.

This is part of XSA-434 / CVE-2023-20569

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 2280b0ee2a)
2023-08-03 19:14:19 +01:00
Andrew Cooper 0ac679428a x86/spec-ctrl: Rework ibpb_calculations()
... in order to make the SRSO mitigations easier to integrate.

 * Check for AMD/Hygon CPUs directly, rather than assuming based on IBPB.
   In particular, Xen supports synthesising the IBPB bit to guests on Intel to
   allow IBPB while dissuading the use of (legacy) IBRS.
 * Collect def_ibpb_entry rather than opencoding the BTC_NO calculation for
   both opt_ibpb_entry_{pv,hvm}.

No functional change.

This is part of XSA-434 / CVE-2023-20569

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 292f68fb77)
2023-08-03 19:14:19 +01:00
Andrew Cooper 49fbb552c4 x86/cpu-policy: Advertise MSR_ARCH_CAPS to guests by default
With xl/libxl now able to control the policy bits for MSR_ARCH_CAPS, it is
safe to advertise to guests by default.  In turn, we don't need the special
case to expose details to dom0.

This advertises MSR_ARCH_CAPS to guests on *all* Intel hardware, even if the
register content ends up being empty.

  - Advertising ARCH_CAPS and not RSBA signals "retpoline is safe here and
    everywhere you might migrate to".  This is important because it avoids the
    guest kernel needing to rely on model checks.

  - Alternatively, levelling for safety across the Broadwell/Skylake divide
    requires advertising ARCH_CAPS and RSBA, meaning "retpoline not safe on
    some hardware you might migrate to".

On Cascade Lake and later hardware, guests can now see RDCL_NO (not vulnerable
to Meltdown) amongst others.  This causes substantial performance
improvements, as guests are no longer applying software mitigations in cases
where they don't need to.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 4b2cdbfe76)
2023-08-03 19:14:19 +01:00
Jan Beulich 7e10b39d9d libxl: allow building with old gcc again
We can't use initializers of unnamed struct/union members just yet.

Fixes: d638fe233c ("libxl: use the cpuid feature names from cpufeatureset.h")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 1aa5acbbec)
2023-08-03 19:14:19 +01:00
Jan Beulich 26a5e35fd8 libxl: avoid shadowing of index()
Because of -Wshadow the build otherwise fails with old enough glibc.

While there also obey line length limits for msr_add().

Fixes: 6d21cedbaa ("libxl: add support for parsing MSR features")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 4f6afde88b)
2023-08-03 19:14:19 +01:00
Roger Pau Monne f1652ccc90 libxl: add support for parsing MSR features
Introduce support for handling MSR features in
libxl_cpuid_parse_config().  The MSR policies are added to the
libxl_cpuid_policy like the CPUID one, which gets passed to
xc_cpuid_apply_policy().

This allows existing users of libxl to provide MSR related features as
key=value pairs to libxl_cpuid_parse_config() without requiring the
usage of a different API.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
(cherry picked from commit 6d21cedbaa)
2023-08-03 19:14:19 +01:00
Roger Pau Monne 1299ea8d76 libxl: use the cpuid feature names from cpufeatureset.h
The current implementation in libxl_cpuid_parse_config() requires
keeping a list of cpuid feature bits that should be mostly in sync
with the contents of cpufeatureset.h.

Avoid such duplication by using the automatically generated list of
cpuid features in INIT_FEATURE_NAMES in order to map feature names to
featureset bits, and then translate from featureset bits into cpuid
leaf, subleaf, register tuple.

Note that the full contents of the previous cpuid translation table
can't be removed.  That's because some feature names allowed by libxl
are not described in the featuresets, or because naming has diverged
and the previous nomenclature is preserved for compatibility reasons.

Should result in no functional change observed by callers, albeit some
new cpuid features will be available as a result of the change.

While there constify cpuid_flags name field.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
(cherry picked from commit d638fe233c)
2023-08-03 19:14:19 +01:00
Roger Pau Monne 548ac09051 libxl: split logic to parse user provided CPUID features
Move the CPUID value parsers out of libxl_cpuid_parse_config() into a
newly created cpuid_add() local helper.  This is in preparation for
also adding MSR feature parsing support.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
(cherry picked from commit e2b1da9b8f)
2023-08-03 19:14:19 +01:00
Roger Pau Monne 53307f5c5d libxl: introduce MSR data in libxl_cpuid_policy
Add a new array field to libxl_cpuid_policy in order to store the MSR
policies.

Adding the MSR data in the libxl_cpuid_policy_list type is done so
that existing users can seamlessly pass MSR features as part of the
CPUID data, without requiring the introduction of a separate
domain_build_info field, and a new set of handlers functions.

Note that support for parsing the old JSON format is kept, as that's
required in order to restore domains or received migrations from
previous tool versions.  Differentiation between the old and the new
formats is done based on whether the contents of the 'cpuid' field is
an array or a map JSON object.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
(cherry picked from commit 5b80cecb74)
2023-08-03 19:14:19 +01:00
Roger Pau Monne 9f6f7e07d0 libxl: change the type of libxl_cpuid_policy_list
Currently libxl_cpuid_policy_list is an opaque type to the users of
libxl, and internally it's an array of xc_xend_cpuid objects.

Change the type to instead be a structure that contains one array for
CPUID policies, in preparation for it also holding another array for
MSR policies.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
(cherry picked from commit 4825d19603)
2023-08-03 19:14:19 +01:00
Roger Pau Monne 44fde35fdd libs/guest: introduce support for setting guest MSRs
Like it's done with CPUID, introduce support for passing MSR values to
xc_cpuid_apply_policy().  The chosen format for expressing MSR policy
data matches the current one used for CPUID.  Note that existing
callers of xc_cpuid_apply_policy() can pass NULL as the value for the
newly introduced 'msr' parameter in order to preserve the same
functionality, and in fact that's done in libxl on this patch.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
(cherry picked from commit ed742cf1b6)
2023-08-03 19:14:19 +01:00
Roger Pau Monne 1e082c9eca libxl: don't ignore the return value from xc_cpuid_apply_policy
Also change libxl__cpuid_legacy to propagate the error from
xc_cpuid_apply_policy into callers.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
(cherry picked from commit 34990446ca)

libs/light: Propagate libxl__arch_domain_create() return code

Commit 34990446ca started to overwrite the `rc` value from
libxl__arch_domain_create(), thus error aren't propagated anymore.

Check `rc` value before doing the next thing.

Fixes: 34990446ca ("libxl: don't ignore the return value from xc_cpuid_apply_policy")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
(cherry picked from commit 8cdfbf95b1)

libxl: fix guest kexec - skip cpuid policy

When a domain performs a kexec (soft reset), libxl__build_pre() is
called with the existing domid.  Calling libxl__cpuid_legacy() on the
existing domain fails since the cpuid policy has already been set, and
the guest isn't rebuilt and doesn't kexec.

xc: error: Failed to set d1's policy (err leaf 0xffffffff, subleaf 0xffffffff, msr 0xffffffff) (17 = File exists): Internal error
libxl: error: libxl_cpuid.c:494:libxl__cpuid_legacy: Domain 1:Failed to apply CPUID policy: File exists
libxl: error: libxl_create.c:1641:domcreate_rebuild_done: Domain 1:cannot (re-)build domain: -3
libxl: error: libxl_xshelp.c:201:libxl__xs_read_mandatory: xenstore read failed: `/libxl/1/type': No such file or directory
libxl: warning: libxl_dom.c:49:libxl__domain_type: unable to get domain type for domid=1, assuming HVM

During a soft_reset, skip calling libxl__cpuid_legacy() to avoid the
issue.  Before commit 34990446ca, the libxl__cpuid_legacy() failure
would have been ignored, so kexec would continue.

Fixes: 34990446ca ("libxl: don't ignore the return value from xc_cpuid_apply_policy")
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
(cherry picked from commit 1e454c2b5b)
2023-08-03 19:14:19 +01:00
Andrew Cooper cf02b6efed x86/cpu-policy: Derive RSBA/RRSBA for guest policies
The RSBA bit, "RSB Alternative", means that the RSB may use alternative
predictors when empty.  From a practical point of view, this mean "Retpoline
not safe".

Enhanced IBRS (officially IBRS_ALL in Intel's docs, previously IBRS_ATT) is a
statement that IBRS is implemented in hardware (as opposed to the form
retrofitted to existing CPUs in microcode).

The RRSBA bit, "Restricted-RSBA", is a combination of RSBA, and the eIBRS
property that predictions are tagged with the mode in which they were learnt.
Therefore, it means "when eIBRS is active, the RSB may fall back to
alternative predictors but restricted to the current prediction mode".  As
such, it's stronger statement than RSBA, but still means "Retpoline not safe".

CPUs are not expected to enumerate both RSBA and RRSBA.

Add feature dependencies for EIBRS and RRSBA.  While technically they're not
linked, absolutely nothing good can come of letting the guest see RRSBA
without EIBRS.  Nor a guest seeing EIBRS without IBRSB.  Furthermore, we use
this dependency to simplify the max derivation logic.

The max policies gets RSBA and RRSBA unconditionally set (with the EIBRS
dependency maybe hiding RRSBA).  We can run any VM, even if it has been told
"somewhere you might run, Retpoline isn't safe".

The default policies are more complicated.  A guest shouldn't see both bits,
but it needs to see one if the current host suffers from any form of RSBA, and
which bit it needs to see depends on whether eIBRS is visible or not.
Therefore, the calculation must be performed after sanitise_featureset().

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit e0586a4ff5)
2023-08-03 19:14:19 +01:00
Andrew Cooper 5059ff1349 x86/spec-ctrl: Fix up the RSBA/RRSBA bits as appropriate
In order to level a VM safely for migration, the toolstack needs to know the
RSBA/RRSBA properties of the CPU, whether or not they happen to be enumerated.

See the code comment for details.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 36525a964f)
2023-08-03 19:14:19 +01:00
Andrew Cooper 927a168c39 x86/spec-ctrl: Rename retpoline_safe() to retpoline_calculations()
This is prep work, split out to simply the diff on the following change.

 * Rename to retpoline_calculations(), and call unconditionally.  It is
   shortly going to synthesise missing enumerations required for guest safety.
 * For the model check switch statement, store the result in a variable and
   break rather than returning directly.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 724c0d94ff)
2023-08-03 19:14:19 +01:00
Andrew Cooper efc4bdd2c9 x86/spec-ctrl: Use a taint for CET without MSR_SPEC_CTRL
Reword the comment for 'S' to include an incompatible set of features on the
same core.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 3f63f45104)

Also minimal fragments from:

  c/s 0bf9efb9ee ("xen/arm: Sanitize cpuinfo ID registers fields")

to introduce TAINT_CPU_OUT_OF_SPEC.
2023-08-03 19:14:19 +01:00
Andrew Cooper 18e759cb87 x86/spec-ctrl: Fix the rendering of FB_CLEAR
FB_CLEAR is a read-only status bit, not a read-write control.  Move it from
"Hardware features" into "Hardware hints".

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 921afcbae8)
2023-08-03 19:14:19 +01:00
Andrew Cooper 5619a526ea x86/cpu-policy: Rearrange guest_common_default_feature_adjustments()
This is prep work, split out to simply the diff on the following change.

 * Split the INTEL check out of the IvyBridge RDRAND check, as the former will
   be reused.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 064f572f96)
2023-08-03 19:14:19 +01:00
Andrew Cooper 06a2b62145 x86/spec-ctrl: Update hardware hints
* Rename IBRS_ALL to EIBRS.  EIBRS is the term that everyone knows, and this
   makes ARCH_CAPS_EIBRS match the X86_FEATURE_EIBRS form.
 * Print RRSBA too, which is also a hint about behaviour.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 94200e1bae)
2023-08-03 19:14:19 +01:00
Andrew Cooper dc89d1f6f3 x86/spec-ctrl: Remove opencoded MSR_ARCH_CAPS check
MSR_ARCH_CAPS data is now included in featureset information.  Replace
opencoded checks with regular feature ones.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 511b9f286c)
2023-08-03 19:14:19 +01:00
Andrew Cooper ad084937fa x86/tsx: Remove opencoded MSR_ARCH_CAPS check
The current cpu_has_tsx_ctrl tristate is serving double pupose; to signal the
first pass through tsx_init(), and the availability of MSR_TSX_CTRL.

Drop the variable, replacing it with a once boolean, and altering
cpu_has_tsx_ctrl to come out of the feature information.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 205a9f9703)
2023-08-03 19:14:19 +01:00
Andrew Cooper 7320e9aa80 x86/vtx: Remove opencoded MSR_ARCH_CAPS check
MSR_ARCH_CAPS data is now included in featureset information.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 8f6bc7f9b7)
2023-08-03 19:14:19 +01:00
Andrew Cooper 834fd82b8e x86/boot: Expose MSR_ARCH_CAPS data in guest max policies
We already have common and default feature adjustment helpers.  Introduce one
for max featuresets too.

Offer MSR_ARCH_CAPS unconditionally in the max policy, and stop clobbering the
data inherited from the Host policy.  This will be necessary to level a VM
safely for migration.  Annotate the ARCH_CAPS CPUID bit as special.  Note:
ARCH_CAPS is still max-only for now, so will not be inhereted by the default
policies.

With this done, the special case for dom0 can be shrunk to just resampling the
Host policy (as ARCH_CAPS isn't visible by default yet).

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit bbb289f3d5)
2023-08-03 19:14:19 +01:00
Andrew Cooper 12f895ef39 x86/boot: Record MSR_ARCH_CAPS for the Raw and Host CPU policy
Extend x86_cpu_policy_fill_native() with a read of ARCH_CAPS based on the
CPUID information just read, removing the specially handling in
calculate_raw_cpu_policy().

Right now, the only use of x86_cpu_policy_fill_native() outside of Xen is the
unit tests.  Getting MSR data in this context is left to whomever first
encounters a genuine need to have it.

Extend generic_identify() to read ARCH_CAPS into x86_capability[], which is
fed into the Host Policy.  This in turn means there's no need to special case
arch_caps in calculate_host_policy().

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 70553000d6)
2023-08-03 19:14:19 +01:00
Andrew Cooper 1ba3e81d73 x86/cpu-policy: MSR_ARCH_CAPS feature names
Seed the default visibility from the dom0 special case, which for the most
part just exposes the *_NO bits.  EIBRS is the one non-*_NO bit, which is
"just" a status bit to the guest indicating a change in implemention of IBRS
which is already fully supported.

Insert a block dependency from the ARCH_CAPS CPUID bit to the entire content
of the MSR.  This is because MSRs have no structure information similar to
CPUID, and used by x86_cpu_policy_clear_out_of_range_leaves(), in order to
bulk-clear inaccessable words.

The overall CPUID bit is still max-only, so all of MSR_ARCH_CAPS is hidden in
the default policies.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit ce8c930851)
2023-08-03 19:14:19 +01:00
Andrew Cooper eed3654bee x86/cpu-policy: Infrastructure for MSR_ARCH_CAPS
Bits through 24 are already defined, meaning that we're not far off needing
the second word.  Put both in right away.

As both halves are present now, the arch_caps field is full width.  Adjust the
unit test, which notices.

The bool bitfield names in the arch_caps union are unused, and somewhat out of
date.  They'll shortly be automatically generated.

Add CPUID and MSR prefixes to the ./xen-cpuid verbose output, now that there
are a mix of the two.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit d9fe459ffa)
2023-08-03 19:14:19 +01:00
Andrew Cooper 775b544ebe x86/boot: Adjust MSR_ARCH_CAPS handling for the Host policy
We are about to move MSR_ARCH_CAPS into featureset, but the order of
operations (copy raw policy, then copy x86_capabilitiles[] in) will end up
clobbering the ARCH_CAPS value.

Some toolstacks use this information to handle TSX compatibility across the
CPUs and microcode versions where support was removed.

To avoid this transient breakage, read from raw_cpu_policy rather than
modifying it in place.  This logic will be removed entirely in due course.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 43912f8dbb)
2023-08-03 19:14:19 +01:00
Andrew Cooper 5d624f0fb7 x86/boot: Rework dom0 feature configuration
Right now, dom0's feature configuration is split between between the common
path and a dom0-specific one.  This mostly is by accident, and causes some
very subtle bugs.

First, start by clearly defining init_dom0_cpuid_policy() to be the domain
that Xen builds automatically.  The late hwdom case is still constructed in a
mostly normal way, with the control domain having full discretion over the CPU
policy.

Identifying this highlights a latent bug - the two halves of the MSR_ARCH_CAPS
bodge are asymmetric with respect to the hardware domain.  This means that
shim, or a control-only dom0 sees the MSR_ARCH_CAPS CPUID bit but none of the
MSR content.  This in turn declares the hardware to be retpoline-safe by
failing to advertise the {R,}RSBA bits appropriately.  Restrict this logic to
the hardware domain, although the special case will cease to exist shortly.

For the CPUID Faulting adjustment, the comment in ctxt_switch_levelling()
isn't actually relevant.  Provide a better explanation.

Move the recalculate_cpuid_policy() call outside of the dom0-cpuid= case.
This is no change for now, but will become necessary shortly.

Finally, place the second half of the MSR_ARCH_CAPS bodge after the
recalculate_cpuid_policy() call.  This is necessary to avoid transiently
breaking the hardware domain's view while the handling is cleaned up.  This
special case will cease to exist shortly.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit ef1987fcb0)
2023-08-03 19:14:19 +01:00
Andrew Cooper f5b0f486dc x86: Remove temporary {cpuid,msr}_policy defines
With all code areas updated, drop the temporary defines and adjust all
remaining users.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 994c1553a1)
2023-08-03 19:14:19 +01:00
Andrew Cooper c1adeb4779 libx86: Update library API for cpu_policy
Adjust the API and comments appropriately.

x86_cpu_policy_fill_native() will eventually contain MSR reads, but leave a
TODO in the short term.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 1b67fccf3b)

tools/libs/guest: Fix build following libx86 changes

I appear to have lost this hunk somewhere...

Fixes: 1b67fccf3b ("libx86: Update library API for cpu_policy")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 48d76e6da9)
2023-08-03 19:14:19 +01:00
Andrew Cooper 738d89d31f tools/fuzz: Rework afl-policy-fuzzer
With cpuid_policy and msr_policy merged to form cpu_policy, merge the
respective fuzzing logic.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit a16dcd48c2)
2023-08-03 19:14:19 +01:00
Andrew Cooper 72895c4e97 x86/emul: Switch x86_emulate_ctxt to cpu_policy
As with struct domain, retain cpuid as a valid alias for local code clarity.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 441b1b2a50)
2023-08-03 19:14:19 +01:00
Andrew Cooper 4e093cb460 x86/boot: Merge CPUID policy initialisation logic into cpu-policy.c
Switch to the newer cpu_policy nomenclature.  Do some easy cleanup of
includes.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 8eb56eb959)
2023-08-03 19:14:19 +01:00
Andrew Cooper 279c1fb626 x86/boot: Move MSR policy initialisation logic into cpu-policy.c
Switch to the newer cpu_policy nomenclature.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 4f20f596ce)
2023-08-03 19:14:19 +01:00
Andrew Cooper 4ff61b27a3 x86: Out-of-inline the policy<->featureset convertors
These are already getting over-large for being inline functions, and are only
going to grow further over time.  Out of line them, yielding the following net
delta from bloat-o-meter:

  add/remove: 2/0 grow/shrink: 0/4 up/down: 276/-1877 (-1601)

Switch to the newer cpu_policy terminology while doing so.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 1027df4c00)
2023-08-03 19:14:19 +01:00
Andrew Cooper bdcc1765f1 x86: Drop struct old_cpu_policy
With all the complicated callers of x86_cpu_policies_are_compatible() updated
to use a single cpu_policy object, we can drop the final user of struct
old_cpu_policy.

Update x86_cpu_policies_are_compatible() to take (new) cpu_policy pointers,
reducing the amount of internal pointer chasing, and update all callers to
pass their cpu_policy objects directly.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 66c5c99656)
2023-08-03 19:14:19 +01:00
Andrew Cooper cfcf833350 x86: Merge xc_cpu_policy's cpuid and msr objects
Right now, they're the same underlying type, containing disjoint information.

Use a single object instead.  Also take the opportunity to rename 'entries' to
'msrs' which is more descriptive, and more in line with nr_msrs being the
count of MSR entries in the API.

test-tsx uses xg_private.h to access the internals of xc_cpu_policy, so needs
updating at the same time.  Take the opportunity to improve the code clarity
by passing a cpu_policy rather than an xc_cpu_policy into some functions.

No practical change.  This undoes the transient doubling of storage space from
earlier patches.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit c9985233ca)
2023-08-03 19:14:19 +01:00
Andrew Cooper 99d01e3729 x86: Merge a domain's {cpuid,msr} policy objects
Right now, they're the same underlying type, containing disjoint information.

Drop the d->arch.msr pointer, and union d->arch.cpuid to give it a second name
of cpu_policy in the interim.

Merge init_domain_{cpuid,msr}_policy() into a single init_domain_cpu_policy(),
moving the implementation into cpu-policy.c

No practical change.  This undoes the transient doubling of storage space from
earlier patches.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit bd13dae348)
2023-08-03 19:14:19 +01:00
Andrew Cooper 83a720e912 x86: Merge the system {cpuid,msr} policy objects
Right now, they're the same underlying type, containing disjoint information.

Introduce a new cpu-policy.{h,c} to be the new location for all policy
handling logic.  Place the combined objects in __ro_after_init, which is new
since the original logic was written.

As we're trying to phase out the use of struct old_cpu_policy entirely, rework
update_domain_cpu_policy() to not pointer-chase through system_policies[].

This in turn allows system_policies[] in sysctl.c to become static and reduced
in scope to XEN_SYSCTL_get_cpu_policy.

No practical change.  This undoes the transient doubling of storage space from
earlier patches.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 6bc3336679)
2023-08-03 19:14:19 +01:00
Andrew Cooper 63e4aa3d3b x86: Merge struct msr_policy into struct cpu_policy
As with the cpuid side, use a temporary define to make struct msr_policy still
work.

Note, this means that domains now have two separate struct cpu_policy
allocations with disjoint information, and system policies are in a similar
position, as well as xc_cpu_policy objects in libxenguest.  All of these
duplications will be addressed in the following patches.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 03812da375)
2023-08-03 19:14:19 +01:00
Andrew Cooper 2e54fb9fec x86: Rename struct cpuid_policy to struct cpu_policy
Also merge lib/x86/cpuid.h entirely into lib/x86/cpu-policy.h

Use a temporary define to make struct cpuid_policy still work.

There's one forward declaration of struct cpuid_policy in
tools/tests/x86_emulator/x86-emulate.h that isn't covered by the define, and
it's easier to rename that now than to rearrange the includes.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 743e530380)
2023-08-03 19:14:19 +01:00
Andrew Cooper 3747c51a68 x86: Rename {domctl,sysctl}.cpu_policy.{cpuid,msr}_policy fields
These weren't great names to begin with, and using {leaves,msrs} matches up
better with the existing nr_{leaves,msr} parameters anyway.

Furthermore, by renaming these fields we can get away with using some #define
trickery to avoid the struct {cpuid,msr}_policy merge needing to happen in a
single changeset.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 21e3ef57e0)

xen: Correct comments after renaming xen_{dom,sys}ctl_cpu_policy fields

Fixes: 21e3ef57e0 ("x86: Rename {domctl,sysctl}.cpu_policy.{cpuid,msr}_policy fields")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 6e06d229d5)
2023-08-03 19:14:19 +01:00
Andrew Cooper edc64afe17 x86: Rename struct cpu_policy to struct old_cpuid_policy
We want to merge struct cpuid_policy and struct msr_policy together, and the
result wants to be called struct cpu_policy.

The current struct cpu_policy, being a pair of pointers, isn't terribly
useful.  Rename the type to struct old_cpu_policy, but it will disappear
entirely once the merge is complete.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit c2ec94c370)
2023-08-03 19:14:19 +01:00
Andrew Cooper 0307a3f68e x86/sysctl: Retrofit XEN_SYSCTL_cpu_featureset_{pv,hvm}_max
Featuresets are supposed to be disappearing when the CPU policy infrastructure
is complete, but that has taken longer than expected, and isn't going to be
complete imminently either.

In the meantime, Xen does have proper default/max featuresets, and xen-cpuid
can even get them via the XEN_SYSCTL_cpu_policy_* interface, but only knows
now to render them nicely via the featureset interface.

Differences between default and max are a frequent source of errors,
frequently too in secret leading up to an embargo, so extend the featureset
sysctl to allow xen-cpuid to render them all nicely.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
(cherry picked from commit 433d012c6c)
2023-08-03 19:14:19 +01:00
Andrew Cooper 25eb98c93c tools/xen-cpuid: Rework the handling of dynamic featuresets
struct fsinfo is the vestigial remnant of an older internal design which
didn't survive very long.

Simplify things by inlining get_featureset() and having a single memory
allocation that gets reused.  This in turn changes featuresets[] to be a
simple list of names, so rename it to fs_names[].

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit ec3474e1dd)
2023-08-03 19:14:19 +01:00