Pull x86 asm updates from Ingo Molnar:
- better support (non-atomic) 64-bit readq()/writeq() variants (Andy
Shevchenko)
- __clear_user() micro-optimization (Alexey Dobriyan)
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/io: Define readq()/writeq() to use 64-bit type
x86/asm/64: Micro-optimize __clear_user() - Use immediate constants
Pull x86 boot updates from Ingo Molnar:
- Centaur CPU updates (David Wang)
- AMD and other CPU topology enumeration improvements and fixes
(Borislav Petkov, Thomas Gleixner, Suravee Suthikulpanit)
- Continued 5-level paging work (Kirill A. Shutemov)
* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Mark __pgtable_l5_enabled __initdata
x86/mm: Mark p4d_offset() __always_inline
x86/mm: Introduce the 'no5lvl' kernel parameter
x86/mm: Stop pretending pgtable_l5_enabled is a variable
x86/mm: Unify pgtable_l5_enabled usage in early boot code
x86/boot/compressed/64: Fix trampoline page table address calculation
x86/CPU: Move x86_cpuinfo::x86_max_cores assignment to detect_num_cpu_cores()
x86/Centaur: Report correct CPU/cache topology
x86/CPU: Move cpu_detect_cache_sizes() into init_intel_cacheinfo()
x86/CPU: Make intel_num_cpu_cores() generic
x86/CPU: Move cpu local function declarations to local header
x86/CPU/AMD: Derive CPU topology from CPUID function 0xB when available
x86/CPU: Modify detect_extended_topology() to return result
x86/CPU/AMD: Calculate last level cache ID from number of sharing threads
x86/CPU: Rename intel_cacheinfo.c to cacheinfo.c
perf/events/amd/uncore: Fix amd_uncore_llc ID to use pre-defined cpu_llc_id
x86/CPU/AMD: Have smp_num_siblings and cpu_llc_id always be present
x86/Centaur: Initialize supported CPU features properly
Pull locking updates from Ingo Molnar:
- Lots of tidying up changes all across the map for Linux's formal
memory/locking-model tooling, by Alan Stern, Akira Yokosawa, Andrea
Parri, Paul E. McKenney and SeongJae Park.
Notable changes beyond an overall update in the tooling itself is the
tidying up of spin_is_locked() semantics, which spills over into the
kernel proper as well.
- qspinlock improvements: the locking algorithm now guarantees forward
progress whereas the previous implementation in mainline could starve
threads indefinitely in cmpxchg() loops. Also other related cleanups
to the qspinlock code (Will Deacon)
- misc smaller improvements, cleanups and fixes all across the locking
subsystem
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
locking/rwsem: Simplify the is-owner-spinnable checks
tools/memory-model: Add reference for 'Simplifying ARM concurrency'
tools/memory-model: Update ASPLOS information
MAINTAINERS, tools/memory-model: Update e-mail address for Andrea Parri
tools/memory-model: Fix coding style in 'lock.cat'
tools/memory-model: Remove out-of-date comments and code from lock.cat
tools/memory-model: Improve mixed-access checking in lock.cat
tools/memory-model: Improve comments in lock.cat
tools/memory-model: Remove duplicated code from lock.cat
tools/memory-model: Flag "cumulativity" and "propagation" tests
tools/memory-model: Add model support for spin_is_locked()
tools/memory-model: Add scripts to test memory model
tools/memory-model: Fix coding style in 'linux-kernel.def'
tools/memory-model: Model 'smp_store_mb()'
tools/memory-order: Update the cheat-sheet to show that smp_mb__after_atomic() orders later RMW operations
tools/memory-order: Improve key for SELF and SV
tools/memory-model: Fix cheat sheet typo
tools/memory-model: Update required version of herdtools7
tools/memory-model: Redefine rb in terms of rcu-fence
tools/memory-model: Rename link and rcu-path to rcu-link and rb
...
Pull dma-mapping updates from Christoph Hellwig:
- replace the force_dma flag with a dma_configure bus method. (Nipun
Gupta, although one patch is іncorrectly attributed to me due to a
git rebase bug)
- use GFP_DMA32 more agressively in dma-direct. (Takashi Iwai)
- remove PCI_DMA_BUS_IS_PHYS and rely on the dma-mapping API to do the
right thing for bounce buffering.
- move dma-debug initialization to common code, and apply a few
cleanups to the dma-debug code.
- cleanup the Kconfig mess around swiotlb selection
- swiotlb comment fixup (Yisheng Xie)
- a trivial swiotlb fix. (Dan Carpenter)
- support swiotlb on RISC-V. (based on a patch from Palmer Dabbelt)
- add a new generic dma-noncoherent dma_map_ops implementation and use
it for arc, c6x and nds32.
- improve scatterlist validity checking in dma-debug. (Robin Murphy)
- add a struct device quirk to limit the dma-mask to 32-bit due to
bridge/system issues, and switch x86 to use it instead of a local
hack for VIA bridges.
- handle devices without a dma_mask more gracefully in the dma-direct
code.
* tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mapping: (48 commits)
dma-direct: don't crash on device without dma_mask
nds32: use generic dma_noncoherent_ops
nds32: implement the unmap_sg DMA operation
nds32: consolidate DMA cache maintainance routines
x86/pci-dma: switch the VIA 32-bit DMA quirk to use the struct device flag
x86/pci-dma: remove the explicit nodac and allowdac option
x86/pci-dma: remove the experimental forcesac boot option
Documentation/x86: remove a stray reference to pci-nommu.c
core, dma-direct: add a flag 32-bit dma limits
dma-mapping: remove unused gfp_t parameter to arch_dma_alloc_attrs
dma-debug: check scatterlist segments
c6x: use generic dma_noncoherent_ops
arc: use generic dma_noncoherent_ops
arc: fix arc_dma_{map,unmap}_page
arc: fix arc_dma_sync_sg_for_{cpu,device}
arc: simplify arc_dma_sync_single_for_{cpu,device}
dma-mapping: provide a generic dma-noncoherent implementation
dma-mapping: simplify Kconfig dependencies
riscv: add swiotlb support
riscv: only enable ZONE_DMA32 for 64-bit
...
According to the Intel Software Developers' Manual, Vol. 4, Order No.
335592, these macros have been reversed since they were added in the
initial turbostat commit. The reversed definitions were presumably
copied from turbostat.c to this file.
Fixes: 9c63a650bb ("tools/power/x86/turbostat: share kernel MSR #defines")
Signed-off-by: Matt Turner <mattst88@gmail.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Instead of globally disabling > 32bit DMA using the arch_dma_supported
hook walk the PCI bus under the actually affected bridge and mark every
device with the dma_32bit_limit flag. This also gets rid of the
arch_dma_supported hook entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Implement HvFlushVirtualAddress{List,Space} hypercalls in a simplistic way:
do full TLB flush with KVM_REQ_TLB_FLUSH and kick vCPUs which are currently
IN_GUEST_MODE.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Hyper-V TLB flush hypercalls definitions will be required for KVM so move
them hyperv-tlfs.h. Structures also need to be renamed as '_pcpu' suffix is
irrelevant for a general-purpose definition.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Changing the VMCS12 layout will break save/restore compatibility with
older kvm releases once the KVM_{GET,SET}_NESTED_STATE ioctls are
accepted upstream. Google has already been using these ioctls for some
time, and we implore the community not to disturb the existing layout.
Move the four most recently added fields to preserve the offsets of
the previously defined fields and reserve locations for the vmread and
vmwrite bitmaps, which will be used in the virtualization of VMCS
shadowing (to improve the performance of double-nesting).
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[Kept the SDM order in vmcs_field_to_offset_table. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Given the fact that the ACPI "EINJ" (error injection) facility is not
universally available, implement software infrastructure to validate the
memcpy_mcsafe() exception handling implementation.
For each potential read exception point in memcpy_mcsafe(), inject a
emulated exception point at the address identified by 'mcsafe_inject'
variable. With this infrastructure implement a test to validate that the
'bytes remaining' calculation is correct for a range of various source
buffer alignments.
This code is compiled out by default. The CONFIG_MCSAFE_DEBUG
configuration symbol needs to be manually enabled by editing
Kconfig.debug. I.e. this functionality can not be accidentally enabled
by a user / distro, it's only for development.
Cc: <x86@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
S390 bpf_jit.S is removed in net-next and had changes in 'net',
since that code isn't used any more take the removal.
TLS data structures split the TX and RX components in 'net-next',
put the new struct members from the bug fix in 'net' into the RX
part.
The 'net-next' tree had some reworking of how the ERSPAN code works in
the GRE tunneling code, overlapping with a one-line headroom
calculation fix in 'net'.
Overlapping changes in __sock_map_ctx_update_elem(), keep the bits
that read the prog members via READ_ONCE() into local variables
before using them.
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge speculative store buffer bypass fixes from Thomas Gleixner:
- rework of the SPEC_CTRL MSR management to accomodate the new fancy
SSBD (Speculative Store Bypass Disable) bit handling.
- the CPU bug and sysfs infrastructure for the exciting new Speculative
Store Bypass 'feature'.
- support for disabling SSB via LS_CFG MSR on AMD CPUs including
Hyperthread synchronization on ZEN.
- PRCTL support for dynamic runtime control of SSB
- SECCOMP integration to automatically disable SSB for sandboxed
processes with a filter flag for opt-out.
- KVM integration to allow guests fiddling with SSBD including the new
software MSR VIRT_SPEC_CTRL to handle the LS_CFG based oddities on
AMD.
- BPF protection against SSB
.. this is just the core and x86 side, other architecture support will
come separately.
* 'speck-v20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits)
bpf: Prevent memory disambiguation attack
x86/bugs: Rename SSBD_NO to SSB_NO
KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD
x86/speculation, KVM: Implement support for VIRT_SPEC_CTRL/LS_CFG
x86/bugs: Rework spec_ctrl base and mask logic
x86/bugs: Remove x86_spec_ctrl_set()
x86/bugs: Expose x86_spec_ctrl_base directly
x86/bugs: Unify x86_spec_ctrl_{set_guest,restore_host}
x86/speculation: Rework speculative_store_bypass_update()
x86/speculation: Add virtualized speculative store bypass disable support
x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL
x86/speculation: Handle HT correctly on AMD
x86/cpufeatures: Add FEATURE_ZEN
x86/cpufeatures: Disentangle SSBD enumeration
x86/cpufeatures: Disentangle MSR_SPEC_CTRL enumeration from IBRS
x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
KVM: SVM: Move spec control call after restore of GS
x86/cpu: Make alternative_msr_write work for 32-bit code
x86/bugs: Fix the parameters alignment and missing void
x86/bugs: Make cpu_show_common() static
...
Pull x86 fixes from Thomas Gleixner:
"An unfortunately larger set of fixes, but a large portion is
selftests:
- Fix the missing clusterid initializaiton for x2apic cluster
management which caused boot failures due to IPIs being sent to the
wrong cluster
- Drop TX_COMPAT when a 64bit executable is exec()'ed from a compat
task
- Wrap access to __supported_pte_mask in __startup_64() where clang
compile fails due to a non PC relative access being generated.
- Two fixes for 5 level paging fallout in the decompressor:
- Handle GOT correctly for paging_prepare() and
cleanup_trampoline()
- Fix the page table handling in cleanup_trampoline() to avoid
page table corruption.
- Stop special casing protection key 0 as this is inconsistent with
the manpage and also inconsistent with the allocation map handling.
- Override the protection key wen moving away from PROT_EXEC to
prevent inaccessible memory.
- Fix and update the protection key selftests to address breakage and
to cover the above issue
- Add a MOV SS self test"
[ Part of the x86 fixes were in the earlier core pull due to dependencies ]
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
x86/mm: Drop TS_COMPAT on 64-bit exec() syscall
x86/apic/x2apic: Initialize cluster ID properly
x86/boot/compressed/64: Fix moving page table out of trampoline memory
x86/boot/compressed/64: Set up GOT for paging_prepare() and cleanup_trampoline()
x86/pkeys: Do not special case protection key 0
x86/pkeys/selftests: Add a test for pkey 0
x86/pkeys/selftests: Save off 'prot' for allocations
x86/pkeys/selftests: Fix pointer math
x86/pkeys: Override pkey when moving away from PROT_EXEC
x86/pkeys/selftests: Fix pkey exhaustion test off-by-one
x86/pkeys/selftests: Add PROT_EXEC test
x86/pkeys/selftests: Factor out "instruction page"
x86/pkeys/selftests: Allow faults on unknown keys
x86/pkeys/selftests: Avoid printf-in-signal deadlocks
x86/pkeys/selftests: Remove dead debugging code, fix dprint_in_signal
x86/pkeys/selftests: Stop using assert()
x86/pkeys/selftests: Give better unexpected fault error messages
x86/selftests: Add mov_to_ss test
x86/mpx/selftests: Adjust the self-test to fresh distros that export the MPX ABI
x86/pkeys/selftests: Adjust the self-test to fresh distros that export the pkeys ABI
...
Pull core fixes from Thomas Gleixner:
- Unbreak the BPF compilation which got broken by the unconditional
requirement of asm-goto, which is not supported by clang.
- Prevent probing on exception masking instructions in uprobes and
kprobes to avoid the issues of the delayed exceptions instead of
having an ugly workaround.
- Prevent a double free_page() in the error path of do_kexec_load()
- A set of objtool updates addressing various issues mostly related to
switch tables and the noreturn detection for recursive sibling calls
- Header sync for tools.
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Detect RIP-relative switch table references, part 2
objtool: Detect RIP-relative switch table references
objtool: Support GCC 8 switch tables
objtool: Support GCC 8's cold subfunctions
objtool: Fix "noreturn" detection for recursive sibling calls
objtool, kprobes/x86: Sync the latest <asm/insn.h> header with tools/objtool/arch/x86/include/asm/insn.h
x86/cpufeature: Guard asm_volatile_goto usage for BPF compilation
uprobes/x86: Prohibit probing on MOV SS instruction
kprobes/x86: Prohibit probing on exception masking instructions
x86/kexec: Avoid double free_page() upon do_kexec_load() failure
The Hyper-V APIC code is built when CONFIG_HYPERV is enabled but the actual
code in that file is guarded with CONFIG_X86_64. There is no point in doing
this. Neither is there a point in having the CONFIG_HYPERV guard in there
because the containing directory is not built when CONFIG_HYPERV=n.
Further for the hv_init_apic() function a stub is provided only for
CONFIG_HYPERV=n, which is pointless as the callsite is not compiled at
all. But for X86_32 the stub is missing and the build fails.
Clean that up:
- Compile hv_apic.c only when CONFIG_X86_64=y
- Make the stub for hv_init_apic() available when CONFG_X86_64=n
Fixes: 6b48cb5f83 ("X86/Hyper-V: Enlighten APIC access")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Michael Kelley <mikelley@microsoft.com>
__pgtable_l5_enabled shouldn't be needed after system has booted, we can
mark it as __initdata, but it requires preparation.
KASAN initialization code is a user of USE_EARLY_PGTABLE_L5, so all
pgtable_l5_enabled() translated to __pgtable_l5_enabled there, including
the one in p4d_offset().
It may lead to section mismatch, if a compiler would not inline
p4d_offset(), but leave it as a standalone function: p4d_offset() is not
marked as __init.
Marking p4d_offset() as __always_inline fixes the issue.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180518103528.59260-7-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The "336996 Speculative Execution Side Channel Mitigations" from
May defines this as SSB_NO, hence lets sync-up.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Since non atomic readq() and writeq() were added some of the drivers
would like to use it in a manner of:
#include <io-64-nonatomic-lo-hi.h>
...
pr_debug("Debug value of some register: %016llx\n", readq(addr));
However, lo_hi_readq() always returns __u64 data, while readq()
on x86_64 defines it as unsigned long. and thus compiler warns
about type mismatch, although they are both 64-bit on x86_64.
Convert readq() and writeq() on x86 to operate on deterministic
64-bit type. The most of architectures in the kernel already are using
either unsigned long long, or u64 type for readq() / writeq().
This change propagates consistency in that sense.
While this is not an issue per se, though if someone wants to address it,
the anchor could be the commit:
797a796a13 ("asm-generic: architecture independent readq/writeq for 32bit environment")
where non-atomic variants had been introduced.
Note, there are only few users of above pattern and they will not be
affected because they do cast returned value. The actual warning has
been issued on not-yet-upstreamed code.
Potentially we might get a new warnings if some 64-bit only code
assigns returned value to unsigned long type of variable. This is
assumed to be addressed on case-by-case basis.
Reported-by: lkp <lkp@intel.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180515115211.55050-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
KVM_HINTS_DEDICATED seems to be somewhat confusing:
Guest doesn't really care whether it's the only task running on a host
CPU as long as it's not preempted.
And there are more reasons for Guest to be preempted than host CPU
sharing, for example, with memory overcommit it can get preempted on a
memory access, post copy migration can cause preemption, etc.
Let's call it KVM_HINTS_REALTIME which seems to better
match what guests expect.
Also, the flag most be set on all vCPUs - current guests assume this.
Note so in the documentation.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Expose the new virtualized architectural mechanism, VIRT_SSBD, for using
speculative store bypass disable (SSBD) under SVM. This will allow guests
to use SSBD on hardware that uses non-architectural mechanisms for enabling
SSBD.
[ tglx: Folded the migration fixup from Paolo Bonzini ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add the necessary logic for supporting the emulated VIRT_SPEC_CTRL MSR to
x86_virt_spec_ctrl(). If either X86_FEATURE_LS_CFG_SSBD or
X86_FEATURE_VIRT_SPEC_CTRL is set then use the new guest_virt_spec_ctrl
argument to check whether the state must be modified on the host. The
update reuses speculative_store_bypass_update() so the ZEN-specific sibling
coordination can be reused.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
x86_spec_ctrl_set() is only used in bugs.c and the extra mask checks there
provide no real value as both call sites can just write x86_spec_ctrl_base
to MSR_SPEC_CTRL. x86_spec_ctrl_base is valid and does not need any extra
masking or checking.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
x86_spec_ctrl_base is the system wide default value for the SPEC_CTRL MSR.
x86_spec_ctrl_get_default() returns x86_spec_ctrl_base and was intended to
prevent modification to that variable. Though the variable is read only
after init and globaly visible already.
Remove the function and export the variable instead.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Function bodies are very similar and are going to grow more almost
identical code. Add a bool arg to determine whether SPEC_CTRL is being set
for the guest or restored to the host.
No functional changes.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The upcoming support for the virtual SPEC_CTRL MSR on AMD needs to reuse
speculative_store_bypass_update() to avoid code duplication. Add an
argument for supplying a thread info (TIF) value and create a wrapper
speculative_store_bypass_update_current() which is used at the existing
call site.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Some AMD processors only support a non-architectural means of enabling
speculative store bypass disable (SSBD). To allow a simplified view of
this to a guest, an architectural definition has been created through a new
CPUID bit, 0x80000008_EBX[25], and a new MSR, 0xc001011f. With this, a
hypervisor can virtualize the existence of this definition and provide an
architectural method for using SSBD to a guest.
Add the new CPUID feature, the new MSR and update the existing SSBD
support to use this MSR when present.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
AMD is proposing a VIRT_SPEC_CTRL MSR to handle the Speculative Store
Bypass Disable via MSR_AMD64_LS_CFG so that guests do not have to care
about the bit position of the SSBD bit and thus facilitate migration.
Also, the sibling coordination on Family 17H CPUs can only be done on
the host.
Extend x86_spec_ctrl_set_guest() and x86_spec_ctrl_restore_host() with an
extra argument for the VIRT_SPEC_CTRL MSR.
Hand in 0 from VMX and in SVM add a new virt_spec_ctrl member to the CPU
data structure which is going to be used in later patches for the actual
implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The AMD64_LS_CFG MSR is a per core MSR on Family 17H CPUs. That means when
hyperthreading is enabled the SSBD bit toggle needs to take both cores into
account. Otherwise the following situation can happen:
CPU0 CPU1
disable SSB
disable SSB
enable SSB <- Enables it for the Core, i.e. for CPU0 as well
So after the SSB enable on CPU1 the task on CPU0 runs with SSB enabled
again.
On Intel the SSBD control is per core as well, but the synchronization
logic is implemented behind the per thread SPEC_CTRL MSR. It works like
this:
CORE_SPEC_CTRL = THREAD0_SPEC_CTRL | THREAD1_SPEC_CTRL
i.e. if one of the threads enables a mitigation then this affects both and
the mitigation is only disabled in the core when both threads disabled it.
Add the necessary synchronization logic for AMD family 17H. Unfortunately
that requires a spinlock to serialize the access to the MSR, but the locks
are only shared between siblings.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Add a ZEN feature bit so family-dependent static_cpu_has() optimizations
can be built for ZEN.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The SSBD enumeration is similarly to the other bits magically shared
between Intel and AMD though the mechanisms are different.
Make X86_FEATURE_SSBD synthetic and set it depending on the vendor specific
features or family dependent setup.
Change the Intel bit to X86_FEATURE_SPEC_CTRL_SSBD to denote that SSBD is
controlled via MSR_SPEC_CTRL and fix up the usage sites.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The availability of the SPEC_CTRL MSR is enumerated by a CPUID bit on
Intel and implied by IBRS or STIBP support on AMD. That's just confusing
and in case an AMD CPU has IBRS not supported because the underlying
problem has been fixed but has another bit valid in the SPEC_CTRL MSR,
the thing falls apart.
Add a synthetic feature bit X86_FEATURE_MSR_SPEC_CTRL to denote the
availability on both Intel and AMD.
While at it replace the boot_cpu_has() checks with static_cpu_has() where
possible. This prevents late microcode loading from exposing SPEC_CTRL, but
late loading is already very limited as it does not reevaluate the
mitigation options and other bits and pieces. Having static_cpu_has() is
the simplest and least fragile solution.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
