Commit Graph

19757 Commits

Author SHA1 Message Date
Tom Lendacky
e70316d17f x86/sev: Check for MWAITX and MONITORX opcodes in the #VC handler
The MWAITX and MONITORX instructions generate the same #VC error code as
the MWAIT and MONITOR instructions, respectively. Update the #VC handler
opcode checking to also support the MWAITX and MONITORX opcodes.

Fixes: e3ef461af3 ("x86/sev: Harden #VC instruction emulation somewhat")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/453d5a7cfb4b9fe818b6fb67f93ae25468bc9e23.1713793161.git.thomas.lendacky@amd.com
2024-04-22 18:38:28 +02:00
Tony Luck
f055b6260e x86/cpu/vfm: Update arch/x86/include/asm/intel-family.h
New CPU #defines encode vendor and family as well as model.

Update the example usage comment in arch/x86/kernel/cpu/match.c

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240416211941.9369-4-tony.luck@intel.com
2024-04-22 11:44:00 +02:00
Paolo Bonzini
a96cb3bf39 Merge x86 bugfixes from Linux 6.9-rc3
Pull fix for SEV-SNP late disable bugs.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-04-19 09:02:22 -04:00
Eric Biggers
9543f6e266 x86/cpufeatures: Fix dependencies for GFNI, VAES, and VPCLMULQDQ
Fix cpuid_deps[] to list the correct dependencies for GFNI, VAES, and
VPCLMULQDQ.  These features don't depend on AVX512, and there exist CPUs
that support these features but not AVX512.  GFNI actually doesn't even
depend on AVX.

This prevents GFNI from being unnecessarily disabled if AVX is disabled
to mitigate the GDS vulnerability.

This also prevents all three features from being unnecessarily disabled
if AVX512VL (or its dependency AVX512F) were to be disabled, but it
looks like there isn't any case where this happens anyway.

Fixes: c128dbfa0f ("x86/cpufeatures: Enable new SSE/AVX/AVX512 CPU features")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20240417060434.47101-1-ebiggers@kernel.org
2024-04-18 17:27:52 +02:00
Josh Poimboeuf
69129794d9 x86/bugs: Fix BHI retpoline check
Confusingly, X86_FEATURE_RETPOLINE doesn't mean retpolines are enabled,
as it also includes the original "AMD retpoline" which isn't a retpoline
at all.

Also replace cpu_feature_enabled() with boot_cpu_has() because this is
before alternatives are patched and cpu_feature_enabled()'s fallback
path is slower than plain old boot_cpu_has().

Fixes: ec9404e40e ("x86/bhi: Add BHI mitigation knob")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/ad3807424a3953f0323c011a643405619f2a4927.1712944776.git.jpoimboe@kernel.org
2024-04-14 11:10:05 +02:00
Li RongQing
90167e9658 x86/sev: Take NUMA node into account when allocating memory for per-CPU SEV data
per-CPU SEV data is dominantly accessed from their own local CPUs,
so allocate them node-local to improve performance.

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Nikunj A Dadhania <nikunj@amd.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/20240412030130.49704-1-lirongqing@baidu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-04-12 12:12:11 +02:00
Ingo Molnar
21f546a43a Merge branch 'x86/urgent' into x86/cpu, to resolve conflict
There's a new conflict between this commit pending in x86/cpu:

  63edbaa48a x86/cpu/topology: Add support for the AMD 0x80000026 leaf

And these fixes in x86/urgent:

  c064b536a8 x86/cpu/amd: Make the NODEID_MSR union actually work
  1b3108f689 x86/cpu/amd: Make the CPUID 0x80000008 parser correct

Resolve them.

 Conflicts:
	arch/x86/kernel/cpu/topology_amd.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-04-12 12:11:45 +02:00
Thomas Gleixner
7211274fe0 x86/cpu/amd: Move TOPOEXT enablement into the topology parser
The topology rework missed that early_init_amd() tries to re-enable the
Topology Extensions when the BIOS disabled them.

The new parser is invoked before early_init_amd() so the re-enable attempt
happens too late.

Move it into the AMD specific topology parser code where it belongs.

Fixes: f7fb3b2dd9 ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/878r1j260l.ffs@tglx
2024-04-12 12:05:54 +02:00
Thomas Gleixner
c064b536a8 x86/cpu/amd: Make the NODEID_MSR union actually work
A system with NODEID_MSR was reported to crash during early boot without
any output.

The reason is that the union which is used for accessing the bitfields in
the MSR is written wrongly and the resulting executable code accesses the
wrong part of the MSR data.

As a consequence a later division by that value results in 0 and that
result is used for another division as divisor, which obviously does not
work well.

The magic world of C, unions and bitfields:

    union {
    	  u64   bita : 3,
	        bitb : 3;
	  u64   all;
    } x;

    x.all = foo();

    a = x.bita;
    b = x.bitb;

results in the effective executable code of:

   a = b = x.bita;

because bita and bitb are treated as union members and therefore both end
up at bit offset 0.

Wrapping the bitfield into an anonymous struct:

    union {
    	  struct {
    	     u64  bita : 3,
	          bitb : 3;
          };
	  u64	  all;
    } x;

works like expected.

Rework the NODEID_MSR union in exactly that way to cure the problem.

Fixes: f7fb3b2dd9 ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Reported-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Laura Nao <laura.nao@collabora.com>
Link: https://lore.kernel.org/r/20240410194311.596282919@linutronix.de
Closes: https://lore.kernel.org/all/20240322175210.124416-1-laura.nao@collabora.com/
2024-04-12 12:05:54 +02:00
Thomas Gleixner
1b3108f689 x86/cpu/amd: Make the CPUID 0x80000008 parser correct
CPUID 0x80000008 ECX.cpu_nthreads describes the number of threads in the
package. The parser uses this value to initialize the SMT domain level.

That's wrong because cpu_nthreads does not describe the number of threads
per physical core. So this needs to set the CORE domain level and let the
later parsers set the SMT shift if available.

Preset the SMT domain level with the assumption of one thread per core,
which is correct ifrt here are no other CPUID leafs to parse, and propagate
cpu_nthreads and the core level APIC bitwidth into the CORE domain.

Fixes: f7fb3b2dd9 ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Reported-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Laura Nao <laura.nao@collabora.com>
Link: https://lore.kernel.org/r/20240410194311.535206450@linutronix.de
2024-04-12 12:05:54 +02:00
Josh Poimboeuf
4f511739c5 x86/bugs: Replace CONFIG_SPECTRE_BHI_{ON,OFF} with CONFIG_MITIGATION_SPECTRE_BHI
For consistency with the other CONFIG_MITIGATION_* options, replace the
CONFIG_SPECTRE_BHI_{ON,OFF} options with a single
CONFIG_MITIGATION_SPECTRE_BHI option.

[ mingo: Fix ]

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nikolay Borisov <nik.borisov@suse.com>
Link: https://lore.kernel.org/r/3833812ea63e7fdbe36bf8b932e63f70d18e2a2a.1712813475.git.jpoimboe@kernel.org
2024-04-12 12:05:54 +02:00
Josh Poimboeuf
36d4fe147c x86/bugs: Remove CONFIG_BHI_MITIGATION_AUTO and spectre_bhi=auto
Unlike most other mitigations' "auto" options, spectre_bhi=auto only
mitigates newer systems, which is confusing and not particularly useful.

Remove it.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/412e9dc87971b622bbbaf64740ebc1f140bff343.1712813475.git.jpoimboe@kernel.org
2024-04-12 12:05:54 +02:00
Paolo Bonzini
eb4441864e KVM: SEV: sync FPU and AVX state at LAUNCH_UPDATE_VMSA time
SEV-ES allows passing custom contents for x87, SSE and AVX state into the VMSA.
Allow userspace to do that with the usual KVM_SET_XSAVE API and only mark
FPU contents as confidential after it has been copied and encrypted into
the VMSA.

Since the XSAVE state for AVX is the first, it does not need the
compacted-state handling of get_xsave_addr().  However, there are other
parts of XSAVE state in the VMSA that currently are not handled, and
the validation logic of get_xsave_addr() is pointless to duplicate
in KVM, so move get_xsave_addr() to public FPU API; it is really just
a facility to operate on XSAVE state and does not expose any internal
details of arch/x86/kernel/fpu.

Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-12-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-04-11 13:08:25 -04:00
Ingo Molnar
5b9b2e6baf Merge tag 'v6.9-rc3' into x86/boot, to pick up fixes before queueing up more changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-04-11 15:36:23 +02:00
Josh Poimboeuf
5f882f3b0a x86/bugs: Clarify that syscall hardening isn't a BHI mitigation
While syscall hardening helps prevent some BHI attacks, there's still
other low-hanging fruit remaining.  Don't classify it as a mitigation
and make it clear that the system may still be vulnerable if it doesn't
have a HW or SW mitigation enabled.

Fixes: ec9404e40e ("x86/bhi: Add BHI mitigation knob")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/b5951dae3fdee7f1520d5136a27be3bdfe95f88b.1712813475.git.jpoimboe@kernel.org
2024-04-11 10:30:33 +02:00
Josh Poimboeuf
1cea8a280d x86/bugs: Fix BHI handling of RRSBA
The ARCH_CAP_RRSBA check isn't correct: RRSBA may have already been
disabled by the Spectre v2 mitigation (or can otherwise be disabled by
the BHI mitigation itself if needed).  In that case retpolines are fine.

Fixes: ec9404e40e ("x86/bhi: Add BHI mitigation knob")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/6f56f13da34a0834b69163467449be7f58f253dc.1712813475.git.jpoimboe@kernel.org
2024-04-11 10:30:33 +02:00
Ingo Molnar
d0485730d2 x86/bugs: Rename various 'ia32_cap' variables to 'x86_arch_cap_msr'
So we are using the 'ia32_cap' value in a number of places,
which got its name from MSR_IA32_ARCH_CAPABILITIES MSR register.

But there's very little 'IA32' about it - this isn't 32-bit only
code, nor does it originate from there, it's just a historic
quirk that many Intel MSR names are prefixed with IA32_.

This is already clear from the helper method around the MSR:
x86_read_arch_cap_msr(), which doesn't have the IA32 prefix.

So rename 'ia32_cap' to 'x86_arch_cap_msr' to be consistent with
its role and with the naming of the helper function.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nikolay Borisov <nik.borisov@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/9592a18a814368e75f8f4b9d74d3883aa4fd1eaf.1712813475.git.jpoimboe@kernel.org
2024-04-11 10:30:33 +02:00
Josh Poimboeuf
cb2db5bb04 x86/bugs: Cache the value of MSR_IA32_ARCH_CAPABILITIES
There's no need to keep reading MSR_IA32_ARCH_CAPABILITIES over and
over.  It's even read in the BHI sysfs function which is a big no-no.
Just read it once and cache it.

Fixes: ec9404e40e ("x86/bhi: Add BHI mitigation knob")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/9592a18a814368e75f8f4b9d74d3883aa4fd1eaf.1712813475.git.jpoimboe@kernel.org
2024-04-11 10:30:33 +02:00
Thomas Gleixner
a9025cd1c6 x86/topology: Don't update cpu_possible_map in topo_set_cpuids()
topo_set_cpuids() updates cpu_present_map and cpu_possible map. It is
invoked during enumeration and "physical hotplug" operations. In the
latter case this results in a kernel crash because cpu_possible_map is
marked read only after init completes.

There is no reason to update cpu_possible_map in that function. During
enumeration cpu_possible_map is not relevant and gets fully initialized
after enumeration completed. On "physical hotplug" the bit is already set
because the kernel allows only CPUs to be plugged which have been
enumerated and associated to a CPU number during early boot.

Remove the bogus update of cpu_possible_map.

Fixes: 0e53e7b656 ("x86/cpu/topology: Sanitize the APIC admission logic")
Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87ttkc6kwx.ffs@tglx
2024-04-10 15:31:38 +02:00
Daniel Sneddon
04f4230e2f x86/bugs: Fix return type of spectre_bhi_state()
The definition of spectre_bhi_state() incorrectly returns a const char
* const. This causes the a compiler warning when building with W=1:

 warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
 2812 | static const char * const spectre_bhi_state(void)

Remove the const qualifier from the pointer.

Fixes: ec9404e40e ("x86/bhi: Add BHI mitigation knob")
Reported-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240409230806.1545822-1-daniel.sneddon@linux.intel.com
2024-04-10 07:05:04 +02:00
Ingo Molnar
dbbe13a6f6 x86/cpu: Improve readability of per-CPU cpumask initialization code
In smp_prepare_cpus_common() and x2apic_prepare_cpu():

 - use 'cpu' instead of 'i'
 - use 'node' instead of 'n'
 - use vertical alignment to improve readability
 - better structure basic blocks
 - reduce col80 checkpatch damage

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
2024-04-10 07:02:33 +02:00
Li RongQing
e0a9ac192f x86/cpu: Take NUMA node into account when allocating per-CPU cpumasks
per-CPU cpumasks are dominantly accessed from their own local CPUs,
so allocate them node-local to improve performance.

[ mingo: Rewrote the changelog. ]

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240410030114.6201-1-lirongqing@baidu.com
2024-04-10 06:55:31 +02:00
Borislav Petkov (AMD)
05d277c9a9 x86/alternatives: Sort local vars in apply_alternatives()
In a reverse x-mas tree.

No functional changes.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240130105941.19707-5-bp@alien8.de
2024-04-09 18:16:57 +02:00
Borislav Petkov (AMD)
c3a3cb5c3d x86/alternatives: Optimize optimize_nops()
Return early if NOPs have already been optimized.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240130105941.19707-4-bp@alien8.de
2024-04-09 18:15:03 +02:00
Borislav Petkov (AMD)
da8f9cf7e7 x86/alternatives: Get rid of __optimize_nops()
There's no need to carve out bits of the NOP optimization functionality
and look at JMP opcodes - simply do one more NOPs optimization pass
at the end of patching.

A lot simpler code.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240130105941.19707-3-bp@alien8.de
2024-04-09 18:12:53 +02:00
Borislav Petkov (AMD)
f796c75837 x86/alternatives: Use a temporary buffer when optimizing NOPs
Instead of optimizing NOPs in-place, use a temporary buffer like the
usual alternatives patching flow does. This obviates the need to grab
locks when patching, see

  6778977590 ("x86/alternatives: Disable interrupts and sync when optimizing NOPs in place")

While at it, add nomenclature definitions clarifying and simplifying the
naming of function-local variables in the alternatives code.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240130105941.19707-2-bp@alien8.de
2024-04-09 18:08:11 +02:00
Borislav Petkov (AMD)
ee8962082a x86/alternatives: Catch late X86_FEATURE modifiers
After alternatives have been patched, changes to the X86_FEATURE flags
won't take effect and could potentially even be wrong.

Warn about it.

This is something which has been long overdue.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Link: https://lore.kernel.org/r/20240327154317.29909-3-bp@alien8.de
2024-04-09 18:03:53 +02:00
Ingo Molnar
d1eec383a8 Merge tag 'v6.9-rc3' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-04-09 09:48:09 +02:00
Tony Luck
7911f145de x86/mce: Implement recovery for errors in TDX/SEAM non-root mode
Machine check SMIs (MSMI) signaled during SEAM operation (typically
inside TDX guests), on a system with Intel eMCA enabled, might eventually
be reported to the kernel #MC handler with the saved RIP on the stack
pointing to the instruction in kernel code after the SEAMCALL instruction
that entered the SEAM operation. Linux currently says that is a fatal
error and shuts down.

There is a new bit in IA32_MCG_STATUS that, when set to 1, indicates
that the machine check didn't originally occur at that saved RIP, but
during SEAM non-root operation.

Add new entries to the severity table to detect this for both data load
and instruction fetch that set the severity to "AR" (action required).

Increase the width of the mcgmask/mcgres fields in "struct severity"
from unsigned char to unsigned short since the new bit is in position 12.

Action required for these errors is just mark the page as poisoned and
return from the machine check handler.

HW ABI notes:
=============

The SEAM_NR bit in IA32_MCG_STATUS hasn't yet made it into the Intel
Software Developers' Manual. But it is described in section 16.5.2
of "Intel(R) Trust Domain Extensions (Intel(R) TDX) Module Base
Architecture Specification" downloadable from:

  https://cdrdv2.intel.com/v1/dl/getContent/733575

Backport notes:
===============

Little value in backporting this patch to stable or LTS kernels as
this is only relevant with support for TDX, which I assume won't be
backported. But for anyone taking this to v6.1 or older, you also
need commit:

  a51cbd0d86 ("x86/mce: Use severity table to handle uncorrected errors in kernel")

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240408180944.44638-1-tony.luck@intel.com
2024-04-09 09:30:36 +02:00
Ingo Molnar
0e6ebfd163 Merge tag 'v6.9-rc3' into x86/cpu, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-04-09 09:28:41 +02:00
Linus Torvalds
2bb69f5fc7 Merge tag 'nativebhi' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mitigations from Thomas Gleixner:
 "Mitigations for the native BHI hardware vulnerabilty:

  Branch History Injection (BHI) attacks may allow a malicious
  application to influence indirect branch prediction in kernel by
  poisoning the branch history. eIBRS isolates indirect branch targets
  in ring0. The BHB can still influence the choice of indirect branch
  predictor entry, and although branch predictor entries are isolated
  between modes when eIBRS is enabled, the BHB itself is not isolated
  between modes.

  Add mitigations against it either with the help of microcode or with
  software sequences for the affected CPUs"

[ This also ends up enabling the full mitigation by default despite the
  system call hardening, because apparently there are other indirect
  calls that are still sufficiently reachable, and the 'auto' case just
  isn't hardened enough.

  We'll have some more inevitable tweaking in the future    - Linus ]

* tag 'nativebhi' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  KVM: x86: Add BHI_NO
  x86/bhi: Mitigate KVM by default
  x86/bhi: Add BHI mitigation knob
  x86/bhi: Enumerate Branch History Injection (BHI) bug
  x86/bhi: Define SPEC_CTRL_BHI_DIS_S
  x86/bhi: Add support for clearing branch history at syscall entry
  x86/syscall: Don't force use of indirect calls for system calls
  x86/bugs: Change commas to semicolons in 'spectre_v2' sysfs file
2024-04-08 20:07:51 -07:00
Pawan Gupta
95a6ccbdc7 x86/bhi: Mitigate KVM by default
BHI mitigation mode spectre_bhi=auto does not deploy the software
mitigation by default. In a cloud environment, it is a likely scenario
where userspace is trusted but the guests are not trusted. Deploying
system wide mitigation in such cases is not desirable.

Update the auto mode to unconditionally mitigate against malicious
guests. Deploy the software sequence at VMexit in auto mode also, when
hardware mitigation is not available. Unlike the force =on mode,
software sequence is not deployed at syscalls in auto mode.

Suggested-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
2024-04-08 19:27:06 +02:00
Pawan Gupta
ec9404e40e x86/bhi: Add BHI mitigation knob
Branch history clearing software sequences and hardware control
BHI_DIS_S were defined to mitigate Branch History Injection (BHI).

Add cmdline spectre_bhi={on|off|auto} to control BHI mitigation:

 auto - Deploy the hardware mitigation BHI_DIS_S, if available.
 on   - Deploy the hardware mitigation BHI_DIS_S, if available,
        otherwise deploy the software sequence at syscall entry and
	VMexit.
 off  - Turn off BHI mitigation.

The default is auto mode which does not deploy the software sequence
mitigation.  This is because of the hardening done in the syscall
dispatch path, which is the likely target of BHI.

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
2024-04-08 19:27:05 +02:00
Pawan Gupta
be482ff950 x86/bhi: Enumerate Branch History Injection (BHI) bug
Mitigation for BHI is selected based on the bug enumeration. Add bits
needed to enumerate BHI bug.

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
2024-04-08 19:27:05 +02:00
Daniel Sneddon
0f4a837615 x86/bhi: Define SPEC_CTRL_BHI_DIS_S
Newer processors supports a hardware control BHI_DIS_S to mitigate
Branch History Injection (BHI). Setting BHI_DIS_S protects the kernel
from userspace BHI attacks without having to manually overwrite the
branch history.

Define MSR_SPEC_CTRL bit BHI_DIS_S and its enumeration CPUID.BHI_CTRL.
Mitigation is enabled later.

Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
2024-04-08 19:27:05 +02:00
Josh Poimboeuf
0cd01ac5dc x86/bugs: Change commas to semicolons in 'spectre_v2' sysfs file
Change the format of the 'spectre_v2' vulnerabilities sysfs file
slightly by converting the commas to semicolons, so that mitigations for
future variants can be grouped together and separated by commas.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2024-04-08 19:27:05 +02:00
Ingo Molnar
5f2ca44ed2 Merge branch 'linus' into x86/urgent, to pick up dependent commit
We want to fix:

  0e11073247 ("x86/retpoline: Do the necessary fixup to the Zen3/4 srso return thunk for !SRSO")

So merge in Linus's latest into x86/urgent to have it available.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-04-06 13:00:32 +02:00
Borislav Petkov (AMD)
3287c22957 x86/microcode/AMD: Remove unused PATCH_MAX_SIZE macro
Orphaned after

  05e91e7211 ("x86/microcode/AMD: Rip out static buffers")

No functional changes.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2024-04-05 23:33:08 +02:00
Arnd Bergmann
9e11fc78e2 x86/microcode/AMD: Avoid -Wformat warning with clang-15
Older versions of clang show a warning for amd.c after a fix for a gcc
warning:

  arch/x86/kernel/cpu/microcode/amd.c:478:47: error: format specifies type \
    'unsigned char' but the argument has type 'u16' (aka 'unsigned short') [-Werror,-Wformat]
                           "amd-ucode/microcode_amd_fam%02hhxh.bin", family);
                                                       ~~~~~~        ^~~~~~
                                                       %02hx

In clang-16 and higher, this warning is disabled by default, but clang-15 is
still supported, and it's trivial to avoid by adapting the types according
to the range of the passed data and the format string.

  [ bp: Massage commit message. ]

Fixes: 2e9064facc ("x86/microcode/amd: Fix snprintf() format string warning in W=1 build")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240405204919.1003409-1-arnd@kernel.org
2024-04-05 23:26:18 +02:00
Linus Torvalds
c88b9b4cde Merge tag 'net-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter, bluetooth and bpf.

  Fairly usual collection of driver and core fixes. The large selftest
  accompanying one of the fixes is also becoming a common occurrence.

  Current release - regressions:

   - ipv6: fix infinite recursion in fib6_dump_done()

   - net/rds: fix possible null-deref in newly added error path

  Current release - new code bugs:

   - net: do not consume a full cacheline for system_page_pool

   - bpf: fix bpf_arena-related file descriptor leaks in the verifier

   - drv: ice: fix freeing uninitialized pointers, fixing misuse of the
     newfangled __free() auto-cleanup

  Previous releases - regressions:

   - x86/bpf: fixes the BPF JIT with retbleed=stuff

   - xen-netfront: add missing skb_mark_for_recycle, fix page pool
     accounting leaks, revealed by recently added explicit warning

   - tcp: fix bind() regression for v6-only wildcard and v4-mapped-v6
     non-wildcard addresses

   - Bluetooth:
      - replace "hci_qca: Set BDA quirk bit if fwnode exists in DT" with
        better workarounds to un-break some buggy Qualcomm devices
      - set conn encrypted before conn establishes, fix re-connecting to
        some headsets which use slightly unusual sequence of msgs

   - mptcp:
      - prevent BPF accessing lowat from a subflow socket
      - don't account accept() of non-MPC client as fallback to TCP

   - drv: mana: fix Rx DMA datasize and skb_over_panic

   - drv: i40e: fix VF MAC filter removal

  Previous releases - always broken:

   - gro: various fixes related to UDP tunnels - netns crossing
     problems, incorrect checksum conversions, and incorrect packet
     transformations which may lead to panics

   - bpf: support deferring bpf_link dealloc to after RCU grace period

   - nf_tables:
      - release batch on table validation from abort path
      - release mutex after nft_gc_seq_end from abort path
      - flush pending destroy work before exit_net release

   - drv: r8169: skip DASH fw status checks when DASH is disabled"

* tag 'net-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (81 commits)
  netfilter: validate user input for expected length
  net/sched: act_skbmod: prevent kernel-infoleak
  net: usb: ax88179_178a: avoid the interface always configured as random address
  net: dsa: sja1105: Fix parameters order in sja1110_pcs_mdio_write_c45()
  net: ravb: Always update error counters
  net: ravb: Always process TX descriptor ring
  netfilter: nf_tables: discard table flag update with pending basechain deletion
  netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get()
  netfilter: nf_tables: reject new basechain after table flag update
  netfilter: nf_tables: flush pending destroy work before exit_net release
  netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path
  netfilter: nf_tables: release batch on table validation from abort path
  Revert "tg3: Remove residual error handling in tg3_suspend"
  tg3: Remove residual error handling in tg3_suspend
  net: mana: Fix Rx DMA datasize and skb_over_panic
  net/sched: fix lockdep splat in qdisc_tree_reduce_backlog()
  net: phy: micrel: lan8814: Fix when enabling/disabling 1-step timestamping
  net: stmmac: fix rx queue priority assignment
  net: txgbe: fix i2c dev name cannot match clkdev
  net: fec: Set mac_managed_pm during probe
  ...
2024-04-04 14:49:10 -07:00
Borislav Petkov (AMD)
3ddf944b32 x86/mce: Make sure to grab mce_sysfs_mutex in set_bank()
Modifying a MCA bank's MCA_CTL bits which control which error types to
be reported is done over

  /sys/devices/system/machinecheck/
  ├── machinecheck0
  │   ├── bank0
  │   ├── bank1
  │   ├── bank10
  │   ├── bank11
  ...

sysfs nodes by writing the new bit mask of events to enable.

When the write is accepted, the kernel deletes all current timers and
reinits all banks.

Doing that in parallel can lead to initializing a timer which is already
armed and in the timer wheel, i.e., in use already:

  ODEBUG: init active (active state 0) object: ffff888063a28000 object
  type: timer_list hint: mce_timer_fn+0x0/0x240 arch/x86/kernel/cpu/mce/core.c:2642
  WARNING: CPU: 0 PID: 8120 at lib/debugobjects.c:514
  debug_print_object+0x1a0/0x2a0 lib/debugobjects.c:514

Fix that by grabbing the sysfs mutex as the rest of the MCA sysfs code
does.

Reported by: Yue Sun <samsun1006219@gmail.com>
Reported by: xingwei lee <xrivendell7@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/CAEkJfYNiENwQY8yV1LYJ9LjJs%2Bx_-PqMv98gKig55=2vbzffRw@mail.gmail.com
2024-04-04 17:25:15 +02:00
Tong Tiangen
cb517619f9 x86/extable: Remove unused fixup type EX_TYPE_COPY
After

  034ff37d34 ("x86: rewrite '__copy_user_nocache' function")

rewrote __copy_user_nocache() to use EX_TYPE_UACCESS instead of the
EX_TYPE_COPY exception type, there are no more EX_TYPE_COPY users, so
remove it.

  [ bp: Massage commit message. ]

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240204082627.3892816-2-tongtiangen@huawei.com
2024-04-04 17:01:40 +02:00
Borislav Petkov (AMD)
0ecaefb303 x86/CPU/AMD: Track SNP host status with cc_platform_*()
The host SNP worthiness can determined later, after alternatives have
been patched, in snp_rmptable_init() depending on cmdline options like
iommu=pt which is incompatible with SNP, for example.

Which means that one cannot use X86_FEATURE_SEV_SNP and will need to
have a special flag for that control.

Use that newly added CC_ATTR_HOST_SEV_SNP in the appropriate places.

Move kdump_sev_callback() to its rightful place, while at it.

Fixes: 216d106c7f ("x86/sev: Add SEV-SNP host initialization support")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Link: https://lore.kernel.org/r/20240327154317.29909-6-bp@alien8.de
2024-04-04 10:40:30 +02:00
Jason A. Donenfeld
99485c4c02 x86/coco: Require seeding RNG with RDRAND on CoCo systems
There are few uses of CoCo that don't rely on working cryptography and
hence a working RNG. Unfortunately, the CoCo threat model means that the
VM host cannot be trusted and may actively work against guests to
extract secrets or manipulate computation. Since a malicious host can
modify or observe nearly all inputs to guests, the only remaining source
of entropy for CoCo guests is RDRAND.

If RDRAND is broken -- due to CPU hardware fault -- the RNG as a whole
is meant to gracefully continue on gathering entropy from other sources,
but since there aren't other sources on CoCo, this is catastrophic.
This is mostly a concern at boot time when initially seeding the RNG, as
after that the consequences of a broken RDRAND are much more
theoretical.

So, try at boot to seed the RNG using 256 bits of RDRAND output. If this
fails, panic(). This will also trigger if the system is booted without
RDRAND, as RDRAND is essential for a safe CoCo boot.

Add this deliberately to be "just a CoCo x86 driver feature" and not
part of the RNG itself. Many device drivers and platforms have some
desire to contribute something to the RNG, and add_device_randomness()
is specifically meant for this purpose.

Any driver can call it with seed data of any quality, or even garbage
quality, and it can only possibly make the quality of the RNG better or
have no effect, but can never make it worse.

Rather than trying to build something into the core of the RNG, consider
the particular CoCo issue just a CoCo issue, and therefore separate it
all out into driver (well, arch/platform) code.

  [ bp: Massage commit message. ]

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Elena Reshetova <elena.reshetova@intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240326160735.73531-1-Jason@zx2c4.com
2024-04-04 10:40:19 +02:00
Li RongQing
af813acf8c x86/fpu: Update fpu_swap_kvm_fpu() uses in comments as well
The following commit:

  d69c1382e1 ("x86/kvm: Convert FPU handling to a single swap buffer")

reworked KVM FPU handling, but forgot to update the comments
in xstate_op_valid(): fpu_swap_kvm_fpu() doesn't exist anymore,
fpu_swap_kvm_fpstate() is used instead.

Update the comments accordingly.

[ mingo: Improved the changelog. ]

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240403091803.818-1-lirongqing@baidu.com
2024-04-04 09:49:42 +02:00
Linus Torvalds
0f099dc9d1 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
 "ARM:

   - Ensure perf events programmed to count during guest execution are
     actually enabled before entering the guest in the nVHE
     configuration

   - Restore out-of-range handler for stage-2 translation faults

   - Several fixes to stage-2 TLB invalidations to avoid stale
     translations, possibly including partial walk caches

   - Fix early handling of architectural VHE-only systems to ensure E2H
     is appropriately set

   - Correct a format specifier warning in the arch_timer selftest

   - Make the KVM banner message correctly handle all of the possible
     configurations

  RISC-V:

   - Remove redundant semicolon in num_isa_ext_regs()

   - Fix APLIC setipnum_le/be write emulation

   - Fix APLIC in_clrip[x] read emulation

  x86:

   - Fix a bug in KVM_SET_CPUID{2,} where KVM looks at the wrong CPUID
     entries (old vs. new) and ultimately neglects to clear PV_UNHALT
     from vCPUs with HLT-exiting disabled

   - Documentation fixes for SEV

   - Fix compat ABI for KVM_MEMORY_ENCRYPT_OP

   - Fix a 14-year-old goof in a declaration shared by host and guest;
     the enabled field used by Linux when running as a guest pushes the
     size of "struct kvm_vcpu_pv_apf_data" from 64 to 68 bytes. This is
     really unconsequential because KVM never consumes anything beyond
     the first 64 bytes, but the resulting struct does not match the
     documentation

  Selftests:

   - Fix spelling mistake in arch_timer selftest"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (25 commits)
  KVM: arm64: Rationalise KVM banner output
  arm64: Fix early handling of FEAT_E2H0 not being implemented
  KVM: arm64: Ensure target address is granule-aligned for range TLBI
  KVM: arm64: Use TLBI_TTL_UNKNOWN in __kvm_tlb_flush_vmid_range()
  KVM: arm64: Don't pass a TLBI level hint when zapping table entries
  KVM: arm64: Don't defer TLB invalidation when zapping table entries
  KVM: selftests: Fix __GUEST_ASSERT() format warnings in ARM's arch timer test
  KVM: arm64: Fix out-of-IPA space translation fault handling
  KVM: arm64: Fix host-programmed guest events in nVHE
  RISC-V: KVM: Fix APLIC in_clrip[x] read emulation
  RISC-V: KVM: Fix APLIC setipnum_le/be write emulation
  RISC-V: KVM: Remove second semicolon
  KVM: selftests: Fix spelling mistake "trigged" -> "triggered"
  Documentation: kvm/sev: clarify usage of KVM_MEMORY_ENCRYPT_OP
  Documentation: kvm/sev: separate description of firmware
  KVM: SEV: fix compat ABI for KVM_MEMORY_ENCRYPT_OP
  KVM: selftests: Check that PV_UNHALT is cleared when HLT exiting is disabled
  KVM: x86: Use actual kvm_cpuid.base for clearing KVM_FEATURE_PV_UNHALT
  KVM: x86: Introduce __kvm_get_hypervisor_cpuid() helper
  KVM: SVM: Return -EINVAL instead of -EBUSY on attempt to re-init SEV/SEV-ES
  ...
2024-04-03 10:26:37 -07:00
Thorsten Blum
0049f04c7d x86/apic: Improve data types to fix Coccinelle warnings
Given that acpi_pm_read_early() returns a u32 (masked to 24 bits), several
variables that store its return value are improved by adjusting their data
types from unsigned long to u32. Specifically, change deltapm's type from
long to u32 because its value fits into 32 bits and it cannot be negative.

These data type improvements resolve the following two Coccinelle/
coccicheck warnings reported by do_div.cocci:

arch/x86/kernel/apic/apic.c:734:1-7: WARNING: do_div() does a 64-by-32
division, please consider using div64_long instead.

arch/x86/kernel/apic/apic.c:742:2-8: WARNING: do_div() does a 64-by-32
division, please consider using div64_long instead.

Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20240318104721.117741-3-thorsten.blum%40toblux.com
2024-04-03 08:32:04 -07:00
Andy Shevchenko
62fbc013c1 x86/rtc: Remove unused intel-mid.h
The rtc driver used to be disabled with a direct check for Intel MID
platforms.  But that direct check was replaced long ago (see second
link).  Remove the (unused since 2016) include.

[ dhansen: rewrite changelog to include some history ]

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20240305161024.1364098-1-andriy.shevchenko%40linux.intel.com
Link: https://lore.kernel.org/all/1460592286-300-5-git-send-email-mcgrof@kernel.org
2024-04-03 08:24:48 -07:00
Reinette Chatre
c3eeb1ffc6 x86/resctrl: Fix uninitialized memory read when last CPU of domain goes offline
Tony encountered this OOPS when the last CPU of a domain goes
offline while running a kernel built with CONFIG_NO_HZ_FULL:

    BUG: kernel NULL pointer dereference, address: 0000000000000000
    #PF: supervisor read access in kernel mode
    #PF: error_code(0x0000) - not-present page
    PGD 0
    Oops: 0000 [#1] PREEMPT SMP NOPTI
    ...
    RIP: 0010:__find_nth_andnot_bit+0x66/0x110
    ...
    Call Trace:
     <TASK>
     ? __die()
     ? page_fault_oops()
     ? exc_page_fault()
     ? asm_exc_page_fault()
     cpumask_any_housekeeping()
     mbm_setup_overflow_handler()
     resctrl_offline_cpu()
     resctrl_arch_offline_cpu()
     cpuhp_invoke_callback()
     cpuhp_thread_fun()
     smpboot_thread_fn()
     kthread()
     ret_from_fork()
     ret_from_fork_asm()
     </TASK>

The NULL pointer dereference is encountered while searching for another
online CPU in the domain (of which there are none) that can be used to
run the MBM overflow handler.

Because the kernel is configured with CONFIG_NO_HZ_FULL the search for
another CPU (in its effort to prefer those CPUs that aren't marked
nohz_full) consults the mask representing the nohz_full CPUs,
tick_nohz_full_mask. On a kernel with CONFIG_CPUMASK_OFFSTACK=y
tick_nohz_full_mask is not allocated unless the kernel is booted with
the "nohz_full=" parameter and because of that any access to
tick_nohz_full_mask needs to be guarded with tick_nohz_full_enabled().

Replace the IS_ENABLED(CONFIG_NO_HZ_FULL) with tick_nohz_full_enabled().
The latter ensures tick_nohz_full_mask can be accessed safely and can be
used whether kernel is built with CONFIG_NO_HZ_FULL enabled or not.

[ Use Ingo's suggestion that combines the two NO_HZ checks into one. ]

Fixes: a4846aaf39 ("x86/resctrl: Add cpumask_any_housekeeping() for limbo/overflow")
Reported-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/ff8dfc8d3dcb04b236d523d1e0de13d2ef585223.1711993956.git.reinette.chatre@intel.com
Closes: https://lore.kernel.org/lkml/ZgIFT5gZgIQ9A9G7@agluck-desk3/
2024-04-03 09:30:01 +02:00
Saurabh Sengar
f87136c057 x86/of: Change x86_dtb_parse_smp_config() to static
x86_dtb_parse_smp_config() is called locally only, change it to static.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/1712068830-4513-5-git-send-email-ssengar@linux.microsoft.com
2024-04-03 08:49:56 +02:00