KVM MMU at runtime.
Default is 0 (off)
+ kvm.nx_huge_pages=
+ [KVM] Controls the software workaround for the
+ X86_BUG_ITLB_MULTIHIT bug.
+ force : Always deploy workaround.
+ off : Never deploy workaround.
+ auto : Deploy workaround based on the presence of
+ X86_BUG_ITLB_MULTIHIT.
+
+ Default is 'auto'.
+
+ If the software workaround is enabled for the host,
+ guests do need not to enable it for nested guests.
+
+ kvm.nx_huge_pages_recovery_ratio=
+ [KVM] Controls how many 4KiB pages are periodically zapped
+ back to huge pages. 0 disables the recovery, otherwise if
+ the value is N KVM will zap 1/Nth of the 4KiB pages every
+ minute. The default is 60.
+
kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
Default is 1 (enabled)
SMT on vulnerable CPUs
off - Unconditionally disable MDS mitigation
+ On TAA-affected machines, mds=off can be prevented by
+ an active TAA mitigation as both vulnerabilities are
+ mitigated with the same mechanism so in order to disable
+ this mitigation, you need to specify tsx_async_abort=off
+ too.
+
Not specifying this option is equivalent to
mds=full.
ssbd=force-off [ARM64]
l1tf=off [X86]
mds=off [X86]
+ tsx_async_abort=off [X86]
+ kvm.nx_huge_pages=off [X86]
+
+ Exceptions:
+ This does not have any effect on
+ kvm.nx_huge_pages when
+ kvm.nx_huge_pages=force.
auto (default)
Mitigate all CPU vulnerabilities, but leave SMT
be fully mitigated, even if it means losing SMT.
Equivalent to: l1tf=flush,nosmt [X86]
mds=full,nosmt [X86]
+ tsx_async_abort=full,nosmt [X86]
mminit_loglevel=
[KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
interruptions from clocksource watchdog are not
acceptable).
+ tsx= [X86] Control Transactional Synchronization
+ Extensions (TSX) feature in Intel processors that
+ support TSX control.
+
+ This parameter controls the TSX feature. The options are:
+
+ on - Enable TSX on the system. Although there are
+ mitigations for all known security vulnerabilities,
+ TSX has been known to be an accelerator for
+ several previous speculation-related CVEs, and
+ so there may be unknown security risks associated
+ with leaving it enabled.
+
+ off - Disable TSX on the system. (Note that this
+ option takes effect only on newer CPUs which are
+ not vulnerable to MDS, i.e., have
+ MSR_IA32_ARCH_CAPABILITIES.MDS_NO=1 and which get
+ the new IA32_TSX_CTRL MSR through a microcode
+ update. This new MSR allows for the reliable
+ deactivation of the TSX functionality.)
+
+ auto - Disable TSX if X86_BUG_TAA is present,
+ otherwise enable TSX on the system.
+
+ Not specifying this option is equivalent to tsx=off.
+
+ See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
+ for more details.
+
+ tsx_async_abort= [X86,INTEL] Control mitigation for the TSX Async
+ Abort (TAA) vulnerability.
+
+ Similar to Micro-architectural Data Sampling (MDS)
+ certain CPUs that support Transactional
+ Synchronization Extensions (TSX) are vulnerable to an
+ exploit against CPU internal buffers which can forward
+ information to a disclosure gadget under certain
+ conditions.
+
+ In vulnerable processors, the speculatively forwarded
+ data can be used in a cache side channel attack, to
+ access data to which the attacker does not have direct
+ access.
+
+ This parameter controls the TAA mitigation. The
+ options are:
+
+ full - Enable TAA mitigation on vulnerable CPUs
+ if TSX is enabled.
+
+ full,nosmt - Enable TAA mitigation and disable SMT on
+ vulnerable CPUs. If TSX is disabled, SMT
+ is not disabled because CPU is not
+ vulnerable to cross-thread TAA attacks.
+ off - Unconditionally disable TAA mitigation
+
+ On MDS-affected machines, tsx_async_abort=off can be
+ prevented by an active MDS mitigation as both vulnerabilities
+ are mitigated with the same mechanism so in order to disable
+ this mitigation, you need to specify mds=off too.
+
+ Not specifying this option is equivalent to
+ tsx_async_abort=full. On CPUs which are MDS affected
+ and deploy MDS mitigation, TAA mitigation is not
+ required and doesn't provide any additional
+ mitigation.
+
+ For details see:
+ Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
+
turbografx.map[2|3]= [HW,JOY]
TurboGraFX parallel port interface
Format:
projects / linux.git / blobdiff