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path: root/Documentation/admin-guide/l1tf.rst
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2018-12-11x86/speculation/l1tf: Drop the swap storage limit restriction when l1tf=offMichal Hocko
Swap storage is restricted to max_swapfile_size (~16TB on x86_64) whenever the system is deemed affected by L1TF vulnerability. Even though the limit is quite high for most deployments it seems to be too restrictive for deployments which are willing to live with the mitigation disabled. We have a customer to deploy 8x 6,4TB PCIe/NVMe SSD swap devices which is clearly out of the limit. Drop the swap restriction when l1tf=off is specified. It also doesn't make much sense to warn about too much memory for the l1tf mitigation when it is forcefully disabled by the administrator. [ tglx: Folded the documentation delta change ] Fixes: 377eeaa8e11f ("x86/speculation/l1tf: Limit swap file size to MAX_PA/2") Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Acked-by: Jiri Kosina <jkosina@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: <linux-mm@kvack.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181113184910.26697-1-mhocko@kernel.org
2018-08-31Documentation/l1tf: Fix small spelling typoSalvatore Bonaccorso
Fix small typo (wiil -> will) in the "3.4. Nested virtual machines" section. Fixes: 5b76a3cff011 ("KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry") Cc: linux-kernel@vger.kernel.org Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-doc@vger.kernel.org Cc: trivial@kernel.org Signed-off-by: Salvatore Bonaccorso <carnil@debian.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-05KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentryPaolo Bonzini
When nested virtualization is in use, VMENTER operations from the nested hypervisor into the nested guest will always be processed by the bare metal hypervisor, and KVM's "conditional cache flushes" mode in particular does a flush on nested vmentry. Therefore, include the "skip L1D flush on vmentry" bit in KVM's suggested ARCH_CAPABILITIES setting. Add the relevant Documentation. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-08-05Documentation/l1tf: Remove Yonah processors from not vulnerable listThomas Gleixner
Dave reported, that it's not confirmed that Yonah processors are unaffected. Remove them from the list. Reported-by: ave Hansen <dave.hansen@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-07-20Documentation/l1tf: Fix typosTony Luck
Fix spelling and other typos Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-07-13Documentation: Add section about CPU vulnerabilitiesThomas Gleixner
Add documentation for the L1TF vulnerability and the mitigation mechanisms: - Explain the problem and risks - Document the mitigation mechanisms - Document the command line controls - Document the sysfs files Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/20180713142323.287429944@linutronix.de