Sean Christopherson 8c737d950c KVM: x86/mmu: Add "never" option to allow sticky disabling of nx_huge_pages ... commit 0b210faf33 upstream. Add a "never" option to the nx_huge_pages module param to allow userspace to do a one-way hard disabling of the mitigation, and don't create the per-VM recovery threads when the mitigation is hard disabled. Letting userspace pinky swear that userspace doesn't want to enable NX mitigation (without reloading KVM) allows certain use cases to avoid the latency problems associated with spawning a kthread for each VM. E.g. in FaaS use cases, the guest kernel is trusted and the host may create 100+ VMs per logical CPU, which can result in 100ms+ latencies when a burst of VMs is created. Reported-by: Li RongQing <lirongqing@baidu.com> Closes: https://lore.kernel.org/all/1679555884-32544-1-git-send-email-lirongqing@baidu.com Cc: Yong He <zhuangel570@gmail.com> Cc: Robert Hoo <robert.hoo.linux@gmail.com> Cc: Kai Huang <kai.huang@intel.com> Reviewed-by: Robert Hoo <robert.hoo.linux@gmail.com> Acked-by: Kai Huang <kai.huang@intel.com> Tested-by: Luiz Capitulino <luizcap@amazon.com> Reviewed-by: Li RongQing <lirongqing@baidu.com> Link: https://lore.kernel.org/r/20230602005859.784190-1-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> [ Resolved a small conflict in arch/x86/kvm/mmu/mmu.c::kvm_mmu_post_init_vm() which is due kvm_nx_lpage_recovery_worker() being renamed in upstream commit 55c510e26a ] Signed-off-by: Luiz Capitulino <luizcap@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-09-13 09:42:26 +02:00
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mmu.c	KVM: x86/mmu: Add "never" option to allow sticky disabling of nx_huge_pages	2023-09-13 09:42:26 +02:00
mmu_internal.h	…
mmutrace.h	…
page_track.c	…
paging_tmpl.h	…
spte.c	…
spte.h	…
tdp_iter.c	…
tdp_iter.h	…
tdp_mmu.c	KVM: x86: Preserve TDP MMU roots until they are explicitly invalidated	2023-08-30 16:11:04 +02:00
tdp_mmu.h	…