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| author | David Matlack <dmatlack@google.com> | 2022-09-21 20:35:37 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-12-27 14:02:57 +0300 |
| commit | 3af15ff47c4df3af7b36ea8315f43c6b0af49253 (patch) | |
| tree | 13148b09b48c519fd850345c9193cd319fb4aa4a /arch/x86/include/asm/kvm_host.h | |
| parent | de4af61ee3c4076eab836fc98ae59dbda98bf690 (diff) | |
| download | linux-3af15ff47c4df3af7b36ea8315f43c6b0af49253.tar.xz | |
KVM: x86/mmu: Change tdp_mmu to a read-only parameter
Change tdp_mmu to a read-only parameter and drop the per-vm
tdp_mmu_enabled. For 32-bit KVM, make tdp_mmu_enabled a macro that is
always false so that the compiler can continue omitting cals to the TDP
MMU.
The TDP MMU was introduced in 5.10 and has been enabled by default since
5.15. At this point there are no known functionality gaps between the
TDP MMU and the shadow MMU, and the TDP MMU uses less memory and scales
better with the number of vCPUs. In other words, there is no good reason
to disable the TDP MMU on a live system.
Purposely do not drop tdp_mmu=N support (i.e. do not force 64-bit KVM to
always use the TDP MMU) since tdp_mmu=N is still used to get test
coverage of KVM's shadow MMU TDP support, which is used in 32-bit KVM.
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220921173546.2674386-2-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm/kvm_host.h')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index f35f1ff4427b..aa4eb8cfcd7e 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1341,21 +1341,12 @@ struct kvm_arch { struct task_struct *nx_huge_page_recovery_thread; #ifdef CONFIG_X86_64 - /* - * Whether the TDP MMU is enabled for this VM. This contains a - * snapshot of the TDP MMU module parameter from when the VM was - * created and remains unchanged for the life of the VM. If this is - * true, TDP MMU handler functions will run for various MMU - * operations. - */ - bool tdp_mmu_enabled; - /* The number of TDP MMU pages across all roots. */ atomic64_t tdp_mmu_pages; /* - * List of kvm_mmu_page structs being used as roots. - * All kvm_mmu_page structs in the list should have + * List of struct kvm_mmu_pages being used as roots. + * All struct kvm_mmu_pages in the list should have * tdp_mmu_page set. * * For reads, this list is protected by: |