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| author | David Matlack <dmatlack@google.com> | 2022-09-21 20:35:37 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-12-29 23:33:16 +0300 |
| commit | 1f98f2bd8ec4df365381ba654db37a39ce20ccdf (patch) | |
| tree | 43983bbd17de46158fc965681af9f6c9da6dbdca /arch/x86/kvm/mmu.h | |
| parent | 79edd55049527596187ee493d5f949fd1eda7067 (diff) | |
| download | linux-1f98f2bd8ec4df365381ba654db37a39ce20ccdf.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/kvm/mmu.h')
| -rw-r--r-- | arch/x86/kvm/mmu.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index 6bdaacb6faa0..168c46fd8dd1 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -230,14 +230,14 @@ static inline bool kvm_shadow_root_allocated(struct kvm *kvm) } #ifdef CONFIG_X86_64 -static inline bool is_tdp_mmu_enabled(struct kvm *kvm) { return kvm->arch.tdp_mmu_enabled; } +extern bool tdp_mmu_enabled; #else -static inline bool is_tdp_mmu_enabled(struct kvm *kvm) { return false; } +#define tdp_mmu_enabled false #endif static inline bool kvm_memslots_have_rmaps(struct kvm *kvm) { - return !is_tdp_mmu_enabled(kvm) || kvm_shadow_root_allocated(kvm); + return !tdp_mmu_enabled || kvm_shadow_root_allocated(kvm); } static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level) |