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author | Paolo Bonzini <pbonzini@redhat.com> | 2024-04-05 14:58:12 +0300 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-04-11 20:18:27 +0300 |
commit | f3b65bbaed7c43d10989380d4b95e2a3e9fe5a6b (patch) | |
tree | 130db7e7016f8406b45898024a04d7ab892e0553 /arch/riscv/kvm | |
parent | 9bc60f733839ab6fcdde0d0b15cbb486123e6402 (diff) | |
download | linux-f3b65bbaed7c43d10989380d4b95e2a3e9fe5a6b.tar.xz |
KVM: delete .change_pte MMU notifier callback
The .change_pte() MMU notifier callback was intended as an
optimization. The original point of it was that KSM could tell KVM to flip
its secondary PTE to a new location without having to first zap it. At
the time there was also an .invalidate_page() callback; both of them were
*not* bracketed by calls to mmu_notifier_invalidate_range_{start,end}(),
and .invalidate_page() also doubled as a fallback implementation of
.change_pte().
Later on, however, both callbacks were changed to occur within an
invalidate_range_start/end() block.
In the case of .change_pte(), commit 6bdb913f0a70 ("mm: wrap calls to
set_pte_at_notify with invalidate_range_start and invalidate_range_end",
2012-10-09) did so to remove the fallback from .invalidate_page() to
.change_pte() and allow sleepable .invalidate_page() hooks.
This however made KVM's usage of the .change_pte() callback completely
moot, because KVM unmaps the sPTEs during .invalidate_range_start()
and therefore .change_pte() has no hope of finding a sPTE to change.
Drop the generic KVM code that dispatches to kvm_set_spte_gfn(), as
well as all the architecture specific implementations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Anup Patel <anup@brainfault.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Message-ID: <20240405115815.3226315-2-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/riscv/kvm')
-rw-r--r-- | arch/riscv/kvm/mmu.c | 20 |
1 files changed, 0 insertions, 20 deletions
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index a9e2fd7245e1..b63650f9b966 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -550,26 +550,6 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) return false; } -bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) -{ - int ret; - kvm_pfn_t pfn = pte_pfn(range->arg.pte); - - if (!kvm->arch.pgd) - return false; - - WARN_ON(range->end - range->start != 1); - - ret = gstage_map_page(kvm, NULL, range->start << PAGE_SHIFT, - __pfn_to_phys(pfn), PAGE_SIZE, true, true); - if (ret) { - kvm_debug("Failed to map G-stage page (error %d)\n", ret); - return true; - } - - return false; -} - bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { pte_t *ptep; |