Messages in this thread Patch in this message | | | From | Lai Jiangshan <> | Subject | [PATCH 7/7] KVM: X86: Also prefetch the last range in __direct_pte_prefetch(). | Date | Tue, 24 Aug 2021 15:55:23 +0800 |
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From: Lai Jiangshan <laijs@linux.alibaba.com>
__direct_pte_prefetch() skips prefetching the last range.
The last range are often the whole range after the faulted spte when guest is touching huge-page-mapped(in guest view) memory forwardly which means prefetching them can reduce pagefault.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> --- arch/x86/kvm/mmu/mmu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index e5932af6f11c..ac260e01e9d8 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -2847,8 +2847,9 @@ static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); spte = sp->spt + i; - for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { - if (is_shadow_present_pte(*spte) || spte == sptep) { + for (i = 0; i <= PTE_PREFETCH_NUM; i++, spte++) { + if (i == PTE_PREFETCH_NUM || + is_shadow_present_pte(*spte) || spte == sptep) { if (!start) continue; if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) -- 2.19.1.6.gb485710b
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