KVM: x86: MMU: Use clear_page() instead of init_shadow_page_table()

Not just in order to clean up the code, but to make it faster by using
enhanced instructions: the initialization became 20-30% faster on our
testing machine.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Takuya Yoshikawa 2015-12-18 18:54:49 +09:00 committed by Paolo Bonzini
parent 481d2bcc84
commit 774926641d

View File

@ -2041,14 +2041,6 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu,
}
}
static void init_shadow_page_table(struct kvm_mmu_page *sp)
{
int i;
for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
sp->spt[i] = 0ull;
}
static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp)
{
sp->write_flooding_count = 0;
@ -2128,7 +2120,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
account_shadowed(vcpu->kvm, sp);
}
sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen;
init_shadow_page_table(sp);
clear_page(sp->spt);
trace_kvm_mmu_get_page(sp, true);
return sp;
}