Re: [PATCH v2 01/25] KVM: x86/mmu: avoid indirect call for get_cr3
From: Paolo Bonzini
Date: Tue Mar 08 2022 - 11:43:22 EST
On 3/8/22 17:32, Sean Christopherson wrote:
Aha! An idea that would provide line of sight to avoiding retpoline in all cases
once we use static_call() for nested_ops, which I really want to do... Drop the
mmu hook entirely and replace it with:
static inline kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu)
{
if (!mmu_is_nested(vcpu))
return kvm_read_cr3(vcpu);
else
return kvm_x86_ops.nested_ops->get_guest_pgd(vcpu);
}
Makes sense, but I think you mean
static inline unsigned long kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu,
struct kvm_mmu *mmu)
{
if (unlikely(vcpu == &vcpu->arch.guest_mmu))
return kvm_x86_ops.nested_ops->get_guest_pgd(vcpu);
else
return kvm_read_cr3(vcpu);
}
?
Paolo