| Message ID | 20230519081711.72906-1-likexu@tencent.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86/mmu: Drop "struct kvm_mmu *mmu" from __kvm_mmu_invalidate_addr() | expand |
On Fri, May 19, 2023, Like Xu wrote: > From: Like Xu <likexu@tencent.com> > > Remove incoming parameter "struct kvm_mmu *mmu" that are no longer used. > Whether the func is using "vcpu->arch.root_mmu" or "vcpu->arch.guest_mmu", > it can be referenced as expected via "vcpu->arch.mmu". Thus the "*mmu" > is replaced by the use of "vcpu->arch.mmu" in commit 19ace7d6ca15 ("KVM: > x86/mmu: Skip calling mmu->sync_spte() when the spte is 0"). > > No functional change is intended. > > Signed-off-by: Like Xu <likexu@tencent.com> > --- > arch/x86/kvm/mmu/mmu.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index c8961f45e3b1..160c40c83330 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -5790,8 +5790,8 @@ int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 err > } > EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); > > -static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, > - u64 addr, hpa_t root_hpa) > +static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, u64 addr, > + hpa_t root_hpa) > { > struct kvm_shadow_walk_iterator iterator; Oof, there's a mess waiting to happen here. for_each_shadow_entry_using_root() and kvm_sync_spte() do indeed operate on vcpu->arch.mmu, but the only reason that doesn't cause explosions is because handle_invept() frees roots instead of doing a manual invalidation. At a glance, I don't see any major roadblocks to switching INVEPT emulation over to use kvm_mmu_invalidate_addr(). I'm leaning towards asserting on @mmu instead of deleting it. diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index c8961f45e3b1..258f12235874 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -5797,6 +5797,14 @@ static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu vcpu_clear_mmio_info(vcpu, addr); + /* + * Walking and synchronizing SPTEs both assume they are operating in + * the context of the current MMU, and would need to be reworked if + * this is ever used to sync the guest_mmu, e.g. to emulate INVEPT. + */ + if (WARN_ON_ONCE(mmu != vcpu->arch.mmu)) + return; + if (!VALID_PAGE(root_hpa)) return; base-commit: 5c291b93e5d665380dbecc6944973583f9565ee5 --
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index c8961f45e3b1..160c40c83330 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -5790,8 +5790,8 @@ int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 err } EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); -static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, - u64 addr, hpa_t root_hpa) +static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, u64 addr, + hpa_t root_hpa) { struct kvm_shadow_walk_iterator iterator; @@ -5839,11 +5839,11 @@ void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, return; if (roots & KVM_MMU_ROOT_CURRENT) - __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->root.hpa); + __kvm_mmu_invalidate_addr(vcpu, addr, mmu->root.hpa); for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) { if (roots & KVM_MMU_ROOT_PREVIOUS(i)) - __kvm_mmu_invalidate_addr(vcpu, mmu, addr, mmu->prev_roots[i].hpa); + __kvm_mmu_invalidate_addr(vcpu, addr, mmu->prev_roots[i].hpa); } } EXPORT_SYMBOL_GPL(kvm_mmu_invalidate_addr);