From 01b7d128b5a7f0d09626c090093ff44155f347c9 Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Thu, 29 Aug 2019 18:52:49 +1000 Subject: [PATCH] KVM: PPC: Book3S: Invalidate multiple TCEs at once Invalidating a TCE cache entry for each updated TCE is quite expensive. This makes use of the new iommu_table_ops::xchg_no_kill()/tce_kill() callbacks to bring down the time spent in mapping a huge guest DMA window; roughly 20s to 10s for each guest's 100GB of DMA space. Signed-off-by: Alexey Kardashevskiy Acked-by: Paul Mackerras Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190829085252.72370-3-aik@ozlabs.ru --- arch/powerpc/kvm/book3s_64_vio.c | 29 +++++++++++++++------- arch/powerpc/kvm/book3s_64_vio_hv.c | 38 +++++++++++++++++++++-------- 2 files changed, 48 insertions(+), 19 deletions(-) diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c index c4b606fe73eb..5834db0a54c6 100644 --- a/arch/powerpc/kvm/book3s_64_vio.c +++ b/arch/powerpc/kvm/book3s_64_vio.c @@ -416,7 +416,7 @@ static void kvmppc_clear_tce(struct mm_struct *mm, struct iommu_table *tbl, unsigned long hpa = 0; enum dma_data_direction dir = DMA_NONE; - iommu_tce_xchg(mm, tbl, entry, &hpa, &dir); + iommu_tce_xchg_no_kill(mm, tbl, entry, &hpa, &dir); } static long kvmppc_tce_iommu_mapped_dec(struct kvm *kvm, @@ -447,7 +447,8 @@ static long kvmppc_tce_iommu_do_unmap(struct kvm *kvm, unsigned long hpa = 0; long ret; - if (WARN_ON_ONCE(iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir))) + if (WARN_ON_ONCE(iommu_tce_xchg_no_kill(kvm->mm, tbl, entry, &hpa, + &dir))) return H_TOO_HARD; if (dir == DMA_NONE) @@ -455,7 +456,7 @@ static long kvmppc_tce_iommu_do_unmap(struct kvm *kvm, ret = kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry); if (ret != H_SUCCESS) - iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir); + iommu_tce_xchg_no_kill(kvm->mm, tbl, entry, &hpa, &dir); return ret; } @@ -501,7 +502,7 @@ long kvmppc_tce_iommu_do_map(struct kvm *kvm, struct iommu_table *tbl, if (mm_iommu_mapped_inc(mem)) return H_TOO_HARD; - ret = iommu_tce_xchg(kvm->mm, tbl, entry, &hpa, &dir); + ret = iommu_tce_xchg_no_kill(kvm->mm, tbl, entry, &hpa, &dir); if (WARN_ON_ONCE(ret)) { mm_iommu_mapped_dec(mem); return H_TOO_HARD; @@ -579,6 +580,8 @@ long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn, ret = kvmppc_tce_iommu_map(vcpu->kvm, stt, stit->tbl, entry, ua, dir); + iommu_tce_kill(stit->tbl, entry, 1); + if (ret != H_SUCCESS) { kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, entry); goto unlock_exit; @@ -656,13 +659,13 @@ long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu, */ if (get_user(tce, tces + i)) { ret = H_TOO_HARD; - goto unlock_exit; + goto invalidate_exit; } tce = be64_to_cpu(tce); if (kvmppc_tce_to_ua(vcpu->kvm, tce, &ua)) { ret = H_PARAMETER; - goto unlock_exit; + goto invalidate_exit; } list_for_each_entry_lockless(stit, &stt->iommu_tables, next) { @@ -673,13 +676,17 @@ long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu, if (ret != H_SUCCESS) { kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, entry); - goto unlock_exit; + goto invalidate_exit; } } kvmppc_tce_put(stt, entry + i, tce); } +invalidate_exit: + list_for_each_entry_lockless(stit, &stt->iommu_tables, next) + iommu_tce_kill(stit->tbl, entry, npages); + unlock_exit: srcu_read_unlock(&vcpu->kvm->srcu, idx); @@ -718,7 +725,7 @@ long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu, continue; if (ret == H_TOO_HARD) - return ret; + goto invalidate_exit; WARN_ON_ONCE(1); kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, entry); @@ -728,6 +735,10 @@ long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu, for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift)) kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value); - return H_SUCCESS; +invalidate_exit: + list_for_each_entry_lockless(stit, &stt->iommu_tables, next) + iommu_tce_kill(stit->tbl, ioba >> stt->page_shift, npages); + + return ret; } EXPORT_SYMBOL_GPL(kvmppc_h_stuff_tce); diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c index b4f20f13b860..ab6eeb8e753e 100644 --- a/arch/powerpc/kvm/book3s_64_vio_hv.c +++ b/arch/powerpc/kvm/book3s_64_vio_hv.c @@ -218,13 +218,14 @@ static long kvmppc_rm_ioba_validate(struct kvmppc_spapr_tce_table *stt, return H_SUCCESS; } -static long iommu_tce_xchg_rm(struct mm_struct *mm, struct iommu_table *tbl, +static long iommu_tce_xchg_no_kill_rm(struct mm_struct *mm, + struct iommu_table *tbl, unsigned long entry, unsigned long *hpa, enum dma_data_direction *direction) { long ret; - ret = tbl->it_ops->exchange_rm(tbl, entry, hpa, direction); + ret = tbl->it_ops->xchg_no_kill(tbl, entry, hpa, direction, true); if (!ret && ((*direction == DMA_FROM_DEVICE) || (*direction == DMA_BIDIRECTIONAL))) { @@ -240,13 +241,20 @@ static long iommu_tce_xchg_rm(struct mm_struct *mm, struct iommu_table *tbl, return ret; } +extern void iommu_tce_kill_rm(struct iommu_table *tbl, + unsigned long entry, unsigned long pages) +{ + if (tbl->it_ops->tce_kill) + tbl->it_ops->tce_kill(tbl, entry, pages, true); +} + static void kvmppc_rm_clear_tce(struct kvm *kvm, struct iommu_table *tbl, unsigned long entry) { unsigned long hpa = 0; enum dma_data_direction dir = DMA_NONE; - iommu_tce_xchg_rm(kvm->mm, tbl, entry, &hpa, &dir); + iommu_tce_xchg_no_kill_rm(kvm->mm, tbl, entry, &hpa, &dir); } static long kvmppc_rm_tce_iommu_mapped_dec(struct kvm *kvm, @@ -278,7 +286,7 @@ static long kvmppc_rm_tce_iommu_do_unmap(struct kvm *kvm, unsigned long hpa = 0; long ret; - if (iommu_tce_xchg_rm(kvm->mm, tbl, entry, &hpa, &dir)) + if (iommu_tce_xchg_no_kill_rm(kvm->mm, tbl, entry, &hpa, &dir)) /* * real mode xchg can fail if struct page crosses * a page boundary @@ -290,7 +298,7 @@ static long kvmppc_rm_tce_iommu_do_unmap(struct kvm *kvm, ret = kvmppc_rm_tce_iommu_mapped_dec(kvm, tbl, entry); if (ret) - iommu_tce_xchg_rm(kvm->mm, tbl, entry, &hpa, &dir); + iommu_tce_xchg_no_kill_rm(kvm->mm, tbl, entry, &hpa, &dir); return ret; } @@ -336,7 +344,7 @@ static long kvmppc_rm_tce_iommu_do_map(struct kvm *kvm, struct iommu_table *tbl, if (WARN_ON_ONCE_RM(mm_iommu_mapped_inc(mem))) return H_TOO_HARD; - ret = iommu_tce_xchg_rm(kvm->mm, tbl, entry, &hpa, &dir); + ret = iommu_tce_xchg_no_kill_rm(kvm->mm, tbl, entry, &hpa, &dir); if (ret) { mm_iommu_mapped_dec(mem); /* @@ -417,6 +425,8 @@ long kvmppc_rm_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn, ret = kvmppc_rm_tce_iommu_map(vcpu->kvm, stt, stit->tbl, entry, ua, dir); + iommu_tce_kill_rm(stit->tbl, entry, 1); + if (ret != H_SUCCESS) { kvmppc_rm_clear_tce(vcpu->kvm, stit->tbl, entry); return ret; @@ -558,7 +568,7 @@ long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu, ua = 0; if (kvmppc_rm_tce_to_ua(vcpu->kvm, tce, &ua, NULL)) { ret = H_PARAMETER; - goto unlock_exit; + goto invalidate_exit; } list_for_each_entry_lockless(stit, &stt->iommu_tables, next) { @@ -569,13 +579,17 @@ long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu, if (ret != H_SUCCESS) { kvmppc_rm_clear_tce(vcpu->kvm, stit->tbl, entry); - goto unlock_exit; + goto invalidate_exit; } } kvmppc_rm_tce_put(stt, entry + i, tce); } +invalidate_exit: + list_for_each_entry_lockless(stit, &stt->iommu_tables, next) + iommu_tce_kill_rm(stit->tbl, entry, npages); + unlock_exit: if (rmap) unlock_rmap(rmap); @@ -618,7 +632,7 @@ long kvmppc_rm_h_stuff_tce(struct kvm_vcpu *vcpu, continue; if (ret == H_TOO_HARD) - return ret; + goto invalidate_exit; WARN_ON_ONCE_RM(1); kvmppc_rm_clear_tce(vcpu->kvm, stit->tbl, entry); @@ -628,7 +642,11 @@ long kvmppc_rm_h_stuff_tce(struct kvm_vcpu *vcpu, for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift)) kvmppc_rm_tce_put(stt, ioba >> stt->page_shift, tce_value); - return H_SUCCESS; +invalidate_exit: + list_for_each_entry_lockless(stit, &stt->iommu_tables, next) + iommu_tce_kill_rm(stit->tbl, ioba >> stt->page_shift, npages); + + return ret; } /* This can be called in either virtual mode or real mode */