From: Ram Pai <linuxram@us.ibm.com> To: kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: ldufour@linux.ibm.com, linuxram@us.ibm.com, cclaudio@linux.ibm.com, bharata@linux.ibm.com, sathnaga@linux.vnet.ibm.com, aneesh.kumar@linux.ibm.com, sukadev@linux.vnet.ibm.com, bauerman@linux.ibm.com, david@gibson.dropbear.id.au Subject: [PATCH v5 2/7] KVM: PPC: Book3S HV: Disable page merging in H_SVM_INIT_START Date: Thu, 23 Jul 2020 13:07:19 -0700 [thread overview] Message-ID: <1595534844-16188-3-git-send-email-linuxram@us.ibm.com> (raw) In-Reply-To: <1595534844-16188-1-git-send-email-linuxram@us.ibm.com> Page-merging of pages in memory-slots associated with a Secure VM, is disabled in H_SVM_PAGE_IN handler. This operation should have been done the much earlier; the moment the VM is initiated for secure-transition. Delaying this operation, increases the probability for those pages to acquire new references , making it impossible to migrate those pages in H_SVM_PAGE_IN handler. Disable page-migration in H_SVM_INIT_START handling. Reviewed-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> --- Documentation/powerpc/ultravisor.rst | 1 + arch/powerpc/kvm/book3s_hv_uvmem.c | 123 +++++++++++++++++++++++++---------- 2 files changed, 89 insertions(+), 35 deletions(-) diff --git a/Documentation/powerpc/ultravisor.rst b/Documentation/powerpc/ultravisor.rst index df136c8..a1c8c37 100644 --- a/Documentation/powerpc/ultravisor.rst +++ b/Documentation/powerpc/ultravisor.rst @@ -895,6 +895,7 @@ Return values One of the following values: * H_SUCCESS on success. + * H_STATE if the VM is not in a position to switch to secure. Description ~~~~~~~~~~~ diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index e6f76bc..533b608 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -211,10 +211,79 @@ static bool kvmppc_gfn_is_uvmem_pfn(unsigned long gfn, struct kvm *kvm, return false; } +static int kvmppc_memslot_page_merge(struct kvm *kvm, + const struct kvm_memory_slot *memslot, bool merge) +{ + unsigned long gfn = memslot->base_gfn; + unsigned long end, start = gfn_to_hva(kvm, gfn); + int ret = 0; + struct vm_area_struct *vma; + int merge_flag = (merge) ? MADV_MERGEABLE : MADV_UNMERGEABLE; + + if (kvm_is_error_hva(start)) + return H_STATE; + + end = start + (memslot->npages << PAGE_SHIFT); + + mmap_write_lock(kvm->mm); + do { + vma = find_vma_intersection(kvm->mm, start, end); + if (!vma) { + ret = H_STATE; + break; + } + ret = ksm_madvise(vma, vma->vm_start, vma->vm_end, + merge_flag, &vma->vm_flags); + if (ret) { + ret = H_STATE; + break; + } + start = vma->vm_end; + } while (end > vma->vm_end); + + mmap_write_unlock(kvm->mm); + return ret; +} + +static void kvmppc_uvmem_memslot_delete(struct kvm *kvm, + const struct kvm_memory_slot *memslot) +{ + uv_unregister_mem_slot(kvm->arch.lpid, memslot->id); + kvmppc_uvmem_slot_free(kvm, memslot); + kvmppc_memslot_page_merge(kvm, memslot, true); +} + +static int kvmppc_uvmem_memslot_create(struct kvm *kvm, + const struct kvm_memory_slot *memslot) +{ + int ret = H_PARAMETER; + + if (kvmppc_memslot_page_merge(kvm, memslot, false)) + return ret; + + if (kvmppc_uvmem_slot_init(kvm, memslot)) + goto out1; + + ret = uv_register_mem_slot(kvm->arch.lpid, + memslot->base_gfn << PAGE_SHIFT, + memslot->npages * PAGE_SIZE, + 0, memslot->id); + if (ret < 0) { + ret = H_PARAMETER; + goto out; + } + return 0; +out: + kvmppc_uvmem_slot_free(kvm, memslot); +out1: + kvmppc_memslot_page_merge(kvm, memslot, true); + return ret; +} + unsigned long kvmppc_h_svm_init_start(struct kvm *kvm) { struct kvm_memslots *slots; - struct kvm_memory_slot *memslot; + struct kvm_memory_slot *memslot, *m; int ret = H_SUCCESS; int srcu_idx; @@ -232,23 +301,24 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm) return H_AUTHORITY; srcu_idx = srcu_read_lock(&kvm->srcu); + + /* register the memslot */ slots = kvm_memslots(kvm); kvm_for_each_memslot(memslot, slots) { - if (kvmppc_uvmem_slot_init(kvm, memslot)) { - ret = H_PARAMETER; - goto out; - } - ret = uv_register_mem_slot(kvm->arch.lpid, - memslot->base_gfn << PAGE_SHIFT, - memslot->npages * PAGE_SIZE, - 0, memslot->id); - if (ret < 0) { - kvmppc_uvmem_slot_free(kvm, memslot); - ret = H_PARAMETER; - goto out; + ret = kvmppc_uvmem_memslot_create(kvm, memslot); + if (ret) + break; + } + + if (ret) { + slots = kvm_memslots(kvm); + kvm_for_each_memslot(m, slots) { + if (m == memslot) + break; + kvmppc_uvmem_memslot_delete(kvm, memslot); } } -out: + srcu_read_unlock(&kvm->srcu, srcu_idx); return ret; } @@ -384,7 +454,7 @@ static struct page *kvmppc_uvmem_get_page(unsigned long gpa, struct kvm *kvm) */ static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start, unsigned long end, unsigned long gpa, struct kvm *kvm, - unsigned long page_shift, bool *downgrade) + unsigned long page_shift) { unsigned long src_pfn, dst_pfn = 0; struct migrate_vma mig; @@ -400,18 +470,6 @@ static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start, mig.src = &src_pfn; mig.dst = &dst_pfn; - /* - * We come here with mmap_lock write lock held just for - * ksm_madvise(), otherwise we only need read mmap_lock. - * Hence downgrade to read lock once ksm_madvise() is done. - */ - ret = ksm_madvise(vma, vma->vm_start, vma->vm_end, - MADV_UNMERGEABLE, &vma->vm_flags); - mmap_write_downgrade(kvm->mm); - *downgrade = true; - if (ret) - return ret; - ret = migrate_vma_setup(&mig); if (ret) return ret; @@ -503,7 +561,6 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, unsigned long flags, unsigned long page_shift) { - bool downgrade = false; unsigned long start, end; struct vm_area_struct *vma; int srcu_idx; @@ -524,7 +581,7 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, ret = H_PARAMETER; srcu_idx = srcu_read_lock(&kvm->srcu); - mmap_write_lock(kvm->mm); + mmap_read_lock(kvm->mm); start = gfn_to_hva(kvm, gfn); if (kvm_is_error_hva(start)) @@ -540,16 +597,12 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, if (!vma || vma->vm_start > start || vma->vm_end < end) goto out_unlock; - if (!kvmppc_svm_page_in(vma, start, end, gpa, kvm, page_shift, - &downgrade)) + if (!kvmppc_svm_page_in(vma, start, end, gpa, kvm, page_shift)) ret = H_SUCCESS; out_unlock: mutex_unlock(&kvm->arch.uvmem_lock); out: - if (downgrade) - mmap_read_unlock(kvm->mm); - else - mmap_write_unlock(kvm->mm); + mmap_read_unlock(kvm->mm); srcu_read_unlock(&kvm->srcu, srcu_idx); return ret; } -- 1.8.3.1
WARNING: multiple messages have this Message-ID (diff)
From: Ram Pai <linuxram@us.ibm.com> To: kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: ldufour@linux.ibm.com, linuxram@us.ibm.com, cclaudio@linux.ibm.com, bharata@linux.ibm.com, sathnaga@linux.vnet.ibm.com, aneesh.kumar@linux.ibm.com, sukadev@linux.vnet.ibm.com, bauerman@linux.ibm.com, david@gibson.dropbear.id.au Subject: [PATCH v5 2/7] KVM: PPC: Book3S HV: Disable page merging in H_SVM_INIT_START Date: Thu, 23 Jul 2020 20:07:19 +0000 [thread overview] Message-ID: <1595534844-16188-3-git-send-email-linuxram@us.ibm.com> (raw) In-Reply-To: <1595534844-16188-1-git-send-email-linuxram@us.ibm.com> Page-merging of pages in memory-slots associated with a Secure VM, is disabled in H_SVM_PAGE_IN handler. This operation should have been done the much earlier; the moment the VM is initiated for secure-transition. Delaying this operation, increases the probability for those pages to acquire new references , making it impossible to migrate those pages in H_SVM_PAGE_IN handler. Disable page-migration in H_SVM_INIT_START handling. Reviewed-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> --- Documentation/powerpc/ultravisor.rst | 1 + arch/powerpc/kvm/book3s_hv_uvmem.c | 123 +++++++++++++++++++++++++---------- 2 files changed, 89 insertions(+), 35 deletions(-) diff --git a/Documentation/powerpc/ultravisor.rst b/Documentation/powerpc/ultravisor.rst index df136c8..a1c8c37 100644 --- a/Documentation/powerpc/ultravisor.rst +++ b/Documentation/powerpc/ultravisor.rst @@ -895,6 +895,7 @@ Return values One of the following values: * H_SUCCESS on success. + * H_STATE if the VM is not in a position to switch to secure. Description ~~~~~~~~~~~ diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index e6f76bc..533b608 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -211,10 +211,79 @@ static bool kvmppc_gfn_is_uvmem_pfn(unsigned long gfn, struct kvm *kvm, return false; } +static int kvmppc_memslot_page_merge(struct kvm *kvm, + const struct kvm_memory_slot *memslot, bool merge) +{ + unsigned long gfn = memslot->base_gfn; + unsigned long end, start = gfn_to_hva(kvm, gfn); + int ret = 0; + struct vm_area_struct *vma; + int merge_flag = (merge) ? MADV_MERGEABLE : MADV_UNMERGEABLE; + + if (kvm_is_error_hva(start)) + return H_STATE; + + end = start + (memslot->npages << PAGE_SHIFT); + + mmap_write_lock(kvm->mm); + do { + vma = find_vma_intersection(kvm->mm, start, end); + if (!vma) { + ret = H_STATE; + break; + } + ret = ksm_madvise(vma, vma->vm_start, vma->vm_end, + merge_flag, &vma->vm_flags); + if (ret) { + ret = H_STATE; + break; + } + start = vma->vm_end; + } while (end > vma->vm_end); + + mmap_write_unlock(kvm->mm); + return ret; +} + +static void kvmppc_uvmem_memslot_delete(struct kvm *kvm, + const struct kvm_memory_slot *memslot) +{ + uv_unregister_mem_slot(kvm->arch.lpid, memslot->id); + kvmppc_uvmem_slot_free(kvm, memslot); + kvmppc_memslot_page_merge(kvm, memslot, true); +} + +static int kvmppc_uvmem_memslot_create(struct kvm *kvm, + const struct kvm_memory_slot *memslot) +{ + int ret = H_PARAMETER; + + if (kvmppc_memslot_page_merge(kvm, memslot, false)) + return ret; + + if (kvmppc_uvmem_slot_init(kvm, memslot)) + goto out1; + + ret = uv_register_mem_slot(kvm->arch.lpid, + memslot->base_gfn << PAGE_SHIFT, + memslot->npages * PAGE_SIZE, + 0, memslot->id); + if (ret < 0) { + ret = H_PARAMETER; + goto out; + } + return 0; +out: + kvmppc_uvmem_slot_free(kvm, memslot); +out1: + kvmppc_memslot_page_merge(kvm, memslot, true); + return ret; +} + unsigned long kvmppc_h_svm_init_start(struct kvm *kvm) { struct kvm_memslots *slots; - struct kvm_memory_slot *memslot; + struct kvm_memory_slot *memslot, *m; int ret = H_SUCCESS; int srcu_idx; @@ -232,23 +301,24 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm) return H_AUTHORITY; srcu_idx = srcu_read_lock(&kvm->srcu); + + /* register the memslot */ slots = kvm_memslots(kvm); kvm_for_each_memslot(memslot, slots) { - if (kvmppc_uvmem_slot_init(kvm, memslot)) { - ret = H_PARAMETER; - goto out; - } - ret = uv_register_mem_slot(kvm->arch.lpid, - memslot->base_gfn << PAGE_SHIFT, - memslot->npages * PAGE_SIZE, - 0, memslot->id); - if (ret < 0) { - kvmppc_uvmem_slot_free(kvm, memslot); - ret = H_PARAMETER; - goto out; + ret = kvmppc_uvmem_memslot_create(kvm, memslot); + if (ret) + break; + } + + if (ret) { + slots = kvm_memslots(kvm); + kvm_for_each_memslot(m, slots) { + if (m = memslot) + break; + kvmppc_uvmem_memslot_delete(kvm, memslot); } } -out: + srcu_read_unlock(&kvm->srcu, srcu_idx); return ret; } @@ -384,7 +454,7 @@ static struct page *kvmppc_uvmem_get_page(unsigned long gpa, struct kvm *kvm) */ static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start, unsigned long end, unsigned long gpa, struct kvm *kvm, - unsigned long page_shift, bool *downgrade) + unsigned long page_shift) { unsigned long src_pfn, dst_pfn = 0; struct migrate_vma mig; @@ -400,18 +470,6 @@ static int kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start, mig.src = &src_pfn; mig.dst = &dst_pfn; - /* - * We come here with mmap_lock write lock held just for - * ksm_madvise(), otherwise we only need read mmap_lock. - * Hence downgrade to read lock once ksm_madvise() is done. - */ - ret = ksm_madvise(vma, vma->vm_start, vma->vm_end, - MADV_UNMERGEABLE, &vma->vm_flags); - mmap_write_downgrade(kvm->mm); - *downgrade = true; - if (ret) - return ret; - ret = migrate_vma_setup(&mig); if (ret) return ret; @@ -503,7 +561,6 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, unsigned long flags, unsigned long page_shift) { - bool downgrade = false; unsigned long start, end; struct vm_area_struct *vma; int srcu_idx; @@ -524,7 +581,7 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, ret = H_PARAMETER; srcu_idx = srcu_read_lock(&kvm->srcu); - mmap_write_lock(kvm->mm); + mmap_read_lock(kvm->mm); start = gfn_to_hva(kvm, gfn); if (kvm_is_error_hva(start)) @@ -540,16 +597,12 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, if (!vma || vma->vm_start > start || vma->vm_end < end) goto out_unlock; - if (!kvmppc_svm_page_in(vma, start, end, gpa, kvm, page_shift, - &downgrade)) + if (!kvmppc_svm_page_in(vma, start, end, gpa, kvm, page_shift)) ret = H_SUCCESS; out_unlock: mutex_unlock(&kvm->arch.uvmem_lock); out: - if (downgrade) - mmap_read_unlock(kvm->mm); - else - mmap_write_unlock(kvm->mm); + mmap_read_unlock(kvm->mm); srcu_read_unlock(&kvm->srcu, srcu_idx); return ret; } -- 1.8.3.1
next prev parent reply other threads:[~2020-07-23 20:14 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-07-23 20:07 [PATCH v5 0/7] Migrate non-migrated pages of a SVM Ram Pai 2020-07-23 20:07 ` Ram Pai 2020-07-23 20:07 ` [PATCH v5 1/7] KVM: PPC: Book3S HV: Fix function definition in book3s_hv_uvmem.c Ram Pai 2020-07-23 20:07 ` Ram Pai 2020-07-23 20:07 ` Ram Pai [this message] 2020-07-23 20:07 ` [PATCH v5 2/7] KVM: PPC: Book3S HV: Disable page merging in H_SVM_INIT_START Ram Pai 2020-07-23 20:07 ` [PATCH v5 3/7] KVM: PPC: Book3S HV: track the state GFNs associated with secure VMs Ram Pai 2020-07-23 20:07 ` Ram Pai 2020-07-23 20:07 ` [PATCH v5 4/7] KVM: PPC: Book3S HV: in H_SVM_INIT_DONE, migrate remaining normal-GFNs to secure-GFNs Ram Pai 2020-07-23 20:07 ` Ram Pai 2020-07-24 4:27 ` Bharata B Rao 2020-07-24 4:39 ` [PATCH v5 4/7] KVM: PPC: Book3S HV: in H_SVM_INIT_DONE, migrate remaining normal-GFNs to secure- Bharata B Rao 2020-07-23 20:07 ` [PATCH v5 5/7] KVM: PPC: Book3S HV: migrate hot plugged memory Ram Pai 2020-07-23 20:07 ` Ram Pai 2020-07-27 3:55 ` Bharata B Rao 2020-07-27 3:55 ` Bharata B Rao 2020-07-23 20:07 ` [PATCH v5 6/7] KVM: PPC: Book3S HV: move kvmppc_svm_page_out up Ram Pai 2020-07-23 20:07 ` Ram Pai 2020-07-27 3:49 ` Bharata B Rao 2020-07-27 3:50 ` Bharata B Rao 2020-07-23 20:07 ` [PATCH v5 7/7] KVM: PPC: Book3S HV: rework secure mem slot dropping Ram Pai 2020-07-23 20:07 ` Ram Pai 2020-07-24 3:03 ` Bharata B Rao 2020-07-24 3:15 ` Bharata B Rao 2020-07-24 7:43 ` Laurent Dufour 2020-07-24 7:43 ` Laurent Dufour 2020-07-24 8:35 ` [PATCH] " Laurent Dufour 2020-07-24 8:35 ` Laurent Dufour 2020-07-27 3:49 ` Bharata B Rao 2020-07-27 3:49 ` Bharata B Rao
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1595534844-16188-3-git-send-email-linuxram@us.ibm.com \ --to=linuxram@us.ibm.com \ --cc=aneesh.kumar@linux.ibm.com \ --cc=bauerman@linux.ibm.com \ --cc=bharata@linux.ibm.com \ --cc=cclaudio@linux.ibm.com \ --cc=david@gibson.dropbear.id.au \ --cc=kvm-ppc@vger.kernel.org \ --cc=ldufour@linux.ibm.com \ --cc=linuxppc-dev@lists.ozlabs.org \ --cc=sathnaga@linux.vnet.ibm.com \ --cc=sukadev@linux.vnet.ibm.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.