From patchwork Tue Jul 9 10:25:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Bharata B Rao X-Patchwork-Id: 1129689 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45jdl36GyBz9sNg for ; Tue, 9 Jul 2019 20:26:07 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726375AbfGIK0H (ORCPT ); Tue, 9 Jul 2019 06:26:07 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:3482 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726018AbfGIK0H (ORCPT ); Tue, 9 Jul 2019 06:26:07 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x69AMmqV023520 for ; Tue, 9 Jul 2019 06:26:05 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0b-001b2d01.pphosted.com with ESMTP id 2tmq455b7r-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 09 Jul 2019 06:26:04 -0400 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 9 Jul 2019 11:25:59 +0100 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x69APvUr52232292 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 9 Jul 2019 10:25:57 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AE201AE04D; Tue, 9 Jul 2019 10:25:57 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B7DEDAE045; Tue, 9 Jul 2019 10:25:55 +0000 (GMT) Received: from bharata.ibmuc.com (unknown [9.85.81.51]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 9 Jul 2019 10:25:55 +0000 (GMT) From: Bharata B Rao To: linuxppc-dev@lists.ozlabs.org Cc: kvm-ppc@vger.kernel.org, linux-mm@kvack.org, paulus@au1.ibm.com, aneesh.kumar@linux.vnet.ibm.com, jglisse@redhat.com, linuxram@us.ibm.com, sukadev@linux.vnet.ibm.com, cclaudio@linux.ibm.com, Bharata B Rao Subject: [PATCH v5 1/7] kvmppc: HMM backend driver to manage pages of secure guest Date: Tue, 9 Jul 2019 15:55:39 +0530 X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190709102545.9187-1-bharata@linux.ibm.com> References: <20190709102545.9187-1-bharata@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19070910-0016-0000-0000-0000029094AC X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19070910-0017-0000-0000-000032EE471C Message-Id: <20190709102545.9187-2-bharata@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-07-09_04:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907090127 Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org HMM driver for KVM PPC to manage page transitions of secure guest via H_SVM_PAGE_IN and H_SVM_PAGE_OUT hcalls. H_SVM_PAGE_IN: Move the content of a normal page to secure page H_SVM_PAGE_OUT: Move the content of a secure page to normal page Private ZONE_DEVICE memory equal to the amount of secure memory available in the platform for running secure guests is created via a HMM device. The movement of pages between normal and secure memory is done by ->alloc_and_copy() callback routine of migrate_vma(). Signed-off-by: Bharata B Rao --- arch/powerpc/include/asm/hvcall.h | 4 + arch/powerpc/include/asm/kvm_book3s_hmm.h | 29 ++ arch/powerpc/include/asm/kvm_host.h | 12 + arch/powerpc/include/asm/ultravisor-api.h | 2 + arch/powerpc/include/asm/ultravisor.h | 17 + arch/powerpc/kvm/Makefile | 3 + arch/powerpc/kvm/book3s_hv.c | 19 + arch/powerpc/kvm/book3s_hv_hmm.c | 482 ++++++++++++++++++++++ 8 files changed, 568 insertions(+) create mode 100644 arch/powerpc/include/asm/kvm_book3s_hmm.h create mode 100644 arch/powerpc/kvm/book3s_hv_hmm.c diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h index 463c63a9fcf1..2f6b952deb0f 100644 --- a/arch/powerpc/include/asm/hvcall.h +++ b/arch/powerpc/include/asm/hvcall.h @@ -337,6 +337,10 @@ #define H_TLB_INVALIDATE 0xF808 #define H_COPY_TOFROM_GUEST 0xF80C +/* Platform-specific hcalls used by the Ultravisor */ +#define H_SVM_PAGE_IN 0xEF00 +#define H_SVM_PAGE_OUT 0xEF04 + /* Values for 2nd argument to H_SET_MODE */ #define H_SET_MODE_RESOURCE_SET_CIABR 1 #define H_SET_MODE_RESOURCE_SET_DAWR 2 diff --git a/arch/powerpc/include/asm/kvm_book3s_hmm.h b/arch/powerpc/include/asm/kvm_book3s_hmm.h new file mode 100644 index 000000000000..21f3de5f2acb --- /dev/null +++ b/arch/powerpc/include/asm/kvm_book3s_hmm.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __POWERPC_KVM_PPC_HMM_H__ +#define __POWERPC_KVM_PPC_HMM_H__ + +#ifdef CONFIG_PPC_UV +extern unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, + unsigned long gra, + unsigned long flags, + unsigned long page_shift); +extern unsigned long kvmppc_h_svm_page_out(struct kvm *kvm, + unsigned long gra, + unsigned long flags, + unsigned long page_shift); +#else +static inline unsigned long +kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gra, + unsigned long flags, unsigned long page_shift) +{ + return H_UNSUPPORTED; +} + +static inline unsigned long +kvmppc_h_svm_page_out(struct kvm *kvm, unsigned long gra, + unsigned long flags, unsigned long page_shift) +{ + return H_UNSUPPORTED; +} +#endif /* CONFIG_PPC_UV */ +#endif /* __POWERPC_KVM_PPC_HMM_H__ */ diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 184becb62ea4..ac1a101beb07 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -858,4 +858,16 @@ static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {} static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} +#ifdef CONFIG_PPC_UV +extern int kvmppc_hmm_init(void); +extern void kvmppc_hmm_free(void); +#else +static inline int kvmppc_hmm_init(void) +{ + return 0; +} + +static inline void kvmppc_hmm_free(void) {} +#endif /* CONFIG_PPC_UV */ + #endif /* __POWERPC_KVM_HOST_H__ */ diff --git a/arch/powerpc/include/asm/ultravisor-api.h b/arch/powerpc/include/asm/ultravisor-api.h index 7c4d0b4ced12..f1c5800ac705 100644 --- a/arch/powerpc/include/asm/ultravisor-api.h +++ b/arch/powerpc/include/asm/ultravisor-api.h @@ -20,5 +20,7 @@ /* opcodes */ #define UV_WRITE_PATE 0xF104 #define UV_RETURN 0xF11C +#define UV_PAGE_IN 0xF128 +#define UV_PAGE_OUT 0xF12C #endif /* _ASM_POWERPC_ULTRAVISOR_API_H */ diff --git a/arch/powerpc/include/asm/ultravisor.h b/arch/powerpc/include/asm/ultravisor.h index 996c1efd6c6d..16f8e0e8ec3f 100644 --- a/arch/powerpc/include/asm/ultravisor.h +++ b/arch/powerpc/include/asm/ultravisor.h @@ -44,6 +44,23 @@ static inline int uv_register_pate(u64 lpid, u64 dw0, u64 dw1) return ucall(UV_WRITE_PATE, retbuf, lpid, dw0, dw1); } +static inline int uv_page_in(u64 lpid, u64 src_ra, u64 dst_gpa, u64 flags, + u64 page_shift) +{ + unsigned long retbuf[UCALL_BUFSIZE]; + + return ucall(UV_PAGE_IN, retbuf, lpid, src_ra, dst_gpa, flags, + page_shift); +} + +static inline int uv_page_out(u64 lpid, u64 dst_ra, u64 src_gpa, u64 flags, + u64 page_shift) +{ + unsigned long retbuf[UCALL_BUFSIZE]; + + return ucall(UV_PAGE_OUT, retbuf, lpid, dst_ra, src_gpa, flags, + page_shift); +} #endif /* !__ASSEMBLY__ */ #endif /* _ASM_POWERPC_ULTRAVISOR_H */ diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile index 4c67cc79de7c..d1a79fb5f806 100644 --- a/arch/powerpc/kvm/Makefile +++ b/arch/powerpc/kvm/Makefile @@ -71,6 +71,9 @@ kvm-hv-y += \ book3s_64_mmu_radix.o \ book3s_hv_nested.o +kvm-hv-$(CONFIG_PPC_UV) += \ + book3s_hv_hmm.o + kvm-hv-$(CONFIG_PPC_TRANSACTIONAL_MEM) += \ book3s_hv_tm.o diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index a104743291a9..8ee66aa0da58 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -75,6 +75,8 @@ #include #include #include +#include +#include #include "book3s.h" @@ -1083,6 +1085,18 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu) kvmppc_get_gpr(vcpu, 5), kvmppc_get_gpr(vcpu, 6)); break; + case H_SVM_PAGE_IN: + ret = kvmppc_h_svm_page_in(vcpu->kvm, + kvmppc_get_gpr(vcpu, 4), + kvmppc_get_gpr(vcpu, 5), + kvmppc_get_gpr(vcpu, 6)); + break; + case H_SVM_PAGE_OUT: + ret = kvmppc_h_svm_page_out(vcpu->kvm, + kvmppc_get_gpr(vcpu, 4), + kvmppc_get_gpr(vcpu, 5), + kvmppc_get_gpr(vcpu, 6)); + break; default: return RESUME_HOST; } @@ -5501,11 +5515,16 @@ static int kvmppc_book3s_init_hv(void) no_mixing_hpt_and_radix = true; } + r = kvmppc_hmm_init(); + if (r < 0) + pr_err("KVM-HV: kvmppc_hmm_init failed %d\n", r); + return r; } static void kvmppc_book3s_exit_hv(void) { + kvmppc_hmm_free(); kvmppc_free_host_rm_ops(); if (kvmppc_radix_possible()) kvmppc_radix_exit(); diff --git a/arch/powerpc/kvm/book3s_hv_hmm.c b/arch/powerpc/kvm/book3s_hv_hmm.c new file mode 100644 index 000000000000..cd34323888b6 --- /dev/null +++ b/arch/powerpc/kvm/book3s_hv_hmm.c @@ -0,0 +1,482 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * HMM driver to manage page migration between normal and secure + * memory. + * + * Based on Jérôme Glisse's HMM dummy driver. + * + * Copyright 2018 Bharata B Rao, IBM Corp. + */ + +/* + * A pseries guest can be run as a secure guest on Ultravisor-enabled + * POWER platforms. On such platforms, this driver will be used to manage + * the movement of guest pages between the normal memory managed by + * hypervisor (HV) and secure memory managed by Ultravisor (UV). + * + * Private ZONE_DEVICE memory equal to the amount of secure memory + * available in the platform for running secure guests is created + * via a HMM device. The movement of pages between normal and secure + * memory is done by ->alloc_and_copy() callback routine of migrate_vma(). + * + * The page-in or page-out requests from UV will come to HV as hcalls and + * HV will call back into UV via uvcalls to satisfy these page requests. + * + * For each page that gets moved into secure memory, a HMM PFN is used + * on the HV side and HMM migration PTE corresponding to that PFN would be + * populated in the QEMU page tables. HMM PFNs are stored in the rmap + * array. Whenever a guest page becomes secure, HMM PFN allocated for + * the same will be populated in the corresponding slot in the rmap + * array. The overloading of rmap array's usage which otherwise is + * used primarily by HPT guests means that this feature (secure + * guest on PEF platforms) is available only for Radix MMU guests. + * Also the same rmap array is used differently by nested HPT guests. + * Hence a secure guest can't have nested guests. + */ + +#include +#include +#include +#include + +struct kvmppc_hmm_device { + struct hmm_device *device; + struct hmm_devmem *devmem; + unsigned long *pfn_bitmap; +}; + +static struct kvmppc_hmm_device kvmppc_hmm; +spinlock_t kvmppc_hmm_lock; + +struct kvmppc_hmm_page_pvt { + unsigned long *rmap; + unsigned int lpid; + unsigned long gpa; +}; + +struct kvmppc_hmm_migrate_args { + unsigned long *rmap; + unsigned int lpid; + unsigned long gpa; + unsigned long page_shift; +}; + +/* + * Bits 60:56 in the rmap entry will be used to identify the + * different uses/functions of rmap. This definition with move + * to a proper header when all other functions are defined. + */ +#define KVMPPC_PFN_HMM (0x2ULL << 56) + +static inline bool kvmppc_is_hmm_pfn(unsigned long pfn) +{ + return !!(pfn & KVMPPC_PFN_HMM); +} + +/* + * Get a free HMM PFN from the pool + * + * Called when a normal page is moved to secure memory (UV_PAGE_IN). HMM + * PFN will be used to keep track of the secure page on HV side. + * + * @rmap here is the slot in the rmap array that corresponds to @gpa. + * Thus a non-zero rmap entry indicates that the corresonding guest + * page has become secure, is not mapped on the HV side. + * + * NOTE: In this and subsequent functions, we pass around and access + * individual elements of kvm_memory_slot->arch.rmap[] without any + * protection. Should we use lock_rmap() here? + */ +static struct page *kvmppc_hmm_get_page(unsigned long *rmap, + unsigned long gpa, unsigned int lpid) +{ + struct page *dpage = NULL; + unsigned long bit, hmm_pfn; + unsigned long nr_pfns = kvmppc_hmm.devmem->pfn_last - + kvmppc_hmm.devmem->pfn_first; + unsigned long flags; + struct kvmppc_hmm_page_pvt *pvt; + + if (kvmppc_is_hmm_pfn(*rmap)) + return NULL; + + spin_lock_irqsave(&kvmppc_hmm_lock, flags); + bit = find_first_zero_bit(kvmppc_hmm.pfn_bitmap, nr_pfns); + if (bit >= nr_pfns) + goto out; + + bitmap_set(kvmppc_hmm.pfn_bitmap, bit, 1); + hmm_pfn = bit + kvmppc_hmm.devmem->pfn_first; + dpage = pfn_to_page(hmm_pfn); + + if (!trylock_page(dpage)) + goto out_clear; + + *rmap = hmm_pfn | KVMPPC_PFN_HMM; + pvt = kzalloc(sizeof(*pvt), GFP_ATOMIC); + if (!pvt) + goto out_unlock; + pvt->rmap = rmap; + pvt->gpa = gpa; + pvt->lpid = lpid; + hmm_devmem_page_set_drvdata(dpage, (unsigned long)pvt); + spin_unlock_irqrestore(&kvmppc_hmm_lock, flags); + + get_page(dpage); + return dpage; + +out_unlock: + unlock_page(dpage); +out_clear: + bitmap_clear(kvmppc_hmm.pfn_bitmap, + hmm_pfn - kvmppc_hmm.devmem->pfn_first, 1); +out: + spin_unlock_irqrestore(&kvmppc_hmm_lock, flags); + return NULL; +} + +/* + * Release the HMM PFN back to the pool + * + * Called when secure page becomes a normal page during UV_PAGE_OUT. + */ +static void kvmppc_hmm_put_page(struct page *page) +{ + unsigned long pfn = page_to_pfn(page); + unsigned long flags; + struct kvmppc_hmm_page_pvt *pvt; + + spin_lock_irqsave(&kvmppc_hmm_lock, flags); + pvt = (struct kvmppc_hmm_page_pvt *)hmm_devmem_page_get_drvdata(page); + hmm_devmem_page_set_drvdata(page, 0); + + bitmap_clear(kvmppc_hmm.pfn_bitmap, + pfn - kvmppc_hmm.devmem->pfn_first, 1); + *(pvt->rmap) = 0; + spin_unlock_irqrestore(&kvmppc_hmm_lock, flags); + kfree(pvt); +} + +/* + * migrate_vma() callback to move page from normal memory to secure memory. + * + * We don't capture the return value of uv_page_in() here because when + * UV asks for a page and then fails to copy it over, we don't care. + */ +static void +kvmppc_hmm_migrate_alloc_and_copy(struct vm_area_struct *vma, + const unsigned long *src_pfn, + unsigned long *dst_pfn, + unsigned long start, + unsigned long end, + void *private) +{ + struct kvmppc_hmm_migrate_args *args = private; + struct page *spage = migrate_pfn_to_page(*src_pfn); + unsigned long pfn = *src_pfn >> MIGRATE_PFN_SHIFT; + struct page *dpage; + + *dst_pfn = 0; + if (!(*src_pfn & MIGRATE_PFN_MIGRATE)) + return; + + dpage = kvmppc_hmm_get_page(args->rmap, args->gpa, args->lpid); + if (!dpage) + return; + + if (spage) + uv_page_in(args->lpid, pfn << args->page_shift, + args->gpa, 0, args->page_shift); + + *dst_pfn = migrate_pfn(page_to_pfn(dpage)) | + MIGRATE_PFN_DEVICE | MIGRATE_PFN_LOCKED; +} + +/* + * This migrate_vma() callback is typically used to updated device + * page tables after successful migration. We have nothing to do here. + * + * Also as we don't care if UV successfully copied over the page in + * kvmppc_hmm_migrate_alloc_and_copy(), we don't bother to check + * dst_pfn for any errors here. + */ +static void +kvmppc_hmm_migrate_finalize_and_map(struct vm_area_struct *vma, + const unsigned long *src_pfn, + const unsigned long *dst_pfn, + unsigned long start, + unsigned long end, + void *private) +{ +} + +static const struct migrate_vma_ops kvmppc_hmm_migrate_ops = { + .alloc_and_copy = kvmppc_hmm_migrate_alloc_and_copy, + .finalize_and_map = kvmppc_hmm_migrate_finalize_and_map, +}; + +/* + * Move page from normal memory to secure memory. + */ +unsigned long +kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, + unsigned long flags, unsigned long page_shift) +{ + unsigned long addr, end; + unsigned long src_pfn, dst_pfn; + struct kvmppc_hmm_migrate_args args; + struct vm_area_struct *vma; + int srcu_idx; + unsigned long gfn = gpa >> page_shift; + struct kvm_memory_slot *slot; + unsigned long *rmap; + int ret = H_SUCCESS; + + if (page_shift != PAGE_SHIFT) + return H_P3; + + if (flags) + return H_P2; + + down_read(&kvm->mm->mmap_sem); + srcu_idx = srcu_read_lock(&kvm->srcu); + slot = gfn_to_memslot(kvm, gfn); + rmap = &slot->arch.rmap[gfn - slot->base_gfn]; + addr = gfn_to_hva(kvm, gpa >> page_shift); + if (kvm_is_error_hva(addr)) { + ret = H_PARAMETER; + goto out; + } + + end = addr + (1UL << page_shift); + vma = find_vma_intersection(kvm->mm, addr, end); + if (!vma || vma->vm_start > addr || vma->vm_end < end) { + ret = H_PARAMETER; + goto out; + } + + args.rmap = rmap; + args.lpid = kvm->arch.lpid; + args.gpa = gpa; + args.page_shift = page_shift; + ret = migrate_vma(&kvmppc_hmm_migrate_ops, vma, addr, end, + &src_pfn, &dst_pfn, &args); + if (ret < 0) + ret = H_PARAMETER; +out: + srcu_read_unlock(&kvm->srcu, srcu_idx); + up_read(&kvm->mm->mmap_sem); + return ret; +} + +/* + * We drop the HMM PFN here, provision a new page and populate + * the same in QEMU page tables. + */ +static void +kvmppc_hmm_fault_migrate_alloc_and_copy(struct vm_area_struct *vma, + const unsigned long *src_pfn, + unsigned long *dst_pfn, + unsigned long start, + unsigned long end, + void *private) +{ + struct page *dpage, *spage; + struct kvmppc_hmm_page_pvt *pvt; + unsigned long pfn; + int ret = U_SUCCESS; + + *dst_pfn = MIGRATE_PFN_ERROR; + spage = migrate_pfn_to_page(*src_pfn); + if (!spage || !(*src_pfn & MIGRATE_PFN_MIGRATE)) + return; + if (!is_zone_device_page(spage)) + return; + dpage = hmm_vma_alloc_locked_page(vma, start); + if (!dpage) + return; + pvt = (struct kvmppc_hmm_page_pvt *) + hmm_devmem_page_get_drvdata(spage); + + pfn = page_to_pfn(dpage); + ret = uv_page_out(pvt->lpid, pfn << PAGE_SHIFT, + pvt->gpa, 0, PAGE_SHIFT); + if (ret == U_SUCCESS) + *dst_pfn = migrate_pfn(pfn) | MIGRATE_PFN_LOCKED; +} + +/* + * We have nothing to do here. + */ +static void +kvmppc_hmm_fault_migrate_finalize_and_map(struct vm_area_struct *vma, + const unsigned long *src_pfn, + const unsigned long *dst_pfn, + unsigned long start, + unsigned long end, + void *private) +{ +} + +static const struct migrate_vma_ops kvmppc_hmm_fault_migrate_ops = { + .alloc_and_copy = kvmppc_hmm_fault_migrate_alloc_and_copy, + .finalize_and_map = kvmppc_hmm_fault_migrate_finalize_and_map, +}; + +/* + * Fault handler callback when HV touches any page that has been + * moved to secure memory, we ask UV to give back the page by + * issuing a UV_PAGE_OUT uvcall. + */ +static vm_fault_t kvmppc_hmm_devmem_fault(struct hmm_devmem *devmem, + struct vm_area_struct *vma, + unsigned long addr, + const struct page *page, + unsigned int flags, + pmd_t *pmdp) +{ + unsigned long end = addr + PAGE_SIZE; + unsigned long src_pfn, dst_pfn = 0; + + if (migrate_vma(&kvmppc_hmm_fault_migrate_ops, vma, addr, end, + &src_pfn, &dst_pfn, NULL)) + return VM_FAULT_SIGBUS; + if (dst_pfn == MIGRATE_PFN_ERROR) + return VM_FAULT_SIGBUS; + return 0; +} + +static void kvmppc_hmm_devmem_free(struct hmm_devmem *devmem, + struct page *page) +{ + kvmppc_hmm_put_page(page); +} + +static const struct hmm_devmem_ops kvmppc_hmm_devmem_ops = { + .free = kvmppc_hmm_devmem_free, + .fault = kvmppc_hmm_devmem_fault, +}; + +/* + * Move page from secure memory to normal memory. + */ +unsigned long +kvmppc_h_svm_page_out(struct kvm *kvm, unsigned long gpa, + unsigned long flags, unsigned long page_shift) +{ + unsigned long addr, end; + struct vm_area_struct *vma; + unsigned long src_pfn, dst_pfn = 0; + int srcu_idx; + int ret = H_SUCCESS; + + if (page_shift != PAGE_SHIFT) + return H_P3; + + if (flags) + return H_P2; + + down_read(&kvm->mm->mmap_sem); + srcu_idx = srcu_read_lock(&kvm->srcu); + addr = gfn_to_hva(kvm, gpa >> page_shift); + if (kvm_is_error_hva(addr)) { + ret = H_PARAMETER; + goto out; + } + + end = addr + (1UL << page_shift); + vma = find_vma_intersection(kvm->mm, addr, end); + if (!vma || vma->vm_start > addr || vma->vm_end < end) { + ret = H_PARAMETER; + goto out; + } + ret = migrate_vma(&kvmppc_hmm_fault_migrate_ops, vma, addr, end, + &src_pfn, &dst_pfn, NULL); + if (ret < 0) + ret = H_PARAMETER; +out: + srcu_read_unlock(&kvm->srcu, srcu_idx); + up_read(&kvm->mm->mmap_sem); + return ret; +} + +static u64 kvmppc_get_secmem_size(void) +{ + struct device_node *np; + int i, len; + const __be32 *prop; + u64 size = 0; + + np = of_find_node_by_path("/ibm,ultravisor/ibm,uv-firmware"); + if (!np) + goto out; + + prop = of_get_property(np, "secure-memory-ranges", &len); + if (!prop) + goto out_put; + + for (i = 0; i < len / (sizeof(*prop) * 4); i++) + size += of_read_number(prop + (i * 4) + 2, 2); + +out_put: + of_node_put(np); +out: + return size; +} + +static int kvmppc_hmm_pages_init(void) +{ + unsigned long nr_pfns = kvmppc_hmm.devmem->pfn_last - + kvmppc_hmm.devmem->pfn_first; + + kvmppc_hmm.pfn_bitmap = kcalloc(BITS_TO_LONGS(nr_pfns), + sizeof(unsigned long), GFP_KERNEL); + if (!kvmppc_hmm.pfn_bitmap) + return -ENOMEM; + + spin_lock_init(&kvmppc_hmm_lock); + + return 0; +} + +int kvmppc_hmm_init(void) +{ + int ret = 0; + unsigned long size; + + size = kvmppc_get_secmem_size(); + if (!size) { + ret = -ENODEV; + goto out; + } + + kvmppc_hmm.device = hmm_device_new(NULL); + if (IS_ERR(kvmppc_hmm.device)) { + ret = PTR_ERR(kvmppc_hmm.device); + goto out; + } + + kvmppc_hmm.devmem = hmm_devmem_add(&kvmppc_hmm_devmem_ops, + &kvmppc_hmm.device->device, size); + if (IS_ERR(kvmppc_hmm.devmem)) { + ret = PTR_ERR(kvmppc_hmm.devmem); + goto out_device; + } + ret = kvmppc_hmm_pages_init(); + if (ret < 0) + goto out_device; + + pr_info("KVMPPC-HMM: Secure Memory size 0x%lx\n", size); + return ret; + +out_device: + hmm_device_put(kvmppc_hmm.device); +out: + return ret; +} + +void kvmppc_hmm_free(void) +{ + kfree(kvmppc_hmm.pfn_bitmap); + hmm_device_put(kvmppc_hmm.device); +}