![Alexey Kardashevskiy](/assets/img/avatar_default.png)
This reworks helpers for checking TCE update parameters in way they can be used in KVM. This should cause no behavioral change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
359 lines
9.4 KiB
C
359 lines
9.4 KiB
C
/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
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* Copyright 2011 David Gibson, IBM Corporation <dwg@au1.ibm.com>
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* Copyright 2016 Alexey Kardashevskiy, IBM Corporation <aik@au1.ibm.com>
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*/
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/kvm.h>
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#include <linux/kvm_host.h>
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#include <linux/highmem.h>
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#include <linux/gfp.h>
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#include <linux/slab.h>
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#include <linux/hugetlb.h>
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#include <linux/list.h>
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#include <asm/tlbflush.h>
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#include <asm/kvm_ppc.h>
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#include <asm/kvm_book3s.h>
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#include <asm/book3s/64/mmu-hash.h>
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#include <asm/mmu_context.h>
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#include <asm/hvcall.h>
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#include <asm/synch.h>
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#include <asm/ppc-opcode.h>
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#include <asm/kvm_host.h>
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#include <asm/udbg.h>
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#include <asm/iommu.h>
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#include <asm/tce.h>
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#define TCES_PER_PAGE (PAGE_SIZE / sizeof(u64))
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/*
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* Finds a TCE table descriptor by LIOBN.
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*
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* WARNING: This will be called in real or virtual mode on HV KVM and virtual
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* mode on PR KVM
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*/
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struct kvmppc_spapr_tce_table *kvmppc_find_table(struct kvm *kvm,
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unsigned long liobn)
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{
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struct kvmppc_spapr_tce_table *stt;
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list_for_each_entry_lockless(stt, &kvm->arch.spapr_tce_tables, list)
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if (stt->liobn == liobn)
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return stt;
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return NULL;
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}
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EXPORT_SYMBOL_GPL(kvmppc_find_table);
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/*
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* Validates TCE address.
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* At the moment flags and page mask are validated.
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* As the host kernel does not access those addresses (just puts them
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* to the table and user space is supposed to process them), we can skip
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* checking other things (such as TCE is a guest RAM address or the page
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* was actually allocated).
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*
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* WARNING: This will be called in real-mode on HV KVM and virtual
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* mode on PR KVM
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*/
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long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt, unsigned long tce)
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{
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unsigned long gpa = tce & ~(TCE_PCI_READ | TCE_PCI_WRITE);
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enum dma_data_direction dir = iommu_tce_direction(tce);
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/* Allow userspace to poison TCE table */
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if (dir == DMA_NONE)
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return H_SUCCESS;
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if (iommu_tce_check_gpa(stt->page_shift, gpa))
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return H_PARAMETER;
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return H_SUCCESS;
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}
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EXPORT_SYMBOL_GPL(kvmppc_tce_validate);
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/* Note on the use of page_address() in real mode,
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*
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* It is safe to use page_address() in real mode on ppc64 because
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* page_address() is always defined as lowmem_page_address()
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* which returns __va(PFN_PHYS(page_to_pfn(page))) which is arithmetic
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* operation and does not access page struct.
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*
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* Theoretically page_address() could be defined different
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* but either WANT_PAGE_VIRTUAL or HASHED_PAGE_VIRTUAL
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* would have to be enabled.
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* WANT_PAGE_VIRTUAL is never enabled on ppc32/ppc64,
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* HASHED_PAGE_VIRTUAL could be enabled for ppc32 only and only
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* if CONFIG_HIGHMEM is defined. As CONFIG_SPARSEMEM_VMEMMAP
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* is not expected to be enabled on ppc32, page_address()
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* is safe for ppc32 as well.
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*
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* WARNING: This will be called in real-mode on HV KVM and virtual
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* mode on PR KVM
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*/
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static u64 *kvmppc_page_address(struct page *page)
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{
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#if defined(HASHED_PAGE_VIRTUAL) || defined(WANT_PAGE_VIRTUAL)
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#error TODO: fix to avoid page_address() here
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#endif
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return (u64 *) page_address(page);
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}
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/*
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* Handles TCE requests for emulated devices.
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* Puts guest TCE values to the table and expects user space to convert them.
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* Called in both real and virtual modes.
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* Cannot fail so kvmppc_tce_validate must be called before it.
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*
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* WARNING: This will be called in real-mode on HV KVM and virtual
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* mode on PR KVM
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*/
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void kvmppc_tce_put(struct kvmppc_spapr_tce_table *stt,
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unsigned long idx, unsigned long tce)
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{
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struct page *page;
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u64 *tbl;
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idx -= stt->offset;
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page = stt->pages[idx / TCES_PER_PAGE];
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tbl = kvmppc_page_address(page);
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tbl[idx % TCES_PER_PAGE] = tce;
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}
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EXPORT_SYMBOL_GPL(kvmppc_tce_put);
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long kvmppc_gpa_to_ua(struct kvm *kvm, unsigned long gpa,
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unsigned long *ua, unsigned long **prmap)
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{
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unsigned long gfn = gpa >> PAGE_SHIFT;
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struct kvm_memory_slot *memslot;
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memslot = search_memslots(kvm_memslots(kvm), gfn);
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if (!memslot)
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return -EINVAL;
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*ua = __gfn_to_hva_memslot(memslot, gfn) |
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(gpa & ~(PAGE_MASK | TCE_PCI_READ | TCE_PCI_WRITE));
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#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
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if (prmap)
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*prmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
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#endif
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return 0;
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}
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EXPORT_SYMBOL_GPL(kvmppc_gpa_to_ua);
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#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
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long kvmppc_rm_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
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unsigned long ioba, unsigned long tce)
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{
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struct kvmppc_spapr_tce_table *stt;
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long ret;
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/* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
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/* liobn, ioba, tce); */
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stt = kvmppc_find_table(vcpu->kvm, liobn);
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if (!stt)
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return H_TOO_HARD;
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ret = kvmppc_ioba_validate(stt, ioba, 1);
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if (ret != H_SUCCESS)
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return ret;
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ret = kvmppc_tce_validate(stt, tce);
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if (ret != H_SUCCESS)
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return ret;
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kvmppc_tce_put(stt, ioba >> stt->page_shift, tce);
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return H_SUCCESS;
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}
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static long kvmppc_rm_ua_to_hpa(struct kvm_vcpu *vcpu,
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unsigned long ua, unsigned long *phpa)
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{
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pte_t *ptep, pte;
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unsigned shift = 0;
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ptep = __find_linux_pte_or_hugepte(vcpu->arch.pgdir, ua, NULL, &shift);
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if (!ptep || !pte_present(*ptep))
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return -ENXIO;
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pte = *ptep;
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if (!shift)
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shift = PAGE_SHIFT;
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/* Avoid handling anything potentially complicated in realmode */
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if (shift > PAGE_SHIFT)
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return -EAGAIN;
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if (!pte_young(pte))
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return -EAGAIN;
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*phpa = (pte_pfn(pte) << PAGE_SHIFT) | (ua & ((1ULL << shift) - 1)) |
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(ua & ~PAGE_MASK);
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return 0;
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}
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long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu,
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unsigned long liobn, unsigned long ioba,
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unsigned long tce_list, unsigned long npages)
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{
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struct kvmppc_spapr_tce_table *stt;
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long i, ret = H_SUCCESS;
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unsigned long tces, entry, ua = 0;
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unsigned long *rmap = NULL;
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bool prereg = false;
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stt = kvmppc_find_table(vcpu->kvm, liobn);
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if (!stt)
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return H_TOO_HARD;
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entry = ioba >> stt->page_shift;
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/*
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* The spec says that the maximum size of the list is 512 TCEs
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* so the whole table addressed resides in 4K page
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*/
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if (npages > 512)
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return H_PARAMETER;
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if (tce_list & (SZ_4K - 1))
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return H_PARAMETER;
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ret = kvmppc_ioba_validate(stt, ioba, npages);
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if (ret != H_SUCCESS)
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return ret;
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if (mm_iommu_preregistered(vcpu->kvm->mm)) {
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/*
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* We get here if guest memory was pre-registered which
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* is normally VFIO case and gpa->hpa translation does not
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* depend on hpt.
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*/
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struct mm_iommu_table_group_mem_t *mem;
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if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, NULL))
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return H_TOO_HARD;
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mem = mm_iommu_lookup_rm(vcpu->kvm->mm, ua, IOMMU_PAGE_SIZE_4K);
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if (mem)
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prereg = mm_iommu_ua_to_hpa_rm(mem, ua, &tces) == 0;
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}
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if (!prereg) {
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/*
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* This is usually a case of a guest with emulated devices only
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* when TCE list is not in preregistered memory.
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* We do not require memory to be preregistered in this case
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* so lock rmap and do __find_linux_pte_or_hugepte().
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*/
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if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, &rmap))
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return H_TOO_HARD;
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rmap = (void *) vmalloc_to_phys(rmap);
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/*
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* Synchronize with the MMU notifier callbacks in
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* book3s_64_mmu_hv.c (kvm_unmap_hva_hv etc.).
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* While we have the rmap lock, code running on other CPUs
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* cannot finish unmapping the host real page that backs
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* this guest real page, so we are OK to access the host
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* real page.
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*/
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lock_rmap(rmap);
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if (kvmppc_rm_ua_to_hpa(vcpu, ua, &tces)) {
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ret = H_TOO_HARD;
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goto unlock_exit;
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}
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}
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for (i = 0; i < npages; ++i) {
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unsigned long tce = be64_to_cpu(((u64 *)tces)[i]);
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ret = kvmppc_tce_validate(stt, tce);
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if (ret != H_SUCCESS)
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goto unlock_exit;
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kvmppc_tce_put(stt, entry + i, tce);
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}
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unlock_exit:
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if (rmap)
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unlock_rmap(rmap);
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return ret;
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}
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long kvmppc_rm_h_stuff_tce(struct kvm_vcpu *vcpu,
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unsigned long liobn, unsigned long ioba,
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unsigned long tce_value, unsigned long npages)
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{
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struct kvmppc_spapr_tce_table *stt;
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long i, ret;
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stt = kvmppc_find_table(vcpu->kvm, liobn);
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if (!stt)
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return H_TOO_HARD;
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ret = kvmppc_ioba_validate(stt, ioba, npages);
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if (ret != H_SUCCESS)
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return ret;
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/* Check permission bits only to allow userspace poison TCE for debug */
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if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ))
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return H_PARAMETER;
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for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
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kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);
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return H_SUCCESS;
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}
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long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
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unsigned long ioba)
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{
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struct kvmppc_spapr_tce_table *stt;
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long ret;
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unsigned long idx;
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struct page *page;
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u64 *tbl;
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stt = kvmppc_find_table(vcpu->kvm, liobn);
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if (!stt)
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return H_TOO_HARD;
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ret = kvmppc_ioba_validate(stt, ioba, 1);
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if (ret != H_SUCCESS)
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return ret;
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idx = (ioba >> stt->page_shift) - stt->offset;
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page = stt->pages[idx / TCES_PER_PAGE];
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tbl = (u64 *)page_address(page);
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vcpu->arch.gpr[4] = tbl[idx % TCES_PER_PAGE];
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return H_SUCCESS;
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}
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EXPORT_SYMBOL_GPL(kvmppc_h_get_tce);
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#endif /* KVM_BOOK3S_HV_POSSIBLE */
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