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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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697d3899dc
This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
197 lines
5.2 KiB
C
197 lines
5.2 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 SUSE Linux Products GmbH 2010
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*
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* Authors: Alexander Graf <agraf@suse.de>
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*/
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#ifndef __ASM_KVM_BOOK3S_64_H__
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#define __ASM_KVM_BOOK3S_64_H__
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#ifdef CONFIG_KVM_BOOK3S_PR
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static inline struct kvmppc_book3s_shadow_vcpu *svcpu_get(struct kvm_vcpu *vcpu)
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{
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preempt_disable();
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return &get_paca()->shadow_vcpu;
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}
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static inline void svcpu_put(struct kvmppc_book3s_shadow_vcpu *svcpu)
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{
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preempt_enable();
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}
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#endif
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#define SPAPR_TCE_SHIFT 12
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#ifdef CONFIG_KVM_BOOK3S_64_HV
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/* For now use fixed-size 16MB page table */
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#define HPT_ORDER 24
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#define HPT_NPTEG (1ul << (HPT_ORDER - 7)) /* 128B per pteg */
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#define HPT_NPTE (HPT_NPTEG << 3) /* 8 PTEs per PTEG */
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#define HPT_HASH_MASK (HPT_NPTEG - 1)
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#endif
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#define VRMA_VSID 0x1ffffffUL /* 1TB VSID reserved for VRMA */
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/*
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* We use a lock bit in HPTE dword 0 to synchronize updates and
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* accesses to each HPTE, and another bit to indicate non-present
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* HPTEs.
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*/
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#define HPTE_V_HVLOCK 0x40UL
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#define HPTE_V_ABSENT 0x20UL
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static inline long try_lock_hpte(unsigned long *hpte, unsigned long bits)
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{
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unsigned long tmp, old;
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asm volatile(" ldarx %0,0,%2\n"
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" and. %1,%0,%3\n"
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" bne 2f\n"
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" ori %0,%0,%4\n"
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" stdcx. %0,0,%2\n"
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" beq+ 2f\n"
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" li %1,%3\n"
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"2: isync"
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: "=&r" (tmp), "=&r" (old)
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: "r" (hpte), "r" (bits), "i" (HPTE_V_HVLOCK)
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: "cc", "memory");
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return old == 0;
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}
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static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
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unsigned long pte_index)
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{
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unsigned long rb, va_low;
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rb = (v & ~0x7fUL) << 16; /* AVA field */
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va_low = pte_index >> 3;
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if (v & HPTE_V_SECONDARY)
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va_low = ~va_low;
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/* xor vsid from AVA */
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if (!(v & HPTE_V_1TB_SEG))
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va_low ^= v >> 12;
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else
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va_low ^= v >> 24;
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va_low &= 0x7ff;
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if (v & HPTE_V_LARGE) {
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rb |= 1; /* L field */
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if (cpu_has_feature(CPU_FTR_ARCH_206) &&
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(r & 0xff000)) {
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/* non-16MB large page, must be 64k */
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/* (masks depend on page size) */
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rb |= 0x1000; /* page encoding in LP field */
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rb |= (va_low & 0x7f) << 16; /* 7b of VA in AVA/LP field */
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rb |= (va_low & 0xfe); /* AVAL field (P7 doesn't seem to care) */
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}
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} else {
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/* 4kB page */
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rb |= (va_low & 0x7ff) << 12; /* remaining 11b of VA */
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}
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rb |= (v >> 54) & 0x300; /* B field */
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return rb;
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}
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static inline unsigned long hpte_page_size(unsigned long h, unsigned long l)
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{
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/* only handle 4k, 64k and 16M pages for now */
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if (!(h & HPTE_V_LARGE))
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return 1ul << 12; /* 4k page */
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if ((l & 0xf000) == 0x1000 && cpu_has_feature(CPU_FTR_ARCH_206))
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return 1ul << 16; /* 64k page */
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if ((l & 0xff000) == 0)
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return 1ul << 24; /* 16M page */
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return 0; /* error */
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}
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static inline unsigned long hpte_rpn(unsigned long ptel, unsigned long psize)
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{
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return ((ptel & HPTE_R_RPN) & ~(psize - 1)) >> PAGE_SHIFT;
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}
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static inline int hpte_cache_flags_ok(unsigned long ptel, unsigned long io_type)
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{
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unsigned int wimg = ptel & HPTE_R_WIMG;
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/* Handle SAO */
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if (wimg == (HPTE_R_W | HPTE_R_I | HPTE_R_M) &&
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cpu_has_feature(CPU_FTR_ARCH_206))
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wimg = HPTE_R_M;
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if (!io_type)
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return wimg == HPTE_R_M;
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return (wimg & (HPTE_R_W | HPTE_R_I)) == io_type;
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}
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/* Return HPTE cache control bits corresponding to Linux pte bits */
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static inline unsigned long hpte_cache_bits(unsigned long pte_val)
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{
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#if _PAGE_NO_CACHE == HPTE_R_I && _PAGE_WRITETHRU == HPTE_R_W
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return pte_val & (HPTE_R_W | HPTE_R_I);
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#else
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return ((pte_val & _PAGE_NO_CACHE) ? HPTE_R_I : 0) +
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((pte_val & _PAGE_WRITETHRU) ? HPTE_R_W : 0);
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#endif
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}
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static inline bool hpte_read_permission(unsigned long pp, unsigned long key)
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{
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if (key)
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return PP_RWRX <= pp && pp <= PP_RXRX;
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return 1;
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}
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static inline bool hpte_write_permission(unsigned long pp, unsigned long key)
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{
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if (key)
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return pp == PP_RWRW;
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return pp <= PP_RWRW;
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}
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static inline int hpte_get_skey_perm(unsigned long hpte_r, unsigned long amr)
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{
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unsigned long skey;
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skey = ((hpte_r & HPTE_R_KEY_HI) >> 57) |
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((hpte_r & HPTE_R_KEY_LO) >> 9);
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return (amr >> (62 - 2 * skey)) & 3;
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}
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static inline void lock_rmap(unsigned long *rmap)
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{
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do {
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while (test_bit(KVMPPC_RMAP_LOCK_BIT, rmap))
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cpu_relax();
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} while (test_and_set_bit_lock(KVMPPC_RMAP_LOCK_BIT, rmap));
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}
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static inline void unlock_rmap(unsigned long *rmap)
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{
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__clear_bit_unlock(KVMPPC_RMAP_LOCK_BIT, rmap);
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}
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static inline bool slot_is_aligned(struct kvm_memory_slot *memslot,
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unsigned long pagesize)
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{
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unsigned long mask = (pagesize >> PAGE_SHIFT) - 1;
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if (pagesize <= PAGE_SIZE)
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return 1;
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return !(memslot->base_gfn & mask) && !(memslot->npages & mask);
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}
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#endif /* __ASM_KVM_BOOK3S_64_H__ */
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