diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_64_mmu_hv.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_64_mmu_hv.c | 887 |
1 files changed, 766 insertions, 121 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 80a57751758..68468d695f1 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -24,6 +24,9 @@ #include <linux/slab.h> #include <linux/hugetlb.h> #include <linux/vmalloc.h> +#include <linux/srcu.h> +#include <linux/anon_inodes.h> +#include <linux/file.h> #include <asm/tlbflush.h> #include <asm/kvm_ppc.h> @@ -34,67 +37,128 @@ #include <asm/ppc-opcode.h> #include <asm/cputable.h> +#include "book3s_hv_cma.h" + /* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */ #define MAX_LPID_970 63 -long kvmppc_alloc_hpt(struct kvm *kvm) +/* Power architecture requires HPT is at least 256kB */ +#define PPC_MIN_HPT_ORDER 18 + +static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, + long pte_index, unsigned long pteh, + unsigned long ptel, unsigned long *pte_idx_ret); +static void kvmppc_rmap_reset(struct kvm *kvm); + +long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp) { - unsigned long hpt; - long lpid; + unsigned long hpt = 0; struct revmap_entry *rev; - struct kvmppc_linear_info *li; - - /* Allocate guest's hashed page table */ - li = kvm_alloc_hpt(); - if (li) { - /* using preallocated memory */ - hpt = (ulong)li->base_virt; - kvm->arch.hpt_li = li; - } else { - /* using dynamic memory */ + struct page *page = NULL; + long order = KVM_DEFAULT_HPT_ORDER; + + if (htab_orderp) { + order = *htab_orderp; + if (order < PPC_MIN_HPT_ORDER) + order = PPC_MIN_HPT_ORDER; + } + + kvm->arch.hpt_cma_alloc = 0; + VM_BUG_ON(order < KVM_CMA_CHUNK_ORDER); + page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT)); + if (page) { + hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page)); + kvm->arch.hpt_cma_alloc = 1; + } + + /* Lastly try successively smaller sizes from the page allocator */ + while (!hpt && order > PPC_MIN_HPT_ORDER) { hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT| - __GFP_NOWARN, HPT_ORDER - PAGE_SHIFT); + __GFP_NOWARN, order - PAGE_SHIFT); + if (!hpt) + --order; } - if (!hpt) { - pr_err("kvm_alloc_hpt: Couldn't alloc HPT\n"); + if (!hpt) return -ENOMEM; - } + kvm->arch.hpt_virt = hpt; + kvm->arch.hpt_order = order; + /* HPTEs are 2**4 bytes long */ + kvm->arch.hpt_npte = 1ul << (order - 4); + /* 128 (2**7) bytes in each HPTEG */ + kvm->arch.hpt_mask = (1ul << (order - 7)) - 1; /* Allocate reverse map array */ - rev = vmalloc(sizeof(struct revmap_entry) * HPT_NPTE); + rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte); if (!rev) { pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n"); goto out_freehpt; } kvm->arch.revmap = rev; + kvm->arch.sdr1 = __pa(hpt) | (order - 18); - lpid = kvmppc_alloc_lpid(); - if (lpid < 0) - goto out_freeboth; + pr_info("KVM guest htab at %lx (order %ld), LPID %x\n", + hpt, order, kvm->arch.lpid); - kvm->arch.sdr1 = __pa(hpt) | (HPT_ORDER - 18); - kvm->arch.lpid = lpid; - - pr_info("KVM guest htab at %lx, LPID %lx\n", hpt, lpid); + if (htab_orderp) + *htab_orderp = order; return 0; - out_freeboth: - vfree(rev); out_freehpt: - free_pages(hpt, HPT_ORDER - PAGE_SHIFT); + if (kvm->arch.hpt_cma_alloc) + kvm_release_hpt(page, 1 << (order - PAGE_SHIFT)); + else + free_pages(hpt, order - PAGE_SHIFT); return -ENOMEM; } +long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp) +{ + long err = -EBUSY; + long order; + + mutex_lock(&kvm->lock); + if (kvm->arch.rma_setup_done) { + kvm->arch.rma_setup_done = 0; + /* order rma_setup_done vs. vcpus_running */ + smp_mb(); + if (atomic_read(&kvm->arch.vcpus_running)) { + kvm->arch.rma_setup_done = 1; + goto out; + } + } + if (kvm->arch.hpt_virt) { + order = kvm->arch.hpt_order; + /* Set the entire HPT to 0, i.e. invalid HPTEs */ + memset((void *)kvm->arch.hpt_virt, 0, 1ul << order); + /* + * Reset all the reverse-mapping chains for all memslots + */ + kvmppc_rmap_reset(kvm); + /* Ensure that each vcpu will flush its TLB on next entry. */ + cpumask_setall(&kvm->arch.need_tlb_flush); + *htab_orderp = order; + err = 0; + } else { + err = kvmppc_alloc_hpt(kvm, htab_orderp); + order = *htab_orderp; + } + out: + mutex_unlock(&kvm->lock); + return err; +} + void kvmppc_free_hpt(struct kvm *kvm) { kvmppc_free_lpid(kvm->arch.lpid); vfree(kvm->arch.revmap); - if (kvm->arch.hpt_li) - kvm_release_hpt(kvm->arch.hpt_li); + if (kvm->arch.hpt_cma_alloc) + kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt), + 1 << (kvm->arch.hpt_order - PAGE_SHIFT)); else - free_pages(kvm->arch.hpt_virt, HPT_ORDER - PAGE_SHIFT); + free_pages(kvm->arch.hpt_virt, + kvm->arch.hpt_order - PAGE_SHIFT); } /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */ @@ -118,7 +182,9 @@ void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, unsigned long addr, hash; unsigned long psize; unsigned long hp0, hp1; + unsigned long idx_ret; long ret; + struct kvm *kvm = vcpu->kvm; psize = 1ul << porder; npages = memslot->npages >> (porder - PAGE_SHIFT); @@ -127,8 +193,8 @@ void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, if (npages > 1ul << (40 - porder)) npages = 1ul << (40 - porder); /* Can't use more than 1 HPTE per HPTEG */ - if (npages > HPT_NPTEG) - npages = HPT_NPTEG; + if (npages > kvm->arch.hpt_mask + 1) + npages = kvm->arch.hpt_mask + 1; hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) | HPTE_V_BOLTED | hpte0_pgsize_encoding(psize); @@ -138,7 +204,7 @@ void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, for (i = 0; i < npages; ++i) { addr = i << porder; /* can't use hpt_hash since va > 64 bits */ - hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & HPT_HASH_MASK; + hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask; /* * We assume that the hash table is empty and no * vcpus are using it at this stage. Since we create @@ -148,7 +214,8 @@ void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, hash = (hash << 3) + 7; hp_v = hp0 | ((addr >> 16) & ~0x7fUL); hp_r = hp1 | addr; - ret = kvmppc_virtmode_h_enter(vcpu, H_EXACT, hash, hp_v, hp_r); + ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r, + &idx_ret); if (ret != H_SUCCESS) { pr_err("KVM: map_vrma at %lx failed, ret=%ld\n", addr, ret); @@ -182,18 +249,21 @@ int kvmppc_mmu_hv_init(void) return 0; } -void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu) -{ -} - static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu) { - kvmppc_set_msr(vcpu, MSR_SF | MSR_ME); + unsigned long msr = vcpu->arch.intr_msr; + + /* If transactional, change to suspend mode on IRQ delivery */ + if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr)) + msr |= MSR_TS_S; + else + msr |= vcpu->arch.shregs.msr & MSR_TS_MASK; + kvmppc_set_msr(vcpu, msr); } /* * This is called to get a reference to a guest page if there isn't - * one already in the kvm->arch.slot_phys[][] arrays. + * one already in the memslot->arch.slot_phys[] array. */ static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn, struct kvm_memory_slot *memslot, @@ -208,7 +278,7 @@ static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn, struct vm_area_struct *vma; unsigned long pfn, i, npages; - physp = kvm->arch.slot_phys[memslot->id]; + physp = memslot->arch.slot_phys; if (!physp) return -EINVAL; if (physp[gfn - memslot->base_gfn]) @@ -286,15 +356,10 @@ static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn, return err; } -/* - * We come here on a H_ENTER call from the guest when we are not - * using mmu notifiers and we don't have the requested page pinned - * already. - */ -long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, - long pte_index, unsigned long pteh, unsigned long ptel) +long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, + long pte_index, unsigned long pteh, + unsigned long ptel, unsigned long *pte_idx_ret) { - struct kvm *kvm = vcpu->kvm; unsigned long psize, gpa, gfn; struct kvm_memory_slot *memslot; long ret; @@ -322,8 +387,8 @@ long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, do_insert: /* Protect linux PTE lookup from page table destruction */ rcu_read_lock_sched(); /* this disables preemption too */ - vcpu->arch.pgdir = current->mm->pgd; - ret = kvmppc_h_enter(vcpu, flags, pte_index, pteh, ptel); + ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel, + current->mm->pgd, false, pte_idx_ret); rcu_read_unlock_sched(); if (ret == H_TOO_HARD) { /* this can't happen */ @@ -334,6 +399,19 @@ long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, } +/* + * We come here on a H_ENTER call from the guest when we are not + * using mmu notifiers and we don't have the requested page pinned + * already. + */ +long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, + long pte_index, unsigned long pteh, + unsigned long ptel) +{ + return kvmppc_virtmode_do_h_enter(vcpu->kvm, flags, pte_index, + pteh, ptel, &vcpu->arch.gpr[4]); +} + static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu, gva_t eaddr) { @@ -365,7 +443,7 @@ static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r, } static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, - struct kvmppc_pte *gpte, bool data) + struct kvmppc_pte *gpte, bool data, bool iswrite) { struct kvm *kvm = vcpu->kvm; struct kvmppc_slb *slbe; @@ -387,11 +465,14 @@ static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, slb_v = vcpu->kvm->arch.vrma_slb_v; } + preempt_disable(); /* Find the HPTE in the hash table */ index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v, HPTE_V_VALID | HPTE_V_ABSENT); - if (index < 0) + if (index < 0) { + preempt_enable(); return -ENOENT; + } hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4)); v = hptep[0] & ~HPTE_V_HVLOCK; gr = kvm->arch.revmap[index].guest_rpte; @@ -399,6 +480,7 @@ static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, /* Unlock the HPTE */ asm volatile("lwsync" : : : "memory"); hptep[0] = v; + preempt_enable(); gpte->eaddr = eaddr; gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff); @@ -476,7 +558,7 @@ static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, * we just return and retry the instruction. */ - if (instruction_is_store(vcpu->arch.last_inst) != !!is_store) + if (instruction_is_store(kvmppc_get_last_inst(vcpu)) != !!is_store) return RESUME_GUEST; /* @@ -503,7 +585,8 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, struct kvm *kvm = vcpu->kvm; unsigned long *hptep, hpte[3], r; unsigned long mmu_seq, psize, pte_size; - unsigned long gfn, hva, pfn; + unsigned long gpa_base, gfn_base; + unsigned long gpa, gfn, hva, pfn; struct kvm_memory_slot *memslot; unsigned long *rmap; struct revmap_entry *rev; @@ -541,19 +624,27 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, /* Translate the logical address and get the page */ psize = hpte_page_size(hpte[0], r); - gfn = hpte_rpn(r, psize); + gpa_base = r & HPTE_R_RPN & ~(psize - 1); + gfn_base = gpa_base >> PAGE_SHIFT; + gpa = gpa_base | (ea & (psize - 1)); + gfn = gpa >> PAGE_SHIFT; memslot = gfn_to_memslot(kvm, gfn); /* No memslot means it's an emulated MMIO region */ - if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) { - unsigned long gpa = (gfn << PAGE_SHIFT) | (ea & (psize - 1)); + if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, dsisr & DSISR_ISSTORE); - } if (!kvm->arch.using_mmu_notifiers) return -EFAULT; /* should never get here */ + /* + * This should never happen, because of the slot_is_aligned() + * check in kvmppc_do_h_enter(). + */ + if (gfn_base < memslot->base_gfn) + return -EFAULT; + /* used to check for invalidations in progress */ mmu_seq = kvm->mmu_notifier_seq; smp_rmb(); @@ -584,12 +675,14 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, return -EFAULT; } else { page = pages[0]; + pfn = page_to_pfn(page); if (PageHuge(page)) { page = compound_head(page); pte_size <<= compound_order(page); } /* if the guest wants write access, see if that is OK */ if (!writing && hpte_is_writable(r)) { + unsigned int hugepage_shift; pte_t *ptep, pte; /* @@ -598,15 +691,15 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, */ rcu_read_lock_sched(); ptep = find_linux_pte_or_hugepte(current->mm->pgd, - hva, NULL); - if (ptep && pte_present(*ptep)) { - pte = kvmppc_read_update_linux_pte(ptep, 1); + hva, &hugepage_shift); + if (ptep) { + pte = kvmppc_read_update_linux_pte(ptep, 1, + hugepage_shift); if (pte_write(pte)) write_ok = 1; } rcu_read_unlock_sched(); } - pfn = page_to_pfn(page); } ret = -EFAULT; @@ -624,8 +717,14 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M; } - /* Set the HPTE to point to pfn */ - r = (r & ~(HPTE_R_PP0 - pte_size)) | (pfn << PAGE_SHIFT); + /* + * Set the HPTE to point to pfn. + * Since the pfn is at PAGE_SIZE granularity, make sure we + * don't mask out lower-order bits if psize < PAGE_SIZE. + */ + if (psize < PAGE_SIZE) + psize = PAGE_SIZE; + r = (r & ~(HPTE_R_PP0 - psize)) | ((pfn << PAGE_SHIFT) & ~(psize - 1)); if (hpte_is_writable(r) && !write_ok) r = hpte_make_readonly(r); ret = RESUME_GUEST; @@ -638,12 +737,13 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, goto out_unlock; hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; - rmap = &memslot->rmap[gfn - memslot->base_gfn]; + /* Always put the HPTE in the rmap chain for the page base address */ + rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn]; lock_rmap(rmap); /* Check if we might have been invalidated; let the guest retry if so */ ret = RESUME_GUEST; - if (mmu_notifier_retry(vcpu, mmu_seq)) { + if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) { unlock_rmap(rmap); goto out_unlock; } @@ -689,9 +789,31 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, goto out_put; } -static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, - int (*handler)(struct kvm *kvm, unsigned long *rmapp, - unsigned long gfn)) +static void kvmppc_rmap_reset(struct kvm *kvm) +{ + struct kvm_memslots *slots; + struct kvm_memory_slot *memslot; + int srcu_idx; + + srcu_idx = srcu_read_lock(&kvm->srcu); + slots = kvm->memslots; + kvm_for_each_memslot(memslot, slots) { + /* + * This assumes it is acceptable to lose reference and + * change bits across a reset. + */ + memset(memslot->arch.rmap, 0, + memslot->npages * sizeof(*memslot->arch.rmap)); + } + srcu_read_unlock(&kvm->srcu, srcu_idx); +} + +static int kvm_handle_hva_range(struct kvm *kvm, + unsigned long start, + unsigned long end, + int (*handler)(struct kvm *kvm, + unsigned long *rmapp, + unsigned long gfn)) { int ret; int retval = 0; @@ -700,15 +822,25 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, slots = kvm_memslots(kvm); kvm_for_each_memslot(memslot, slots) { - unsigned long start = memslot->userspace_addr; - unsigned long end; + unsigned long hva_start, hva_end; + gfn_t gfn, gfn_end; - end = start + (memslot->npages << PAGE_SHIFT); - if (hva >= start && hva < end) { - gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT; + hva_start = max(start, memslot->userspace_addr); + hva_end = min(end, memslot->userspace_addr + + (memslot->npages << PAGE_SHIFT)); + if (hva_start >= hva_end) + continue; + /* + * {gfn(page) | page intersects with [hva_start, hva_end)} = + * {gfn, gfn+1, ..., gfn_end-1}. + */ + gfn = hva_to_gfn_memslot(hva_start, memslot); + gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot); + + for (; gfn < gfn_end; ++gfn) { + gfn_t gfn_offset = gfn - memslot->base_gfn; - ret = handler(kvm, &memslot->rmap[gfn_offset], - memslot->base_gfn + gfn_offset); + ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn); retval |= ret; } } @@ -716,6 +848,13 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, return retval; } +static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, + int (*handler)(struct kvm *kvm, unsigned long *rmapp, + unsigned long gfn)) +{ + return kvm_handle_hva_range(kvm, hva, hva + 1, handler); +} + static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, unsigned long gfn) { @@ -763,12 +902,16 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, psize = hpte_page_size(hptep[0], ptel); if ((hptep[0] & HPTE_V_VALID) && hpte_rpn(ptel, psize) == gfn) { - hptep[0] |= HPTE_V_ABSENT; + if (kvm->arch.using_mmu_notifiers) + hptep[0] |= HPTE_V_ABSENT; kvmppc_invalidate_hpte(kvm, hptep, i); /* Harvest R and C */ rcbits = hptep[1] & (HPTE_R_R | HPTE_R_C); *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT; - rev[i].guest_rpte = ptel | rcbits; + if (rcbits & ~rev[i].guest_rpte) { + rev[i].guest_rpte = ptel | rcbits; + note_hpte_modification(kvm, &rev[i]); + } } unlock_rmap(rmapp); hptep[0] &= ~HPTE_V_HVLOCK; @@ -776,13 +919,43 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, return 0; } -int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) +int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva) { if (kvm->arch.using_mmu_notifiers) kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); return 0; } +int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end) +{ + if (kvm->arch.using_mmu_notifiers) + kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp); + return 0; +} + +void kvmppc_core_flush_memslot_hv(struct kvm *kvm, + struct kvm_memory_slot *memslot) +{ + unsigned long *rmapp; + unsigned long gfn; + unsigned long n; + + rmapp = memslot->arch.rmap; + gfn = memslot->base_gfn; + for (n = memslot->npages; n; --n) { + /* + * Testing the present bit without locking is OK because + * the memslot has been marked invalid already, and hence + * no new HPTEs referencing this page can be created, + * thus the present bit can't go from 0 to 1. + */ + if (*rmapp & KVMPPC_RMAP_PRESENT) + kvm_unmap_rmapp(kvm, rmapp, gfn); + ++rmapp; + ++gfn; + } +} + static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, unsigned long gfn) { @@ -822,7 +995,10 @@ static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, /* Now check and modify the HPTE */ if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) { kvmppc_clear_ref_hpte(kvm, hptep, i); - rev[i].guest_rpte |= HPTE_R_R; + if (!(rev[i].guest_rpte & HPTE_R_R)) { + rev[i].guest_rpte |= HPTE_R_R; + note_hpte_modification(kvm, &rev[i]); + } ret = 1; } hptep[0] &= ~HPTE_V_HVLOCK; @@ -832,7 +1008,7 @@ static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, return ret; } -int kvm_age_hva(struct kvm *kvm, unsigned long hva) +int kvm_age_hva_hv(struct kvm *kvm, unsigned long hva) { if (!kvm->arch.using_mmu_notifiers) return 0; @@ -870,36 +1046,47 @@ static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp, return ret; } -int kvm_test_age_hva(struct kvm *kvm, unsigned long hva) +int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva) { if (!kvm->arch.using_mmu_notifiers) return 0; return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp); } -void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) +void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte) { if (!kvm->arch.using_mmu_notifiers) return; kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); } -static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) +static int vcpus_running(struct kvm *kvm) +{ + return atomic_read(&kvm->arch.vcpus_running) != 0; +} + +/* + * Returns the number of system pages that are dirty. + * This can be more than 1 if we find a huge-page HPTE. + */ +static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp) { struct revmap_entry *rev = kvm->arch.revmap; unsigned long head, i, j; + unsigned long n; + unsigned long v, r; unsigned long *hptep; - int ret = 0; + int npages_dirty = 0; retry: lock_rmap(rmapp); if (*rmapp & KVMPPC_RMAP_CHANGED) { *rmapp &= ~KVMPPC_RMAP_CHANGED; - ret = 1; + npages_dirty = 1; } if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { unlock_rmap(rmapp); - return ret; + return npages_dirty; } i = head = *rmapp & KVMPPC_RMAP_INDEX; @@ -907,7 +1094,22 @@ static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); j = rev[i].forw; - if (!(hptep[1] & HPTE_R_C)) + /* + * Checking the C (changed) bit here is racy since there + * is no guarantee about when the hardware writes it back. + * If the HPTE is not writable then it is stable since the + * page can't be written to, and we would have done a tlbie + * (which forces the hardware to complete any writeback) + * when making the HPTE read-only. + * If vcpus are running then this call is racy anyway + * since the page could get dirtied subsequently, so we + * expect there to be a further call which would pick up + * any delayed C bit writeback. + * Otherwise we need to do the tlbie even if C==0 in + * order to pick up any delayed writeback of C. + */ + if (!(hptep[1] & HPTE_R_C) && + (!hpte_is_writable(hptep[1]) || vcpus_running(kvm))) continue; if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { @@ -919,36 +1121,83 @@ static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) } /* Now check and modify the HPTE */ - if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) { - /* need to make it temporarily absent to clear C */ - hptep[0] |= HPTE_V_ABSENT; - kvmppc_invalidate_hpte(kvm, hptep, i); - hptep[1] &= ~HPTE_R_C; + if (!(hptep[0] & HPTE_V_VALID)) + continue; + + /* need to make it temporarily absent so C is stable */ + hptep[0] |= HPTE_V_ABSENT; + kvmppc_invalidate_hpte(kvm, hptep, i); + v = hptep[0]; + r = hptep[1]; + if (r & HPTE_R_C) { + hptep[1] = r & ~HPTE_R_C; + if (!(rev[i].guest_rpte & HPTE_R_C)) { + rev[i].guest_rpte |= HPTE_R_C; + note_hpte_modification(kvm, &rev[i]); + } + n = hpte_page_size(v, r); + n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT; + if (n > npages_dirty) + npages_dirty = n; eieio(); - hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; - rev[i].guest_rpte |= HPTE_R_C; - ret = 1; } - hptep[0] &= ~HPTE_V_HVLOCK; + v &= ~(HPTE_V_ABSENT | HPTE_V_HVLOCK); + v |= HPTE_V_VALID; + hptep[0] = v; } while ((i = j) != head); unlock_rmap(rmapp); - return ret; + return npages_dirty; } -long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) +static void harvest_vpa_dirty(struct kvmppc_vpa *vpa, + struct kvm_memory_slot *memslot, + unsigned long *map) { - unsigned long i; - unsigned long *rmapp, *map; + unsigned long gfn; + + if (!vpa->dirty || !vpa->pinned_addr) + return; + gfn = vpa->gpa >> PAGE_SHIFT; + if (gfn < memslot->base_gfn || + gfn >= memslot->base_gfn + memslot->npages) + return; + + vpa->dirty = false; + if (map) + __set_bit_le(gfn - memslot->base_gfn, map); +} + +long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot, + unsigned long *map) +{ + unsigned long i, j; + unsigned long *rmapp; + struct kvm_vcpu *vcpu; preempt_disable(); - rmapp = memslot->rmap; - map = memslot->dirty_bitmap; + rmapp = memslot->arch.rmap; for (i = 0; i < memslot->npages; ++i) { - if (kvm_test_clear_dirty(kvm, rmapp)) - __set_bit_le(i, map); + int npages = kvm_test_clear_dirty_npages(kvm, rmapp); + /* + * Note that if npages > 0 then i must be a multiple of npages, + * since we always put huge-page HPTEs in the rmap chain + * corresponding to their page base address. + */ + if (npages && map) + for (j = i; npages; ++j, --npages) + __set_bit_le(j, map); ++rmapp; } + + /* Harvest dirty bits from VPA and DTL updates */ + /* Note: we never modify the SLB shadow buffer areas */ + kvm_for_each_vcpu(i, vcpu, kvm) { + spin_lock(&vcpu->arch.vpa_update_lock); + harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map); + harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map); + spin_unlock(&vcpu->arch.vpa_update_lock); + } preempt_enable(); return 0; } @@ -960,23 +1209,25 @@ void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, unsigned long gfn = gpa >> PAGE_SHIFT; struct page *page, *pages[1]; int npages; - unsigned long hva, psize, offset; + unsigned long hva, offset; unsigned long pa; unsigned long *physp; + int srcu_idx; + srcu_idx = srcu_read_lock(&kvm->srcu); memslot = gfn_to_memslot(kvm, gfn); if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) - return NULL; + goto err; if (!kvm->arch.using_mmu_notifiers) { - physp = kvm->arch.slot_phys[memslot->id]; + physp = memslot->arch.slot_phys; if (!physp) - return NULL; + goto err; physp += gfn - memslot->base_gfn; pa = *physp; if (!pa) { if (kvmppc_get_guest_page(kvm, gfn, memslot, PAGE_SIZE) < 0) - return NULL; + goto err; pa = *physp; } page = pfn_to_page(pa >> PAGE_SHIFT); @@ -985,25 +1236,419 @@ void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, hva = gfn_to_hva_memslot(memslot, gfn); npages = get_user_pages_fast(hva, 1, 1, pages); if (npages < 1) - return NULL; + goto err; page = pages[0]; } - psize = PAGE_SIZE; - if (PageHuge(page)) { - page = compound_head(page); - psize <<= compound_order(page); - } - offset = gpa & (psize - 1); + srcu_read_unlock(&kvm->srcu, srcu_idx); + + offset = gpa & (PAGE_SIZE - 1); if (nb_ret) - *nb_ret = psize - offset; + *nb_ret = PAGE_SIZE - offset; return page_address(page) + offset; + + err: + srcu_read_unlock(&kvm->srcu, srcu_idx); + return NULL; } -void kvmppc_unpin_guest_page(struct kvm *kvm, void *va) +void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa, + bool dirty) { struct page *page = virt_to_page(va); + struct kvm_memory_slot *memslot; + unsigned long gfn; + unsigned long *rmap; + int srcu_idx; put_page(page); + + if (!dirty || !kvm->arch.using_mmu_notifiers) + return; + + /* We need to mark this page dirty in the rmap chain */ + gfn = gpa >> PAGE_SHIFT; + srcu_idx = srcu_read_lock(&kvm->srcu); + memslot = gfn_to_memslot(kvm, gfn); + if (memslot) { + rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; + lock_rmap(rmap); + *rmap |= KVMPPC_RMAP_CHANGED; + unlock_rmap(rmap); + } + srcu_read_unlock(&kvm->srcu, srcu_idx); +} + +/* + * Functions for reading and writing the hash table via reads and + * writes on a file descriptor. + * + * Reads return the guest view of the hash table, which has to be + * pieced together from the real hash table and the guest_rpte + * values in the revmap array. + * + * On writes, each HPTE written is considered in turn, and if it + * is valid, it is written to the HPT as if an H_ENTER with the + * exact flag set was done. When the invalid count is non-zero + * in the header written to the stream, the kernel will make + * sure that that many HPTEs are invalid, and invalidate them + * if not. + */ + +struct kvm_htab_ctx { + unsigned long index; + unsigned long flags; + struct kvm *kvm; + int first_pass; +}; + +#define HPTE_SIZE (2 * sizeof(unsigned long)) + +/* + * Returns 1 if this HPT entry has been modified or has pending + * R/C bit changes. + */ +static int hpte_dirty(struct revmap_entry *revp, unsigned long *hptp) +{ + unsigned long rcbits_unset; + + if (revp->guest_rpte & HPTE_GR_MODIFIED) + return 1; + + /* Also need to consider changes in reference and changed bits */ + rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); + if ((hptp[0] & HPTE_V_VALID) && (hptp[1] & rcbits_unset)) + return 1; + + return 0; +} + +static long record_hpte(unsigned long flags, unsigned long *hptp, + unsigned long *hpte, struct revmap_entry *revp, + int want_valid, int first_pass) +{ + unsigned long v, r; + unsigned long rcbits_unset; + int ok = 1; + int valid, dirty; + + /* Unmodified entries are uninteresting except on the first pass */ + dirty = hpte_dirty(revp, hptp); + if (!first_pass && !dirty) + return 0; + + valid = 0; + if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) { + valid = 1; + if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && + !(hptp[0] & HPTE_V_BOLTED)) + valid = 0; + } + if (valid != want_valid) + return 0; + + v = r = 0; + if (valid || dirty) { + /* lock the HPTE so it's stable and read it */ + preempt_disable(); + while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) + cpu_relax(); + v = hptp[0]; + + /* re-evaluate valid and dirty from synchronized HPTE value */ + valid = !!(v & HPTE_V_VALID); + dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); + + /* Harvest R and C into guest view if necessary */ + rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); + if (valid && (rcbits_unset & hptp[1])) { + revp->guest_rpte |= (hptp[1] & (HPTE_R_R | HPTE_R_C)) | + HPTE_GR_MODIFIED; + dirty = 1; + } + + if (v & HPTE_V_ABSENT) { + v &= ~HPTE_V_ABSENT; + v |= HPTE_V_VALID; + valid = 1; + } + if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED)) + valid = 0; + + r = revp->guest_rpte; + /* only clear modified if this is the right sort of entry */ + if (valid == want_valid && dirty) { + r &= ~HPTE_GR_MODIFIED; + revp->guest_rpte = r; + } + asm volatile(PPC_RELEASE_BARRIER "" : : : "memory"); + hptp[0] &= ~HPTE_V_HVLOCK; + preempt_enable(); + if (!(valid == want_valid && (first_pass || dirty))) + ok = 0; + } + hpte[0] = v; + hpte[1] = r; + return ok; +} + +static ssize_t kvm_htab_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct kvm_htab_ctx *ctx = file->private_data; + struct kvm *kvm = ctx->kvm; + struct kvm_get_htab_header hdr; + unsigned long *hptp; + struct revmap_entry *revp; + unsigned long i, nb, nw; + unsigned long __user *lbuf; + struct kvm_get_htab_header __user *hptr; + unsigned long flags; + int first_pass; + unsigned long hpte[2]; + + if (!access_ok(VERIFY_WRITE, buf, count)) + return -EFAULT; + + first_pass = ctx->first_pass; + flags = ctx->flags; + + i = ctx->index; + hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); + revp = kvm->arch.revmap + i; + lbuf = (unsigned long __user *)buf; + + nb = 0; + while (nb + sizeof(hdr) + HPTE_SIZE < count) { + /* Initialize header */ + hptr = (struct kvm_get_htab_header __user *)buf; + hdr.n_valid = 0; + hdr.n_invalid = 0; + nw = nb; + nb += sizeof(hdr); + lbuf = (unsigned long __user *)(buf + sizeof(hdr)); + + /* Skip uninteresting entries, i.e. clean on not-first pass */ + if (!first_pass) { + while (i < kvm->arch.hpt_npte && + !hpte_dirty(revp, hptp)) { + ++i; + hptp += 2; + ++revp; + } + } + hdr.index = i; + + /* Grab a series of valid entries */ + while (i < kvm->arch.hpt_npte && + hdr.n_valid < 0xffff && + nb + HPTE_SIZE < count && + record_hpte(flags, hptp, hpte, revp, 1, first_pass)) { + /* valid entry, write it out */ + ++hdr.n_valid; + if (__put_user(hpte[0], lbuf) || + __put_user(hpte[1], lbuf + 1)) + return -EFAULT; + nb += HPTE_SIZE; + lbuf += 2; + ++i; + hptp += 2; + ++revp; + } + /* Now skip invalid entries while we can */ + while (i < kvm->arch.hpt_npte && + hdr.n_invalid < 0xffff && + record_hpte(flags, hptp, hpte, revp, 0, first_pass)) { + /* found an invalid entry */ + ++hdr.n_invalid; + ++i; + hptp += 2; + ++revp; + } + + if (hdr.n_valid || hdr.n_invalid) { + /* write back the header */ + if (__copy_to_user(hptr, &hdr, sizeof(hdr))) + return -EFAULT; + nw = nb; + buf = (char __user *)lbuf; + } else { + nb = nw; + } + + /* Check if we've wrapped around the hash table */ + if (i >= kvm->arch.hpt_npte) { + i = 0; + ctx->first_pass = 0; + break; + } + } + + ctx->index = i; + + return nb; +} + +static ssize_t kvm_htab_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct kvm_htab_ctx *ctx = file->private_data; + struct kvm *kvm = ctx->kvm; + struct kvm_get_htab_header hdr; + unsigned long i, j; + unsigned long v, r; + unsigned long __user *lbuf; + unsigned long *hptp; + unsigned long tmp[2]; + ssize_t nb; + long int err, ret; + int rma_setup; + + if (!access_ok(VERIFY_READ, buf, count)) + return -EFAULT; + + /* lock out vcpus from running while we're doing this */ + mutex_lock(&kvm->lock); + rma_setup = kvm->arch.rma_setup_done; + if (rma_setup) { + kvm->arch.rma_setup_done = 0; /* temporarily */ + /* order rma_setup_done vs. vcpus_running */ + smp_mb(); + if (atomic_read(&kvm->arch.vcpus_running)) { + kvm->arch.rma_setup_done = 1; + mutex_unlock(&kvm->lock); + return -EBUSY; + } + } + + err = 0; + for (nb = 0; nb + sizeof(hdr) <= count; ) { + err = -EFAULT; + if (__copy_from_user(&hdr, buf, sizeof(hdr))) + break; + + err = 0; + if (nb + hdr.n_valid * HPTE_SIZE > count) + break; + + nb += sizeof(hdr); + buf += sizeof(hdr); + + err = -EINVAL; + i = hdr.index; + if (i >= kvm->arch.hpt_npte || + i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte) + break; + + hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); + lbuf = (unsigned long __user *)buf; + for (j = 0; j < hdr.n_valid; ++j) { + err = -EFAULT; + if (__get_user(v, lbuf) || __get_user(r, lbuf + 1)) + goto out; + err = -EINVAL; + if (!(v & HPTE_V_VALID)) + goto out; + lbuf += 2; + nb += HPTE_SIZE; + + if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) + kvmppc_do_h_remove(kvm, 0, i, 0, tmp); + err = -EIO; + ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r, + tmp); + if (ret != H_SUCCESS) { + pr_err("kvm_htab_write ret %ld i=%ld v=%lx " + "r=%lx\n", ret, i, v, r); + goto out; + } + if (!rma_setup && is_vrma_hpte(v)) { + unsigned long psize = hpte_base_page_size(v, r); + unsigned long senc = slb_pgsize_encoding(psize); + unsigned long lpcr; + + kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T | + (VRMA_VSID << SLB_VSID_SHIFT_1T); + lpcr = senc << (LPCR_VRMASD_SH - 4); + kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD); + rma_setup = 1; + } + ++i; + hptp += 2; + } + + for (j = 0; j < hdr.n_invalid; ++j) { + if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) + kvmppc_do_h_remove(kvm, 0, i, 0, tmp); + ++i; + hptp += 2; + } + err = 0; + } + + out: + /* Order HPTE updates vs. rma_setup_done */ + smp_wmb(); + kvm->arch.rma_setup_done = rma_setup; + mutex_unlock(&kvm->lock); + + if (err) + return err; + return nb; +} + +static int kvm_htab_release(struct inode *inode, struct file *filp) +{ + struct kvm_htab_ctx *ctx = filp->private_data; + + filp->private_data = NULL; + if (!(ctx->flags & KVM_GET_HTAB_WRITE)) + atomic_dec(&ctx->kvm->arch.hpte_mod_interest); + kvm_put_kvm(ctx->kvm); + kfree(ctx); + return 0; +} + +static const struct file_operations kvm_htab_fops = { + .read = kvm_htab_read, + .write = kvm_htab_write, + .llseek = default_llseek, + .release = kvm_htab_release, +}; + +int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf) +{ + int ret; + struct kvm_htab_ctx *ctx; + int rwflag; + + /* reject flags we don't recognize */ + if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE)) + return -EINVAL; + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + kvm_get_kvm(kvm); + ctx->kvm = kvm; + ctx->index = ghf->start_index; + ctx->flags = ghf->flags; + ctx->first_pass = 1; + + rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY; + ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC); + if (ret < 0) { + kvm_put_kvm(kvm); + return ret; + } + + if (rwflag == O_RDONLY) { + mutex_lock(&kvm->slots_lock); + atomic_inc(&kvm->arch.hpte_mod_interest); + /* make sure kvmppc_do_h_enter etc. see the increment */ + synchronize_srcu_expedited(&kvm->srcu); + mutex_unlock(&kvm->slots_lock); + } + + return ret; } void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) |