diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_64_mmu_hv.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_64_mmu_hv.c | 407 |
1 files changed, 393 insertions, 14 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 2a89a36e7263..8cc18abd6dde 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -25,6 +25,8 @@ #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> @@ -41,6 +43,11 @@ /* 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; @@ -138,10 +145,11 @@ long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp) /* Set the entire HPT to 0, i.e. invalid HPTEs */ memset((void *)kvm->arch.hpt_virt, 0, 1ul << order); /* - * Set the whole last_vcpu array to an invalid vcpu number. - * This ensures that each vcpu will flush its TLB on next entry. + * Reset all the reverse-mapping chains for all memslots */ - memset(kvm->arch.last_vcpu, 0xff, sizeof(kvm->arch.last_vcpu)); + 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 { @@ -185,6 +193,7 @@ 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; @@ -216,7 +225,8 @@ 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); @@ -354,15 +364,10 @@ 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; @@ -390,8 +395,8 @@ 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 */ @@ -402,6 +407,19 @@ 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) { @@ -756,6 +774,25 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, goto out_put; } +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, @@ -1131,6 +1168,348 @@ void kvmppc_unpin_guest_page(struct kvm *kvm, void *va) put_page(page); } +/* + * 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)) + +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; + int ok = 1; + int valid, dirty; + + /* Unmodified entries are uninteresting except on the first pass */ + dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); + 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]; + if (v & HPTE_V_ABSENT) { + v &= ~HPTE_V_ABSENT; + v |= HPTE_V_VALID; + } + /* re-evaluate valid and dirty from synchronized HPTE value */ + valid = !!(v & HPTE_V_VALID); + if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED)) + valid = 0; + r = revp->guest_rpte | (hptp[1] & (HPTE_R_R | HPTE_R_C)); + dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); + /* 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 && + !(revp->guest_rpte & HPTE_GR_MODIFIED)) { + ++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_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 = kvm->arch.lpcr & ~LPCR_VRMASD; + lpcr |= senc << (LPCR_VRMASD_SH - 4); + kvm->arch.lpcr = lpcr; + 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 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); + 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) { struct kvmppc_mmu *mmu = &vcpu->arch.mmu; |