diff options
author | H. Peter Anvin <hpa@zytor.com> | 2012-05-30 12:11:26 -0700 |
---|---|---|
committer | H. Peter Anvin <hpa@zytor.com> | 2012-05-30 12:11:32 -0700 |
commit | bbd771474ec44b516107685d77e1c80bbe09f141 (patch) | |
tree | 0cb15781539a68f27b4ea6c89f827282630cbce6 /arch/x86/kvm/x86.c | |
parent | 403e1c5b7495d7b80fae9fc4d0a7a6f5abdc3307 (diff) | |
parent | 319b6ffc6df892e4ccffff823cc5521a4a5d2dca (diff) |
Merge branch 'x86/trampoline' into x86/urgent
x86/trampoline contains an urgent commit which is necessarily on a
newer baseline.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
-rw-r--r-- | arch/x86/kvm/x86.c | 280 |
1 files changed, 154 insertions, 126 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 185a2b823a2..be6d54929fa 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2147,6 +2147,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_ASYNC_PF: case KVM_CAP_GET_TSC_KHZ: case KVM_CAP_PCI_2_3: + case KVM_CAP_KVMCLOCK_CTRL: r = 1; break; case KVM_CAP_COALESCED_MMIO: @@ -2597,6 +2598,23 @@ static int kvm_vcpu_ioctl_x86_set_xcrs(struct kvm_vcpu *vcpu, return r; } +/* + * kvm_set_guest_paused() indicates to the guest kernel that it has been + * stopped by the hypervisor. This function will be called from the host only. + * EINVAL is returned when the host attempts to set the flag for a guest that + * does not support pv clocks. + */ +static int kvm_set_guest_paused(struct kvm_vcpu *vcpu) +{ + struct pvclock_vcpu_time_info *src = &vcpu->arch.hv_clock; + if (!vcpu->arch.time_page) + return -EINVAL; + src->flags |= PVCLOCK_GUEST_STOPPED; + mark_page_dirty(vcpu->kvm, vcpu->arch.time >> PAGE_SHIFT); + kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); + return 0; +} + long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { @@ -2873,6 +2891,10 @@ long kvm_arch_vcpu_ioctl(struct file *filp, r = vcpu->arch.virtual_tsc_khz; goto out; } + case KVM_KVMCLOCK_CTRL: { + r = kvm_set_guest_paused(vcpu); + goto out; + } default: r = -EINVAL; } @@ -3045,57 +3067,32 @@ static int kvm_vm_ioctl_reinject(struct kvm *kvm, } /** - * write_protect_slot - write protect a slot for dirty logging - * @kvm: the kvm instance - * @memslot: the slot we protect - * @dirty_bitmap: the bitmap indicating which pages are dirty - * @nr_dirty_pages: the number of dirty pages + * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot + * @kvm: kvm instance + * @log: slot id and address to which we copy the log * - * We have two ways to find all sptes to protect: - * 1. Use kvm_mmu_slot_remove_write_access() which walks all shadow pages and - * checks ones that have a spte mapping a page in the slot. - * 2. Use kvm_mmu_rmap_write_protect() for each gfn found in the bitmap. + * We need to keep it in mind that VCPU threads can write to the bitmap + * concurrently. So, to avoid losing data, we keep the following order for + * each bit: * - * Generally speaking, if there are not so many dirty pages compared to the - * number of shadow pages, we should use the latter. + * 1. Take a snapshot of the bit and clear it if needed. + * 2. Write protect the corresponding page. + * 3. Flush TLB's if needed. + * 4. Copy the snapshot to the userspace. * - * Note that letting others write into a page marked dirty in the old bitmap - * by using the remaining tlb entry is not a problem. That page will become - * write protected again when we flush the tlb and then be reported dirty to - * the user space by copying the old bitmap. - */ -static void write_protect_slot(struct kvm *kvm, - struct kvm_memory_slot *memslot, - unsigned long *dirty_bitmap, - unsigned long nr_dirty_pages) -{ - spin_lock(&kvm->mmu_lock); - - /* Not many dirty pages compared to # of shadow pages. */ - if (nr_dirty_pages < kvm->arch.n_used_mmu_pages) { - unsigned long gfn_offset; - - for_each_set_bit(gfn_offset, dirty_bitmap, memslot->npages) { - unsigned long gfn = memslot->base_gfn + gfn_offset; - - kvm_mmu_rmap_write_protect(kvm, gfn, memslot); - } - kvm_flush_remote_tlbs(kvm); - } else - kvm_mmu_slot_remove_write_access(kvm, memslot->id); - - spin_unlock(&kvm->mmu_lock); -} - -/* - * Get (and clear) the dirty memory log for a memory slot. + * Between 2 and 3, the guest may write to the page using the remaining TLB + * entry. This is not a problem because the page will be reported dirty at + * step 4 using the snapshot taken before and step 3 ensures that successive + * writes will be logged for the next call. */ -int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, - struct kvm_dirty_log *log) +int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { int r; struct kvm_memory_slot *memslot; - unsigned long n, nr_dirty_pages; + unsigned long n, i; + unsigned long *dirty_bitmap; + unsigned long *dirty_bitmap_buffer; + bool is_dirty = false; mutex_lock(&kvm->slots_lock); @@ -3104,49 +3101,42 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, goto out; memslot = id_to_memslot(kvm->memslots, log->slot); + + dirty_bitmap = memslot->dirty_bitmap; r = -ENOENT; - if (!memslot->dirty_bitmap) + if (!dirty_bitmap) goto out; n = kvm_dirty_bitmap_bytes(memslot); - nr_dirty_pages = memslot->nr_dirty_pages; - /* If nothing is dirty, don't bother messing with page tables. */ - if (nr_dirty_pages) { - struct kvm_memslots *slots, *old_slots; - unsigned long *dirty_bitmap, *dirty_bitmap_head; + dirty_bitmap_buffer = dirty_bitmap + n / sizeof(long); + memset(dirty_bitmap_buffer, 0, n); - dirty_bitmap = memslot->dirty_bitmap; - dirty_bitmap_head = memslot->dirty_bitmap_head; - if (dirty_bitmap == dirty_bitmap_head) - dirty_bitmap_head += n / sizeof(long); - memset(dirty_bitmap_head, 0, n); + spin_lock(&kvm->mmu_lock); - r = -ENOMEM; - slots = kmemdup(kvm->memslots, sizeof(*kvm->memslots), GFP_KERNEL); - if (!slots) - goto out; + for (i = 0; i < n / sizeof(long); i++) { + unsigned long mask; + gfn_t offset; - memslot = id_to_memslot(slots, log->slot); - memslot->nr_dirty_pages = 0; - memslot->dirty_bitmap = dirty_bitmap_head; - update_memslots(slots, NULL); + if (!dirty_bitmap[i]) + continue; - old_slots = kvm->memslots; - rcu_assign_pointer(kvm->memslots, slots); - synchronize_srcu_expedited(&kvm->srcu); - kfree(old_slots); + is_dirty = true; - write_protect_slot(kvm, memslot, dirty_bitmap, nr_dirty_pages); + mask = xchg(&dirty_bitmap[i], 0); + dirty_bitmap_buffer[i] = mask; - r = -EFAULT; - if (copy_to_user(log->dirty_bitmap, dirty_bitmap, n)) - goto out; - } else { - r = -EFAULT; - if (clear_user(log->dirty_bitmap, n)) - goto out; + offset = i * BITS_PER_LONG; + kvm_mmu_write_protect_pt_masked(kvm, memslot, offset, mask); } + if (is_dirty) + kvm_flush_remote_tlbs(kvm); + + spin_unlock(&kvm->mmu_lock); + + r = -EFAULT; + if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n)) + goto out; r = 0; out: @@ -3728,9 +3718,8 @@ struct read_write_emulator_ops { static int read_prepare(struct kvm_vcpu *vcpu, void *val, int bytes) { if (vcpu->mmio_read_completed) { - memcpy(val, vcpu->mmio_data, bytes); trace_kvm_mmio(KVM_TRACE_MMIO_READ, bytes, - vcpu->mmio_phys_addr, *(u64 *)val); + vcpu->mmio_fragments[0].gpa, *(u64 *)val); vcpu->mmio_read_completed = 0; return 1; } @@ -3766,8 +3755,9 @@ static int read_exit_mmio(struct kvm_vcpu *vcpu, gpa_t gpa, static int write_exit_mmio(struct kvm_vcpu *vcpu, gpa_t gpa, void *val, int bytes) { - memcpy(vcpu->mmio_data, val, bytes); - memcpy(vcpu->run->mmio.data, vcpu->mmio_data, 8); + struct kvm_mmio_fragment *frag = &vcpu->mmio_fragments[0]; + + memcpy(vcpu->run->mmio.data, frag->data, frag->len); return X86EMUL_CONTINUE; } @@ -3794,10 +3784,7 @@ static int emulator_read_write_onepage(unsigned long addr, void *val, gpa_t gpa; int handled, ret; bool write = ops->write; - - if (ops->read_write_prepare && - ops->read_write_prepare(vcpu, val, bytes)) - return X86EMUL_CONTINUE; + struct kvm_mmio_fragment *frag; ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, write); @@ -3823,15 +3810,19 @@ mmio: bytes -= handled; val += handled; - vcpu->mmio_needed = 1; - vcpu->run->exit_reason = KVM_EXIT_MMIO; - vcpu->run->mmio.phys_addr = vcpu->mmio_phys_addr = gpa; - vcpu->mmio_size = bytes; - vcpu->run->mmio.len = min(vcpu->mmio_size, 8); - vcpu->run->mmio.is_write = vcpu->mmio_is_write = write; - vcpu->mmio_index = 0; + while (bytes) { + unsigned now = min(bytes, 8U); - return ops->read_write_exit_mmio(vcpu, gpa, val, bytes); + frag = &vcpu->mmio_fragments[vcpu->mmio_nr_fragments++]; + frag->gpa = gpa; + frag->data = val; + frag->len = now; + + gpa += now; + val += now; + bytes -= now; + } + return X86EMUL_CONTINUE; } int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr, @@ -3840,10 +3831,18 @@ int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr, struct read_write_emulator_ops *ops) { struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt); + gpa_t gpa; + int rc; + + if (ops->read_write_prepare && + ops->read_write_prepare(vcpu, val, bytes)) + return X86EMUL_CONTINUE; + + vcpu->mmio_nr_fragments = 0; /* Crossing a page boundary? */ if (((addr + bytes - 1) ^ addr) & PAGE_MASK) { - int rc, now; + int now; now = -addr & ~PAGE_MASK; rc = emulator_read_write_onepage(addr, val, now, exception, @@ -3856,8 +3855,25 @@ int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr, bytes -= now; } - return emulator_read_write_onepage(addr, val, bytes, exception, - vcpu, ops); + rc = emulator_read_write_onepage(addr, val, bytes, exception, + vcpu, ops); + if (rc != X86EMUL_CONTINUE) + return rc; + + if (!vcpu->mmio_nr_fragments) + return rc; + + gpa = vcpu->mmio_fragments[0].gpa; + + vcpu->mmio_needed = 1; + vcpu->mmio_cur_fragment = 0; + + vcpu->run->mmio.len = vcpu->mmio_fragments[0].len; + vcpu->run->mmio.is_write = vcpu->mmio_is_write = ops->write; + vcpu->run->exit_reason = KVM_EXIT_MMIO; + vcpu->run->mmio.phys_addr = gpa; + + return ops->read_write_exit_mmio(vcpu, gpa, val, bytes); } static int emulator_read_emulated(struct x86_emulate_ctxt *ctxt, @@ -5263,10 +5279,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_deliver_pmi(vcpu); } - r = kvm_mmu_reload(vcpu); - if (unlikely(r)) - goto out; - if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) { inject_pending_event(vcpu); @@ -5282,6 +5294,12 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) } } + r = kvm_mmu_reload(vcpu); + if (unlikely(r)) { + kvm_x86_ops->cancel_injection(vcpu); + goto out; + } + preempt_disable(); kvm_x86_ops->prepare_guest_switch(vcpu); @@ -5456,33 +5474,55 @@ static int __vcpu_run(struct kvm_vcpu *vcpu) return r; } +/* + * Implements the following, as a state machine: + * + * read: + * for each fragment + * write gpa, len + * exit + * copy data + * execute insn + * + * write: + * for each fragment + * write gpa, len + * copy data + * exit + */ static int complete_mmio(struct kvm_vcpu *vcpu) { struct kvm_run *run = vcpu->run; + struct kvm_mmio_fragment *frag; int r; if (!(vcpu->arch.pio.count || vcpu->mmio_needed)) return 1; if (vcpu->mmio_needed) { - vcpu->mmio_needed = 0; + /* Complete previous fragment */ + frag = &vcpu->mmio_fragments[vcpu->mmio_cur_fragment++]; if (!vcpu->mmio_is_write) - memcpy(vcpu->mmio_data + vcpu->mmio_index, - run->mmio.data, 8); - vcpu->mmio_index += 8; - if (vcpu->mmio_index < vcpu->mmio_size) { - run->exit_reason = KVM_EXIT_MMIO; - run->mmio.phys_addr = vcpu->mmio_phys_addr + vcpu->mmio_index; - memcpy(run->mmio.data, vcpu->mmio_data + vcpu->mmio_index, 8); - run->mmio.len = min(vcpu->mmio_size - vcpu->mmio_index, 8); - run->mmio.is_write = vcpu->mmio_is_write; - vcpu->mmio_needed = 1; - return 0; + memcpy(frag->data, run->mmio.data, frag->len); + if (vcpu->mmio_cur_fragment == vcpu->mmio_nr_fragments) { + vcpu->mmio_needed = 0; + if (vcpu->mmio_is_write) + return 1; + vcpu->mmio_read_completed = 1; + goto done; } + /* Initiate next fragment */ + ++frag; + run->exit_reason = KVM_EXIT_MMIO; + run->mmio.phys_addr = frag->gpa; if (vcpu->mmio_is_write) - return 1; - vcpu->mmio_read_completed = 1; + memcpy(run->mmio.data, frag->data, frag->len); + run->mmio.len = frag->len; + run->mmio.is_write = vcpu->mmio_is_write; + return 0; + } +done: vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); r = emulate_instruction(vcpu, EMULTYPE_NO_DECODE); srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); @@ -6399,21 +6439,9 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu) kvm_cpu_has_interrupt(vcpu)); } -void kvm_vcpu_kick(struct kvm_vcpu *vcpu) +int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) { - int me; - int cpu = vcpu->cpu; - - if (waitqueue_active(&vcpu->wq)) { - wake_up_interruptible(&vcpu->wq); - ++vcpu->stat.halt_wakeup; - } - - me = get_cpu(); - if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) - if (kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE) - smp_send_reschedule(cpu); - put_cpu(); + return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE; } int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu) |