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:
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)
{
r = vcpu->arch.virtual_tsc_khz;
goto out;
}
+ case KVM_KVMCLOCK_CTRL: {
+ r = kvm_set_guest_paused(vcpu);
+ goto out;
+ }
default:
r = -EINVAL;
}
}
/**
- * 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);
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:
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;
}
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;
}
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);
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,
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,
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,
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);
}
}
+ 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);
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);
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)
projects / ~andy / linux / blobdiff