--- /dev/null
+/*
+ * 8259 interrupt controller emulation
+ *
+ * Copyright (c) 2003-2004 Fabrice Bellard
+ * Copyright (c) 2007 Intel Corporation
+ * Copyright 2009 Red Hat, Inc. and/or its affiliates.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ * Authors:
+ * Yaozu (Eddie) Dong <Eddie.dong@intel.com>
+ * Port from Qemu.
+ */
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include "irq.h"
+
+#include <linux/kvm_host.h>
+#include "trace.h"
+
+#define pr_pic_unimpl(fmt, ...) \
+ pr_err_ratelimited("kvm: pic: " fmt, ## __VA_ARGS__)
+
+static void pic_irq_request(struct kvm *kvm, int level);
+
+static void pic_lock(struct kvm_pic *s)
+ __acquires(&s->lock)
+{
+ spin_lock(&s->lock);
+}
+
+static void pic_unlock(struct kvm_pic *s)
+ __releases(&s->lock)
+{
+ bool wakeup = s->wakeup_needed;
+ struct kvm_vcpu *vcpu, *found = NULL;
+ int i;
+
+ s->wakeup_needed = false;
+
+ spin_unlock(&s->lock);
+
+ if (wakeup) {
+ kvm_for_each_vcpu(i, vcpu, s->kvm) {
+ if (kvm_apic_accept_pic_intr(vcpu)) {
+ found = vcpu;
+ break;
+ }
+ }
+
+ if (!found)
+ return;
+
+ kvm_make_request(KVM_REQ_EVENT, found);
+ kvm_vcpu_kick(found);
+ }
+}
+
+static void pic_clear_isr(struct kvm_kpic_state *s, int irq)
+{
+ s->isr &= ~(1 << irq);
+ if (s != &s->pics_state->pics[0])
+ irq += 8;
+ /*
+ * We are dropping lock while calling ack notifiers since ack
+ * notifier callbacks for assigned devices call into PIC recursively.
+ * Other interrupt may be delivered to PIC while lock is dropped but
+ * it should be safe since PIC state is already updated at this stage.
+ */
+ pic_unlock(s->pics_state);
+ kvm_notify_acked_irq(s->pics_state->kvm, SELECT_PIC(irq), irq);
+ pic_lock(s->pics_state);
+}
+
+/*
+ * set irq level. If an edge is detected, then the IRR is set to 1
+ */
+static inline int pic_set_irq1(struct kvm_kpic_state *s, int irq, int level)
+{
+ int mask, ret = 1;
+ mask = 1 << irq;
+ if (s->elcr & mask) /* level triggered */
+ if (level) {
+ ret = !(s->irr & mask);
+ s->irr |= mask;
+ s->last_irr |= mask;
+ } else {
+ s->irr &= ~mask;
+ s->last_irr &= ~mask;
+ }
+ else /* edge triggered */
+ if (level) {
+ if ((s->last_irr & mask) == 0) {
+ ret = !(s->irr & mask);
+ s->irr |= mask;
+ }
+ s->last_irr |= mask;
+ } else
+ s->last_irr &= ~mask;
+
+ return (s->imr & mask) ? -1 : ret;
+}
+
+/*
+ * return the highest priority found in mask (highest = smallest
+ * number). Return 8 if no irq
+ */
+static inline int get_priority(struct kvm_kpic_state *s, int mask)
+{
+ int priority;
+ if (mask == 0)
+ return 8;
+ priority = 0;
+ while ((mask & (1 << ((priority + s->priority_add) & 7))) == 0)
+ priority++;
+ return priority;
+}
+
+/*
+ * return the pic wanted interrupt. return -1 if none
+ */
+static int pic_get_irq(struct kvm_kpic_state *s)
+{
+ int mask, cur_priority, priority;
+
+ mask = s->irr & ~s->imr;
+ priority = get_priority(s, mask);
+ if (priority == 8)
+ return -1;
+ /*
+ * compute current priority. If special fully nested mode on the
+ * master, the IRQ coming from the slave is not taken into account
+ * for the priority computation.
+ */
+ mask = s->isr;
+ if (s->special_fully_nested_mode && s == &s->pics_state->pics[0])
+ mask &= ~(1 << 2);
+ cur_priority = get_priority(s, mask);
+ if (priority < cur_priority)
+ /*
+ * higher priority found: an irq should be generated
+ */
+ return (priority + s->priority_add) & 7;
+ else
+ return -1;
+}
+
+/*
+ * raise irq to CPU if necessary. must be called every time the active
+ * irq may change
+ */
+static void pic_update_irq(struct kvm_pic *s)
+{
+ int irq2, irq;
+
+ irq2 = pic_get_irq(&s->pics[1]);
+ if (irq2 >= 0) {
+ /*
+ * if irq request by slave pic, signal master PIC
+ */
+ pic_set_irq1(&s->pics[0], 2, 1);
+ pic_set_irq1(&s->pics[0], 2, 0);
+ }
+ irq = pic_get_irq(&s->pics[0]);
+ pic_irq_request(s->kvm, irq >= 0);
+}
+
+void kvm_pic_update_irq(struct kvm_pic *s)
+{
+ pic_lock(s);
+ pic_update_irq(s);
+ pic_unlock(s);
+}
+
+int kvm_pic_set_irq(struct kvm_pic *s, int irq, int irq_source_id, int level)
+{
+ int ret, irq_level;
+
+ BUG_ON(irq < 0 || irq >= PIC_NUM_PINS);
+
+ pic_lock(s);
+ irq_level = __kvm_irq_line_state(&s->irq_states[irq],
+ irq_source_id, level);
+ ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
+ pic_update_irq(s);
+ trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
+ s->pics[irq >> 3].imr, ret == 0);
+ pic_unlock(s);
+
+ return ret;
+}
+
+void kvm_pic_clear_all(struct kvm_pic *s, int irq_source_id)
+{
+ int i;
+
+ pic_lock(s);
+ for (i = 0; i < PIC_NUM_PINS; i++)
+ __clear_bit(irq_source_id, &s->irq_states[i]);
+ pic_unlock(s);
+}
+
+/*
+ * acknowledge interrupt 'irq'
+ */
+static inline void pic_intack(struct kvm_kpic_state *s, int irq)
+{
+ s->isr |= 1 << irq;
+ /*
+ * We don't clear a level sensitive interrupt here
+ */
+ if (!(s->elcr & (1 << irq)))
+ s->irr &= ~(1 << irq);
+
+ if (s->auto_eoi) {
+ if (s->rotate_on_auto_eoi)
+ s->priority_add = (irq + 1) & 7;
+ pic_clear_isr(s, irq);
+ }
+
+}
+
+int kvm_pic_read_irq(struct kvm *kvm)
+{
+ int irq, irq2, intno;
+ struct kvm_pic *s = pic_irqchip(kvm);
+
+ s->output = 0;
+
+ pic_lock(s);
+ irq = pic_get_irq(&s->pics[0]);
+ if (irq >= 0) {
+ pic_intack(&s->pics[0], irq);
+ if (irq == 2) {
+ irq2 = pic_get_irq(&s->pics[1]);
+ if (irq2 >= 0)
+ pic_intack(&s->pics[1], irq2);
+ else
+ /*
+ * spurious IRQ on slave controller
+ */
+ irq2 = 7;
+ intno = s->pics[1].irq_base + irq2;
+ irq = irq2 + 8;
+ } else
+ intno = s->pics[0].irq_base + irq;
+ } else {
+ /*
+ * spurious IRQ on host controller
+ */
+ irq = 7;
+ intno = s->pics[0].irq_base + irq;
+ }
+ pic_update_irq(s);
+ pic_unlock(s);
+
+ return intno;
+}
+
+void kvm_pic_reset(struct kvm_kpic_state *s)
+{
+ int irq, i;
+ struct kvm_vcpu *vcpu;
+ u8 edge_irr = s->irr & ~s->elcr;
+ bool found = false;
+
+ s->last_irr = 0;
+ s->irr &= s->elcr;
+ s->imr = 0;
+ s->priority_add = 0;
+ s->special_mask = 0;
+ s->read_reg_select = 0;
+ if (!s->init4) {
+ s->special_fully_nested_mode = 0;
+ s->auto_eoi = 0;
+ }
+ s->init_state = 1;
+
+ kvm_for_each_vcpu(i, vcpu, s->pics_state->kvm)
+ if (kvm_apic_accept_pic_intr(vcpu)) {
+ found = true;
+ break;
+ }
+
+
+ if (!found)
+ return;
+
+ for (irq = 0; irq < PIC_NUM_PINS/2; irq++)
+ if (edge_irr & (1 << irq))
+ pic_clear_isr(s, irq);
+}
+
+static void pic_ioport_write(void *opaque, u32 addr, u32 val)
+{
+ struct kvm_kpic_state *s = opaque;
+ int priority, cmd, irq;
+
+ addr &= 1;
+ if (addr == 0) {
+ if (val & 0x10) {
+ s->init4 = val & 1;
+ if (val & 0x02)
+ pr_pic_unimpl("single mode not supported");
+ if (val & 0x08)
+ pr_pic_unimpl(
+ "level sensitive irq not supported");
+ kvm_pic_reset(s);
+ } else if (val & 0x08) {
+ if (val & 0x04)
+ s->poll = 1;
+ if (val & 0x02)
+ s->read_reg_select = val & 1;
+ if (val & 0x40)
+ s->special_mask = (val >> 5) & 1;
+ } else {
+ cmd = val >> 5;
+ switch (cmd) {
+ case 0:
+ case 4:
+ s->rotate_on_auto_eoi = cmd >> 2;
+ break;
+ case 1: /* end of interrupt */
+ case 5:
+ priority = get_priority(s, s->isr);
+ if (priority != 8) {
+ irq = (priority + s->priority_add) & 7;
+ if (cmd == 5)
+ s->priority_add = (irq + 1) & 7;
+ pic_clear_isr(s, irq);
+ pic_update_irq(s->pics_state);
+ }
+ break;
+ case 3:
+ irq = val & 7;
+ pic_clear_isr(s, irq);
+ pic_update_irq(s->pics_state);
+ break;
+ case 6:
+ s->priority_add = (val + 1) & 7;
+ pic_update_irq(s->pics_state);
+ break;
+ case 7:
+ irq = val & 7;
+ s->priority_add = (irq + 1) & 7;
+ pic_clear_isr(s, irq);
+ pic_update_irq(s->pics_state);
+ break;
+ default:
+ break; /* no operation */
+ }
+ }
+ } else
+ switch (s->init_state) {
+ case 0: { /* normal mode */
+ u8 imr_diff = s->imr ^ val,
+ off = (s == &s->pics_state->pics[0]) ? 0 : 8;
+ s->imr = val;
+ for (irq = 0; irq < PIC_NUM_PINS/2; irq++)
+ if (imr_diff & (1 << irq))
+ kvm_fire_mask_notifiers(
+ s->pics_state->kvm,
+ SELECT_PIC(irq + off),
+ irq + off,
+ !!(s->imr & (1 << irq)));
+ pic_update_irq(s->pics_state);
+ break;
+ }
+ case 1:
+ s->irq_base = val & 0xf8;
+ s->init_state = 2;
+ break;
+ case 2:
+ if (s->init4)
+ s->init_state = 3;
+ else
+ s->init_state = 0;
+ break;
+ case 3:
+ s->special_fully_nested_mode = (val >> 4) & 1;
+ s->auto_eoi = (val >> 1) & 1;
+ s->init_state = 0;
+ break;
+ }
+}
+
+static u32 pic_poll_read(struct kvm_kpic_state *s, u32 addr1)
+{
+ int ret;
+
+ ret = pic_get_irq(s);
+ if (ret >= 0) {
+ if (addr1 >> 7) {
+ s->pics_state->pics[0].isr &= ~(1 << 2);
+ s->pics_state->pics[0].irr &= ~(1 << 2);
+ }
+ s->irr &= ~(1 << ret);
+ pic_clear_isr(s, ret);
+ if (addr1 >> 7 || ret != 2)
+ pic_update_irq(s->pics_state);
+ } else {
+ ret = 0x07;
+ pic_update_irq(s->pics_state);
+ }
+
+ return ret;
+}
+
+static u32 pic_ioport_read(void *opaque, u32 addr1)
+{
+ struct kvm_kpic_state *s = opaque;
+ unsigned int addr;
+ int ret;
+
+ addr = addr1;
+ addr &= 1;
+ if (s->poll) {
+ ret = pic_poll_read(s, addr1);
+ s->poll = 0;
+ } else
+ if (addr == 0)
+ if (s->read_reg_select)
+ ret = s->isr;
+ else
+ ret = s->irr;
+ else
+ ret = s->imr;
+ return ret;
+}
+
+static void elcr_ioport_write(void *opaque, u32 addr, u32 val)
+{
+ struct kvm_kpic_state *s = opaque;
+ s->elcr = val & s->elcr_mask;
+}
+
+static u32 elcr_ioport_read(void *opaque, u32 addr1)
+{
+ struct kvm_kpic_state *s = opaque;
+ return s->elcr;
+}
+
+static int picdev_in_range(gpa_t addr)
+{
+ switch (addr) {
+ case 0x20:
+ case 0x21:
+ case 0xa0:
+ case 0xa1:
+ case 0x4d0:
+ case 0x4d1:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+static int picdev_write(struct kvm_pic *s,
+ gpa_t addr, int len, const void *val)
+{
+ unsigned char data = *(unsigned char *)val;
+ if (!picdev_in_range(addr))
+ return -EOPNOTSUPP;
+
+ if (len != 1) {
+ pr_pic_unimpl("non byte write\n");
+ return 0;
+ }
+ pic_lock(s);
+ switch (addr) {
+ case 0x20:
+ case 0x21:
+ case 0xa0:
+ case 0xa1:
+ pic_ioport_write(&s->pics[addr >> 7], addr, data);
+ break;
+ case 0x4d0:
+ case 0x4d1:
+ elcr_ioport_write(&s->pics[addr & 1], addr, data);
+ break;
+ }
+ pic_unlock(s);
+ return 0;
+}
+
+static int picdev_read(struct kvm_pic *s,
+ gpa_t addr, int len, void *val)
+{
+ unsigned char data = 0;
+ if (!picdev_in_range(addr))
+ return -EOPNOTSUPP;
+
+ if (len != 1) {
+ memset(val, 0, len);
+ pr_pic_unimpl("non byte read\n");
+ return 0;
+ }
+ pic_lock(s);
+ switch (addr) {
+ case 0x20:
+ case 0x21:
+ case 0xa0:
+ case 0xa1:
+ data = pic_ioport_read(&s->pics[addr >> 7], addr);
+ break;
+ case 0x4d0:
+ case 0x4d1:
+ data = elcr_ioport_read(&s->pics[addr & 1], addr);
+ break;
+ }
+ *(unsigned char *)val = data;
+ pic_unlock(s);
+ return 0;
+}
+
+static int picdev_master_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+ gpa_t addr, int len, const void *val)
+{
+ return picdev_write(container_of(dev, struct kvm_pic, dev_master),
+ addr, len, val);
+}
+
+static int picdev_master_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+ gpa_t addr, int len, void *val)
+{
+ return picdev_read(container_of(dev, struct kvm_pic, dev_master),
+ addr, len, val);
+}
+
+static int picdev_slave_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+ gpa_t addr, int len, const void *val)
+{
+ return picdev_write(container_of(dev, struct kvm_pic, dev_slave),
+ addr, len, val);
+}
+
+static int picdev_slave_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+ gpa_t addr, int len, void *val)
+{
+ return picdev_read(container_of(dev, struct kvm_pic, dev_slave),
+ addr, len, val);
+}
+
+static int picdev_eclr_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+ gpa_t addr, int len, const void *val)
+{
+ return picdev_write(container_of(dev, struct kvm_pic, dev_eclr),
+ addr, len, val);
+}
+
+static int picdev_eclr_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+ gpa_t addr, int len, void *val)
+{
+ return picdev_read(container_of(dev, struct kvm_pic, dev_eclr),
+ addr, len, val);
+}
+
+/*
+ * callback when PIC0 irq status changed
+ */
+static void pic_irq_request(struct kvm *kvm, int level)
+{
+ struct kvm_pic *s = pic_irqchip(kvm);
+
+ if (!s->output)
+ s->wakeup_needed = true;
+ s->output = level;
+}
+
+static const struct kvm_io_device_ops picdev_master_ops = {
+ .read = picdev_master_read,
+ .write = picdev_master_write,
+};
+
+static const struct kvm_io_device_ops picdev_slave_ops = {
+ .read = picdev_slave_read,
+ .write = picdev_slave_write,
+};
+
+static const struct kvm_io_device_ops picdev_eclr_ops = {
+ .read = picdev_eclr_read,
+ .write = picdev_eclr_write,
+};
+
+struct kvm_pic *kvm_create_pic(struct kvm *kvm)
+{
+ struct kvm_pic *s;
+ int ret;
+
+ s = kzalloc(sizeof(struct kvm_pic), GFP_KERNEL);
+ if (!s)
+ return NULL;
+ spin_lock_init(&s->lock);
+ s->kvm = kvm;
+ s->pics[0].elcr_mask = 0xf8;
+ s->pics[1].elcr_mask = 0xde;
+ s->pics[0].pics_state = s;
+ s->pics[1].pics_state = s;
+
+ /*
+ * Initialize PIO device
+ */
+ kvm_iodevice_init(&s->dev_master, &picdev_master_ops);
+ kvm_iodevice_init(&s->dev_slave, &picdev_slave_ops);
+ kvm_iodevice_init(&s->dev_eclr, &picdev_eclr_ops);
+ mutex_lock(&kvm->slots_lock);
+ ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, 0x20, 2,
+ &s->dev_master);
+ if (ret < 0)
+ goto fail_unlock;
+
+ ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, 0xa0, 2, &s->dev_slave);
+ if (ret < 0)
+ goto fail_unreg_2;
+
+ ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, 0x4d0, 2, &s->dev_eclr);
+ if (ret < 0)
+ goto fail_unreg_1;
+
+ mutex_unlock(&kvm->slots_lock);
+
+ return s;
+
+fail_unreg_1:
+ kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &s->dev_slave);
+
+fail_unreg_2:
+ kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &s->dev_master);
+
+fail_unlock:
+ mutex_unlock(&kvm->slots_lock);
+
+ kfree(s);
+
+ return NULL;
+}
+
+void kvm_destroy_pic(struct kvm *kvm)
+{
+ struct kvm_pic *vpic = kvm->arch.vpic;
+
+ if (vpic) {
+ kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &vpic->dev_master);
+ kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &vpic->dev_slave);
+ kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &vpic->dev_eclr);
+ kvm->arch.vpic = NULL;
+ kfree(vpic);
+ }
+}
Code Review / kvmfornfv.git / blobdiff