KVM: In-kernel I/O APIC model
This allows in-kernel host-side device drivers to raise guest interrupts
without going to userspace.
[avi: fix level-triggered interrupt redelivery on eoi]
[avi: add missing #include]
[avi: avoid redelivery of edge-triggered interrupt]
[avi: implement polarity]
[avi: don't deliver edge-triggered interrupts when unmasking]
[avi: fix host oops on invalid guest access]
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/ioapic.c b/drivers/kvm/ioapic.c
new file mode 100644
index 0000000..c7992e6
--- /dev/null
+++ b/drivers/kvm/ioapic.c
@@ -0,0 +1,388 @@
+/*
+ * Copyright (C) 2001 MandrakeSoft S.A.
+ *
+ * MandrakeSoft S.A.
+ * 43, rue d'Aboukir
+ * 75002 Paris - France
+ * http://www.linux-mandrake.com/
+ * http://www.mandrakesoft.com/
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Yunhong Jiang <yunhong.jiang@intel.com>
+ * Yaozu (Eddie) Dong <eddie.dong@intel.com>
+ * Based on Xen 3.1 code.
+ */
+
+#include "kvm.h"
+#include <linux/kvm.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/smp.h>
+#include <linux/hrtimer.h>
+#include <linux/io.h>
+#include <asm/processor.h>
+#include <asm/msr.h>
+#include <asm/page.h>
+#include <asm/current.h>
+#include <asm/apicdef.h>
+#include <asm/io_apic.h>
+#include "irq.h"
+/* #define ioapic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg) */
+#define ioapic_debug(fmt, arg...)
+static void ioapic_deliver(struct kvm_ioapic *vioapic, int irq);
+
+static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
+ unsigned long addr,
+ unsigned long length)
+{
+ unsigned long result = 0;
+
+ switch (ioapic->ioregsel) {
+ case IOAPIC_REG_VERSION:
+ result = ((((IOAPIC_NUM_PINS - 1) & 0xff) << 16)
+ | (IOAPIC_VERSION_ID & 0xff));
+ break;
+
+ case IOAPIC_REG_APIC_ID:
+ case IOAPIC_REG_ARB_ID:
+ result = ((ioapic->id & 0xf) << 24);
+ break;
+
+ default:
+ {
+ u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
+ u64 redir_content;
+
+ ASSERT(redir_index < IOAPIC_NUM_PINS);
+
+ redir_content = ioapic->redirtbl[redir_index].bits;
+ result = (ioapic->ioregsel & 0x1) ?
+ (redir_content >> 32) & 0xffffffff :
+ redir_content & 0xffffffff;
+ break;
+ }
+ }
+
+ return result;
+}
+
+static void ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx)
+{
+ union ioapic_redir_entry *pent;
+
+ pent = &ioapic->redirtbl[idx];
+
+ if (!pent->fields.mask) {
+ ioapic_deliver(ioapic, idx);
+ if (pent->fields.trig_mode == IOAPIC_LEVEL_TRIG)
+ pent->fields.remote_irr = 1;
+ }
+ if (!pent->fields.trig_mode)
+ ioapic->irr &= ~(1 << idx);
+}
+
+static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
+{
+ unsigned index;
+
+ switch (ioapic->ioregsel) {
+ case IOAPIC_REG_VERSION:
+ /* Writes are ignored. */
+ break;
+
+ case IOAPIC_REG_APIC_ID:
+ ioapic->id = (val >> 24) & 0xf;
+ break;
+
+ case IOAPIC_REG_ARB_ID:
+ break;
+
+ default:
+ index = (ioapic->ioregsel - 0x10) >> 1;
+
+ ioapic_debug("change redir index %x val %x", index, val);
+ if (index >= IOAPIC_NUM_PINS)
+ return;
+ if (ioapic->ioregsel & 1) {
+ ioapic->redirtbl[index].bits &= 0xffffffff;
+ ioapic->redirtbl[index].bits |= (u64) val << 32;
+ } else {
+ ioapic->redirtbl[index].bits &= ~0xffffffffULL;
+ ioapic->redirtbl[index].bits |= (u32) val;
+ ioapic->redirtbl[index].fields.remote_irr = 0;
+ }
+ if (ioapic->irr & (1 << index))
+ ioapic_service(ioapic, index);
+ break;
+ }
+}
+
+static void ioapic_inj_irq(struct kvm_ioapic *ioapic,
+ struct kvm_lapic *target,
+ u8 vector, u8 trig_mode, u8 delivery_mode)
+{
+ ioapic_debug("irq %d trig %d deliv %d", vector, trig_mode,
+ delivery_mode);
+
+ ASSERT((delivery_mode == dest_Fixed) ||
+ (delivery_mode == dest_LowestPrio));
+
+ kvm_apic_set_irq(target, vector, trig_mode);
+}
+
+static u32 ioapic_get_delivery_bitmask(struct kvm_ioapic *ioapic, u8 dest,
+ u8 dest_mode)
+{
+ u32 mask = 0;
+ int i;
+ struct kvm *kvm = ioapic->kvm;
+ struct kvm_vcpu *vcpu;
+
+ ioapic_debug("dest %d dest_mode %d", dest, dest_mode);
+
+ if (dest_mode == 0) { /* Physical mode. */
+ if (dest == 0xFF) { /* Broadcast. */
+ for (i = 0; i < KVM_MAX_VCPUS; ++i)
+ if (kvm->vcpus[i] && kvm->vcpus[i]->apic)
+ mask |= 1 << i;
+ return mask;
+ }
+ for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+ vcpu = kvm->vcpus[i];
+ if (!vcpu)
+ continue;
+ if (kvm_apic_match_physical_addr(vcpu->apic, dest)) {
+ if (vcpu->apic)
+ mask = 1 << i;
+ break;
+ }
+ }
+ } else if (dest != 0) /* Logical mode, MDA non-zero. */
+ for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+ vcpu = kvm->vcpus[i];
+ if (!vcpu)
+ continue;
+ if (vcpu->apic &&
+ kvm_apic_match_logical_addr(vcpu->apic, dest))
+ mask |= 1 << vcpu->vcpu_id;
+ }
+ ioapic_debug("mask %x", mask);
+ return mask;
+}
+
+static void ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
+{
+ u8 dest = ioapic->redirtbl[irq].fields.dest_id;
+ u8 dest_mode = ioapic->redirtbl[irq].fields.dest_mode;
+ u8 delivery_mode = ioapic->redirtbl[irq].fields.delivery_mode;
+ u8 vector = ioapic->redirtbl[irq].fields.vector;
+ u8 trig_mode = ioapic->redirtbl[irq].fields.trig_mode;
+ u32 deliver_bitmask;
+ struct kvm_lapic *target;
+ struct kvm_vcpu *vcpu;
+ int vcpu_id;
+
+ ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x "
+ "vector=%x trig_mode=%x",
+ dest, dest_mode, delivery_mode, vector, trig_mode);
+
+ deliver_bitmask = ioapic_get_delivery_bitmask(ioapic, dest, dest_mode);
+ if (!deliver_bitmask) {
+ ioapic_debug("no target on destination");
+ return;
+ }
+
+ switch (delivery_mode) {
+ case dest_LowestPrio:
+ target =
+ kvm_apic_round_robin(ioapic->kvm, vector, deliver_bitmask);
+ if (target != NULL)
+ ioapic_inj_irq(ioapic, target, vector,
+ trig_mode, delivery_mode);
+ else
+ ioapic_debug("null round robin: "
+ "mask=%x vector=%x delivery_mode=%x",
+ deliver_bitmask, vector, dest_LowestPrio);
+ break;
+ case dest_Fixed:
+ for (vcpu_id = 0; deliver_bitmask != 0; vcpu_id++) {
+ if (!(deliver_bitmask & (1 << vcpu_id)))
+ continue;
+ deliver_bitmask &= ~(1 << vcpu_id);
+ vcpu = ioapic->kvm->vcpus[vcpu_id];
+ if (vcpu) {
+ target = vcpu->apic;
+ ioapic_inj_irq(ioapic, target, vector,
+ trig_mode, delivery_mode);
+ }
+ }
+ break;
+
+ /* TODO: NMI */
+ default:
+ printk(KERN_WARNING "Unsupported delivery mode %d\n",
+ delivery_mode);
+ break;
+ }
+}
+
+void kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level)
+{
+ u32 old_irr = ioapic->irr;
+ u32 mask = 1 << irq;
+ union ioapic_redir_entry entry;
+
+ if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
+ entry = ioapic->redirtbl[irq];
+ level ^= entry.fields.polarity;
+ if (!level)
+ ioapic->irr &= ~mask;
+ else {
+ ioapic->irr |= mask;
+ if ((!entry.fields.trig_mode && old_irr != ioapic->irr)
+ || !entry.fields.remote_irr)
+ ioapic_service(ioapic, irq);
+ }
+ }
+}
+
+static int get_eoi_gsi(struct kvm_ioapic *ioapic, int vector)
+{
+ int i;
+
+ for (i = 0; i < IOAPIC_NUM_PINS; i++)
+ if (ioapic->redirtbl[i].fields.vector == vector)
+ return i;
+ return -1;
+}
+
+void kvm_ioapic_update_eoi(struct kvm *kvm, int vector)
+{
+ struct kvm_ioapic *ioapic = kvm->vioapic;
+ union ioapic_redir_entry *ent;
+ int gsi;
+
+ gsi = get_eoi_gsi(ioapic, vector);
+ if (gsi == -1) {
+ printk(KERN_WARNING "Can't find redir item for %d EOI\n",
+ vector);
+ return;
+ }
+
+ ent = &ioapic->redirtbl[gsi];
+ ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
+
+ ent->fields.remote_irr = 0;
+ if (!ent->fields.mask && (ioapic->irr & (1 << gsi)))
+ ioapic_deliver(ioapic, gsi);
+}
+
+static int ioapic_in_range(struct kvm_io_device *this, gpa_t addr)
+{
+ struct kvm_ioapic *ioapic = (struct kvm_ioapic *)this->private;
+
+ return ((addr >= ioapic->base_address &&
+ (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
+}
+
+static void ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
+ void *val)
+{
+ struct kvm_ioapic *ioapic = (struct kvm_ioapic *)this->private;
+ u32 result;
+
+ ioapic_debug("addr %lx", (unsigned long)addr);
+ ASSERT(!(addr & 0xf)); /* check alignment */
+
+ addr &= 0xff;
+ switch (addr) {
+ case IOAPIC_REG_SELECT:
+ result = ioapic->ioregsel;
+ break;
+
+ case IOAPIC_REG_WINDOW:
+ result = ioapic_read_indirect(ioapic, addr, len);
+ break;
+
+ default:
+ result = 0;
+ break;
+ }
+ switch (len) {
+ case 8:
+ *(u64 *) val = result;
+ break;
+ case 1:
+ case 2:
+ case 4:
+ memcpy(val, (char *)&result, len);
+ break;
+ default:
+ printk(KERN_WARNING "ioapic: wrong length %d\n", len);
+ }
+}
+
+static void ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
+ const void *val)
+{
+ struct kvm_ioapic *ioapic = (struct kvm_ioapic *)this->private;
+ u32 data;
+
+ ioapic_debug("ioapic_mmio_write addr=%lx len=%d val=%p\n",
+ addr, len, val);
+ ASSERT(!(addr & 0xf)); /* check alignment */
+ if (len == 4 || len == 8)
+ data = *(u32 *) val;
+ else {
+ printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
+ return;
+ }
+
+ addr &= 0xff;
+ switch (addr) {
+ case IOAPIC_REG_SELECT:
+ ioapic->ioregsel = data;
+ break;
+
+ case IOAPIC_REG_WINDOW:
+ ioapic_write_indirect(ioapic, data);
+ break;
+
+ default:
+ break;
+ }
+}
+
+int kvm_ioapic_init(struct kvm *kvm)
+{
+ struct kvm_ioapic *ioapic;
+ int i;
+
+ ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
+ if (!ioapic)
+ return -ENOMEM;
+ kvm->vioapic = ioapic;
+ for (i = 0; i < IOAPIC_NUM_PINS; i++)
+ ioapic->redirtbl[i].fields.mask = 1;
+ ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
+ ioapic->dev.read = ioapic_mmio_read;
+ ioapic->dev.write = ioapic_mmio_write;
+ ioapic->dev.in_range = ioapic_in_range;
+ ioapic->dev.private = ioapic;
+ ioapic->kvm = kvm;
+ kvm_io_bus_register_dev(&kvm->mmio_bus, &ioapic->dev);
+ return 0;
+}