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>

6 files changed, 458 insertions, 8 deletions

diff --git a/drivers/kvm/Makefile b/drivers/kvm/Makefile
index 3bf7276b032d..e5a8f4d3e973 100644
--- a/drivers/kvm/Makefile
+++ b/drivers/kvm/Makefile
@@ -2,7 +2,7 @@
 # Makefile for Kernel-based Virtual Machine module
 #
 
-kvm-objs := kvm_main.o mmu.o x86_emulate.o i8259.o irq.o lapic.o
+kvm-objs := kvm_main.o mmu.o x86_emulate.o i8259.o irq.o lapic.o ioapic.o
 obj-$(CONFIG_KVM) += kvm.o
 kvm-intel-objs = vmx.o
 obj-$(CONFIG_KVM_INTEL) += kvm-intel.o
diff --git a/drivers/kvm/ioapic.c b/drivers/kvm/ioapic.c
new file mode 100644
index 000000000000..c7992e667fdb
--- /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;
+}
diff --git a/drivers/kvm/irq.c b/drivers/kvm/irq.c
index 0b4430a0cae0..5265f8267b3b 100644
--- a/drivers/kvm/irq.c
+++ b/drivers/kvm/irq.c
@@ -74,7 +74,3 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
                 smp_call_function_single(ipi_pcpu, vcpu_kick_intr, vcpu, 0, 0);
 }
 
-void kvm_ioapic_update_eoi(struct kvm *kvm, int vector)
-{
-        /* TODO: for kernel IOAPIC */
-}
diff --git a/drivers/kvm/irq.h b/drivers/kvm/irq.h
index 57e23bdac530..6ed856a41e23 100644
--- a/drivers/kvm/irq.h
+++ b/drivers/kvm/irq.h
@@ -60,6 +60,50 @@ int kvm_pic_read_irq(struct kvm_pic *s);
 int kvm_cpu_get_interrupt(struct kvm_vcpu *v);
 int kvm_cpu_has_interrupt(struct kvm_vcpu *v);
 
+#define IOAPIC_NUM_PINS  24
+#define IOAPIC_VERSION_ID 0x11  /* IOAPIC version */
+#define IOAPIC_EDGE_TRIG  0
+#define IOAPIC_LEVEL_TRIG 1
+
+#define IOAPIC_DEFAULT_BASE_ADDRESS  0xfec00000
+#define IOAPIC_MEM_LENGTH            0x100
+
+/* Direct registers. */
+#define IOAPIC_REG_SELECT  0x00
+#define IOAPIC_REG_WINDOW  0x10
+#define IOAPIC_REG_EOI     0x40 /* IA64 IOSAPIC only */
+
+/* Indirect registers. */
+#define IOAPIC_REG_APIC_ID 0x00 /* x86 IOAPIC only */
+#define IOAPIC_REG_VERSION 0x01
+#define IOAPIC_REG_ARB_ID  0x02 /* x86 IOAPIC only */
+
+struct kvm_ioapic {
+        u64 base_address;
+        u32 ioregsel;
+        u32 id;
+        u32 irr;
+        u32 pad;
+        union ioapic_redir_entry {
+                u64 bits;
+                struct {
+                        u8 vector;
+                        u8 delivery_mode:3;
+                        u8 dest_mode:1;
+                        u8 delivery_status:1;
+                        u8 polarity:1;
+                        u8 remote_irr:1;
+                        u8 trig_mode:1;
+                        u8 mask:1;
+                        u8 reserve:7;
+                        u8 reserved[4];
+                        u8 dest_id;
+                } fields;
+        } redirtbl[IOAPIC_NUM_PINS];
+        struct kvm_io_device dev;
+        struct kvm *kvm;
+};
+
 struct kvm_lapic {
         unsigned long base_address;
         struct kvm_io_device dev;
@@ -96,8 +140,15 @@ void kvm_free_apic(struct kvm_lapic *apic);
 u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu);
 void kvm_lapic_set_tpr(struct kvm_vcpu *vcpu, unsigned long cr8);
 void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value);
+struct kvm_lapic *kvm_apic_round_robin(struct kvm *kvm, u8 vector,
+                                       unsigned long bitmap);
 u64 kvm_get_apic_base(struct kvm_vcpu *vcpu);
 void kvm_set_apic_base(struct kvm_vcpu *vcpu, u64 data);
+int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u16 dest);
 void kvm_ioapic_update_eoi(struct kvm *kvm, int vector);
+int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda);
+int kvm_apic_set_irq(struct kvm_lapic *apic, u8 vec, u8 trig);
+int kvm_ioapic_init(struct kvm *kvm);
+void kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level);
 
 #endif
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index a5790cb21ffc..8d07a993af94 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -410,6 +410,7 @@ struct kvm {
         struct kvm_io_bus mmio_bus;
         struct kvm_io_bus pio_bus;
         struct kvm_pic *vpic;
+        struct kvm_ioapic *vioapic;
 };
 
 static inline struct kvm_pic *pic_irqchip(struct kvm *kvm)
@@ -417,6 +418,11 @@ static inline struct kvm_pic *pic_irqchip(struct kvm *kvm)
         return kvm->vpic;
 }
 
+static inline struct kvm_ioapic *ioapic_irqchip(struct kvm *kvm)
+{
+        return kvm->vioapic;
+}
+
 static inline int irqchip_in_kernel(struct kvm *kvm)
 {
         return pic_irqchip(kvm) != 0;
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 401e3cdc4607..ffbdadd87971 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -381,6 +381,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
         kvm_io_bus_destroy(&kvm->pio_bus);
         kvm_io_bus_destroy(&kvm->mmio_bus);
         kfree(kvm->vpic);
+        kfree(kvm->vioapic);
         kvm_free_vcpus(kvm);
         kvm_free_physmem(kvm);
         kfree(kvm);
@@ -2771,8 +2772,14 @@ static long kvm_vm_ioctl(struct file *filp,
         case KVM_CREATE_IRQCHIP:
                 r = -ENOMEM;
                 kvm->vpic = kvm_create_pic(kvm);
-                if (kvm->vpic)
-                        r = 0;
+                if (kvm->vpic) {
+                        r = kvm_ioapic_init(kvm);
+                        if (r) {
+                                kfree(kvm->vpic);
+                                kvm->vpic = NULL;
+                                goto out;
+                        }
+                }
                 else
                         goto out;
                 break;
@@ -2787,7 +2794,9 @@ static long kvm_vm_ioctl(struct file *filp,
                                 kvm_pic_set_irq(pic_irqchip(kvm),
                                         irq_event.irq,
                                         irq_event.level);
-                        /* TODO: IOAPIC */
+                        kvm_ioapic_set_irq(kvm->vioapic,
+                                        irq_event.irq,
+                                        irq_event.level);
                         r = 0;
                 }
                 break;