[PATCH 067/104] KVM: In-kernel I/O APIC model

Avi Kivity
2007-09-17T08:31:49Z

From: Eddie Dong <eddie.dong-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

This allows in-kernel host-side device drivers to raise guest interrupts
without going to userspace.

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/Makefile | 2 +-
drivers/kvm/ioapic.c | 397 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/kvm/irq.c | 4 -
drivers/kvm/irq.h | 50 ++++++
drivers/kvm/kvm.h | 1 +
drivers/kvm/kvm_main.c | 15 ++-
6 files changed, 461 insertions(+), 8 deletions(-)
create mode 100644 drivers/kvm/ioapic.c

diff --git a/drivers/kvm/Makefile b/drivers/kvm/Makefile
index 3bf7276..e5a8f4d 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 0000000..3ee13c3
--- /dev/null
+++ b/drivers/kvm/ioapic.c
@@ -0,0 +1,397 @@
+/*
+ * 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-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
+ * Yaozu (Eddie) Dong <eddie.dong-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
+ * 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 "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;
+ }
+}
+
+static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
+{
+ int 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);
+ ASSERT(irq < IOAPIC_NUM_PINS);
+ 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;
+ }
+ 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 mask = 1 << irq;
+ union ioapic_redir_entry entry;
+
+ if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
+ entry = ioapic->redirtbl[irq];
+ if (!level)
+ ioapic->irr &= ~mask;
+ if (entry.fields.trig_mode) { /* level triggered */
+ if (level && !entry.fields.remote_irr) {
+ ioapic->irr |= mask;
+ ioapic_service(ioapic, irq);
+ }
+ } else if (level && !(ioapic->irr & mask)) {
+ /*
+ * edge triggered
+ */
+ ioapic->irr |= mask;
+ 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;
+ /*
+ * TODO:
+ * qemu ioapic doesn't re-deliver level
+ * triggered irq at the time of APIC EOI.
+ * Adding back following code sme time causes RHEL5U
+ * guest boot no progress at ethernet bringup, so
+ * leave it same with qemu for now and revisit later.
+ */
+/*
+ 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 0b4430a..5265f82 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 57e23bd..fff5733 100644
--- a/drivers/kvm/irq.h
+++ b/drivers/kvm/irq.h
@@ -60,6 +60,49 @@ 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 {
+ struct kvm_io_device dev;
+ unsigned long base_address;
+ struct kvm *kvm;
+ u32 ioregsel;
+ u32 id;
+ u32 irr;
+ 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_lapic {
unsigned long base_address;
struct kvm_io_device dev;
@@ -96,8 +139,15 @@ 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 a5790cb..0a11b0f 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)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 401e3cd..ffbdadd 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;