kvm: x86: add support for KVM_CAP_SPLIT_IRQCHIP

This patch adds support for split IRQ chip mode. When
KVM_CAP_SPLIT_IRQCHIP is enabled:

    1.) The PIC, PIT, and IOAPIC are implemented in userspace while
    the LAPIC is implemented by KVM.

    2.) The software IOAPIC delivers interrupts to the KVM LAPIC via
    kvm_set_irq. Interrupt delivery is configured via the MSI routing
    table, for which routes are reserved in target-i386/kvm.c then
    configured in hw/intc/ioapic.c

    3.) KVM delivers IOAPIC EOIs via a new exit KVM_EXIT_IOAPIC_EOI,
    which is handled in target-i386/kvm.c and relayed to the software
    IOAPIC via ioapic_eoi_broadcast.

Signed-off-by: Matt Gingell <gingell@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2015-12-17 17:16:08 +01:00
parent 32c18a2dba
commit 15eafc2e60
11 changed files with 148 additions and 14 deletions

View file

@ -25,6 +25,8 @@
#include "hw/i386/pc.h"
#include "hw/i386/ioapic.h"
#include "hw/i386/ioapic_internal.h"
#include "include/hw/pci/msi.h"
#include "sysemu/kvm.h"
//#define DEBUG_IOAPIC
@ -35,6 +37,10 @@
#define DPRINTF(fmt, ...)
#endif
#define APIC_DELIVERY_MODE_SHIFT 8
#define APIC_POLARITY_SHIFT 14
#define APIC_TRIG_MODE_SHIFT 15
static IOAPICCommonState *ioapics[MAX_IOAPICS];
/* global variable from ioapic_common.c */
@ -54,6 +60,8 @@ static void ioapic_service(IOAPICCommonState *s)
for (i = 0; i < IOAPIC_NUM_PINS; i++) {
mask = 1 << i;
if (s->irr & mask) {
int coalesce = 0;
entry = s->ioredtbl[i];
if (!(entry & IOAPIC_LVT_MASKED)) {
trig_mode = ((entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1);
@ -64,6 +72,7 @@ static void ioapic_service(IOAPICCommonState *s)
if (trig_mode == IOAPIC_TRIGGER_EDGE) {
s->irr &= ~mask;
} else {
coalesce = s->ioredtbl[i] & IOAPIC_LVT_REMOTE_IRR;
s->ioredtbl[i] |= IOAPIC_LVT_REMOTE_IRR;
}
if (delivery_mode == IOAPIC_DM_EXTINT) {
@ -71,8 +80,23 @@ static void ioapic_service(IOAPICCommonState *s)
} else {
vector = entry & IOAPIC_VECTOR_MASK;
}
apic_deliver_irq(dest, dest_mode, delivery_mode,
vector, trig_mode);
#ifdef CONFIG_KVM
if (kvm_irqchip_is_split()) {
if (trig_mode == IOAPIC_TRIGGER_EDGE) {
kvm_set_irq(kvm_state, i, 1);
kvm_set_irq(kvm_state, i, 0);
} else {
if (!coalesce) {
kvm_set_irq(kvm_state, i, 1);
}
}
continue;
}
#else
(void)coalesce;
#endif
apic_deliver_irq(dest, dest_mode, delivery_mode, vector,
trig_mode);
}
}
}
@ -116,6 +140,44 @@ static void ioapic_set_irq(void *opaque, int vector, int level)
}
}
static void ioapic_update_kvm_routes(IOAPICCommonState *s)
{
#ifdef CONFIG_KVM
int i;
if (kvm_irqchip_is_split()) {
for (i = 0; i < IOAPIC_NUM_PINS; i++) {
uint64_t entry = s->ioredtbl[i];
uint8_t trig_mode;
uint8_t delivery_mode;
uint8_t dest;
uint8_t dest_mode;
uint64_t pin_polarity;
MSIMessage msg;
trig_mode = ((entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1);
dest = entry >> IOAPIC_LVT_DEST_SHIFT;
dest_mode = (entry >> IOAPIC_LVT_DEST_MODE_SHIFT) & 1;
pin_polarity = (entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1;
delivery_mode =
(entry >> IOAPIC_LVT_DELIV_MODE_SHIFT) & IOAPIC_DM_MASK;
msg.address = APIC_DEFAULT_ADDRESS;
msg.address |= dest_mode << 2;
msg.address |= dest << 12;
msg.data = entry & IOAPIC_VECTOR_MASK;
msg.data |= delivery_mode << APIC_DELIVERY_MODE_SHIFT;
msg.data |= pin_polarity << APIC_POLARITY_SHIFT;
msg.data |= trig_mode << APIC_TRIG_MODE_SHIFT;
kvm_irqchip_update_msi_route(kvm_state, i, msg, NULL);
}
kvm_irqchip_commit_routes(kvm_state);
}
#endif
}
void ioapic_eoi_broadcast(int vector)
{
IOAPICCommonState *s;
@ -229,6 +291,8 @@ ioapic_mem_write(void *opaque, hwaddr addr, uint64_t val,
}
break;
}
ioapic_update_kvm_routes(s);
}
static const MemoryRegionOps ioapic_io_ops = {