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xics-kvm: Support for in-kernel XICS interrupt controller

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Recent (host) kernels support emulating the PAPR defined "XICS" interrupt
controller system within KVM.  This patch allows qemu to initialize and
configure the in-kernel XICS, and keep its state in sync with qemu's XICS
state as necessary.

This should give considerable performance improvements.  e.g. on a simple
IPI ping-pong test between hardware threads, using qemu XICS gives us
around 5,000 irqs/second, whereas the in-kernel XICS gives us around
70,000 irqs/s on the same hardware configuration.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[Mike Qiu <qiudayu@linux.vnet.ibm.com>: fixed mistype which caused ics_set_kvm_state() to fail]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
David Gibson 2013-09-26 16:18:44 +10:00 committed by Alexander Graf
parent 5eb92ccc3f
commit 11ad93f681
5 changed files with 520 additions and 1 deletions
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1
default-configs/ppc64-softmmu.mak
View File

@ -46,6 +46,7 @@ CONFIG_E500=y
CONFIG_OPENPIC_KVM=$(and $(CONFIG_E500),$(CONFIG_KVM))
# For pSeries
CONFIG_XICS=$(CONFIG_PSERIES)
CONFIG_XICS_KVM=$(and $(CONFIG_PSERIES),$(CONFIG_KVM))
# For PReP
CONFIG_I82378=y
CONFIG_I8259=y

1
hw/intc/Makefile.objs
View File

@ -23,3 +23,4 @@ obj-$(CONFIG_OMAP) += omap_intc.o
obj-$(CONFIG_OPENPIC_KVM) += openpic_kvm.o
obj-$(CONFIG_SH4) += sh_intc.o
obj-$(CONFIG_XICS) += xics.o
obj-$(CONFIG_XICS_KVM) += xics_kvm.o

488
hw/intc/xics_kvm.c Normal file
View File

@ -0,0 +1,488 @@
/*
* QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator
*
* PAPR Virtualized Interrupt System, aka ICS/ICP aka xics, in-kernel emulation
*
* Copyright (c) 2013 David Gibson, IBM Corporation.
*
* 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.
*
*/
#include "hw/hw.h"
#include "trace.h"
#include "hw/ppc/spapr.h"
#include "hw/ppc/xics.h"
#include "kvm_ppc.h"
#include "qemu/config-file.h"
#include "qemu/error-report.h"
#include <sys/ioctl.h>
typedef struct KVMXICSState {
XICSState parent_obj;
uint32_t set_xive_token;
uint32_t get_xive_token;
uint32_t int_off_token;
uint32_t int_on_token;
int kernel_xics_fd;
} KVMXICSState;
/*
* ICP-KVM
*/
static void icp_get_kvm_state(ICPState *ss)
{
uint64_t state;
struct kvm_one_reg reg = {
.id = KVM_REG_PPC_ICP_STATE,
.addr = (uintptr_t)&state,
};
int ret;
/* ICP for this CPU thread is not in use, exiting */
if (!ss->cs) {
return;
}
ret = kvm_vcpu_ioctl(ss->cs, KVM_GET_ONE_REG, &reg);
if (ret != 0) {
error_report("Unable to retrieve KVM interrupt controller state"
" for CPU %d: %s", ss->cs->cpu_index, strerror(errno));
exit(1);
}
ss->xirr = state >> KVM_REG_PPC_ICP_XISR_SHIFT;
ss->mfrr = (state >> KVM_REG_PPC_ICP_MFRR_SHIFT)
& KVM_REG_PPC_ICP_MFRR_MASK;
ss->pending_priority = (state >> KVM_REG_PPC_ICP_PPRI_SHIFT)
& KVM_REG_PPC_ICP_PPRI_MASK;
}
static int icp_set_kvm_state(ICPState *ss, int version_id)
{
uint64_t state;
struct kvm_one_reg reg = {
.id = KVM_REG_PPC_ICP_STATE,
.addr = (uintptr_t)&state,
};
int ret;
/* ICP for this CPU thread is not in use, exiting */
if (!ss->cs) {
return 0;
}
state = ((uint64_t)ss->xirr << KVM_REG_PPC_ICP_XISR_SHIFT)
| ((uint64_t)ss->mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT)
| ((uint64_t)ss->pending_priority << KVM_REG_PPC_ICP_PPRI_SHIFT);
ret = kvm_vcpu_ioctl(ss->cs, KVM_SET_ONE_REG, &reg);
if (ret != 0) {
error_report("Unable to restore KVM interrupt controller state (0x%"
PRIx64 ") for CPU %d: %s", state, ss->cs->cpu_index,
strerror(errno));
return ret;
}
return 0;
}
static void icp_kvm_reset(DeviceState *dev)
{
ICPState *icp = ICP(dev);
icp->xirr = 0;
icp->pending_priority = 0xff;
icp->mfrr = 0xff;
/* Make all outputs are deasserted */
qemu_set_irq(icp->output, 0);
icp_set_kvm_state(icp, 1);
}
static void icp_kvm_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
ICPStateClass *icpc = ICP_CLASS(klass);
dc->reset = icp_kvm_reset;
icpc->pre_save = icp_get_kvm_state;
icpc->post_load = icp_set_kvm_state;
}
static const TypeInfo icp_kvm_info = {
.name = TYPE_KVM_ICP,
.parent = TYPE_ICP,
.instance_size = sizeof(ICPState),
.class_init = icp_kvm_class_init,
.class_size = sizeof(ICPStateClass),
};
/*
* ICS-KVM
*/
static void ics_get_kvm_state(ICSState *ics)
{
KVMXICSState *icpkvm = KVM_XICS(ics->icp);
uint64_t state;
struct kvm_device_attr attr = {
.flags = 0,
.group = KVM_DEV_XICS_GRP_SOURCES,
.addr = (uint64_t)(uintptr_t)&state,
};
int i;
for (i = 0; i < ics->nr_irqs; i++) {
ICSIRQState *irq = &ics->irqs[i];
int ret;
attr.attr = i + ics->offset;
ret = ioctl(icpkvm->kernel_xics_fd, KVM_GET_DEVICE_ATTR, &attr);
if (ret != 0) {
error_report("Unable to retrieve KVM interrupt controller state"
" for IRQ %d: %s", i + ics->offset, strerror(errno));
exit(1);
}
irq->server = state & KVM_XICS_DESTINATION_MASK;
irq->saved_priority = (state >> KVM_XICS_PRIORITY_SHIFT)
& KVM_XICS_PRIORITY_MASK;
/*
* To be consistent with the software emulation in xics.c, we
* split out the masked state + priority that we get from the
* kernel into 'current priority' (0xff if masked) and
* 'saved priority' (if masked, this is the priority the
* interrupt had before it was masked). Masking and unmasking
* are done with the ibm,int-off and ibm,int-on RTAS calls.
*/
if (state & KVM_XICS_MASKED) {
irq->priority = 0xff;
} else {
irq->priority = irq->saved_priority;
}
if (state & KVM_XICS_PENDING) {
if (state & KVM_XICS_LEVEL_SENSITIVE) {
irq->status |= XICS_STATUS_ASSERTED;
} else {
/*
* A pending edge-triggered interrupt (or MSI)
* must have been rejected previously when we
* first detected it and tried to deliver it,
* so mark it as pending and previously rejected
* for consistency with how xics.c works.
*/
irq->status |= XICS_STATUS_MASKED_PENDING
| XICS_STATUS_REJECTED;
}
}
}
}
static int ics_set_kvm_state(ICSState *ics, int version_id)
{
KVMXICSState *icpkvm = KVM_XICS(ics->icp);
uint64_t state;
struct kvm_device_attr attr = {
.flags = 0,
.group = KVM_DEV_XICS_GRP_SOURCES,
.addr = (uint64_t)(uintptr_t)&state,
};
int i;
for (i = 0; i < ics->nr_irqs; i++) {
ICSIRQState *irq = &ics->irqs[i];
int ret;
attr.attr = i + ics->offset;
state = irq->server;
state |= (uint64_t)(irq->saved_priority & KVM_XICS_PRIORITY_MASK)
<< KVM_XICS_PRIORITY_SHIFT;
if (irq->priority != irq->saved_priority) {
assert(irq->priority == 0xff);
state |= KVM_XICS_MASKED;
}
if (ics->islsi[i]) {
state |= KVM_XICS_LEVEL_SENSITIVE;
if (irq->status & XICS_STATUS_ASSERTED) {
state |= KVM_XICS_PENDING;
}
} else {
if (irq->status & XICS_STATUS_MASKED_PENDING) {
state |= KVM_XICS_PENDING;
}
}
ret = ioctl(icpkvm->kernel_xics_fd, KVM_SET_DEVICE_ATTR, &attr);
if (ret != 0) {
error_report("Unable to restore KVM interrupt controller state"
" for IRQs %d: %s", i + ics->offset, strerror(errno));
return ret;
}
}
return 0;
}
static void ics_kvm_set_irq(void *opaque, int srcno, int val)
{
ICSState *ics = opaque;
struct kvm_irq_level args;
int rc;
args.irq = srcno + ics->offset;
if (!ics->islsi[srcno]) {
if (!val) {
return;
}
args.level = KVM_INTERRUPT_SET;
} else {
args.level = val ? KVM_INTERRUPT_SET_LEVEL : KVM_INTERRUPT_UNSET;
}
rc = kvm_vm_ioctl(kvm_state, KVM_IRQ_LINE, &args);
if (rc < 0) {
perror("kvm_irq_line");
}
}
static void ics_kvm_reset(DeviceState *dev)
{
ics_set_kvm_state(ICS(dev), 1);
}
static void ics_kvm_realize(DeviceState *dev, Error **errp)
{
ICSState *ics = ICS(dev);
if (!ics->nr_irqs) {
error_setg(errp, "Number of interrupts needs to be greater 0");
return;
}
ics->irqs = g_malloc0(ics->nr_irqs * sizeof(ICSIRQState));
ics->islsi = g_malloc0(ics->nr_irqs * sizeof(bool));
ics->qirqs = qemu_allocate_irqs(ics_kvm_set_irq, ics, ics->nr_irqs);
}
static void ics_kvm_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
ICSStateClass *icsc = ICS_CLASS(klass);
dc->realize = ics_kvm_realize;
dc->reset = ics_kvm_reset;
icsc->pre_save = ics_get_kvm_state;
icsc->post_load = ics_set_kvm_state;
}
static const TypeInfo ics_kvm_info = {
.name = TYPE_KVM_ICS,
.parent = TYPE_ICS,
.instance_size = sizeof(ICSState),
.class_init = ics_kvm_class_init,
};
/*
* XICS-KVM
*/
static void xics_kvm_cpu_setup(XICSState *icp, PowerPCCPU *cpu)
{
CPUState *cs;
ICPState *ss;
KVMXICSState *icpkvm = KVM_XICS(icp);
cs = CPU(cpu);
ss = &icp->ss[cs->cpu_index];
assert(cs->cpu_index < icp->nr_servers);
if (icpkvm->kernel_xics_fd == -1) {
abort();
}
if (icpkvm->kernel_xics_fd != -1) {
int ret;
struct kvm_enable_cap xics_enable_cap = {
.cap = KVM_CAP_IRQ_XICS,
.flags = 0,
.args = {icpkvm->kernel_xics_fd, cs->cpu_index, 0, 0},
};
ss->cs = cs;
ret = kvm_vcpu_ioctl(ss->cs, KVM_ENABLE_CAP, &xics_enable_cap);
if (ret < 0) {
error_report("Unable to connect CPU%d to kernel XICS: %s",
cs->cpu_index, strerror(errno));
exit(1);
}
}
}
static void xics_kvm_set_nr_irqs(XICSState *icp, uint32_t nr_irqs, Error **errp)
{
icp->nr_irqs = icp->ics->nr_irqs = nr_irqs;
}
static void xics_kvm_set_nr_servers(XICSState *icp, uint32_t nr_servers,
Error **errp)
{
int i;
icp->nr_servers = nr_servers;
icp->ss = g_malloc0(icp->nr_servers*sizeof(ICPState));
for (i = 0; i < icp->nr_servers; i++) {
char buffer[32];
object_initialize(&icp->ss[i], sizeof(icp->ss[i]), TYPE_KVM_ICP);
snprintf(buffer, sizeof(buffer), "icp[%d]", i);
object_property_add_child(OBJECT(icp), buffer, OBJECT(&icp->ss[i]),
errp);
}
}
static void rtas_dummy(PowerPCCPU *cpu, sPAPREnvironment *spapr,
uint32_t token,
uint32_t nargs, target_ulong args,
uint32_t nret, target_ulong rets)
{
error_report("pseries: %s must never be called for in-kernel XICS",
__func__);
}
static void xics_kvm_realize(DeviceState *dev, Error **errp)
{
KVMXICSState *icpkvm = KVM_XICS(dev);
XICSState *icp = XICS_COMMON(dev);
int i, rc;
Error *error = NULL;
struct kvm_create_device xics_create_device = {
.type = KVM_DEV_TYPE_XICS,
.flags = 0,
};
if (!kvm_enabled() || !kvm_check_extension(kvm_state, KVM_CAP_IRQ_XICS)) {
error_setg(errp,
"KVM and IRQ_XICS capability must be present for in-kernel XICS");
goto fail;
}
icpkvm->set_xive_token = spapr_rtas_register("ibm,set-xive", rtas_dummy);
icpkvm->get_xive_token = spapr_rtas_register("ibm,get-xive", rtas_dummy);
icpkvm->int_off_token = spapr_rtas_register("ibm,int-off", rtas_dummy);
icpkvm->int_on_token = spapr_rtas_register("ibm,int-on", rtas_dummy);
rc = kvmppc_define_rtas_kernel_token(icpkvm->set_xive_token,
"ibm,set-xive");
if (rc < 0) {
error_setg(errp, "kvmppc_define_rtas_kernel_token: ibm,set-xive");
goto fail;
}
rc = kvmppc_define_rtas_kernel_token(icpkvm->get_xive_token,
"ibm,get-xive");
if (rc < 0) {
error_setg(errp, "kvmppc_define_rtas_kernel_token: ibm,get-xive");
goto fail;
}
rc = kvmppc_define_rtas_kernel_token(icpkvm->int_on_token, "ibm,int-on");
if (rc < 0) {
error_setg(errp, "kvmppc_define_rtas_kernel_token: ibm,int-on");
goto fail;
}
rc = kvmppc_define_rtas_kernel_token(icpkvm->int_off_token, "ibm,int-off");
if (rc < 0) {
error_setg(errp, "kvmppc_define_rtas_kernel_token: ibm,int-off");
goto fail;
}
/* Create the kernel ICP */
rc = kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &xics_create_device);
if (rc < 0) {
error_setg_errno(errp, -rc, "Error on KVM_CREATE_DEVICE for XICS");
goto fail;
}
icpkvm->kernel_xics_fd = xics_create_device.fd;
object_property_set_bool(OBJECT(icp->ics), true, "realized", &error);
if (error) {
error_propagate(errp, error);
goto fail;
}
assert(icp->nr_servers);
for (i = 0; i < icp->nr_servers; i++) {
object_property_set_bool(OBJECT(&icp->ss[i]), true, "realized", &error);
if (error) {
error_propagate(errp, error);
goto fail;
}
}
return;
fail:
kvmppc_define_rtas_kernel_token(0, "ibm,set-xive");
kvmppc_define_rtas_kernel_token(0, "ibm,get-xive");
kvmppc_define_rtas_kernel_token(0, "ibm,int-on");
kvmppc_define_rtas_kernel_token(0, "ibm,int-off");
}
static void xics_kvm_initfn(Object *obj)
{
XICSState *xics = XICS_COMMON(obj);
xics->ics = ICS(object_new(TYPE_KVM_ICS));
object_property_add_child(obj, "ics", OBJECT(xics->ics), NULL);
xics->ics->icp = xics;
}
static void xics_kvm_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
XICSStateClass *xsc = XICS_COMMON_CLASS(oc);
dc->realize = xics_kvm_realize;
xsc->cpu_setup = xics_kvm_cpu_setup;
xsc->set_nr_irqs = xics_kvm_set_nr_irqs;
xsc->set_nr_servers = xics_kvm_set_nr_servers;
}
static const TypeInfo xics_kvm_info = {
.name = TYPE_KVM_XICS,
.parent = TYPE_XICS_COMMON,
.instance_size = sizeof(KVMXICSState),
.class_init = xics_kvm_class_init,
.instance_init = xics_kvm_initfn,
};
static void xics_kvm_register_types(void)
{
type_register_static(&xics_kvm_info);
type_register_static(&ics_kvm_info);
type_register_static(&icp_kvm_info);
}
type_init(xics_kvm_register_types)

21
hw/ppc/spapr.c
View File

@ -168,7 +168,26 @@ static XICSState *xics_system_init(int nr_servers, int nr_irqs)
{
XICSState *icp = NULL;
icp = try_create_xics(TYPE_XICS, nr_servers, nr_irqs);
if (kvm_enabled()) {
QemuOpts *machine_opts = qemu_get_machine_opts();
bool irqchip_allowed = qemu_opt_get_bool(machine_opts,
"kernel_irqchip", true);
bool irqchip_required = qemu_opt_get_bool(machine_opts,
"kernel_irqchip", false);
if (irqchip_allowed) {
icp = try_create_xics(TYPE_KVM_XICS, nr_servers, nr_irqs);
}
if (irqchip_required && !icp) {
perror("Failed to create in-kernel XICS\n");
abort();
}
}
if (!icp) {
icp = try_create_xics(TYPE_XICS, nr_servers, nr_irqs);
}
if (!icp) {
perror("Failed to create XICS\n");
abort();

10
include/hw/ppc/xics.h
View File

@ -35,6 +35,9 @@
#define TYPE_XICS "xics"
#define XICS(obj) OBJECT_CHECK(XICSState, (obj), TYPE_XICS)
#define TYPE_KVM_XICS "xics-kvm"
#define KVM_XICS(obj) OBJECT_CHECK(KVMXICSState, (obj), TYPE_KVM_XICS)
#define XICS_COMMON_CLASS(klass) \
OBJECT_CLASS_CHECK(XICSStateClass, (klass), TYPE_XICS_COMMON)
#define XICS_CLASS(klass) \
@ -82,6 +85,9 @@ struct XICSState {
#define TYPE_ICP "icp"
#define ICP(obj) OBJECT_CHECK(ICPState, (obj), TYPE_ICP)
#define TYPE_KVM_ICP "icp-kvm"
#define KVM_ICP(obj) OBJECT_CHECK(ICPState, (obj), TYPE_KVM_ICP)
#define ICP_CLASS(klass) \
OBJECT_CLASS_CHECK(ICPStateClass, (klass), TYPE_ICP)
#define ICP_GET_CLASS(obj) \
@ -98,6 +104,7 @@ struct ICPState {
/*< private >*/
DeviceState parent_obj;
/*< public >*/
CPUState *cs;
uint32_t xirr;
uint8_t pending_priority;
uint8_t mfrr;
@ -107,6 +114,9 @@ struct ICPState {
#define TYPE_ICS "ics"
#define ICS(obj) OBJECT_CHECK(ICSState, (obj), TYPE_ICS)
#define TYPE_KVM_ICS "icskvm"
#define KVM_ICS(obj) OBJECT_CHECK(ICSState, (obj), TYPE_KVM_ICS)
#define ICS_CLASS(klass) \
OBJECT_CLASS_CHECK(ICSStateClass, (klass), TYPE_ICS)
#define ICS_GET_CLASS(obj) \