The interrupt mode is chosen by the CAS negotiation process and
activated after a reset to take into account the required changes in
the machine. This brings new constraints on how the associated KVM IRQ
device is initialized.
Currently, each model takes care of the initialization of the KVM
device in their realize method but this is not possible anymore as the
initialization needs to done globaly when the interrupt mode is known,
i.e. when machine is reseted. It also means that we need a way to
delete a KVM device when another mode is chosen.
Also, to support migration, the QEMU objects holding the state to
transfer should always be available but not necessarily activated.
The overall approach of this proposal is to initialize both interrupt
mode at the QEMU level and keep the IRQ number space in sync to allow
switching from one mode to another. For the KVM side of things, the
whole initialization of the KVM device, sources and presenters, is
grouped in a single routine. The XICS and XIVE sPAPR IRQ reset
handlers are modified accordingly to handle the init and delete
sequences of the KVM device. The post_load handlers also are, to take
into account a possible change of interrupt mode after transfer.
As KVM is now initialized at reset, we loose the possiblity to
fallback to the QEMU emulated mode in case of failure and failures
become fatal to the machine.
Signed-off-by: Cédric Le Goater <c...@kaod.org>
---
hw/intc/spapr_xive_kvm.c | 48 +++++++++++-----------
hw/intc/xics_kvm.c | 18 ++++++---
hw/ppc/spapr_irq.c | 86 +++++++++++++++++++++++++++++-----------
3 files changed, 98 insertions(+), 54 deletions(-)
diff --git a/hw/intc/spapr_xive_kvm.c b/hw/intc/spapr_xive_kvm.c
index 0672d8bcbc6b..9c7d36f51e3d 100644
--- a/hw/intc/spapr_xive_kvm.c
+++ b/hw/intc/spapr_xive_kvm.c
@@ -148,7 +148,6 @@ static void xive_tctx_kvm_init(XiveTCTX *tctx, Error **errp)
static void xive_tctx_kvm_realize(DeviceState *dev, Error **errp)
{
- XiveTCTX *tctx = XIVE_TCTX_KVM(dev);
XiveTCTXClass *xtc = XIVE_TCTX_BASE_GET_CLASS(dev);
Error *local_err = NULL;
@@ -157,12 +156,6 @@ static void xive_tctx_kvm_realize(DeviceState *dev, Error
**errp)
error_propagate(errp, local_err);
return;
}
-
- xive_tctx_kvm_init(tctx, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- return;
- }
}
static void xive_tctx_kvm_class_init(ObjectClass *klass, void *data)
@@ -222,12 +215,9 @@ static void xive_source_kvm_init(XiveSource *xsrc, Error
**errp)
static void xive_source_kvm_reset(DeviceState *dev)
{
- XiveSource *xsrc = XIVE_SOURCE_KVM(dev);
XiveSourceClass *xsc = XIVE_SOURCE_BASE_GET_CLASS(dev);
xsc->parent_reset(dev);
-
- xive_source_kvm_init(xsrc, &error_fatal);
}
/*
@@ -346,12 +336,6 @@ static void xive_source_kvm_realize(DeviceState *dev,
Error **errp)
xsrc->qirqs = qemu_allocate_irqs(xive_source_kvm_set_irq, xsrc,
xsrc->nr_irqs);
-
- xive_source_kvm_mmap(xsrc, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- return;
- }
}
static void xive_source_kvm_unrealize(DeviceState *dev, Error **errp)
@@ -823,6 +807,7 @@ void spapr_xive_kvm_init(sPAPRXive *xive, Error **errp)
{
Error *local_err = NULL;
size_t tima_len;
+ CPUState *cs;
if (!kvm_enabled() || !kvmppc_has_cap_xive()) {
error_setg(errp,
@@ -850,7 +835,18 @@ void spapr_xive_kvm_init(sPAPRXive *xive, Error **errp)
return;
}
- /* Let the XiveSource KVM model handle the mapping for the moment */
+ xive_source_kvm_mmap(&xive->source, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+
+ /* Create the KVM interrupt sources */
+ xive_source_kvm_init(&xive->source, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
/* TIMA KVM mapping
*
@@ -869,6 +865,17 @@ void spapr_xive_kvm_init(sPAPRXive *xive, Error **errp)
"xive.tima", tima_len, xive->tm_mmap);
sysbus_init_mmio(SYS_BUS_DEVICE(xive), &xive->tm_mmio);
+ /* Connect the presenters to the VCPU */
+ CPU_FOREACH(cs) {
+ PowerPCCPU *cpu = POWERPC_CPU(cs);
+
+ xive_tctx_kvm_init(XIVE_TCTX_BASE(cpu->intc), &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+ }
+
kvm_kernel_irqchip = true;
kvm_msi_via_irqfd_allowed = true;
kvm_gsi_direct_mapping = true;
@@ -920,16 +927,9 @@ void spapr_xive_kvm_fini(sPAPRXive *xive, Error **errp)
static void spapr_xive_kvm_realize(DeviceState *dev, Error **errp)
{
- sPAPRXive *xive = SPAPR_XIVE_KVM(dev);
sPAPRXiveClass *sxc = SPAPR_XIVE_BASE_GET_CLASS(dev);
Error *local_err = NULL;
- spapr_xive_kvm_init(xive, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- return;
- }
-
/* Initialize the source and the local routing tables */
sxc->parent_realize(dev, &local_err);
if (local_err) {
diff --git a/hw/intc/xics_kvm.c b/hw/intc/xics_kvm.c
index a7e3ec32a761..c89fa943847c 100644
--- a/hw/intc/xics_kvm.c
+++ b/hw/intc/xics_kvm.c
@@ -190,12 +190,6 @@ static void icp_kvm_realize(DeviceState *dev, Error **errp)
error_propagate(errp, local_err);
return;
}
-
- icp_kvm_init(ICP(dev), &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- return;
- }
}
static void icp_kvm_class_init(ObjectClass *klass, void *data)
@@ -427,6 +421,8 @@ static void rtas_dummy(PowerPCCPU *cpu, sPAPRMachineState
*spapr,
int xics_kvm_init(sPAPRMachineState *spapr, Error **errp)
{
int rc;
+ CPUState *cs;
+ Error *local_err = NULL;
if (!kvm_enabled() || !kvm_check_extension(kvm_state, KVM_CAP_IRQ_XICS)) {
error_setg(errp,
@@ -475,6 +471,16 @@ int xics_kvm_init(sPAPRMachineState *spapr, Error **errp)
kvm_msi_via_irqfd_allowed = true;
kvm_gsi_direct_mapping = true;
+ /* Connect the presenters to the VCPU */
+ CPU_FOREACH(cs) {
+ PowerPCCPU *cpu = POWERPC_CPU(cs);
+
+ icp_kvm_init(ICP(cpu->intc), &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ goto fail;
+ }
+ }
return 0;
fail:
diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
index 79ead51c630d..f1720a8dda33 100644
--- a/hw/ppc/spapr_irq.c
+++ b/hw/ppc/spapr_irq.c
@@ -98,20 +98,14 @@ static void spapr_irq_init_xics(sPAPRMachineState *spapr,
int nr_irqs,
MachineState *machine = MACHINE(spapr);
Error *local_err = NULL;
- if (kvm_enabled()) {
- if (machine_kernel_irqchip_allowed(machine) &&
- !xics_kvm_init(spapr, &local_err)) {
- spapr->icp_type = TYPE_KVM_ICP;
- spapr->ics = spapr_ics_create(spapr, TYPE_ICS_KVM, nr_irqs,
- &local_err);
- }
- if (machine_kernel_irqchip_required(machine) && !spapr->ics) {
- error_prepend(&local_err,
- "kernel_irqchip requested but unavailable: ");
- goto error;
+ if (kvm_enabled() && machine_kernel_irqchip_allowed(machine)) {
+ spapr->icp_type = TYPE_KVM_ICP;
+ spapr->ics = spapr_ics_create(spapr, TYPE_ICS_KVM, nr_irqs,
+ &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
}
- error_free(local_err);
- local_err = NULL;
}
if (!spapr->ics) {
@@ -119,10 +113,11 @@ static void spapr_irq_init_xics(sPAPRMachineState *spapr,
int nr_irqs,
spapr->icp_type = TYPE_ICP;
spapr->ics = spapr_ics_create(spapr, TYPE_ICS_SIMPLE, nr_irqs,
&local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
}
-
-error:
- error_propagate(errp, local_err);
}
#define ICS_IRQ_FREE(ics, srcno) \
@@ -218,11 +213,28 @@ static int spapr_irq_post_load_xics(sPAPRMachineState
*spapr, int version_id)
static void spapr_irq_reset_xics(sPAPRMachineState *spapr, Error **errp)
{
+ MachineState *machine = MACHINE(spapr);
CPUState *cs;
+ Error *local_err = NULL;
CPU_FOREACH(cs) {
spapr_cpu_core_set_intc(POWERPC_CPU(cs), spapr->icp_type);
}
+
+ if (kvm_enabled() && machine_kernel_irqchip_allowed(machine)) {
+ xics_kvm_fini(spapr, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ error_prepend(errp, "KVM XICS fini failed: ");
+ return;
+ }
+ xics_kvm_init(spapr, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ error_prepend(errp, "KVM XICS init failed: ");
+ return;
+ }
+ }
}
#define SPAPR_IRQ_XICS_NR_IRQS 0x1000
@@ -288,10 +300,8 @@ static void spapr_irq_init_xive(sPAPRMachineState *spapr,
int nr_irqs,
spapr->xive_tctx_type = TYPE_XIVE_TCTX_KVM;
spapr->xive = spapr_xive_create(spapr, TYPE_SPAPR_XIVE_KVM, nr_irqs,
nr_servers, &local_err);
-
- if (local_err && machine_kernel_irqchip_required(machine)) {
+ if (local_err) {
error_propagate(errp, local_err);
- error_prepend(errp, "kernel_irqchip requested but init failed : ");
return;
}
@@ -375,12 +385,29 @@ static int spapr_irq_post_load_xive(sPAPRMachineState
*spapr, int version_id)
static void spapr_irq_reset_xive(sPAPRMachineState *spapr, Error **errp)
{
+ MachineState *machine = MACHINE(spapr);
CPUState *cs;
+ Error *local_err = NULL;
CPU_FOREACH(cs) {
spapr_cpu_core_set_intc(POWERPC_CPU(cs), spapr->xive_tctx_type);
}
+ if (kvm_enabled() && machine_kernel_irqchip_allowed(machine)) {
+ spapr_xive_kvm_fini(spapr->xive, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ error_prepend(errp, "KVM XIVE fini failed: ");
+ return;
+ }
+ spapr_xive_kvm_init(spapr->xive, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ error_prepend(errp, "KVM XIVE init failed: ");
+ return;
+ }
+ }
+
spapr_xive_mmio_map(spapr->xive);
}
@@ -432,11 +459,6 @@ static void spapr_irq_init_dual(sPAPRMachineState *spapr,
int nr_irqs,
{
Error *local_err = NULL;
- if (kvm_enabled()) {
- error_setg(errp, "No KVM support for the 'dual' machine");
- return;
- }
-
spapr_irq_xics.init(spapr, spapr_irq_xics.nr_irqs, nr_servers, &local_err);
if (local_err) {
error_propagate(errp, local_err);
@@ -510,10 +532,15 @@ static Object
*spapr_irq_cpu_intc_create_dual(sPAPRMachineState *spapr,
static int spapr_irq_post_load_dual(sPAPRMachineState *spapr, int version_id)
{
+ MachineState *machine = MACHINE(spapr);
+
/*
* Force a reset of the XIVE backend after migration.
*/
if (spapr_ovec_test(spapr->ov5_cas, OV5_XIVE_EXPLOIT)) {
+ if (kvm_enabled() && machine_kernel_irqchip_allowed(machine)) {
+ xics_kvm_fini(spapr, &error_fatal);
+ }
spapr_irq_xive.reset(spapr, &error_fatal);
}
@@ -522,6 +549,17 @@ static int spapr_irq_post_load_dual(sPAPRMachineState
*spapr, int version_id)
static void spapr_irq_reset_dual(sPAPRMachineState *spapr, Error **errp)
{
+ MachineState *machine = MACHINE(spapr);
+
+ /*
+ * Destroy all the KVM IRQ devices. This also clears the VCPU
+ * presenters
+ */
+ if (kvm_enabled() && machine_kernel_irqchip_allowed(machine)) {
+ xics_kvm_fini(spapr, &error_fatal);
+ spapr_xive_kvm_fini(spapr->xive, &error_fatal);
+ }
+
/*
* Only XICS is reseted at startup as it is the default interrupt
* mode.
--
2.17.2
