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Re: [PATCH 09/20] spapr: Clarify and fix handling of nr_irqs
From: |
David Gibson |
Subject: |
Re: [PATCH 09/20] spapr: Clarify and fix handling of nr_irqs |
Date: |
Thu, 26 Sep 2019 11:03:24 +1000 |
User-agent: |
Mutt/1.12.1 (2019-06-15) |
On Wed, Sep 25, 2019 at 09:05:34AM +0200, Cédric Le Goater wrote:
> On 25/09/2019 08:45, David Gibson wrote:
> > Both the XICS and XIVE interrupt backends have a "nr-irqs" property, but
> > it means slightly different things. For XICS (or, strictly, the ICS) it
> > indicates the number of "real" external IRQs. Those start at XICS_IRQ_BASE
> > (0x1000) and don't include the special IPI vector. For XIVE, however, it
> > includes the whole IRQ space, including XIVE's many IPI vectors.
> >
> > The spapr code currently doesn't handle this sensibly, with the nr_irqs
> > value in SpaprIrq having different meanings depending on the backend.
> > We fix this by renaming nr_irqs to nr_xirqs and making it always indicate
> > just the number of external irqs, adjusting the value we pass to XIVE
> > accordingly. We also use move to using common constants in most of the
> > irq configurations, to make it clearer that the IRQ space looks the same
> > to the guest (and emulated devices), even if the backend is different.
> >
> > Signed-off-by: David Gibson <address@hidden>
>
> Reviewed-by: Cédric Le Goater <address@hidden>
>
> one comment below,
>
> > ---
> > hw/ppc/spapr_irq.c | 48 +++++++++++++++-----------------------
> > include/hw/ppc/spapr_irq.h | 19 +++++++++------
> > 2 files changed, 31 insertions(+), 36 deletions(-)
> >
> > diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
> > index 8c26fa2d1e..5190a33e08 100644
> > --- a/hw/ppc/spapr_irq.c
> > +++ b/hw/ppc/spapr_irq.c
> > @@ -92,7 +92,7 @@ static void spapr_irq_init_kvm(SpaprMachineState *spapr,
> > * XICS IRQ backend.
> > */
> >
> > -static void spapr_irq_init_xics(SpaprMachineState *spapr, int nr_irqs,
> > +static void spapr_irq_init_xics(SpaprMachineState *spapr, int nr_xirqs,
> > Error **errp)
> > {
> > Object *obj;
> > @@ -102,7 +102,7 @@ static void spapr_irq_init_xics(SpaprMachineState
> > *spapr, int nr_irqs,
> > object_property_add_child(OBJECT(spapr), "ics", obj, &error_abort);
> > object_property_add_const_link(obj, ICS_PROP_XICS, OBJECT(spapr),
> > &error_fatal);
> > - object_property_set_int(obj, nr_irqs, "nr-irqs", &error_fatal);
> > + object_property_set_int(obj, nr_xirqs, "nr-irqs", &error_fatal);
> > object_property_set_bool(obj, true, "realized", &local_err);
> > if (local_err) {
> > error_propagate(errp, local_err);
> > @@ -234,13 +234,9 @@ static void spapr_irq_init_kvm_xics(SpaprMachineState
> > *spapr, Error **errp)
> > }
> > }
> >
> > -#define SPAPR_IRQ_XICS_NR_IRQS 0x1000
> > -#define SPAPR_IRQ_XICS_NR_MSIS \
> > - (XICS_IRQ_BASE + SPAPR_IRQ_XICS_NR_IRQS - SPAPR_IRQ_MSI)
> > -
> > SpaprIrq spapr_irq_xics = {
> > - .nr_irqs = SPAPR_IRQ_XICS_NR_IRQS,
> > - .nr_msis = SPAPR_IRQ_XICS_NR_MSIS,
> > + .nr_xirqs = SPAPR_NR_XIRQS,
> > + .nr_msis = SPAPR_NR_MSIS,
> > .ov5 = SPAPR_OV5_XIVE_LEGACY,
> >
> > .init = spapr_irq_init_xics,
> > @@ -260,7 +256,7 @@ SpaprIrq spapr_irq_xics = {
> > /*
> > * XIVE IRQ backend.
> > */
> > -static void spapr_irq_init_xive(SpaprMachineState *spapr, int nr_irqs,
> > +static void spapr_irq_init_xive(SpaprMachineState *spapr, int nr_xirqs,
> > Error **errp)
> > {
> > uint32_t nr_servers = spapr_max_server_number(spapr);
> > @@ -268,7 +264,7 @@ static void spapr_irq_init_xive(SpaprMachineState
> > *spapr, int nr_irqs,
> > int i;
> >
> > dev = qdev_create(NULL, TYPE_SPAPR_XIVE);
> > - qdev_prop_set_uint32(dev, "nr-irqs", nr_irqs);
> > + qdev_prop_set_uint32(dev, "nr-irqs", nr_xirqs + SPAPR_XIRQ_BASE);
> > /*
> > * 8 XIVE END structures per CPU. One for each available priority
> > */
> > @@ -308,7 +304,7 @@ static qemu_irq spapr_qirq_xive(SpaprMachineState
> > *spapr, int irq)
> > {
> > SpaprXive *xive = spapr->xive;
> >
> > - if (irq >= xive->nr_irqs) {
> > + if ((irq < SPAPR_XIRQ_BASE) || (irq >= xive->nr_irqs)) {
>
> So IPIs cannot be pulsed ? I think that is OK in QEMU.
They can be pulsed, they just can't be retrieved via the spapr_qirq()
interface. Since that interface basically exists for the spapr root
devices (VIO and PHBs) to find the qemu_irqs to wire themselves up to,
I think that's fine.
If we discover some reason we need to grab IPI qirqs by global number
then we can revisit this.
I'll add a comment to clarify this in the later patch where I unify
the qirq implementations.
> XIVE unifies all the interrupts at the controller level. Any one can trigger
> an interrupt with a store on the associate ESB page.
Absolutely, and nothing's stopping them.
>
> > return NULL;
> > }
> >
> > @@ -409,12 +405,9 @@ static void spapr_irq_init_kvm_xive(SpaprMachineState
> > *spapr, Error **errp)
> > * with XICS.
> > */
> >
> > -#define SPAPR_IRQ_XIVE_NR_IRQS 0x2000
> > -#define SPAPR_IRQ_XIVE_NR_MSIS (SPAPR_IRQ_XIVE_NR_IRQS - SPAPR_IRQ_MSI)
> > -
> > SpaprIrq spapr_irq_xive = {
> > - .nr_irqs = SPAPR_IRQ_XIVE_NR_IRQS,
> > - .nr_msis = SPAPR_IRQ_XIVE_NR_MSIS,
> > + .nr_xirqs = SPAPR_NR_XIRQS,
> > + .nr_msis = SPAPR_NR_MSIS,
> > .ov5 = SPAPR_OV5_XIVE_EXPLOIT,
> >
> > .init = spapr_irq_init_xive,
> > @@ -450,18 +443,18 @@ static SpaprIrq *spapr_irq_current(SpaprMachineState
> > *spapr)
> > &spapr_irq_xive : &spapr_irq_xics;
> > }
> >
> > -static void spapr_irq_init_dual(SpaprMachineState *spapr, int nr_irqs,
> > +static void spapr_irq_init_dual(SpaprMachineState *spapr, int nr_xirqs,
> > Error **errp)
> > {
> > Error *local_err = NULL;
> >
> > - spapr_irq_xics.init(spapr, spapr_irq_xics.nr_irqs, &local_err);
> > + spapr_irq_xics.init(spapr, spapr_irq_xics.nr_xirqs, &local_err);
> > if (local_err) {
> > error_propagate(errp, local_err);
> > return;
> > }
> >
> > - spapr_irq_xive.init(spapr, spapr_irq_xive.nr_irqs, &local_err);
> > + spapr_irq_xive.init(spapr, spapr_irq_xive.nr_xirqs, &local_err);
> > if (local_err) {
> > error_propagate(errp, local_err);
> > return;
> > @@ -586,12 +579,9 @@ static const char
> > *spapr_irq_get_nodename_dual(SpaprMachineState *spapr)
> > /*
> > * Define values in sync with the XIVE and XICS backend
> > */
> > -#define SPAPR_IRQ_DUAL_NR_IRQS 0x2000
> > -#define SPAPR_IRQ_DUAL_NR_MSIS (SPAPR_IRQ_DUAL_NR_IRQS - SPAPR_IRQ_MSI)
> > -
> > SpaprIrq spapr_irq_dual = {
> > - .nr_irqs = SPAPR_IRQ_DUAL_NR_IRQS,
> > - .nr_msis = SPAPR_IRQ_DUAL_NR_MSIS,
> > + .nr_xirqs = SPAPR_NR_XIRQS,
> > + .nr_msis = SPAPR_NR_MSIS,
> > .ov5 = SPAPR_OV5_XIVE_BOTH,
> >
> > .init = spapr_irq_init_dual,
> > @@ -693,10 +683,10 @@ void spapr_irq_init(SpaprMachineState *spapr, Error
> > **errp)
> > spapr_irq_msi_init(spapr, spapr->irq->nr_msis);
> > }
> >
> > - spapr->irq->init(spapr, spapr->irq->nr_irqs, errp);
> > + spapr->irq->init(spapr, spapr->irq->nr_xirqs, errp);
> >
> > spapr->qirqs = qemu_allocate_irqs(spapr->irq->set_irq, spapr,
> > - spapr->irq->nr_irqs);
> > + spapr->irq->nr_xirqs +
> > SPAPR_XIRQ_BASE);
> > }
> >
> > int spapr_irq_claim(SpaprMachineState *spapr, int irq, bool lsi, Error
> > **errp)
> > @@ -804,11 +794,11 @@ int spapr_irq_find(SpaprMachineState *spapr, int num,
> > bool align, Error **errp)
> > return first + ics->offset;
> > }
> >
> > -#define SPAPR_IRQ_XICS_LEGACY_NR_IRQS 0x400
> > +#define SPAPR_IRQ_XICS_LEGACY_NR_XIRQS 0x400
> >
> > SpaprIrq spapr_irq_xics_legacy = {
> > - .nr_irqs = SPAPR_IRQ_XICS_LEGACY_NR_IRQS,
> > - .nr_msis = SPAPR_IRQ_XICS_LEGACY_NR_IRQS,
> > + .nr_xirqs = SPAPR_IRQ_XICS_LEGACY_NR_XIRQS,
> > + .nr_msis = SPAPR_IRQ_XICS_LEGACY_NR_XIRQS,
> > .ov5 = SPAPR_OV5_XIVE_LEGACY,
> >
> > .init = spapr_irq_init_xics,
> > diff --git a/include/hw/ppc/spapr_irq.h b/include/hw/ppc/spapr_irq.h
> > index 5db305165c..a8f9a2ab11 100644
> > --- a/include/hw/ppc/spapr_irq.h
> > +++ b/include/hw/ppc/spapr_irq.h
> > @@ -16,13 +16,18 @@
> > * IRQ range offsets per device type
> > */
> > #define SPAPR_IRQ_IPI 0x0
> > -#define SPAPR_IRQ_EPOW 0x1000 /* XICS_IRQ_BASE offset */
> > -#define SPAPR_IRQ_HOTPLUG 0x1001
> > -#define SPAPR_IRQ_VIO 0x1100 /* 256 VIO devices */
> > -#define SPAPR_IRQ_PCI_LSI 0x1200 /* 32+ PHBs devices */
> >
> > -#define SPAPR_IRQ_MSI 0x1300 /* Offset of the dynamic range covered
> > - * by the bitmap allocator */
> > +#define SPAPR_XIRQ_BASE XICS_IRQ_BASE /* 0x1000 */
> > +#define SPAPR_IRQ_EPOW (SPAPR_XIRQ_BASE + 0x0000)
> > +#define SPAPR_IRQ_HOTPLUG (SPAPR_XIRQ_BASE + 0x0001)
> > +#define SPAPR_IRQ_VIO (SPAPR_XIRQ_BASE + 0x0100) /* 256 VIO
> > devices */
> > +#define SPAPR_IRQ_PCI_LSI (SPAPR_XIRQ_BASE + 0x0200) /* 32+ PHBs
> > devices */
> > +
> > +/* Offset of the dynamic range covered by the bitmap allocator */
> > +#define SPAPR_IRQ_MSI (SPAPR_XIRQ_BASE + 0x0300)
> > +
> > +#define SPAPR_NR_XIRQS 0x1000
> > +#define SPAPR_NR_MSIS (SPAPR_XIRQ_BASE + SPAPR_NR_XIRQS -
> > SPAPR_IRQ_MSI)
> >
> > typedef struct SpaprMachineState SpaprMachineState;
> >
> > @@ -32,7 +37,7 @@ int spapr_irq_msi_alloc(SpaprMachineState *spapr,
> > uint32_t num, bool align,
> > void spapr_irq_msi_free(SpaprMachineState *spapr, int irq, uint32_t num);
> >
> > typedef struct SpaprIrq {
> > - uint32_t nr_irqs;
> > + uint32_t nr_xirqs;
> > uint32_t nr_msis;
> > uint8_t ov5;
> >
> >
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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- Re: [PATCH 11/20] spapr: Fix indexing of XICS irqs, (continued)
[PATCH 16/20] spapr, xics, xive: Better use of assert()s on irq claim/free paths, David Gibson, 2019/09/25
[PATCH 09/20] spapr: Clarify and fix handling of nr_irqs, David Gibson, 2019/09/25
Re: [PATCH 09/20] spapr: Clarify and fix handling of nr_irqs, Greg Kurz, 2019/09/25
[PATCH 20/20] spapr: Eliminate SpaprIrq::init hook, David Gibson, 2019/09/25
- Re: [PATCH 20/20] spapr: Eliminate SpaprIrq::init hook, Cédric Le Goater, 2019/09/25
- Re: [PATCH 20/20] spapr: Eliminate SpaprIrq::init hook, David Gibson, 2019/09/25
- Re: [PATCH 20/20] spapr: Eliminate SpaprIrq::init hook, Cédric Le Goater, 2019/09/26
- Re: [PATCH 20/20] spapr: Eliminate SpaprIrq::init hook, David Gibson, 2019/09/26
- Re: [PATCH 20/20] spapr: Eliminate SpaprIrq::init hook, Greg Kurz, 2019/09/26
- Re: [PATCH 20/20] spapr: Eliminate SpaprIrq::init hook, David Gibson, 2019/09/27
- Re: [PATCH 20/20] spapr: Eliminate SpaprIrq::init hook, Greg Kurz, 2019/09/27