Re: [Qemu-devel] [PATCH 2/8] xics: add flags for interrupts

[Alexander Graf <agraf@suse.de>]

On 14.03.14 05:18, Alexey Kardashevskiy wrote:
> We will need soon an "allocated" flag for every interrupt to support
> interrupt configuration change which may happen during migration.
>
> This replaces a separate lslsi[] array with a byte in the ICSIRQState
> struct and defines "LSI" and "MSI" flags. Neither of these flags set
> signals that the descriptor is not in use.
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
>   hw/intc/xics.c        | 17 +++++++++++------
>   hw/intc/xics_kvm.c    |  5 ++---
>   include/hw/ppc/xics.h |  4 +++-
>   3 files changed, 16 insertions(+), 10 deletions(-)
>
> diff --git a/hw/intc/xics.c b/hw/intc/xics.c
> index 64aabe7..7eac85a 100644
> --- a/hw/intc/xics.c
> +++ b/hw/intc/xics.c
> @@ -438,7 +438,7 @@ static void ics_set_irq(void *opaque, int srcno, int val)
>   {
>       ICSState *ics = (ICSState *)opaque;
>   
> -    if (ics->islsi[srcno]) {
> +    if (ics->irqs[srcno].flags & XICS_FLAGS_LSI) {
>           set_irq_lsi(ics, srcno, val);
>       } else {
>           set_irq_msi(ics, srcno, val);
> @@ -475,7 +475,7 @@ static void ics_write_xive(ICSState *ics, int nr, int server,
>   
>       trace_xics_ics_write_xive(nr, srcno, server, priority);
>   
> -    if (ics->islsi[srcno]) {
> +    if (ics->irqs[srcno].flags & XICS_FLAGS_LSI) {
>           write_xive_lsi(ics, srcno);
>       } else {
>           write_xive_msi(ics, srcno);
> @@ -497,7 +497,7 @@ static void ics_resend(ICSState *ics)
>   
>       for (i = 0; i < ics->nr_irqs; i++) {
>           /* FIXME: filter by server#? */
> -        if (ics->islsi[i]) {
> +        if (ics->irqs[i].flags & XICS_FLAGS_LSI) {
>               resend_lsi(ics, i);
>           } else {
>               resend_msi(ics, i);
> @@ -512,7 +512,7 @@ static void ics_eoi(ICSState *ics, int nr)
>   
>       trace_xics_ics_eoi(nr);
>   
> -    if (ics->islsi[srcno]) {
> +    if (ics->irqs[srcno].flags & XICS_FLAGS_LSI) {
>           irq->status &= ~XICS_STATUS_SENT;
>       }
>   }
> @@ -609,7 +609,6 @@ static void ics_realize(DeviceState *dev, Error **errp)
>           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_set_irq, ics, ics->nr_irqs);
>   }
>   
> @@ -646,11 +645,17 @@ qemu_irq xics_get_qirq(XICSState *icp, int irq)
>       return icp->ics->qirqs[irq - icp->ics->offset];
>   }
>   
> +static void ics_set_irq_type(ICSState *ics, int irq, bool lsi)
> +{
> +    ics->irqs[irq - ics->offset].flags |=
> +        lsi ? XICS_FLAGS_LSI : XICS_FLAGS_MSI;

If I configure an IRQ as LSI then as MSI this doesn't work. Sure, we 
probably don't do this but in general this is not how a "set" function 
should behave.


Alex