On Fri, May 06, 2016 at 10:53:45PM +0200, Radim Krčmář wrote:
> The only way to send interrupts from outside of APIC devices is to use
> the MSI-inspired memory mapped interface. The interface is not
> sufficient because interrupt remapping in extended mode can exceed 8 bit
> destination ids.
>
> The proper way to deliver interrupts would be to design a bus (QPI), but
> that is a big undertaking. Real IR unit stores excessive bits in the
> high work of MSI address register, which would be bit [63:40] in memory
> address space, so I was considering two options:
> - a new special address space for APIC to handle MSI-compatible writes
> - one callback to the APIC class that delivers extended MSIs
>
> This patch uses latter option, because it was easier for me, but I think
> the former one could be a tad nicer.
>
> Signed-off-by: Radim Krčmář <rkrc...@redhat.com>
Reviewed-by: Eduardo Habkost <ehabk...@redhat.com>
But I have a suggestion below:
> ---
> hw/i386/kvm/apic.c | 21 ++++++++++++++-------
> hw/i386/xen/xen_apic.c | 7 +++++++
> hw/intc/apic.c | 7 +++++++
> include/hw/i386/apic_internal.h | 5 +++++
> 4 files changed, 33 insertions(+), 7 deletions(-)
>
> diff --git a/hw/i386/kvm/apic.c b/hw/i386/kvm/apic.c
> index 3c7c8fa00709..7881f13abb96 100644
> --- a/hw/i386/kvm/apic.c
> +++ b/hw/i386/kvm/apic.c
> @@ -147,6 +147,17 @@ static void kvm_apic_external_nmi(APICCommonState *s)
> run_on_cpu(CPU(s->cpu), do_inject_external_nmi, s);
> }
>
> +static void kvm_deliver_msi(MSIMessage *msg)
> +{
> + int ret;
> +
> + ret = kvm_irqchip_send_msi(kvm_state, *msg);
> + if (ret < 0) {
> + fprintf(stderr, "KVM: injection failed, MSI lost (%s)\n",
> + strerror(-ret));
> + }
> +}
> +
> static uint64_t kvm_apic_mem_read(void *opaque, hwaddr addr,
> unsigned size)
> {
> @@ -157,13 +168,7 @@ static void kvm_apic_mem_write(void *opaque, hwaddr addr,
> uint64_t data, unsigned size)
> {
> MSIMessage msg = { .address = addr, .data = data };
> - int ret;
> -
> - ret = kvm_irqchip_send_msi(kvm_state, msg);
> - if (ret < 0) {
> - fprintf(stderr, "KVM: injection failed, MSI lost (%s)\n",
> - strerror(-ret));
> - }
> + kvm_deliver_msi(&msg);
> }
You could call APICCommonClass::deliver_msi() here. Then (in a
follow-up patch?) both kvm_apic_mem_write() and
xen_apic_mem_write() could be replaced by a common function like:
void apic_msi_write(void *opaque, hwaddr addr, uint64_t data, unsigned size)
{
APICommonState *s = opaque;
APICCommonClass *k = APIC_COMMON_GET_CLASS(s);
MSIMessage msg = { .address = addr, .data = data };
k->deliver_msi(&msg);
}
(apic_mem_writel() is more complex, but maybe it could call the
common function instead of calling apic_send_msi() directly)
>
> static const MemoryRegionOps kvm_apic_io_ops = {
> @@ -202,6 +207,8 @@ static void kvm_apic_class_init(ObjectClass *klass, void
> *data)
> k->enable_tpr_reporting = kvm_apic_enable_tpr_reporting;
> k->vapic_base_update = kvm_apic_vapic_base_update;
> k->external_nmi = kvm_apic_external_nmi;
> +
> + k->deliver_msi = kvm_deliver_msi;
> }
>
> static const TypeInfo kvm_apic_info = {
> diff --git a/hw/i386/xen/xen_apic.c b/hw/i386/xen/xen_apic.c
> index 21d68ee04b0a..0f34f63d449d 100644
> --- a/hw/i386/xen/xen_apic.c
> +++ b/hw/i386/xen/xen_apic.c
> @@ -68,6 +68,11 @@ static void xen_apic_external_nmi(APICCommonState *s)
> {
> }
>
> +static void xen_deliver_msi(MSIMessage *msi)
> +{
> + xen_hvm_inject_msi(msi->address, msi->data);
> +}
> +
> static void xen_apic_class_init(ObjectClass *klass, void *data)
> {
> APICCommonClass *k = APIC_COMMON_CLASS(klass);
> @@ -78,6 +83,8 @@ static void xen_apic_class_init(ObjectClass *klass, void
> *data)
> k->get_tpr = xen_apic_get_tpr;
> k->vapic_base_update = xen_apic_vapic_base_update;
> k->external_nmi = xen_apic_external_nmi;
> +
> + k->deliver_msi = xen_deliver_msi;
> }
>
> static const TypeInfo xen_apic_info = {
> diff --git a/hw/intc/apic.c b/hw/intc/apic.c
> index 28c2ea540608..b893942c6e73 100644
> --- a/hw/intc/apic.c
> +++ b/hw/intc/apic.c
> @@ -877,6 +877,11 @@ static void apic_realize(DeviceState *dev, Error **errp)
> msi_nonbroken = true;
> }
>
> +static void apic_deliver_msi(MSIMessage *msi)
> +{
> + apic_send_msi(msi->address, msi->data);
> +}
> +
> static void apic_class_init(ObjectClass *klass, void *data)
> {
> APICCommonClass *k = APIC_COMMON_CLASS(klass);
> @@ -889,6 +894,8 @@ static void apic_class_init(ObjectClass *klass, void
> *data)
> k->external_nmi = apic_external_nmi;
> k->pre_save = apic_pre_save;
> k->post_load = apic_post_load;
> +
> + k->deliver_msi = apic_deliver_msi;
> }
>
> static const TypeInfo apic_info = {
> diff --git a/include/hw/i386/apic_internal.h b/include/hw/i386/apic_internal.h
> index 74fe935e8eab..227ef30c5027 100644
> --- a/include/hw/i386/apic_internal.h
> +++ b/include/hw/i386/apic_internal.h
> @@ -146,6 +146,11 @@ typedef struct APICCommonClass
> void (*pre_save)(APICCommonState *s);
> void (*post_load)(APICCommonState *s);
> void (*reset)(APICCommonState *s);
> +
> + /* deliver_msi emulates an APIC bus and its proper place would be in a
> new
> + * device, but it's convenient to have it here for now.
> + */
> + void (*deliver_msi)(MSIMessage *msi);
> } APICCommonClass;
>
> struct APICCommonState {
> --
> 2.8.2
>
--
Eduardo
