[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [RFC PATCH] spapr/xive: Allocate vCPU IPIs from local context
From: |
Greg Kurz |
Subject: |
Re: [RFC PATCH] spapr/xive: Allocate vCPU IPIs from local context |
Date: |
Fri, 1 Oct 2021 12:38:07 +0200 |
On Fri, 1 Oct 2021 11:59:45 +0200
Cédric Le Goater <clg@kaod.org> wrote:
> >>> Maybe it would be simpler to call xive_source_is_initialized() instead of
> >>> xive_eas_is_valid() in cases like this, e.g. hcall code since it is shared
> >>> between emulation and KVM ?
> >>
> >> Yes but we need a better check than :
> >>
> >> if (lisn < SPAPR_XIRQ_BASE) {
> >> return !!xive_get_field64(EAS_END_INDEX, xive->eat[lisn].w);
> >> }
> >>
> >> This is more an heuristic than a precise test on the "validity" of
> >> a source at the KVM level.
> >>
> >
> > I guess we should be able to get kvmppc_xive_irq_state::valid from
> > KVM by making the KVM_DEV_XIVE_GRP_SOURCE attribute readable. Would
> > that be enough ?
>
> A bit slow may be. Or an extra bit in the XiveSource 'status' field
> to reflect KVM initialization.
>
> C.
>
Something like this ?
diff --git a/hw/intc/spapr_xive_kvm.c b/hw/intc/spapr_xive_kvm.c
index 42f72b68fc00..6eba58b0ff10 100644
--- a/hw/intc/spapr_xive_kvm.c
+++ b/hw/intc/spapr_xive_kvm.c
@@ -232,6 +232,7 @@ int kvmppc_xive_source_reset_one(XiveSource *xsrc, int
srcno, Error **errp)
{
SpaprXive *xive = SPAPR_XIVE(xsrc->xive);
uint64_t state = 0;
+ int ret;
assert(xive->fd != -1);
@@ -242,8 +243,15 @@ int kvmppc_xive_source_reset_one(XiveSource *xsrc, int
srcno, Error **errp)
}
}
- return kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE, srcno, &state,
- true, errp);
+ ret = kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE, srcno, &state,
+ true, errp);
+ if (ret < 0) {
+ return ret;
+ }
+
+ xsrc->status[srcno] |= XIVE_STATUS_KVM;
+
+ return 0;
}
static int kvmppc_xive_source_reset(XiveSource *xsrc, Error **errp)
diff --git a/include/hw/ppc/xive.h b/include/hw/ppc/xive.h
index 445eccfe6b73..d85520beb64a 100644
--- a/include/hw/ppc/xive.h
+++ b/include/hw/ppc/xive.h
@@ -252,6 +252,7 @@ static inline hwaddr xive_source_esb_mgmt(XiveSource *xsrc,
int srcno)
* When doing an EOI, the Q bit will indicate if the interrupt
* needs to be re-triggered.
*/
+#define XIVE_STATUS_KVM 0x8 /* Set when initialized in KVM */
#define XIVE_STATUS_ASSERTED 0x4 /* Extra bit for LSI */
#define XIVE_ESB_VAL_P 0x2
#define XIVE_ESB_VAL_Q 0x1