diff options
| -rw-r--r-- | docs/specs/ppc-spapr-xive.rst | 5 | ||||
| -rw-r--r-- | hw/ppc/spapr_irq.c | 12 |
2 files changed, 13 insertions, 4 deletions
diff --git a/docs/specs/ppc-spapr-xive.rst b/docs/specs/ppc-spapr-xive.rst index 7199db7..7144347 100644 --- a/docs/specs/ppc-spapr-xive.rst +++ b/docs/specs/ppc-spapr-xive.rst @@ -126,6 +126,9 @@ xics XICS KVM XICS emul. XICS KVM (1) QEMU warns with ``warning: kernel_irqchip requested but unavailable: IRQ_XIVE capability must be present for KVM`` + In some cases (old host kernels or KVM nested guests), one may hit a + QEMU/KVM incompatibility due to device destruction in reset. QEMU fails + with ``KVM is incompatible with ic-mode=dual,kernel-irqchip=on`` (2) QEMU fails with ``kernel_irqchip requested but unavailable: IRQ_XIVE capability must be present for KVM`` @@ -148,7 +151,7 @@ xics XICS KVM XICS emul. XICS KVM mode (XICS), either don't set the ic-mode machine property or try ic-mode=xics or ic-mode=dual`` (4) QEMU/KVM incompatibility due to device destruction in reset. QEMU fails - with ``KVM is too old to support ic-mode=dual,kernel-irqchip=on`` + with ``KVM is incompatible with ic-mode=dual,kernel-irqchip=on`` XIVE Device tree properties diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c index 2f8f7d6..72bb938 100644 --- a/hw/ppc/spapr_irq.c +++ b/hw/ppc/spapr_irq.c @@ -139,6 +139,7 @@ SpaprIrq spapr_irq_dual = { static int spapr_irq_check(SpaprMachineState *spapr, Error **errp) { + ERRP_GUARD(); MachineState *machine = MACHINE(spapr); /* @@ -179,14 +180,19 @@ static int spapr_irq_check(SpaprMachineState *spapr, Error **errp) /* * On a POWER9 host, some older KVM XICS devices cannot be destroyed and - * re-created. Detect that early to avoid QEMU to exit later when the - * guest reboots. + * re-created. Same happens with KVM nested guests. Detect that early to + * avoid QEMU to exit later when the guest reboots. */ if (kvm_enabled() && spapr->irq == &spapr_irq_dual && kvm_kernel_irqchip_required() && xics_kvm_has_broken_disconnect(spapr)) { - error_setg(errp, "KVM is too old to support ic-mode=dual,kernel-irqchip=on"); + error_setg(errp, + "KVM is incompatible with ic-mode=dual,kernel-irqchip=on"); + error_append_hint(errp, + "This can happen with an old KVM or in a KVM nested guest.\n"); + error_append_hint(errp, + "Try without kernel-irqchip or with kernel-irqchip=off.\n"); return -1; } |