From 7abc0c6d35306a41a48eda7ab2b7b2d51f32f86b Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Thu, 13 Jun 2019 18:45:05 +0200 Subject: xics/spapr: Detect old KVM XICS on POWER9 hosts Older KVMs on POWER9 don't support destroying/recreating a KVM XICS device, which is required by 'dual' interrupt controller mode. This causes QEMU to emit a warning when the guest is rebooted and to fall back on XICS emulation: qemu-system-ppc64: warning: kernel_irqchip allowed but unavailable: Error on KVM_CREATE_DEVICE for XICS: File exists If kernel irqchip is required, QEMU will thus exit when the guest is first rebooted. Failing QEMU this late may be a painful experience for the user. Detect that and exit at machine init instead. Signed-off-by: Greg Kurz Message-Id: <156044430517.125694.6207865998817342638.stgit@bahia.lab.toulouse-stg.fr.ibm.com> Signed-off-by: David Gibson --- docs/specs/ppc-spapr-xive.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'docs/specs') diff --git a/docs/specs/ppc-spapr-xive.rst b/docs/specs/ppc-spapr-xive.rst index 7a64c9d..6159bc6 100644 --- a/docs/specs/ppc-spapr-xive.rst +++ b/docs/specs/ppc-spapr-xive.rst @@ -142,8 +142,8 @@ xics XICS KVM XICS emul. XICS KVM (3) QEMU fails at CAS with ``Guest requested unavailable interrupt 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. This - needs to be addressed more cleanly with an error. +(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`` XIVE Device tree properties -- cgit v1.1