On Wed, May 15, 2019 at 07:04:24PM +0200, Greg Kurz wrote: > If a machine is started with ic-mode=xive but the guest only knows > about XICS, eg. an RHEL 7.6 guest, the kernel panics. This is > expected but a bit unfortunate since the crash doesn't provide > much information for the end user to guess what's happening. > > Detect that during CAS and exit QEMU with a proper error message > instead, like it is already done for the MMU. > > Even if this is less likely to happen, the opposite case of a guest > that only knows about XIVE would certainly fail all the same if the > machine is started with ic-mode=xics. > > Also, the only valid values a guest can pass in byte 23 of OV5 during > CAS are 0b00 (XIVE legacy mode) and 0b01 (XIVE exploitation mode). Any > other value is a bug, at least with the current spec. Again, it does > not seem right to let the guest go on without a precise idea of the > interrupt mode it asked for. > > Handle these cases as well. > > Reported-by: Satheesh Rajendran <sathn...@linux.vnet.ibm.com> > Signed-off-by: Greg Kurz <gr...@kaod.org> > --- > hw/ppc/spapr_hcall.c | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c > index 6c16d2b12040..63a55614b83d 100644 > --- a/hw/ppc/spapr_hcall.c > +++ b/hw/ppc/spapr_hcall.c > @@ -1513,6 +1513,7 @@ static target_ulong > h_client_architecture_support(PowerPCCPU *cpu, > bool guest_radix; > Error *local_err = NULL; > bool raw_mode_supported = false; > + bool guest_xive; > > cas_pvr = cas_check_pvr(spapr, cpu, &addr, &raw_mode_supported, > &local_err); > if (local_err) { > @@ -1545,10 +1546,17 @@ static target_ulong > h_client_architecture_support(PowerPCCPU *cpu, > error_report("guest requested hash and radix MMU, which is > invalid."); > exit(EXIT_FAILURE); > } > + if (spapr_ovec_test(ov5_guest, OV5_XIVE_BOTH)) { > + error_report("guest requested an invalid interrupt mode"); > + exit(EXIT_FAILURE); > + } > + > /* The radix/hash bit in byte 24 requires special handling: */ > guest_radix = spapr_ovec_test(ov5_guest, OV5_MMU_RADIX_300); > spapr_ovec_clear(ov5_guest, OV5_MMU_RADIX_300); > > + guest_xive = spapr_ovec_test(ov5_guest, OV5_XIVE_EXPLOIT); > + > /* > * HPT resizing is a bit of a special case, because when enabled > * we assume an HPT guest will support it until it says it > @@ -1632,6 +1640,22 @@ static target_ulong > h_client_architecture_support(PowerPCCPU *cpu, > ov5_updates) != 0); > } > > + /* > + * Ensure the guest asks for an interrupt mode we support; otherwise > + * terminate the boot. > + */ > + if (guest_xive) { > + if (spapr->irq->ov5 == SPAPR_OV5_XIVE_LEGACY) { > + error_report("Guest requested unavailable interrupt mode > (XIVE)"); > + exit(EXIT_FAILURE); > + } > + } else { > + if (spapr->irq->ov5 == SPAPR_OV5_XIVE_EXPLOIT) { > + error_report("Guest requested unavailable interrupt mode > (XICS)");
Looks like there is a typo in the error msg reported, instead it should be something like below "Guest requested unavailable interrupt mode(XIVE), please use supported interrupt mode(ic-type=xics)" Same for the previous check aswell. Coz, I booted 3.10(kernel) guest with ic-type=xive and got a below error, which seems wrong 2019-05-16T06:24:58.713261Z qemu-system-ppc64: Guest requested unavailable interrupt mode (XICS) Regards, -Satheesh. > + exit(EXIT_FAILURE); > + } > + } > + > /* > * Generate a machine reset when we have an update of the > * interrupt mode. Only required when the machine supports both >