El 15/10/15 a les 13.30, Paul Durrant ha escrit: >> -----Original Message----- >> From: xen-devel-boun...@lists.xen.org [mailto:xen-devel- >> boun...@lists.xen.org] On Behalf Of Andrew Cooper >> Sent: 14 October 2015 17:02 >> To: Jan Beulich; Roger Pau Monne >> Cc: xen-de...@lists.xenproject.org >> Subject: Re: [Xen-devel] [PATCH v7 23/32] xen/x86: make sure the HVM >> callback vector is correctly set >> >> On 14/10/15 16:54, Jan Beulich wrote: >>>>>> On 02.10.15 at 17:48, <roger....@citrix.com> wrote: >>>> --- a/xen/arch/x86/hvm/irq.c >>>> +++ b/xen/arch/x86/hvm/irq.c >>>> @@ -330,6 +330,10 @@ void hvm_set_callback_via(struct domain *d, >> uint64_t >>>> via) >>>> (via_type > HVMIRQ_callback_vector) ) >>>> via_type = HVMIRQ_callback_none; >>>> >>>> + if ( via_type != HVMIRQ_callback_vector && >>>> + (!has_vlapic(d) || !has_vioapic(d) || !has_vpic(d)) ) >>>> + return; >>> Why are both IO-APIC and PIC required? Doesn't one suffice, or >>> can't MSI-like interrupts even get delivered without either? >> >> In real hardware, MSI-like interrupts have no interaction with the >> IO-APIC or PIC. >> >> In fact, the purpose of the IO-APIC is to turn legacy line interrupts >> into MSI interrupts. The PICs were from the pre-MSI days where it >> asserted the #INTR pin on the processor. >> >> Our virtual interrupt infrastructure should behave in a consistent manor. >> > > IIRC both the intx and gsi variants of the callback via go in at the vioapic > level.
OK, so I can remove the PIC requirement. Roger. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
