> -----Original Message----- > From: David Woodhouse [mailto:dwmw2@xxxxxxxxxxxxx] > Sent: Wednesday, January 28, 2015 11:38 PM > To: Wu, Feng > Cc: tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; hpa@xxxxxxxxx; x86@xxxxxxxxxx; > gleb@xxxxxxxxxx; pbonzini@xxxxxxxxxx; joro@xxxxxxxxxx; > alex.williamson@xxxxxxxxxx; jiang.liu@xxxxxxxxxxxxxxx; eric.auger@xxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; > kvm@xxxxxxxxxxxxxxx > Subject: Re: [v3 08/26] iommu, x86: Add intel_irq_remapping_capability() for > Intel > > On Fri, 2014-12-12 at 23:14 +0800, Feng Wu wrote: > > Add the Intel side implementation for capability in > > struct irq_remap_ops. > > > > Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx> > > Reviewed-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx> > > > +static bool intel_irq_remapping_capability(enum irq_remap_cap cap) > > +{ > > + struct dmar_drhd_unit *drhd; > > + struct intel_iommu *iommu; > > + > > + switch (cap) { > > + case IRQ_POSTING_CAP: > > + /* > > + * If 1) posted-interrupts is disabled by user > > + * or 2) irq remapping is disabled, posted-interrupts > > + * is not supported. > > + */ > > + if (disable_irq_post || !irq_remapping_enabled) > > + return 0; > > + > > + for_each_iommu(iommu, drhd) > > + if (!cap_pi_support(iommu->cap)) > > + return 0; > > + > > If a new IOMMU is hotplugged now which doesn't support posted > interrupts, what happens? Good question, Just had a offline discussion with Jiang Liu, actually, there is the same question for IR. In the current implementation, If IR is in use and a new IOMMU without IR capability is hotplugged, it will reject this hotplugging. I think I can simple follow the same policy for PI. Thanks, Feng > > -- > David Woodhouse Open Source Technology > Centre > David.Woodhouse@xxxxxxxxx Intel > Corporation ��.n��������+%������w��{.n�����o�^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�
