On 21 November 2012 20:29, Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, Nov 21, 2012 at 1:15 PM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: >> + default_vmcr = readl_relaxed(vgic_vctrl_base + GICH_VMCR); >> + default_vmcr |= (0x1f << 27); /* Priority */ >> + default_vmcr &= ~0x21f; /* Clear VEM, VMCPBR, VMFIQEn, VMAckCtl, VMGrp1En, VMGrp0En */ >> + > > actually, why are we reading hardware state here at all? Don't we want > to run with a spceifically controlled setup that we can simply > compile-time define? Good point, yes. (I suppose in some sense it's a property of the guest CPU, or at least the guest-visible GIC, but let's not get into configuring GICs :-)) > (granted teh meaning of all these fields has already faded far back in > my memory, so maybe this question is nonsense) Most of them are defined to reset-to-zero by the GIC v2 spec. The remaining ones we're not setting here are the binary-point ones (which reset to the hardware-supported-minimum) and the reserved fields (which are SBZP). So probably the right thing is to write a fixed correct value to the VMCR which specifies the minimum-binary-point-fields used by the A15's GIC, and then readback to check that the host GIC supports at least those minima. -- PMM _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
