[PATCH v3 18/19] KVM: ARM: vgic: add the GICv3 backend

[christoffer.dall@linaro.org (Christoffer Dall)]

On Thu, May 15, 2014 at 09:13:02AM +0100, Marc Zyngier wrote:
> On Fri, May 09 2014 at  3:07:31 pm BST, Christoffer Dall <christoffer.dall@linaro.org> wrote:
> > On Wed, Apr 16, 2014 at 02:39:50PM +0100, Marc Zyngier wrote:
> >> Introduce the support code for emulating a GICv2 on top of GICv3
> >> hardware.
> >>
> >> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >> ---
> >>  include/kvm/arm_vgic.h |  26 ++++++
> >>  virt/kvm/arm/vgic-v3.c | 220 +++++++++++++++++++++++++++++++++++++++++++++++++
> >>  virt/kvm/arm/vgic.c    |   2 +
> >>  3 files changed, 248 insertions(+)
> >>  create mode 100644 virt/kvm/arm/vgic-v3.c
> >>
> 
> [...]
> 
> >> diff --git a/virt/kvm/arm/vgic-v3.c b/virt/kvm/arm/vgic-v3.c
> >> new file mode 100644
> >> index 0000000..a804a73
> >> --- /dev/null
> >> +++ b/virt/kvm/arm/vgic-v3.c
> >> @@ -0,0 +1,220 @@
> >> +/*
> >> + * Copyright (C) 2013 ARM Limited, All Rights Reserved.
> >> + * Author: Marc Zyngier <marc.zyngier@arm.com>
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify
> >> + * it under the terms of the GNU General Public License version 2 as
> >> + * published by the Free Software Foundation.
> >> + *
> >> + * This program is distributed in the hope that it will be useful,
> >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> >> + * GNU General Public License for more details.
> >> + *
> >> + * You should have received a copy of the GNU General Public License
> >> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> >> + */
> >> +
> >> +#include <linux/cpu.h>
> >> +#include <linux/kvm.h>
> >> +#include <linux/kvm_host.h>
> >> +#include <linux/interrupt.h>
> >> +#include <linux/io.h>
> >> +#include <linux/of.h>
> >> +#include <linux/of_address.h>
> >> +#include <linux/of_irq.h>
> >> +
> >> +#include <linux/irqchip/arm-gic-v3.h>
> >> +
> >> +#include <asm/kvm_emulate.h>
> >> +#include <asm/kvm_arm.h>
> >> +#include <asm/kvm_mmu.h>
> >> +
> >> +/* These are for GICv2 emulation only */
> >
> > Is this really true, seems like you're using them to form the lr values
> > for the hardware below.
> >
> >> +#define GICH_LR_VIRTUALID            (0x3ffUL << 0)
> >> +#define GICH_LR_PHYSID_CPUID_SHIFT   (10)
> >> +#define GICH_LR_PHYSID_CPUID         (7UL << GICH_LR_PHYSID_CPUID_SHIFT)
> >
> > can't we include them from the existing header file then?
> 
> I've given this some more thought, and I think they actually belong
> here. The arm-gic-v3.h file is really relevant to GICv3 used in v3
> mode. Here, we're using the GICv3 HW to inject GICv2-style interrupts
> (ID limited to 1023, CPUID present in the LR...).
> 
> So I'd rather keep them here than expose it to the outside world, as I
> fear this would be rather confusing.
> 
Fair enough.

-Christoffer