[PATCH v4 04/13] ARM: KVM: Initial VGIC MMIO support code
Christoffer Dall
c.dall at virtualopensystems.com
Tue Nov 13 08:32:15 EST 2012
On Mon, Nov 12, 2012 at 3:54 AM, Dong Aisheng <b29396 at freescale.com> wrote:
> On Sat, Nov 10, 2012 at 04:44:44PM +0100, Christoffer Dall wrote:
>> From: Marc Zyngier <marc.zyngier at arm.com>
>>
>> Wire the initial in-kernel MMIO support code for the VGIC, used
>> for the distributor emulation.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
>> Signed-off-by: Christoffer Dall <c.dall at virtualopensystems.com>
>> ---
>> arch/arm/include/asm/kvm_vgic.h | 6 +-
>> arch/arm/kvm/Makefile | 1
>> arch/arm/kvm/vgic.c | 138 +++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 144 insertions(+), 1 deletion(-)
>> create mode 100644 arch/arm/kvm/vgic.c
>>
>> diff --git a/arch/arm/include/asm/kvm_vgic.h b/arch/arm/include/asm/kvm_vgic.h
>> index d75540a..b444ecf 100644
>> --- a/arch/arm/include/asm/kvm_vgic.h
>> +++ b/arch/arm/include/asm/kvm_vgic.h
>> @@ -30,7 +30,11 @@ struct kvm_vcpu;
>> struct kvm_run;
>> struct kvm_exit_mmio;
>>
>> -#ifndef CONFIG_KVM_ARM_VGIC
>> +#ifdef CONFIG_KVM_ARM_VGIC
>> +bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
>> + struct kvm_exit_mmio *mmio);
>> +
>> +#else
>> static inline int kvm_vgic_hyp_init(void)
>> {
>> return 0;
>> diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile
>> index 8a4f396..c019f02 100644
>> --- a/arch/arm/kvm/Makefile
>> +++ b/arch/arm/kvm/Makefile
>> @@ -20,3 +20,4 @@ obj-$(CONFIG_KVM_ARM_HOST) += $(addprefix ../../../virt/kvm/, kvm_main.o coalesc
>>
>> obj-$(CONFIG_KVM_ARM_HOST) += arm.o guest.o mmu.o emulate.o reset.o
>> obj-$(CONFIG_KVM_ARM_HOST) += coproc.o coproc_a15.o mmio.o decode.o
>> +obj-$(CONFIG_KVM_ARM_VGIC) += vgic.o
>> diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c
>> new file mode 100644
>> index 0000000..26ada3b
>> --- /dev/null
>> +++ b/arch/arm/kvm/vgic.c
>> @@ -0,0 +1,138 @@
>> +/*
>> + * Copyright (C) 2012 ARM Ltd.
>> + * Author: Marc Zyngier <marc.zyngier at 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, write to the Free Software
>> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
>> + */
>> +
>> +#include <linux/kvm.h>
>> +#include <linux/kvm_host.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <asm/kvm_emulate.h>
>> +
>> +#define ACCESS_READ_VALUE (1 << 0)
>> +#define ACCESS_READ_RAZ (0 << 0)
>> +#define ACCESS_READ_MASK(x) ((x) & (1 << 0))
>> +#define ACCESS_WRITE_IGNORED (0 << 1)
>> +#define ACCESS_WRITE_SETBIT (1 << 1)
>> +#define ACCESS_WRITE_CLEARBIT (2 << 1)
>> +#define ACCESS_WRITE_VALUE (3 << 1)
>> +#define ACCESS_WRITE_MASK(x) ((x) & (3 << 1))
>> +
>> +/**
>> + * vgic_reg_access - access vgic register
>> + * @mmio: pointer to the data describing the mmio access
>> + * @reg: pointer to the virtual backing of the vgic distributor struct
>
> Is this correct?
>
>> + * @offset: least significant 2 bits used for word offset
>> + * @mode: ACCESS_ mode (see defines above)
>> + *
>> + * Helper to make vgic register access easier using one of the access
>> + * modes defined for vgic register access
>> + * (read,raz,write-ignored,setbit,clearbit,write)
>> + */
>> +static void vgic_reg_access(struct kvm_exit_mmio *mmio, u32 *reg,
>> + u32 offset, int mode)
>> +{
>> + int word_offset = offset & 3;
>> + int shift = word_offset * 8;
>> + u32 mask;
>> + u32 regval;
>> +
>> + /*
>> + * Any alignment fault should have been delivered to the guest
>> + * directly (ARM ARM B3.12.7 "Prioritization of aborts").
>> + */
>> +
>> + mask = (~0U) >> (word_offset * 8);
>> + if (reg)
>> + regval = *reg;
>> + else {
>> + BUG_ON(mode != (ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED));
>> + regval = 0;
>> + }
>> +
>> + if (mmio->is_write) {
>> + u32 data = (*((u32 *)mmio->data) & mask) << shift;
>> + switch (ACCESS_WRITE_MASK(mode)) {
>> + case ACCESS_WRITE_IGNORED:
>> + return;
>> +
>> + case ACCESS_WRITE_SETBIT:
>> + regval |= data;
>> + break;
>> +
>> + case ACCESS_WRITE_CLEARBIT:
>> + regval &= ~data;
>> + break;
>> +
>> + case ACCESS_WRITE_VALUE:
>> + regval = (regval & ~(mask << shift)) | data;
>> + break;
>> + }
>> + *reg = regval;
>> + } else {
>> + switch (ACCESS_READ_MASK(mode)) {
>> + case ACCESS_READ_RAZ:
>> + regval = 0;
>> + /* fall through */
>> +
>> + case ACCESS_READ_VALUE:
>> + *((u32 *)mmio->data) = (regval >> shift) & mask;
>> + }
>> + }
>> +}
>> +
>> +/* All this should be handled by kvm_bus_io_*()... FIXME!!! */
>> +struct mmio_range {
>> + unsigned long base;
>> + unsigned long len;
>> + bool (*handle_mmio)(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
>> + u32 offset);
>> +};
>> +
>> +static const struct mmio_range vgic_ranges[] = {
>> + {}
>> +};
>> +
>> +static const
>> +struct mmio_range *find_matching_range(const struct mmio_range *ranges,
>> + struct kvm_exit_mmio *mmio,
>> + unsigned long base)
>> +{
>> + const struct mmio_range *r = ranges;
>> + unsigned long addr = mmio->phys_addr - base;
>> +
>> + while (r->len) {
>> + if (addr >= r->base &&
>> + (addr + mmio->len) <= (r->base + r->len))
>> + return r;
>> + r++;
>> + }
>> +
>> + return NULL;
>> +}
>> +
>> +/**
>> + * vgic_handle_mmio - handle an in-kernel MMIO access
>> + * @vcpu: pointer to the vcpu performing the access
>> + * @mmio: pointer to the data describing the access
>
> Can we also have @run here?
>
>> + *
>> + * returns true if the MMIO access has been performed in kernel space,
>> + * and false if it needs to be emulated in user space.
>> + */
>> +bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run, struct kvm_exit_mmio *mmio)
>> +{
>> + return KVM_EXIT_MMIO;
>> +}
>>
thanks,
fixed
-Christoffer
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