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Diffstat (limited to 'arch/arm/kvm/vgic.c')
| -rw-r--r-- | arch/arm/kvm/vgic.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c new file mode 100644 index 000000000000..c400661409ab --- /dev/null +++ b/arch/arm/kvm/vgic.c @@ -0,0 +1,153 @@ +/* + * Copyright (C) 2012 ARM Ltd. + * 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, 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)) + +static u32 mmio_data_read(struct kvm_exit_mmio *mmio, u32 mask) +{ + return *((u32 *)mmio->data) & mask; +} + +static void mmio_data_write(struct kvm_exit_mmio *mmio, u32 mask, u32 value) +{ + *((u32 *)mmio->data) = value & mask; +} + +/** + * vgic_reg_access - access vgic register + * @mmio: pointer to the data describing the mmio access + * @reg: pointer to the virtual backing of vgic distributor data + * @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, + phys_addr_t offset, int mode) +{ + int word_offset = (offset & 3) * 8; + u32 mask = (1UL << (mmio->len * 8)) - 1; + u32 regval; + + /* + * Any alignment fault should have been delivered to the guest + * directly (ARM ARM B3.12.7 "Prioritization of aborts"). + */ + + if (reg) { + regval = *reg; + } else { + BUG_ON(mode != (ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED)); + regval = 0; + } + + if (mmio->is_write) { + u32 data = mmio_data_read(mmio, mask) << word_offset; + 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 << word_offset)) | data; + break; + } + *reg = regval; + } else { + switch (ACCESS_READ_MASK(mode)) { + case ACCESS_READ_RAZ: + regval = 0; + /* fall through */ + + case ACCESS_READ_VALUE: + mmio_data_write(mmio, mask, regval >> word_offset); + } + } +} + +/* + * I would have liked to use the kvm_bus_io_*() API instead, but it + * cannot cope with banked registers (only the VM pointer is passed + * around, and we need the vcpu). One of these days, someone please + * fix it! + */ +struct mmio_range { + phys_addr_t base; + unsigned long len; + bool (*handle_mmio)(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio, + phys_addr_t 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, + phys_addr_t base) +{ + const struct mmio_range *r = ranges; + phys_addr_t 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 + * @run: pointer to the kvm_run structure + * @mmio: pointer to the data describing the access + * + * 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; +} |