diff options
Diffstat (limited to 'arch/mips/kvm/dyntrans.c')
| -rw-r--r-- | arch/mips/kvm/dyntrans.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/arch/mips/kvm/dyntrans.c b/arch/mips/kvm/dyntrans.c new file mode 100644 index 000000000..521121bde --- /dev/null +++ b/arch/mips/kvm/dyntrans.c @@ -0,0 +1,148 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * KVM/MIPS: Binary Patching for privileged instructions, reduces traps. + * + * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved. + * Authors: Sanjay Lal <sanjayl@kymasys.com> + */ + +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/kvm_host.h> +#include <linux/module.h> +#include <linux/vmalloc.h> +#include <linux/fs.h> +#include <linux/bootmem.h> +#include <asm/cacheflush.h> + +#include "commpage.h" + +#define SYNCI_TEMPLATE 0x041f0000 +#define SYNCI_BASE(x) (((x) >> 21) & 0x1f) +#define SYNCI_OFFSET ((x) & 0xffff) + +#define LW_TEMPLATE 0x8c000000 +#define CLEAR_TEMPLATE 0x00000020 +#define SW_TEMPLATE 0xac000000 + +int kvm_mips_trans_cache_index(uint32_t inst, uint32_t *opc, + struct kvm_vcpu *vcpu) +{ + int result = 0; + unsigned long kseg0_opc; + uint32_t synci_inst = 0x0; + + /* Replace the CACHE instruction, with a NOP */ + kseg0_opc = + CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa + (vcpu, (unsigned long) opc)); + memcpy((void *)kseg0_opc, (void *)&synci_inst, sizeof(uint32_t)); + local_flush_icache_range(kseg0_opc, kseg0_opc + 32); + + return result; +} + +/* + * Address based CACHE instructions are transformed into synci(s). A little + * heavy for just D-cache invalidates, but avoids an expensive trap + */ +int kvm_mips_trans_cache_va(uint32_t inst, uint32_t *opc, + struct kvm_vcpu *vcpu) +{ + int result = 0; + unsigned long kseg0_opc; + uint32_t synci_inst = SYNCI_TEMPLATE, base, offset; + + base = (inst >> 21) & 0x1f; + offset = inst & 0xffff; + synci_inst |= (base << 21); + synci_inst |= offset; + + kseg0_opc = + CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa + (vcpu, (unsigned long) opc)); + memcpy((void *)kseg0_opc, (void *)&synci_inst, sizeof(uint32_t)); + local_flush_icache_range(kseg0_opc, kseg0_opc + 32); + + return result; +} + +int kvm_mips_trans_mfc0(uint32_t inst, uint32_t *opc, struct kvm_vcpu *vcpu) +{ + int32_t rt, rd, sel; + uint32_t mfc0_inst; + unsigned long kseg0_opc, flags; + + rt = (inst >> 16) & 0x1f; + rd = (inst >> 11) & 0x1f; + sel = inst & 0x7; + + if ((rd == MIPS_CP0_ERRCTL) && (sel == 0)) { + mfc0_inst = CLEAR_TEMPLATE; + mfc0_inst |= ((rt & 0x1f) << 16); + } else { + mfc0_inst = LW_TEMPLATE; + mfc0_inst |= ((rt & 0x1f) << 16); + mfc0_inst |= + offsetof(struct mips_coproc, + reg[rd][sel]) + offsetof(struct kvm_mips_commpage, + cop0); + } + + if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) { + kseg0_opc = + CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa + (vcpu, (unsigned long) opc)); + memcpy((void *)kseg0_opc, (void *)&mfc0_inst, sizeof(uint32_t)); + local_flush_icache_range(kseg0_opc, kseg0_opc + 32); + } else if (KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) { + local_irq_save(flags); + memcpy((void *)opc, (void *)&mfc0_inst, sizeof(uint32_t)); + local_flush_icache_range((unsigned long)opc, + (unsigned long)opc + 32); + local_irq_restore(flags); + } else { + kvm_err("%s: Invalid address: %p\n", __func__, opc); + return -EFAULT; + } + + return 0; +} + +int kvm_mips_trans_mtc0(uint32_t inst, uint32_t *opc, struct kvm_vcpu *vcpu) +{ + int32_t rt, rd, sel; + uint32_t mtc0_inst = SW_TEMPLATE; + unsigned long kseg0_opc, flags; + + rt = (inst >> 16) & 0x1f; + rd = (inst >> 11) & 0x1f; + sel = inst & 0x7; + + mtc0_inst |= ((rt & 0x1f) << 16); + mtc0_inst |= + offsetof(struct mips_coproc, + reg[rd][sel]) + offsetof(struct kvm_mips_commpage, cop0); + + if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) { + kseg0_opc = + CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa + (vcpu, (unsigned long) opc)); + memcpy((void *)kseg0_opc, (void *)&mtc0_inst, sizeof(uint32_t)); + local_flush_icache_range(kseg0_opc, kseg0_opc + 32); + } else if (KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) { + local_irq_save(flags); + memcpy((void *)opc, (void *)&mtc0_inst, sizeof(uint32_t)); + local_flush_icache_range((unsigned long)opc, + (unsigned long)opc + 32); + local_irq_restore(flags); + } else { + kvm_err("%s: Invalid address: %p\n", __func__, opc); + return -EFAULT; + } + + return 0; +} |