blob: f1527a465c1b1b071356b18ea066a468b30edabb [file] [log] [blame]
/*
* 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 kvm_mips_commpage,
cop0.reg[rd][sel]);
}
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 kvm_mips_commpage, cop0.reg[rd][sel]);
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;
}