50c8308538
Currently, the following instructions are translated: - CACHE (indexed) - CACHE (va based): translated to a SYNCI, overkill on D-CACHE operations, but still much faster than a trap. - mfc0/mtc0: the virtual COP0 registers for the guest are implemented as 2-D array. [COP#][SEL] and this is mapped into the guest kernel address space @ VA 0x0. mfc0/mtc0 operations are transformed to load/stores. Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
149 lines
3.9 KiB
C
149 lines
3.9 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* KVM/MIPS: Binary Patching for privileged instructions, reduces traps.
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*
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* Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
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* Authors: Sanjay Lal <sanjayl@kymasys.com>
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*/
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#include <linux/errno.h>
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#include <linux/err.h>
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#include <linux/kvm_host.h>
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#include <linux/module.h>
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#include <linux/vmalloc.h>
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#include <linux/fs.h>
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#include <linux/bootmem.h>
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#include "kvm_mips_comm.h"
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#define SYNCI_TEMPLATE 0x041f0000
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#define SYNCI_BASE(x) (((x) >> 21) & 0x1f)
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#define SYNCI_OFFSET ((x) & 0xffff)
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#define LW_TEMPLATE 0x8c000000
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#define CLEAR_TEMPLATE 0x00000020
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#define SW_TEMPLATE 0xac000000
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int
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kvm_mips_trans_cache_index(uint32_t inst, uint32_t *opc,
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struct kvm_vcpu *vcpu)
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{
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int result = 0;
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unsigned long kseg0_opc;
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uint32_t synci_inst = 0x0;
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/* Replace the CACHE instruction, with a NOP */
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kseg0_opc =
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CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
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(vcpu, (unsigned long) opc));
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memcpy((void *)kseg0_opc, (void *)&synci_inst, sizeof(uint32_t));
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mips32_SyncICache(kseg0_opc, 32);
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return result;
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}
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/*
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* Address based CACHE instructions are transformed into synci(s). A little heavy
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* for just D-cache invalidates, but avoids an expensive trap
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*/
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int
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kvm_mips_trans_cache_va(uint32_t inst, uint32_t *opc,
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struct kvm_vcpu *vcpu)
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{
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int result = 0;
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unsigned long kseg0_opc;
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uint32_t synci_inst = SYNCI_TEMPLATE, base, offset;
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base = (inst >> 21) & 0x1f;
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offset = inst & 0xffff;
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synci_inst |= (base << 21);
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synci_inst |= offset;
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kseg0_opc =
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CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
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(vcpu, (unsigned long) opc));
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memcpy((void *)kseg0_opc, (void *)&synci_inst, sizeof(uint32_t));
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mips32_SyncICache(kseg0_opc, 32);
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return result;
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}
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int
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kvm_mips_trans_mfc0(uint32_t inst, uint32_t *opc, struct kvm_vcpu *vcpu)
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{
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int32_t rt, rd, sel;
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uint32_t mfc0_inst;
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unsigned long kseg0_opc, flags;
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rt = (inst >> 16) & 0x1f;
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rd = (inst >> 11) & 0x1f;
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sel = inst & 0x7;
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if ((rd == MIPS_CP0_ERRCTL) && (sel == 0)) {
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mfc0_inst = CLEAR_TEMPLATE;
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mfc0_inst |= ((rt & 0x1f) << 16);
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} else {
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mfc0_inst = LW_TEMPLATE;
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mfc0_inst |= ((rt & 0x1f) << 16);
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mfc0_inst |=
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offsetof(struct mips_coproc,
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reg[rd][sel]) + offsetof(struct kvm_mips_commpage,
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cop0);
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}
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if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) {
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kseg0_opc =
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CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
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(vcpu, (unsigned long) opc));
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memcpy((void *)kseg0_opc, (void *)&mfc0_inst, sizeof(uint32_t));
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mips32_SyncICache(kseg0_opc, 32);
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} else if (KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
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local_irq_save(flags);
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memcpy((void *)opc, (void *)&mfc0_inst, sizeof(uint32_t));
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mips32_SyncICache((unsigned long) opc, 32);
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local_irq_restore(flags);
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} else {
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kvm_err("%s: Invalid address: %p\n", __func__, opc);
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return -EFAULT;
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}
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return 0;
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}
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int
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kvm_mips_trans_mtc0(uint32_t inst, uint32_t *opc, struct kvm_vcpu *vcpu)
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{
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int32_t rt, rd, sel;
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uint32_t mtc0_inst = SW_TEMPLATE;
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unsigned long kseg0_opc, flags;
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rt = (inst >> 16) & 0x1f;
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rd = (inst >> 11) & 0x1f;
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sel = inst & 0x7;
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mtc0_inst |= ((rt & 0x1f) << 16);
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mtc0_inst |=
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offsetof(struct mips_coproc,
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reg[rd][sel]) + offsetof(struct kvm_mips_commpage, cop0);
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if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) {
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kseg0_opc =
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CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
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(vcpu, (unsigned long) opc));
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memcpy((void *)kseg0_opc, (void *)&mtc0_inst, sizeof(uint32_t));
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mips32_SyncICache(kseg0_opc, 32);
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} else if (KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
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local_irq_save(flags);
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memcpy((void *)opc, (void *)&mtc0_inst, sizeof(uint32_t));
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mips32_SyncICache((unsigned long) opc, 32);
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local_irq_restore(flags);
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} else {
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kvm_err("%s: Invalid address: %p\n", __func__, opc);
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return -EFAULT;
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}
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return 0;
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}
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