https://github.com/torvalds/linux
Tip revision: 2241ab53cbb5cdb08a6b2d4688feb13971058f65 authored by Linus Torvalds on 22 January 2023, 00:27:01 UTC
Linux 6.2-rc5
Linux 6.2-rc5
Tip revision: 2241ab5
emulate_loadstore.c
// SPDX-License-Identifier: GPL-2.0-only
/*
*
* Copyright IBM Corp. 2007
* Copyright 2011 Freescale Semiconductor, Inc.
*
* Authors: Hollis Blanchard <hollisb@us.ibm.com>
*/
#include <linux/jiffies.h>
#include <linux/hrtimer.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kvm_host.h>
#include <linux/clockchips.h>
#include <asm/reg.h>
#include <asm/time.h>
#include <asm/byteorder.h>
#include <asm/kvm_ppc.h>
#include <asm/disassemble.h>
#include <asm/ppc-opcode.h>
#include <asm/sstep.h>
#include "timing.h"
#include "trace.h"
#ifdef CONFIG_PPC_FPU
static bool kvmppc_check_fp_disabled(struct kvm_vcpu *vcpu)
{
if (!(kvmppc_get_msr(vcpu) & MSR_FP)) {
kvmppc_core_queue_fpunavail(vcpu);
return true;
}
return false;
}
#endif /* CONFIG_PPC_FPU */
#ifdef CONFIG_VSX
static bool kvmppc_check_vsx_disabled(struct kvm_vcpu *vcpu)
{
if (!(kvmppc_get_msr(vcpu) & MSR_VSX)) {
kvmppc_core_queue_vsx_unavail(vcpu);
return true;
}
return false;
}
#endif /* CONFIG_VSX */
#ifdef CONFIG_ALTIVEC
static bool kvmppc_check_altivec_disabled(struct kvm_vcpu *vcpu)
{
if (!(kvmppc_get_msr(vcpu) & MSR_VEC)) {
kvmppc_core_queue_vec_unavail(vcpu);
return true;
}
return false;
}
#endif /* CONFIG_ALTIVEC */
/*
* XXX to do:
* lfiwax, lfiwzx
* vector loads and stores
*
* Instructions that trap when used on cache-inhibited mappings
* are not emulated here: multiple and string instructions,
* lq/stq, and the load-reserve/store-conditional instructions.
*/
int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
{
u32 inst;
enum emulation_result emulated = EMULATE_FAIL;
struct instruction_op op;
/* this default type might be overwritten by subcategories */
kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst);
if (emulated != EMULATE_DONE)
return emulated;
vcpu->arch.mmio_vsx_copy_nums = 0;
vcpu->arch.mmio_vsx_offset = 0;
vcpu->arch.mmio_copy_type = KVMPPC_VSX_COPY_NONE;
vcpu->arch.mmio_sp64_extend = 0;
vcpu->arch.mmio_sign_extend = 0;
vcpu->arch.mmio_vmx_copy_nums = 0;
vcpu->arch.mmio_vmx_offset = 0;
vcpu->arch.mmio_host_swabbed = 0;
emulated = EMULATE_FAIL;
vcpu->arch.regs.msr = vcpu->arch.shared->msr;
if (analyse_instr(&op, &vcpu->arch.regs, ppc_inst(inst)) == 0) {
int type = op.type & INSTR_TYPE_MASK;
int size = GETSIZE(op.type);
vcpu->mmio_is_write = OP_IS_STORE(type);
switch (type) {
case LOAD: {
int instr_byte_swap = op.type & BYTEREV;
if (op.type & SIGNEXT)
emulated = kvmppc_handle_loads(vcpu,
op.reg, size, !instr_byte_swap);
else
emulated = kvmppc_handle_load(vcpu,
op.reg, size, !instr_byte_swap);
if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
break;
}
#ifdef CONFIG_PPC_FPU
case LOAD_FP:
if (kvmppc_check_fp_disabled(vcpu))
return EMULATE_DONE;
if (op.type & FPCONV)
vcpu->arch.mmio_sp64_extend = 1;
if (op.type & SIGNEXT)
emulated = kvmppc_handle_loads(vcpu,
KVM_MMIO_REG_FPR|op.reg, size, 1);
else
emulated = kvmppc_handle_load(vcpu,
KVM_MMIO_REG_FPR|op.reg, size, 1);
if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
break;
#endif
#ifdef CONFIG_ALTIVEC
case LOAD_VMX:
if (kvmppc_check_altivec_disabled(vcpu))
return EMULATE_DONE;
/* Hardware enforces alignment of VMX accesses */
vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
if (size == 16) { /* lvx */
vcpu->arch.mmio_copy_type =
KVMPPC_VMX_COPY_DWORD;
} else if (size == 4) { /* lvewx */
vcpu->arch.mmio_copy_type =
KVMPPC_VMX_COPY_WORD;
} else if (size == 2) { /* lvehx */
vcpu->arch.mmio_copy_type =
KVMPPC_VMX_COPY_HWORD;
} else if (size == 1) { /* lvebx */
vcpu->arch.mmio_copy_type =
KVMPPC_VMX_COPY_BYTE;
} else
break;
vcpu->arch.mmio_vmx_offset =
(vcpu->arch.vaddr_accessed & 0xf)/size;
if (size == 16) {
vcpu->arch.mmio_vmx_copy_nums = 2;
emulated = kvmppc_handle_vmx_load(vcpu,
KVM_MMIO_REG_VMX|op.reg,
8, 1);
} else {
vcpu->arch.mmio_vmx_copy_nums = 1;
emulated = kvmppc_handle_vmx_load(vcpu,
KVM_MMIO_REG_VMX|op.reg,
size, 1);
}
break;
#endif
#ifdef CONFIG_VSX
case LOAD_VSX: {
int io_size_each;
if (op.vsx_flags & VSX_CHECK_VEC) {
if (kvmppc_check_altivec_disabled(vcpu))
return EMULATE_DONE;
} else {
if (kvmppc_check_vsx_disabled(vcpu))
return EMULATE_DONE;
}
if (op.vsx_flags & VSX_FPCONV)
vcpu->arch.mmio_sp64_extend = 1;
if (op.element_size == 8) {
if (op.vsx_flags & VSX_SPLAT)
vcpu->arch.mmio_copy_type =
KVMPPC_VSX_COPY_DWORD_LOAD_DUMP;
else
vcpu->arch.mmio_copy_type =
KVMPPC_VSX_COPY_DWORD;
} else if (op.element_size == 4) {
if (op.vsx_flags & VSX_SPLAT)
vcpu->arch.mmio_copy_type =
KVMPPC_VSX_COPY_WORD_LOAD_DUMP;
else
vcpu->arch.mmio_copy_type =
KVMPPC_VSX_COPY_WORD;
} else
break;
if (size < op.element_size) {
/* precision convert case: lxsspx, etc */
vcpu->arch.mmio_vsx_copy_nums = 1;
io_size_each = size;
} else { /* lxvw4x, lxvd2x, etc */
vcpu->arch.mmio_vsx_copy_nums =
size/op.element_size;
io_size_each = op.element_size;
}
emulated = kvmppc_handle_vsx_load(vcpu,
KVM_MMIO_REG_VSX|op.reg, io_size_each,
1, op.type & SIGNEXT);
break;
}
#endif
case STORE:
/* if need byte reverse, op.val has been reversed by
* analyse_instr().
*/
emulated = kvmppc_handle_store(vcpu, op.val, size, 1);
if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
break;
#ifdef CONFIG_PPC_FPU
case STORE_FP:
if (kvmppc_check_fp_disabled(vcpu))
return EMULATE_DONE;
/* The FP registers need to be flushed so that
* kvmppc_handle_store() can read actual FP vals
* from vcpu->arch.
*/
if (vcpu->kvm->arch.kvm_ops->giveup_ext)
vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
MSR_FP);
if (op.type & FPCONV)
vcpu->arch.mmio_sp64_extend = 1;
emulated = kvmppc_handle_store(vcpu,
VCPU_FPR(vcpu, op.reg), size, 1);
if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
break;
#endif
#ifdef CONFIG_ALTIVEC
case STORE_VMX:
if (kvmppc_check_altivec_disabled(vcpu))
return EMULATE_DONE;
/* Hardware enforces alignment of VMX accesses. */
vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
if (vcpu->kvm->arch.kvm_ops->giveup_ext)
vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
MSR_VEC);
if (size == 16) { /* stvx */
vcpu->arch.mmio_copy_type =
KVMPPC_VMX_COPY_DWORD;
} else if (size == 4) { /* stvewx */
vcpu->arch.mmio_copy_type =
KVMPPC_VMX_COPY_WORD;
} else if (size == 2) { /* stvehx */
vcpu->arch.mmio_copy_type =
KVMPPC_VMX_COPY_HWORD;
} else if (size == 1) { /* stvebx */
vcpu->arch.mmio_copy_type =
KVMPPC_VMX_COPY_BYTE;
} else
break;
vcpu->arch.mmio_vmx_offset =
(vcpu->arch.vaddr_accessed & 0xf)/size;
if (size == 16) {
vcpu->arch.mmio_vmx_copy_nums = 2;
emulated = kvmppc_handle_vmx_store(vcpu,
op.reg, 8, 1);
} else {
vcpu->arch.mmio_vmx_copy_nums = 1;
emulated = kvmppc_handle_vmx_store(vcpu,
op.reg, size, 1);
}
break;
#endif
#ifdef CONFIG_VSX
case STORE_VSX: {
int io_size_each;
if (op.vsx_flags & VSX_CHECK_VEC) {
if (kvmppc_check_altivec_disabled(vcpu))
return EMULATE_DONE;
} else {
if (kvmppc_check_vsx_disabled(vcpu))
return EMULATE_DONE;
}
if (vcpu->kvm->arch.kvm_ops->giveup_ext)
vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
MSR_VSX);
if (op.vsx_flags & VSX_FPCONV)
vcpu->arch.mmio_sp64_extend = 1;
if (op.element_size == 8)
vcpu->arch.mmio_copy_type =
KVMPPC_VSX_COPY_DWORD;
else if (op.element_size == 4)
vcpu->arch.mmio_copy_type =
KVMPPC_VSX_COPY_WORD;
else
break;
if (size < op.element_size) {
/* precise conversion case, like stxsspx */
vcpu->arch.mmio_vsx_copy_nums = 1;
io_size_each = size;
} else { /* stxvw4x, stxvd2x, etc */
vcpu->arch.mmio_vsx_copy_nums =
size/op.element_size;
io_size_each = op.element_size;
}
emulated = kvmppc_handle_vsx_store(vcpu,
op.reg, io_size_each, 1);
break;
}
#endif
case CACHEOP:
/* Do nothing. The guest is performing dcbi because
* hardware DMA is not snooped by the dcache, but
* emulated DMA either goes through the dcache as
* normal writes, or the host kernel has handled dcache
* coherence.
*/
emulated = EMULATE_DONE;
break;
default:
break;
}
}
trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
/* Advance past emulated instruction. */
if (emulated != EMULATE_FAIL)
kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
return emulated;
}