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linux/arch/arm64/kvm/sys_regs.c

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/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* Derived from arch/arm/kvm/coproc.c:
* Copyright (C) 2012 - Virtual Open Systems and Columbia University
* Authors: Rusty Russell <rusty@rustcorp.com.au>
* Christoffer Dall <c.dall@virtualopensystems.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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/mm.h>
#include <linux/kvm_host.h>
#include <linux/uaccess.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_host.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_coproc.h>
#include <asm/kvm_mmu.h>
#include <asm/cacheflush.h>
#include <asm/cputype.h>
#include <trace/events/kvm.h>
#include "sys_regs.h"
/*
* All of this file is extremly similar to the ARM coproc.c, but the
* types are different. My gut feeling is that it should be pretty
* easy to merge, but that would be an ABI breakage -- again. VFP
* would also need to be abstracted.
*
* For AArch32, we only take care of what is being trapped. Anything
* that has to do with init and userspace access has to go via the
* 64bit interface.
*/
/* 3 bits per cache level, as per CLIDR, but non-existent caches always 0 */
static u32 cache_levels;
/* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */
#define CSSELR_MAX 12
/* Which cache CCSIDR represents depends on CSSELR value. */
static u32 get_ccsidr(u32 csselr)
{
u32 ccsidr;
/* Make sure noone else changes CSSELR during this! */
local_irq_disable();
/* Put value into CSSELR */
asm volatile("msr csselr_el1, %x0" : : "r" (csselr));
isb();
/* Read result out of CCSIDR */
asm volatile("mrs %0, ccsidr_el1" : "=r" (ccsidr));
local_irq_enable();
return ccsidr;
}
static void do_dc_cisw(u32 val)
{
asm volatile("dc cisw, %x0" : : "r" (val));
dsb();
}
static void do_dc_csw(u32 val)
{
asm volatile("dc csw, %x0" : : "r" (val));
dsb();
}
/* See note at ARM ARM B1.14.4 */
static bool access_dcsw(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
unsigned long val;
int cpu;
if (!p->is_write)
return read_from_write_only(vcpu, p);
cpu = get_cpu();
cpumask_setall(&vcpu->arch.require_dcache_flush);
cpumask_clear_cpu(cpu, &vcpu->arch.require_dcache_flush);
/* If we were already preempted, take the long way around */
if (cpu != vcpu->arch.last_pcpu) {
flush_cache_all();
goto done;
}
val = *vcpu_reg(vcpu, p->Rt);
switch (p->CRm) {
case 6: /* Upgrade DCISW to DCCISW, as per HCR.SWIO */
case 14: /* DCCISW */
do_dc_cisw(val);
break;
case 10: /* DCCSW */
do_dc_csw(val);
break;
}
done:
put_cpu();
return true;
}
/*
* Generic accessor for VM registers. Only called as long as HCR_TVM
* is set.
*/
static bool access_vm_reg(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
unsigned long val;
BUG_ON(!p->is_write);
val = *vcpu_reg(vcpu, p->Rt);
if (!p->is_aarch32) {
vcpu_sys_reg(vcpu, r->reg) = val;
} else {
vcpu_cp15(vcpu, r->reg) = val & 0xffffffffUL;
if (!p->is_32bit)
vcpu_cp15(vcpu, r->reg + 1) = val >> 32;
}
return true;
}
/*
* SCTLR_EL1 accessor. Only called as long as HCR_TVM is set. If the
* guest enables the MMU, we stop trapping the VM sys_regs and leave
* it in complete control of the caches.
*/
static bool access_sctlr(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
access_vm_reg(vcpu, p, r);
if (vcpu_has_cache_enabled(vcpu)) { /* MMU+Caches enabled? */
vcpu->arch.hcr_el2 &= ~HCR_TVM;
stage2_flush_vm(vcpu->kvm);
}
return true;
}
/*
* We could trap ID_DFR0 and tell the guest we don't support performance
* monitoring. Unfortunately the patch to make the kernel check ID_DFR0 was
* NAKed, so it will read the PMCR anyway.
*
* Therefore we tell the guest we have 0 counters. Unfortunately, we
* must always support PMCCNTR (the cycle counter): we just RAZ/WI for
* all PM registers, which doesn't crash the guest kernel at least.
*/
static bool pm_fake(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write)
return ignore_write(vcpu, p);
else
return read_zero(vcpu, p);
}
static void reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
u64 amair;
asm volatile("mrs %0, amair_el1\n" : "=r" (amair));
vcpu_sys_reg(vcpu, AMAIR_EL1) = amair;
}
static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
/*
* Simply map the vcpu_id into the Aff0 field of the MPIDR.
*/
vcpu_sys_reg(vcpu, MPIDR_EL1) = (1UL << 31) | (vcpu->vcpu_id & 0xff);
}
/*
* Architected system registers.
* Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2
*/
static const struct sys_reg_desc sys_reg_descs[] = {
/* DC ISW */
{ Op0(0b01), Op1(0b000), CRn(0b0111), CRm(0b0110), Op2(0b010),
access_dcsw },
/* DC CSW */
{ Op0(0b01), Op1(0b000), CRn(0b0111), CRm(0b1010), Op2(0b010),
access_dcsw },
/* DC CISW */
{ Op0(0b01), Op1(0b000), CRn(0b0111), CRm(0b1110), Op2(0b010),
access_dcsw },
/* TEECR32_EL1 */
{ Op0(0b10), Op1(0b010), CRn(0b0000), CRm(0b0000), Op2(0b000),
NULL, reset_val, TEECR32_EL1, 0 },
/* TEEHBR32_EL1 */
{ Op0(0b10), Op1(0b010), CRn(0b0001), CRm(0b0000), Op2(0b000),
NULL, reset_val, TEEHBR32_EL1, 0 },
/* DBGVCR32_EL2 */
{ Op0(0b10), Op1(0b100), CRn(0b0000), CRm(0b0111), Op2(0b000),
NULL, reset_val, DBGVCR32_EL2, 0 },
/* MPIDR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0000), Op2(0b101),
NULL, reset_mpidr, MPIDR_EL1 },
/* SCTLR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0001), CRm(0b0000), Op2(0b000),
access_sctlr, reset_val, SCTLR_EL1, 0x00C50078 },
/* CPACR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0001), CRm(0b0000), Op2(0b010),
NULL, reset_val, CPACR_EL1, 0 },
/* TTBR0_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0010), CRm(0b0000), Op2(0b000),
access_vm_reg, reset_unknown, TTBR0_EL1 },
/* TTBR1_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0010), CRm(0b0000), Op2(0b001),
access_vm_reg, reset_unknown, TTBR1_EL1 },
/* TCR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0010), CRm(0b0000), Op2(0b010),
access_vm_reg, reset_val, TCR_EL1, 0 },
/* AFSR0_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0101), CRm(0b0001), Op2(0b000),
access_vm_reg, reset_unknown, AFSR0_EL1 },
/* AFSR1_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0101), CRm(0b0001), Op2(0b001),
access_vm_reg, reset_unknown, AFSR1_EL1 },
/* ESR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0101), CRm(0b0010), Op2(0b000),
access_vm_reg, reset_unknown, ESR_EL1 },
/* FAR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0110), CRm(0b0000), Op2(0b000),
access_vm_reg, reset_unknown, FAR_EL1 },
/* PAR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0111), CRm(0b0100), Op2(0b000),
NULL, reset_unknown, PAR_EL1 },
/* PMINTENSET_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1001), CRm(0b1110), Op2(0b001),
pm_fake },
/* PMINTENCLR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1001), CRm(0b1110), Op2(0b010),
pm_fake },
/* MAIR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1010), CRm(0b0010), Op2(0b000),
access_vm_reg, reset_unknown, MAIR_EL1 },
/* AMAIR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1010), CRm(0b0011), Op2(0b000),
access_vm_reg, reset_amair_el1, AMAIR_EL1 },
/* VBAR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b0000), Op2(0b000),
NULL, reset_val, VBAR_EL1, 0 },
/* CONTEXTIDR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1101), CRm(0b0000), Op2(0b001),
access_vm_reg, reset_val, CONTEXTIDR_EL1, 0 },
/* TPIDR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1101), CRm(0b0000), Op2(0b100),
NULL, reset_unknown, TPIDR_EL1 },
/* CNTKCTL_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1110), CRm(0b0001), Op2(0b000),
NULL, reset_val, CNTKCTL_EL1, 0},
/* CSSELR_EL1 */
{ Op0(0b11), Op1(0b010), CRn(0b0000), CRm(0b0000), Op2(0b000),
NULL, reset_unknown, CSSELR_EL1 },
/* PMCR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b000),
pm_fake },
/* PMCNTENSET_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b001),
pm_fake },
/* PMCNTENCLR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b010),
pm_fake },
/* PMOVSCLR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b011),
pm_fake },
/* PMSWINC_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b100),
pm_fake },
/* PMSELR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b101),
pm_fake },
/* PMCEID0_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b110),
pm_fake },
/* PMCEID1_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b111),
pm_fake },
/* PMCCNTR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b000),
pm_fake },
/* PMXEVTYPER_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b001),
pm_fake },
/* PMXEVCNTR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b010),
pm_fake },
/* PMUSERENR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1110), Op2(0b000),
pm_fake },
/* PMOVSSET_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1110), Op2(0b011),
pm_fake },
/* TPIDR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1101), CRm(0b0000), Op2(0b010),
NULL, reset_unknown, TPIDR_EL0 },
/* TPIDRRO_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1101), CRm(0b0000), Op2(0b011),
NULL, reset_unknown, TPIDRRO_EL0 },
/* DACR32_EL2 */
{ Op0(0b11), Op1(0b100), CRn(0b0011), CRm(0b0000), Op2(0b000),
NULL, reset_unknown, DACR32_EL2 },
/* IFSR32_EL2 */
{ Op0(0b11), Op1(0b100), CRn(0b0101), CRm(0b0000), Op2(0b001),
NULL, reset_unknown, IFSR32_EL2 },
/* FPEXC32_EL2 */
{ Op0(0b11), Op1(0b100), CRn(0b0101), CRm(0b0011), Op2(0b000),
NULL, reset_val, FPEXC32_EL2, 0x70 },
};
/*
* Trapped cp15 registers. TTBR0/TTBR1 get a double encoding,
* depending on the way they are accessed (as a 32bit or a 64bit
* register).
*/
static const struct sys_reg_desc cp15_regs[] = {
{ Op1( 0), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, c2_TTBR0 },
{ Op1( 0), CRn( 1), CRm( 0), Op2( 0), access_sctlr, NULL, c1_SCTLR },
{ Op1( 0), CRn( 2), CRm( 0), Op2( 0), access_vm_reg, NULL, c2_TTBR0 },
{ Op1( 0), CRn( 2), CRm( 0), Op2( 1), access_vm_reg, NULL, c2_TTBR1 },
{ Op1( 0), CRn( 2), CRm( 0), Op2( 2), access_vm_reg, NULL, c2_TTBCR },
{ Op1( 0), CRn( 3), CRm( 0), Op2( 0), access_vm_reg, NULL, c3_DACR },
{ Op1( 0), CRn( 5), CRm( 0), Op2( 0), access_vm_reg, NULL, c5_DFSR },
{ Op1( 0), CRn( 5), CRm( 0), Op2( 1), access_vm_reg, NULL, c5_IFSR },
{ Op1( 0), CRn( 5), CRm( 1), Op2( 0), access_vm_reg, NULL, c5_ADFSR },
{ Op1( 0), CRn( 5), CRm( 1), Op2( 1), access_vm_reg, NULL, c5_AIFSR },
{ Op1( 0), CRn( 6), CRm( 0), Op2( 0), access_vm_reg, NULL, c6_DFAR },
{ Op1( 0), CRn( 6), CRm( 0), Op2( 2), access_vm_reg, NULL, c6_IFAR },
/*
* DC{C,I,CI}SW operations:
*/
{ Op1( 0), CRn( 7), CRm( 6), Op2( 2), access_dcsw },
{ Op1( 0), CRn( 7), CRm(10), Op2( 2), access_dcsw },
{ Op1( 0), CRn( 7), CRm(14), Op2( 2), access_dcsw },
{ Op1( 0), CRn( 9), CRm(12), Op2( 0), pm_fake },
{ Op1( 0), CRn( 9), CRm(12), Op2( 1), pm_fake },
{ Op1( 0), CRn( 9), CRm(12), Op2( 2), pm_fake },
{ Op1( 0), CRn( 9), CRm(12), Op2( 3), pm_fake },
{ Op1( 0), CRn( 9), CRm(12), Op2( 5), pm_fake },
{ Op1( 0), CRn( 9), CRm(12), Op2( 6), pm_fake },
{ Op1( 0), CRn( 9), CRm(12), Op2( 7), pm_fake },
{ Op1( 0), CRn( 9), CRm(13), Op2( 0), pm_fake },
{ Op1( 0), CRn( 9), CRm(13), Op2( 1), pm_fake },
{ Op1( 0), CRn( 9), CRm(13), Op2( 2), pm_fake },
{ Op1( 0), CRn( 9), CRm(14), Op2( 0), pm_fake },
{ Op1( 0), CRn( 9), CRm(14), Op2( 1), pm_fake },
{ Op1( 0), CRn( 9), CRm(14), Op2( 2), pm_fake },
{ Op1( 0), CRn(10), CRm( 2), Op2( 0), access_vm_reg, NULL, c10_PRRR },
{ Op1( 0), CRn(10), CRm( 2), Op2( 1), access_vm_reg, NULL, c10_NMRR },
{ Op1( 0), CRn(10), CRm( 3), Op2( 0), access_vm_reg, NULL, c10_AMAIR0 },
{ Op1( 0), CRn(10), CRm( 3), Op2( 1), access_vm_reg, NULL, c10_AMAIR1 },
{ Op1( 0), CRn(13), CRm( 0), Op2( 1), access_vm_reg, NULL, c13_CID },
{ Op1( 1), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, c2_TTBR1 },
};
/* Target specific emulation tables */
static struct kvm_sys_reg_target_table *target_tables[KVM_ARM_NUM_TARGETS];
void kvm_register_target_sys_reg_table(unsigned int target,
struct kvm_sys_reg_target_table *table)
{
target_tables[target] = table;
}
/* Get specific register table for this target. */
static const struct sys_reg_desc *get_target_table(unsigned target,
bool mode_is_64,
size_t *num)
{
struct kvm_sys_reg_target_table *table;
table = target_tables[target];
if (mode_is_64) {
*num = table->table64.num;
return table->table64.table;
} else {
*num = table->table32.num;
return table->table32.table;
}
}
static const struct sys_reg_desc *find_reg(const struct sys_reg_params *params,
const struct sys_reg_desc table[],
unsigned int num)
{
unsigned int i;
for (i = 0; i < num; i++) {
const struct sys_reg_desc *r = &table[i];
if (params->Op0 != r->Op0)
continue;
if (params->Op1 != r->Op1)
continue;
if (params->CRn != r->CRn)
continue;
if (params->CRm != r->CRm)
continue;
if (params->Op2 != r->Op2)
continue;
return r;
}
return NULL;
}
int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
kvm_inject_undefined(vcpu);
return 1;
}
int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
kvm_inject_undefined(vcpu);
return 1;
}
static void emulate_cp15(struct kvm_vcpu *vcpu,
const struct sys_reg_params *params)
{
size_t num;
const struct sys_reg_desc *table, *r;
table = get_target_table(vcpu->arch.target, false, &num);
/* Search target-specific then generic table. */
r = find_reg(params, table, num);
if (!r)
r = find_reg(params, cp15_regs, ARRAY_SIZE(cp15_regs));
if (likely(r)) {
/*
* Not having an accessor means that we have
* configured a trap that we don't know how to
* handle. This certainly qualifies as a gross bug
* that should be fixed right away.
*/
BUG_ON(!r->access);
if (likely(r->access(vcpu, params, r))) {
/* Skip instruction, since it was emulated */
kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
return;
}
/* If access function fails, it should complain. */
}
kvm_err("Unsupported guest CP15 access at: %08lx\n", *vcpu_pc(vcpu));
print_sys_reg_instr(params);
kvm_inject_undefined(vcpu);
}
/**
* kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access
* @vcpu: The VCPU pointer
* @run: The kvm_run struct
*/
int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
struct sys_reg_params params;
u32 hsr = kvm_vcpu_get_hsr(vcpu);
int Rt2 = (hsr >> 10) & 0xf;
params.is_aarch32 = true;
params.is_32bit = false;
params.CRm = (hsr >> 1) & 0xf;
params.Rt = (hsr >> 5) & 0xf;
params.is_write = ((hsr & 1) == 0);
params.Op0 = 0;
params.Op1 = (hsr >> 16) & 0xf;
params.Op2 = 0;
params.CRn = 0;
/*
* Massive hack here. Store Rt2 in the top 32bits so we only
* have one register to deal with. As we use the same trap
* backends between AArch32 and AArch64, we get away with it.
*/
if (params.is_write) {
u64 val = *vcpu_reg(vcpu, params.Rt);
val &= 0xffffffff;
val |= *vcpu_reg(vcpu, Rt2) << 32;
*vcpu_reg(vcpu, params.Rt) = val;
}
emulate_cp15(vcpu, &params);
/* Do the opposite hack for the read side */
if (!params.is_write) {
u64 val = *vcpu_reg(vcpu, params.Rt);
val >>= 32;
*vcpu_reg(vcpu, Rt2) = val;
}
return 1;
}
/**
* kvm_handle_cp15_32 -- handles a mrc/mcr trap on a guest CP15 access
* @vcpu: The VCPU pointer
* @run: The kvm_run struct
*/
int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
struct sys_reg_params params;
u32 hsr = kvm_vcpu_get_hsr(vcpu);
params.is_aarch32 = true;
params.is_32bit = true;
params.CRm = (hsr >> 1) & 0xf;
params.Rt = (hsr >> 5) & 0xf;
params.is_write = ((hsr & 1) == 0);
params.CRn = (hsr >> 10) & 0xf;
params.Op0 = 0;
params.Op1 = (hsr >> 14) & 0x7;
params.Op2 = (hsr >> 17) & 0x7;
emulate_cp15(vcpu, &params);
return 1;
}
static int emulate_sys_reg(struct kvm_vcpu *vcpu,
const struct sys_reg_params *params)
{
size_t num;
const struct sys_reg_desc *table, *r;
table = get_target_table(vcpu->arch.target, true, &num);
/* Search target-specific then generic table. */
r = find_reg(params, table, num);
if (!r)
r = find_reg(params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
if (likely(r)) {
/*
* Not having an accessor means that we have
* configured a trap that we don't know how to
* handle. This certainly qualifies as a gross bug
* that should be fixed right away.
*/
BUG_ON(!r->access);
if (likely(r->access(vcpu, params, r))) {
/* Skip instruction, since it was emulated */
kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
return 1;
}
/* If access function fails, it should complain. */
} else {
kvm_err("Unsupported guest sys_reg access at: %lx\n",
*vcpu_pc(vcpu));
print_sys_reg_instr(params);
}
kvm_inject_undefined(vcpu);
return 1;
}
static void reset_sys_reg_descs(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *table, size_t num)
{
unsigned long i;
for (i = 0; i < num; i++)
if (table[i].reset)
table[i].reset(vcpu, &table[i]);
}
/**
* kvm_handle_sys_reg -- handles a mrs/msr trap on a guest sys_reg access
* @vcpu: The VCPU pointer
* @run: The kvm_run struct
*/
int kvm_handle_sys_reg(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
struct sys_reg_params params;
unsigned long esr = kvm_vcpu_get_hsr(vcpu);
params.is_aarch32 = false;
params.is_32bit = false;
params.Op0 = (esr >> 20) & 3;
params.Op1 = (esr >> 14) & 0x7;
params.CRn = (esr >> 10) & 0xf;
params.CRm = (esr >> 1) & 0xf;
params.Op2 = (esr >> 17) & 0x7;
params.Rt = (esr >> 5) & 0x1f;
params.is_write = !(esr & 1);
return emulate_sys_reg(vcpu, &params);
}
/******************************************************************************
* Userspace API
*****************************************************************************/
static bool index_to_params(u64 id, struct sys_reg_params *params)
{
switch (id & KVM_REG_SIZE_MASK) {
case KVM_REG_SIZE_U64:
/* Any unused index bits means it's not valid. */
if (id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK
| KVM_REG_ARM_COPROC_MASK
| KVM_REG_ARM64_SYSREG_OP0_MASK
| KVM_REG_ARM64_SYSREG_OP1_MASK
| KVM_REG_ARM64_SYSREG_CRN_MASK
| KVM_REG_ARM64_SYSREG_CRM_MASK
| KVM_REG_ARM64_SYSREG_OP2_MASK))
return false;
params->Op0 = ((id & KVM_REG_ARM64_SYSREG_OP0_MASK)
>> KVM_REG_ARM64_SYSREG_OP0_SHIFT);
params->Op1 = ((id & KVM_REG_ARM64_SYSREG_OP1_MASK)
>> KVM_REG_ARM64_SYSREG_OP1_SHIFT);
params->CRn = ((id & KVM_REG_ARM64_SYSREG_CRN_MASK)
>> KVM_REG_ARM64_SYSREG_CRN_SHIFT);
params->CRm = ((id & KVM_REG_ARM64_SYSREG_CRM_MASK)
>> KVM_REG_ARM64_SYSREG_CRM_SHIFT);
params->Op2 = ((id & KVM_REG_ARM64_SYSREG_OP2_MASK)
>> KVM_REG_ARM64_SYSREG_OP2_SHIFT);
return true;
default:
return false;
}
}
/* Decode an index value, and find the sys_reg_desc entry. */
static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
u64 id)
{
size_t num;
const struct sys_reg_desc *table, *r;
struct sys_reg_params params;
/* We only do sys_reg for now. */
if ((id & KVM_REG_ARM_COPROC_MASK) != KVM_REG_ARM64_SYSREG)
return NULL;
if (!index_to_params(id, &params))
return NULL;
table = get_target_table(vcpu->arch.target, true, &num);
r = find_reg(&params, table, num);
if (!r)
r = find_reg(&params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
/* Not saved in the sys_reg array? */
if (r && !r->reg)
r = NULL;
return r;
}
/*
* These are the invariant sys_reg registers: we let the guest see the
* host versions of these, so they're part of the guest state.
*
* A future CPU may provide a mechanism to present different values to
* the guest, or a future kvm may trap them.
*/
#define FUNCTION_INVARIANT(reg) \
static void get_##reg(struct kvm_vcpu *v, \
const struct sys_reg_desc *r) \
{ \
u64 val; \
\
asm volatile("mrs %0, " __stringify(reg) "\n" \
: "=r" (val)); \
((struct sys_reg_desc *)r)->val = val; \
}
FUNCTION_INVARIANT(midr_el1)
FUNCTION_INVARIANT(ctr_el0)
FUNCTION_INVARIANT(revidr_el1)
FUNCTION_INVARIANT(id_pfr0_el1)
FUNCTION_INVARIANT(id_pfr1_el1)
FUNCTION_INVARIANT(id_dfr0_el1)
FUNCTION_INVARIANT(id_afr0_el1)
FUNCTION_INVARIANT(id_mmfr0_el1)
FUNCTION_INVARIANT(id_mmfr1_el1)
FUNCTION_INVARIANT(id_mmfr2_el1)
FUNCTION_INVARIANT(id_mmfr3_el1)
FUNCTION_INVARIANT(id_isar0_el1)
FUNCTION_INVARIANT(id_isar1_el1)
FUNCTION_INVARIANT(id_isar2_el1)
FUNCTION_INVARIANT(id_isar3_el1)
FUNCTION_INVARIANT(id_isar4_el1)
FUNCTION_INVARIANT(id_isar5_el1)
FUNCTION_INVARIANT(clidr_el1)
FUNCTION_INVARIANT(aidr_el1)
/* ->val is filled in by kvm_sys_reg_table_init() */
static struct sys_reg_desc invariant_sys_regs[] = {
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0000), Op2(0b000),
NULL, get_midr_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0000), Op2(0b110),
NULL, get_revidr_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b000),
NULL, get_id_pfr0_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b001),
NULL, get_id_pfr1_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b010),
NULL, get_id_dfr0_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b011),
NULL, get_id_afr0_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b100),
NULL, get_id_mmfr0_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b101),
NULL, get_id_mmfr1_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b110),
NULL, get_id_mmfr2_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b111),
NULL, get_id_mmfr3_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b000),
NULL, get_id_isar0_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b001),
NULL, get_id_isar1_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b010),
NULL, get_id_isar2_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b011),
NULL, get_id_isar3_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b100),
NULL, get_id_isar4_el1 },
{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b101),
NULL, get_id_isar5_el1 },
{ Op0(0b11), Op1(0b001), CRn(0b0000), CRm(0b0000), Op2(0b001),
NULL, get_clidr_el1 },
{ Op0(0b11), Op1(0b001), CRn(0b0000), CRm(0b0000), Op2(0b111),
NULL, get_aidr_el1 },
{ Op0(0b11), Op1(0b011), CRn(0b0000), CRm(0b0000), Op2(0b001),
NULL, get_ctr_el0 },
};
static int reg_from_user(void *val, const void __user *uaddr, u64 id)
{
/* This Just Works because we are little endian. */
if (copy_from_user(val, uaddr, KVM_REG_SIZE(id)) != 0)
return -EFAULT;
return 0;
}
static int reg_to_user(void __user *uaddr, const void *val, u64 id)
{
/* This Just Works because we are little endian. */
if (copy_to_user(uaddr, val, KVM_REG_SIZE(id)) != 0)
return -EFAULT;
return 0;
}
static int get_invariant_sys_reg(u64 id, void __user *uaddr)
{
struct sys_reg_params params;
const struct sys_reg_desc *r;
if (!index_to_params(id, &params))
return -ENOENT;
r = find_reg(&params, invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs));
if (!r)
return -ENOENT;
return reg_to_user(uaddr, &r->val, id);
}
static int set_invariant_sys_reg(u64 id, void __user *uaddr)
{
struct sys_reg_params params;
const struct sys_reg_desc *r;
int err;
u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */
if (!index_to_params(id, &params))
return -ENOENT;
r = find_reg(&params, invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs));
if (!r)
return -ENOENT;
err = reg_from_user(&val, uaddr, id);
if (err)
return err;
/* This is what we mean by invariant: you can't change it. */
if (r->val != val)
return -EINVAL;
return 0;
}
static bool is_valid_cache(u32 val)
{
u32 level, ctype;
if (val >= CSSELR_MAX)
return -ENOENT;
/* Bottom bit is Instruction or Data bit. Next 3 bits are level. */
level = (val >> 1);
ctype = (cache_levels >> (level * 3)) & 7;
switch (ctype) {
case 0: /* No cache */
return false;
case 1: /* Instruction cache only */
return (val & 1);
case 2: /* Data cache only */
case 4: /* Unified cache */
return !(val & 1);
case 3: /* Separate instruction and data caches */
return true;
default: /* Reserved: we can't know instruction or data. */
return false;
}
}
static int demux_c15_get(u64 id, void __user *uaddr)
{
u32 val;
u32 __user *uval = uaddr;
/* Fail if we have unknown bits set. */
if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
| ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
return -ENOENT;
switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
case KVM_REG_ARM_DEMUX_ID_CCSIDR:
if (KVM_REG_SIZE(id) != 4)
return -ENOENT;
val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
>> KVM_REG_ARM_DEMUX_VAL_SHIFT;
if (!is_valid_cache(val))
return -ENOENT;
return put_user(get_ccsidr(val), uval);
default:
return -ENOENT;
}
}
static int demux_c15_set(u64 id, void __user *uaddr)
{
u32 val, newval;
u32 __user *uval = uaddr;
/* Fail if we have unknown bits set. */
if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
| ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
return -ENOENT;
switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
case KVM_REG_ARM_DEMUX_ID_CCSIDR:
if (KVM_REG_SIZE(id) != 4)
return -ENOENT;
val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
>> KVM_REG_ARM_DEMUX_VAL_SHIFT;
if (!is_valid_cache(val))
return -ENOENT;
if (get_user(newval, uval))
return -EFAULT;
/* This is also invariant: you can't change it. */
if (newval != get_ccsidr(val))
return -EINVAL;
return 0;
default:
return -ENOENT;
}
}
int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
const struct sys_reg_desc *r;
void __user *uaddr = (void __user *)(unsigned long)reg->addr;
if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
return demux_c15_get(reg->id, uaddr);
if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
return -ENOENT;
r = index_to_sys_reg_desc(vcpu, reg->id);
if (!r)
return get_invariant_sys_reg(reg->id, uaddr);
return reg_to_user(uaddr, &vcpu_sys_reg(vcpu, r->reg), reg->id);
}
int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
const struct sys_reg_desc *r;
void __user *uaddr = (void __user *)(unsigned long)reg->addr;
if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
return demux_c15_set(reg->id, uaddr);
if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
return -ENOENT;
r = index_to_sys_reg_desc(vcpu, reg->id);
if (!r)
return set_invariant_sys_reg(reg->id, uaddr);
return reg_from_user(&vcpu_sys_reg(vcpu, r->reg), uaddr, reg->id);
}
static unsigned int num_demux_regs(void)
{
unsigned int i, count = 0;
for (i = 0; i < CSSELR_MAX; i++)
if (is_valid_cache(i))
count++;
return count;
}
static int write_demux_regids(u64 __user *uindices)
{
u64 val = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX;
unsigned int i;
val |= KVM_REG_ARM_DEMUX_ID_CCSIDR;
for (i = 0; i < CSSELR_MAX; i++) {
if (!is_valid_cache(i))
continue;
if (put_user(val | i, uindices))
return -EFAULT;
uindices++;
}
return 0;
}
static u64 sys_reg_to_index(const struct sys_reg_desc *reg)
{
return (KVM_REG_ARM64 | KVM_REG_SIZE_U64 |
KVM_REG_ARM64_SYSREG |
(reg->Op0 << KVM_REG_ARM64_SYSREG_OP0_SHIFT) |
(reg->Op1 << KVM_REG_ARM64_SYSREG_OP1_SHIFT) |
(reg->CRn << KVM_REG_ARM64_SYSREG_CRN_SHIFT) |
(reg->CRm << KVM_REG_ARM64_SYSREG_CRM_SHIFT) |
(reg->Op2 << KVM_REG_ARM64_SYSREG_OP2_SHIFT));
}
static bool copy_reg_to_user(const struct sys_reg_desc *reg, u64 __user **uind)
{
if (!*uind)
return true;
if (put_user(sys_reg_to_index(reg), *uind))
return false;
(*uind)++;
return true;
}
/* Assumed ordered tables, see kvm_sys_reg_table_init. */
static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind)
{
const struct sys_reg_desc *i1, *i2, *end1, *end2;
unsigned int total = 0;
size_t num;
/* We check for duplicates here, to allow arch-specific overrides. */
i1 = get_target_table(vcpu->arch.target, true, &num);
end1 = i1 + num;
i2 = sys_reg_descs;
end2 = sys_reg_descs + ARRAY_SIZE(sys_reg_descs);
BUG_ON(i1 == end1 || i2 == end2);
/* Walk carefully, as both tables may refer to the same register. */
while (i1 || i2) {
int cmp = cmp_sys_reg(i1, i2);
/* target-specific overrides generic entry. */
if (cmp <= 0) {
/* Ignore registers we trap but don't save. */
if (i1->reg) {
if (!copy_reg_to_user(i1, &uind))
return -EFAULT;
total++;
}
} else {
/* Ignore registers we trap but don't save. */
if (i2->reg) {
if (!copy_reg_to_user(i2, &uind))
return -EFAULT;
total++;
}
}
if (cmp <= 0 && ++i1 == end1)
i1 = NULL;
if (cmp >= 0 && ++i2 == end2)
i2 = NULL;
}
return total;
}
unsigned long kvm_arm_num_sys_reg_descs(struct kvm_vcpu *vcpu)
{
return ARRAY_SIZE(invariant_sys_regs)
+ num_demux_regs()
+ walk_sys_regs(vcpu, (u64 __user *)NULL);
}
int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
{
unsigned int i;
int err;
/* Then give them all the invariant registers' indices. */
for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) {
if (put_user(sys_reg_to_index(&invariant_sys_regs[i]), uindices))
return -EFAULT;
uindices++;
}
err = walk_sys_regs(vcpu, uindices);
if (err < 0)
return err;
uindices += err;
return write_demux_regids(uindices);
}
void kvm_sys_reg_table_init(void)
{
unsigned int i;
struct sys_reg_desc clidr;
/* Make sure tables are unique and in order. */
for (i = 1; i < ARRAY_SIZE(sys_reg_descs); i++)
BUG_ON(cmp_sys_reg(&sys_reg_descs[i-1], &sys_reg_descs[i]) >= 0);
/* We abuse the reset function to overwrite the table itself. */
for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++)
invariant_sys_regs[i].reset(NULL, &invariant_sys_regs[i]);
/*
* CLIDR format is awkward, so clean it up. See ARM B4.1.20:
*
* If software reads the Cache Type fields from Ctype1
* upwards, once it has seen a value of 0b000, no caches
* exist at further-out levels of the hierarchy. So, for
* example, if Ctype3 is the first Cache Type field with a
* value of 0b000, the values of Ctype4 to Ctype7 must be
* ignored.
*/
get_clidr_el1(NULL, &clidr); /* Ugly... */
cache_levels = clidr.val;
for (i = 0; i < 7; i++)
if (((cache_levels >> (i*3)) & 7) == 0)
break;
/* Clear all higher bits. */
cache_levels &= (1 << (i*3))-1;
}
/**
* kvm_reset_sys_regs - sets system registers to reset value
* @vcpu: The VCPU pointer
*
* This function finds the right table above and sets the registers on the
* virtual CPU struct to their architecturally defined reset values.
*/
void kvm_reset_sys_regs(struct kvm_vcpu *vcpu)
{
size_t num;
const struct sys_reg_desc *table;
/* Catch someone adding a register without putting in reset entry. */
memset(&vcpu->arch.ctxt.sys_regs, 0x42, sizeof(vcpu->arch.ctxt.sys_regs));
/* Generic chip reset first (so target could override). */
reset_sys_reg_descs(vcpu, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
table = get_target_table(vcpu->arch.target, true, &num);
reset_sys_reg_descs(vcpu, table, num);
for (num = 1; num < NR_SYS_REGS; num++)
if (vcpu_sys_reg(vcpu, num) == 0x4242424242424242)
panic("Didn't reset vcpu_sys_reg(%zi)", num);
}
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