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linux/arch/arm/kvm/coproc.c
Marc Zyngier 6a077e4ab9 ARM: KVM: perform save/restore of PAR 
Not saving PAR is an unfortunate oversight. If the guest performs
an AT* operation and gets scheduled out before reading the result
of the translation from PAR, it could become corrupted by another
guest or the host.

Saving this register is made slightly more complicated as KVM also
uses it on the permission fault handling path, leading to an ugly
"stash and restore" sequence. Fortunately, this is already a slow
path so we don't really care. Also, Linux doesn't do any AT*
operation, so Linux guests are not impacted by this bug.

  [ Slightly tweaked to use an even register as first operand to ldrd
    and strd operations in interrupts_head.S - Christoffer ]

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-06-26 10:50:04 -07:00

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/*
* 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, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#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/cacheflush.h>
#include <asm/cputype.h>
#include <trace/events/kvm.h>
#include <asm/vfp.h>
#include "../vfp/vfpinstr.h"
#include "trace.h"
#include "coproc.h"
/******************************************************************************
* Co-processor emulation
*****************************************************************************/
/* 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
int kvm_handle_cp10_id(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
kvm_inject_undefined(vcpu);
return 1;
}
int kvm_handle_cp_0_13_access(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
/*
* We can get here, if the host has been built without VFPv3 support,
* but the guest attempted a floating point operation.
*/
kvm_inject_undefined(vcpu);
return 1;
}
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;
}
/* See note at ARM ARM B1.14.4 */
static bool access_dcsw(struct kvm_vcpu *vcpu,
const struct coproc_params *p,
const struct coproc_reg *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->Rt1);
switch (p->CRm) {
case 6: /* Upgrade DCISW to DCCISW, as per HCR.SWIO */
case 14: /* DCCISW */
asm volatile("mcr p15, 0, %0, c7, c14, 2" : : "r" (val));
break;
case 10: /* DCCSW */
asm volatile("mcr p15, 0, %0, c7, c10, 2" : : "r" (val));
break;
}
done:
put_cpu();
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 coproc_params *p,
const struct coproc_reg *r)
{
if (p->is_write)
return ignore_write(vcpu, p);
else
return read_zero(vcpu, p);
}
#define access_pmcr pm_fake
#define access_pmcntenset pm_fake
#define access_pmcntenclr pm_fake
#define access_pmovsr pm_fake
#define access_pmselr pm_fake
#define access_pmceid0 pm_fake
#define access_pmceid1 pm_fake
#define access_pmccntr pm_fake
#define access_pmxevtyper pm_fake
#define access_pmxevcntr pm_fake
#define access_pmuserenr pm_fake
#define access_pmintenset pm_fake
#define access_pmintenclr pm_fake
/* Architected CP15 registers.
* Important: Must be sorted ascending by CRn, CRM, Op1, Op2
*/
static const struct coproc_reg cp15_regs[] = {
/* CSSELR: swapped by interrupt.S. */
{ CRn( 0), CRm( 0), Op1( 2), Op2( 0), is32,
NULL, reset_unknown, c0_CSSELR },
/* TTBR0/TTBR1: swapped by interrupt.S. */
{ CRm( 2), Op1( 0), is64, NULL, reset_unknown64, c2_TTBR0 },
{ CRm( 2), Op1( 1), is64, NULL, reset_unknown64, c2_TTBR1 },
/* TTBCR: swapped by interrupt.S. */
{ CRn( 2), CRm( 0), Op1( 0), Op2( 2), is32,
NULL, reset_val, c2_TTBCR, 0x00000000 },
/* DACR: swapped by interrupt.S. */
{ CRn( 3), CRm( 0), Op1( 0), Op2( 0), is32,
NULL, reset_unknown, c3_DACR },
/* DFSR/IFSR/ADFSR/AIFSR: swapped by interrupt.S. */
{ CRn( 5), CRm( 0), Op1( 0), Op2( 0), is32,
NULL, reset_unknown, c5_DFSR },
{ CRn( 5), CRm( 0), Op1( 0), Op2( 1), is32,
NULL, reset_unknown, c5_IFSR },
{ CRn( 5), CRm( 1), Op1( 0), Op2( 0), is32,
NULL, reset_unknown, c5_ADFSR },
{ CRn( 5), CRm( 1), Op1( 0), Op2( 1), is32,
NULL, reset_unknown, c5_AIFSR },
/* DFAR/IFAR: swapped by interrupt.S. */
{ CRn( 6), CRm( 0), Op1( 0), Op2( 0), is32,
NULL, reset_unknown, c6_DFAR },
{ CRn( 6), CRm( 0), Op1( 0), Op2( 2), is32,
NULL, reset_unknown, c6_IFAR },
/* PAR swapped by interrupt.S */
{ CRn( 7), Op1( 0), is64, NULL, reset_unknown64, c7_PAR },
/*
* DC{C,I,CI}SW operations:
*/
{ CRn( 7), CRm( 6), Op1( 0), Op2( 2), is32, access_dcsw},
{ CRn( 7), CRm(10), Op1( 0), Op2( 2), is32, access_dcsw},
{ CRn( 7), CRm(14), Op1( 0), Op2( 2), is32, access_dcsw},
/*
* Dummy performance monitor implementation.
*/
{ CRn( 9), CRm(12), Op1( 0), Op2( 0), is32, access_pmcr},
{ CRn( 9), CRm(12), Op1( 0), Op2( 1), is32, access_pmcntenset},
{ CRn( 9), CRm(12), Op1( 0), Op2( 2), is32, access_pmcntenclr},
{ CRn( 9), CRm(12), Op1( 0), Op2( 3), is32, access_pmovsr},
{ CRn( 9), CRm(12), Op1( 0), Op2( 5), is32, access_pmselr},
{ CRn( 9), CRm(12), Op1( 0), Op2( 6), is32, access_pmceid0},
{ CRn( 9), CRm(12), Op1( 0), Op2( 7), is32, access_pmceid1},
{ CRn( 9), CRm(13), Op1( 0), Op2( 0), is32, access_pmccntr},
{ CRn( 9), CRm(13), Op1( 0), Op2( 1), is32, access_pmxevtyper},
{ CRn( 9), CRm(13), Op1( 0), Op2( 2), is32, access_pmxevcntr},
{ CRn( 9), CRm(14), Op1( 0), Op2( 0), is32, access_pmuserenr},
{ CRn( 9), CRm(14), Op1( 0), Op2( 1), is32, access_pmintenset},
{ CRn( 9), CRm(14), Op1( 0), Op2( 2), is32, access_pmintenclr},
/* PRRR/NMRR (aka MAIR0/MAIR1): swapped by interrupt.S. */
{ CRn(10), CRm( 2), Op1( 0), Op2( 0), is32,
NULL, reset_unknown, c10_PRRR},
{ CRn(10), CRm( 2), Op1( 0), Op2( 1), is32,
NULL, reset_unknown, c10_NMRR},
/* VBAR: swapped by interrupt.S. */
{ CRn(12), CRm( 0), Op1( 0), Op2( 0), is32,
NULL, reset_val, c12_VBAR, 0x00000000 },
/* CONTEXTIDR/TPIDRURW/TPIDRURO/TPIDRPRW: swapped by interrupt.S. */
{ CRn(13), CRm( 0), Op1( 0), Op2( 1), is32,
NULL, reset_val, c13_CID, 0x00000000 },
{ CRn(13), CRm( 0), Op1( 0), Op2( 2), is32,
NULL, reset_unknown, c13_TID_URW },
{ CRn(13), CRm( 0), Op1( 0), Op2( 3), is32,
NULL, reset_unknown, c13_TID_URO },
{ CRn(13), CRm( 0), Op1( 0), Op2( 4), is32,
NULL, reset_unknown, c13_TID_PRIV },
/* CNTKCTL: swapped by interrupt.S. */
{ CRn(14), CRm( 1), Op1( 0), Op2( 0), is32,
NULL, reset_val, c14_CNTKCTL, 0x00000000 },
};
/* Target specific emulation tables */
static struct kvm_coproc_target_table *target_tables[KVM_ARM_NUM_TARGETS];
void kvm_register_target_coproc_table(struct kvm_coproc_target_table *table)
{
target_tables[table->target] = table;
}
/* Get specific register table for this target. */
static const struct coproc_reg *get_target_table(unsigned target, size_t *num)
{
struct kvm_coproc_target_table *table;
table = target_tables[target];
*num = table->num;
return table->table;
}
static const struct coproc_reg *find_reg(const struct coproc_params *params,
const struct coproc_reg table[],
unsigned int num)
{
unsigned int i;
for (i = 0; i < num; i++) {
const struct coproc_reg *r = &table[i];
if (params->is_64bit != r->is_64)
continue;
if (params->CRn != r->CRn)
continue;
if (params->CRm != r->CRm)
continue;
if (params->Op1 != r->Op1)
continue;
if (params->Op2 != r->Op2)
continue;
return r;
}
return NULL;
}
static int emulate_cp15(struct kvm_vcpu *vcpu,
const struct coproc_params *params)
{
size_t num;
const struct coproc_reg *table, *r;
trace_kvm_emulate_cp15_imp(params->Op1, params->Rt1, params->CRn,
params->CRm, params->Op2, params->is_write);
table = get_target_table(vcpu->arch.target, &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)) {
/* If we don't have an accessor, we should never get here! */
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 CP15 access at: %08lx\n",
*vcpu_pc(vcpu));
print_cp_instr(params);
}
kvm_inject_undefined(vcpu);
return 1;
}
/**
* 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 coproc_params params;
params.CRm = (kvm_vcpu_get_hsr(vcpu) >> 1) & 0xf;
params.Rt1 = (kvm_vcpu_get_hsr(vcpu) >> 5) & 0xf;
params.is_write = ((kvm_vcpu_get_hsr(vcpu) & 1) == 0);
params.is_64bit = true;
params.Op1 = (kvm_vcpu_get_hsr(vcpu) >> 16) & 0xf;
params.Op2 = 0;
params.Rt2 = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf;
params.CRn = 0;
return emulate_cp15(vcpu, &params);
}
static void reset_coproc_regs(struct kvm_vcpu *vcpu,
const struct coproc_reg *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_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 coproc_params params;
params.CRm = (kvm_vcpu_get_hsr(vcpu) >> 1) & 0xf;
params.Rt1 = (kvm_vcpu_get_hsr(vcpu) >> 5) & 0xf;
params.is_write = ((kvm_vcpu_get_hsr(vcpu) & 1) == 0);
params.is_64bit = false;
params.CRn = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf;
params.Op1 = (kvm_vcpu_get_hsr(vcpu) >> 14) & 0x7;
params.Op2 = (kvm_vcpu_get_hsr(vcpu) >> 17) & 0x7;
params.Rt2 = 0;
return emulate_cp15(vcpu, &params);
}
/******************************************************************************
* Userspace API
*****************************************************************************/
static bool index_to_params(u64 id, struct coproc_params *params)
{
switch (id & KVM_REG_SIZE_MASK) {
case KVM_REG_SIZE_U32:
/* 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_ARM_32_CRN_MASK
| KVM_REG_ARM_CRM_MASK
| KVM_REG_ARM_OPC1_MASK
| KVM_REG_ARM_32_OPC2_MASK))
return false;
params->is_64bit = false;
params->CRn = ((id & KVM_REG_ARM_32_CRN_MASK)
>> KVM_REG_ARM_32_CRN_SHIFT);
params->CRm = ((id & KVM_REG_ARM_CRM_MASK)
>> KVM_REG_ARM_CRM_SHIFT);
params->Op1 = ((id & KVM_REG_ARM_OPC1_MASK)
>> KVM_REG_ARM_OPC1_SHIFT);
params->Op2 = ((id & KVM_REG_ARM_32_OPC2_MASK)
>> KVM_REG_ARM_32_OPC2_SHIFT);
return true;
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_ARM_CRM_MASK
| KVM_REG_ARM_OPC1_MASK))
return false;
params->is_64bit = true;
params->CRm = ((id & KVM_REG_ARM_CRM_MASK)
>> KVM_REG_ARM_CRM_SHIFT);
params->Op1 = ((id & KVM_REG_ARM_OPC1_MASK)
>> KVM_REG_ARM_OPC1_SHIFT);
params->Op2 = 0;
params->CRn = 0;
return true;
default:
return false;
}
}
/* Decode an index value, and find the cp15 coproc_reg entry. */
static const struct coproc_reg *index_to_coproc_reg(struct kvm_vcpu *vcpu,
u64 id)
{
size_t num;
const struct coproc_reg *table, *r;
struct coproc_params params;
/* We only do cp15 for now. */
if ((id & KVM_REG_ARM_COPROC_MASK) >> KVM_REG_ARM_COPROC_SHIFT != 15)
return NULL;
if (!index_to_params(id, &params))
return NULL;
table = get_target_table(vcpu->arch.target, &num);
r = find_reg(&params, table, num);
if (!r)
r = find_reg(&params, cp15_regs, ARRAY_SIZE(cp15_regs));
/* Not saved in the cp15 array? */
if (r && !r->reg)
r = NULL;
return r;
}
/*
* These are the invariant cp15 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.
*/
/* Unfortunately, there's no register-argument for mrc, so generate. */
#define FUNCTION_FOR32(crn, crm, op1, op2, name) \
static void get_##name(struct kvm_vcpu *v, \
const struct coproc_reg *r) \
{ \
u32 val; \
\
asm volatile("mrc p15, " __stringify(op1) \
", %0, c" __stringify(crn) \
", c" __stringify(crm) \
", " __stringify(op2) "\n" : "=r" (val)); \
((struct coproc_reg *)r)->val = val; \
}
FUNCTION_FOR32(0, 0, 0, 0, MIDR)
FUNCTION_FOR32(0, 0, 0, 1, CTR)
FUNCTION_FOR32(0, 0, 0, 2, TCMTR)
FUNCTION_FOR32(0, 0, 0, 3, TLBTR)
FUNCTION_FOR32(0, 0, 0, 6, REVIDR)
FUNCTION_FOR32(0, 1, 0, 0, ID_PFR0)
FUNCTION_FOR32(0, 1, 0, 1, ID_PFR1)
FUNCTION_FOR32(0, 1, 0, 2, ID_DFR0)
FUNCTION_FOR32(0, 1, 0, 3, ID_AFR0)
FUNCTION_FOR32(0, 1, 0, 4, ID_MMFR0)
FUNCTION_FOR32(0, 1, 0, 5, ID_MMFR1)
FUNCTION_FOR32(0, 1, 0, 6, ID_MMFR2)
FUNCTION_FOR32(0, 1, 0, 7, ID_MMFR3)
FUNCTION_FOR32(0, 2, 0, 0, ID_ISAR0)
FUNCTION_FOR32(0, 2, 0, 1, ID_ISAR1)
FUNCTION_FOR32(0, 2, 0, 2, ID_ISAR2)
FUNCTION_FOR32(0, 2, 0, 3, ID_ISAR3)
FUNCTION_FOR32(0, 2, 0, 4, ID_ISAR4)
FUNCTION_FOR32(0, 2, 0, 5, ID_ISAR5)
FUNCTION_FOR32(0, 0, 1, 1, CLIDR)
FUNCTION_FOR32(0, 0, 1, 7, AIDR)
/* ->val is filled in by kvm_invariant_coproc_table_init() */
static struct coproc_reg invariant_cp15[] = {
{ CRn( 0), CRm( 0), Op1( 0), Op2( 0), is32, NULL, get_MIDR },
{ CRn( 0), CRm( 0), Op1( 0), Op2( 1), is32, NULL, get_CTR },
{ CRn( 0), CRm( 0), Op1( 0), Op2( 2), is32, NULL, get_TCMTR },
{ CRn( 0), CRm( 0), Op1( 0), Op2( 3), is32, NULL, get_TLBTR },
{ CRn( 0), CRm( 0), Op1( 0), Op2( 6), is32, NULL, get_REVIDR },
{ CRn( 0), CRm( 1), Op1( 0), Op2( 0), is32, NULL, get_ID_PFR0 },
{ CRn( 0), CRm( 1), Op1( 0), Op2( 1), is32, NULL, get_ID_PFR1 },
{ CRn( 0), CRm( 1), Op1( 0), Op2( 2), is32, NULL, get_ID_DFR0 },
{ CRn( 0), CRm( 1), Op1( 0), Op2( 3), is32, NULL, get_ID_AFR0 },
{ CRn( 0), CRm( 1), Op1( 0), Op2( 4), is32, NULL, get_ID_MMFR0 },
{ CRn( 0), CRm( 1), Op1( 0), Op2( 5), is32, NULL, get_ID_MMFR1 },
{ CRn( 0), CRm( 1), Op1( 0), Op2( 6), is32, NULL, get_ID_MMFR2 },
{ CRn( 0), CRm( 1), Op1( 0), Op2( 7), is32, NULL, get_ID_MMFR3 },
{ CRn( 0), CRm( 2), Op1( 0), Op2( 0), is32, NULL, get_ID_ISAR0 },
{ CRn( 0), CRm( 2), Op1( 0), Op2( 1), is32, NULL, get_ID_ISAR1 },
{ CRn( 0), CRm( 2), Op1( 0), Op2( 2), is32, NULL, get_ID_ISAR2 },
{ CRn( 0), CRm( 2), Op1( 0), Op2( 3), is32, NULL, get_ID_ISAR3 },
{ CRn( 0), CRm( 2), Op1( 0), Op2( 4), is32, NULL, get_ID_ISAR4 },
{ CRn( 0), CRm( 2), Op1( 0), Op2( 5), is32, NULL, get_ID_ISAR5 },
{ CRn( 0), CRm( 0), Op1( 1), Op2( 1), is32, NULL, get_CLIDR },
{ CRn( 0), CRm( 0), Op1( 1), Op2( 7), is32, NULL, get_AIDR },
};
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_cp15(u64 id, void __user *uaddr)
{
struct coproc_params params;
const struct coproc_reg *r;
if (!index_to_params(id, &params))
return -ENOENT;
r = find_reg(&params, invariant_cp15, ARRAY_SIZE(invariant_cp15));
if (!r)
return -ENOENT;
return reg_to_user(uaddr, &r->val, id);
}
static int set_invariant_cp15(u64 id, void __user *uaddr)
{
struct coproc_params params;
const struct coproc_reg *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_cp15, ARRAY_SIZE(invariant_cp15));
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;
}
}
/* 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("mcr p15, 2, %0, c0, c0, 0" : : "r" (csselr));
isb();
/* Read result out of CCSIDR */
asm volatile("mrc p15, 1, %0, c0, c0, 0" : "=r" (ccsidr));
local_irq_enable();
return ccsidr;
}
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;
}
}
#ifdef CONFIG_VFPv3
static const int vfp_sysregs[] = { KVM_REG_ARM_VFP_FPEXC,
KVM_REG_ARM_VFP_FPSCR,
KVM_REG_ARM_VFP_FPINST,
KVM_REG_ARM_VFP_FPINST2,
KVM_REG_ARM_VFP_MVFR0,
KVM_REG_ARM_VFP_MVFR1,
KVM_REG_ARM_VFP_FPSID };
static unsigned int num_fp_regs(void)
{
if (((fmrx(MVFR0) & MVFR0_A_SIMD_MASK) >> MVFR0_A_SIMD_BIT) == 2)
return 32;
else
return 16;
}
static unsigned int num_vfp_regs(void)
{
/* Normal FP regs + control regs. */
return num_fp_regs() + ARRAY_SIZE(vfp_sysregs);
}
static int copy_vfp_regids(u64 __user *uindices)
{
unsigned int i;
const u64 u32reg = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_VFP;
const u64 u64reg = KVM_REG_ARM | KVM_REG_SIZE_U64 | KVM_REG_ARM_VFP;
for (i = 0; i < num_fp_regs(); i++) {
if (put_user((u64reg | KVM_REG_ARM_VFP_BASE_REG) + i,
uindices))
return -EFAULT;
uindices++;
}
for (i = 0; i < ARRAY_SIZE(vfp_sysregs); i++) {
if (put_user(u32reg | vfp_sysregs[i], uindices))
return -EFAULT;
uindices++;
}
return num_vfp_regs();
}
static int vfp_get_reg(const struct kvm_vcpu *vcpu, u64 id, void __user *uaddr)
{
u32 vfpid = (id & KVM_REG_ARM_VFP_MASK);
u32 val;
/* 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;
if (vfpid < num_fp_regs()) {
if (KVM_REG_SIZE(id) != 8)
return -ENOENT;
return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpregs[vfpid],
id);
}
/* FP control registers are all 32 bit. */
if (KVM_REG_SIZE(id) != 4)
return -ENOENT;
switch (vfpid) {
case KVM_REG_ARM_VFP_FPEXC:
return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpexc, id);
case KVM_REG_ARM_VFP_FPSCR:
return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpscr, id);
case KVM_REG_ARM_VFP_FPINST:
return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpinst, id);
case KVM_REG_ARM_VFP_FPINST2:
return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpinst2, id);
case KVM_REG_ARM_VFP_MVFR0:
val = fmrx(MVFR0);
return reg_to_user(uaddr, &val, id);
case KVM_REG_ARM_VFP_MVFR1:
val = fmrx(MVFR1);
return reg_to_user(uaddr, &val, id);
case KVM_REG_ARM_VFP_FPSID:
val = fmrx(FPSID);
return reg_to_user(uaddr, &val, id);
default:
return -ENOENT;
}
}
static int vfp_set_reg(struct kvm_vcpu *vcpu, u64 id, const void __user *uaddr)
{
u32 vfpid = (id & KVM_REG_ARM_VFP_MASK);
u32 val;
/* 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;
if (vfpid < num_fp_regs()) {
if (KVM_REG_SIZE(id) != 8)
return -ENOENT;
return reg_from_user(&vcpu->arch.vfp_guest.fpregs[vfpid],
uaddr, id);
}
/* FP control registers are all 32 bit. */
if (KVM_REG_SIZE(id) != 4)
return -ENOENT;
switch (vfpid) {
case KVM_REG_ARM_VFP_FPEXC:
return reg_from_user(&vcpu->arch.vfp_guest.fpexc, uaddr, id);
case KVM_REG_ARM_VFP_FPSCR:
return reg_from_user(&vcpu->arch.vfp_guest.fpscr, uaddr, id);
case KVM_REG_ARM_VFP_FPINST:
return reg_from_user(&vcpu->arch.vfp_guest.fpinst, uaddr, id);
case KVM_REG_ARM_VFP_FPINST2:
return reg_from_user(&vcpu->arch.vfp_guest.fpinst2, uaddr, id);
/* These are invariant. */
case KVM_REG_ARM_VFP_MVFR0:
if (reg_from_user(&val, uaddr, id))
return -EFAULT;
if (val != fmrx(MVFR0))
return -EINVAL;
return 0;
case KVM_REG_ARM_VFP_MVFR1:
if (reg_from_user(&val, uaddr, id))
return -EFAULT;
if (val != fmrx(MVFR1))
return -EINVAL;
return 0;
case KVM_REG_ARM_VFP_FPSID:
if (reg_from_user(&val, uaddr, id))
return -EFAULT;
if (val != fmrx(FPSID))
return -EINVAL;
return 0;
default:
return -ENOENT;
}
}
#else /* !CONFIG_VFPv3 */
static unsigned int num_vfp_regs(void)
{
return 0;
}
static int copy_vfp_regids(u64 __user *uindices)
{
return 0;
}
static int vfp_get_reg(const struct kvm_vcpu *vcpu, u64 id, void __user *uaddr)
{
return -ENOENT;
}
static int vfp_set_reg(struct kvm_vcpu *vcpu, u64 id, const void __user *uaddr)
{
return -ENOENT;
}
#endif /* !CONFIG_VFPv3 */
int kvm_arm_coproc_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
const struct coproc_reg *r;
void __user *uaddr = (void __user *)(long)reg->addr;
if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
return demux_c15_get(reg->id, uaddr);
if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_VFP)
return vfp_get_reg(vcpu, reg->id, uaddr);
r = index_to_coproc_reg(vcpu, reg->id);
if (!r)
return get_invariant_cp15(reg->id, uaddr);
/* Note: copies two regs if size is 64 bit. */
return reg_to_user(uaddr, &vcpu->arch.cp15[r->reg], reg->id);
}
int kvm_arm_coproc_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
const struct coproc_reg *r;
void __user *uaddr = (void __user *)(long)reg->addr;
if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
return demux_c15_set(reg->id, uaddr);
if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_VFP)
return vfp_set_reg(vcpu, reg->id, uaddr);
r = index_to_coproc_reg(vcpu, reg->id);
if (!r)
return set_invariant_cp15(reg->id, uaddr);
/* Note: copies two regs if size is 64 bit */
return reg_from_user(&vcpu->arch.cp15[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 cp15_to_index(const struct coproc_reg *reg)
{
u64 val = KVM_REG_ARM | (15 << KVM_REG_ARM_COPROC_SHIFT);
if (reg->is_64) {
val |= KVM_REG_SIZE_U64;
val |= (reg->Op1 << KVM_REG_ARM_OPC1_SHIFT);
val |= (reg->CRm << KVM_REG_ARM_CRM_SHIFT);
} else {
val |= KVM_REG_SIZE_U32;
val |= (reg->Op1 << KVM_REG_ARM_OPC1_SHIFT);
val |= (reg->Op2 << KVM_REG_ARM_32_OPC2_SHIFT);
val |= (reg->CRm << KVM_REG_ARM_CRM_SHIFT);
val |= (reg->CRn << KVM_REG_ARM_32_CRN_SHIFT);
}
return val;
}
static bool copy_reg_to_user(const struct coproc_reg *reg, u64 __user **uind)
{
if (!*uind)
return true;
if (put_user(cp15_to_index(reg), *uind))
return false;
(*uind)++;
return true;
}
/* Assumed ordered tables, see kvm_coproc_table_init. */
static int walk_cp15(struct kvm_vcpu *vcpu, u64 __user *uind)
{
const struct coproc_reg *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, &num);
end1 = i1 + num;
i2 = cp15_regs;
end2 = cp15_regs + ARRAY_SIZE(cp15_regs);
BUG_ON(i1 == end1 || i2 == end2);
/* Walk carefully, as both tables may refer to the same register. */
while (i1 || i2) {
int cmp = cmp_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_coproc_regs(struct kvm_vcpu *vcpu)
{
return ARRAY_SIZE(invariant_cp15)
+ num_demux_regs()
+ num_vfp_regs()
+ walk_cp15(vcpu, (u64 __user *)NULL);
}
int kvm_arm_copy_coproc_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_cp15); i++) {
if (put_user(cp15_to_index(&invariant_cp15[i]), uindices))
return -EFAULT;
uindices++;
}
err = walk_cp15(vcpu, uindices);
if (err < 0)
return err;
uindices += err;
err = copy_vfp_regids(uindices);
if (err < 0)
return err;
uindices += err;
return write_demux_regids(uindices);
}
void kvm_coproc_table_init(void)
{
unsigned int i;
/* Make sure tables are unique and in order. */
for (i = 1; i < ARRAY_SIZE(cp15_regs); i++)
BUG_ON(cmp_reg(&cp15_regs[i-1], &cp15_regs[i]) >= 0);
/* We abuse the reset function to overwrite the table itself. */
for (i = 0; i < ARRAY_SIZE(invariant_cp15); i++)
invariant_cp15[i].reset(NULL, &invariant_cp15[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.
*/
asm volatile("mrc p15, 1, %0, c0, c0, 1" : "=r" (cache_levels));
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_coprocs - sets cp15 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_coprocs(struct kvm_vcpu *vcpu)
{
size_t num;
const struct coproc_reg *table;
/* Catch someone adding a register without putting in reset entry. */
memset(vcpu->arch.cp15, 0x42, sizeof(vcpu->arch.cp15));
/* Generic chip reset first (so target could override). */
reset_coproc_regs(vcpu, cp15_regs, ARRAY_SIZE(cp15_regs));
table = get_target_table(vcpu->arch.target, &num);
reset_coproc_regs(vcpu, table, num);
for (num = 1; num < NR_CP15_REGS; num++)
if (vcpu->arch.cp15[num] == 0x42424242)
panic("Didn't reset vcpu->arch.cp15[%zi]", num);
}
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