linux/arch/arm64/include/asm/kvm_emulate.h
Reiji Watanabe 26bf74bd9f KVM: arm64: mixed-width check should be skipped for uninitialized vCPUs
KVM allows userspace to configure either all EL1 32bit or 64bit vCPUs
for a guest.  At vCPU reset, vcpu_allowed_register_width() checks
if the vcpu's register width is consistent with all other vCPUs'.
Since the checking is done even against vCPUs that are not initialized
(KVM_ARM_VCPU_INIT has not been done) yet, the uninitialized vCPUs
are erroneously treated as 64bit vCPU, which causes the function to
incorrectly detect a mixed-width VM.

Introduce KVM_ARCH_FLAG_EL1_32BIT and KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED
bits for kvm->arch.flags.  A value of the EL1_32BIT bit indicates that
the guest needs to be configured with all 32bit or 64bit vCPUs, and
a value of the REG_WIDTH_CONFIGURED bit indicates if a value of the
EL1_32BIT bit is valid (already set up). Values in those bits are set at
the first KVM_ARM_VCPU_INIT for the guest based on KVM_ARM_VCPU_EL1_32BIT
configuration for the vCPU.

Check vcpu's register width against those new bits at the vcpu's
KVM_ARM_VCPU_INIT (instead of against other vCPUs' register width).

Fixes: 66e94d5caf ("KVM: arm64: Prevent mixed-width VM creation")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220329031924.619453-2-reijiw@google.com
2022-04-06 12:29:45 +01:00

491 lines
12 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* Derived from arch/arm/include/kvm_emulate.h
* Copyright (C) 2012 - Virtual Open Systems and Columbia University
* Author: Christoffer Dall <c.dall@virtualopensystems.com>
*/
#ifndef __ARM64_KVM_EMULATE_H__
#define __ARM64_KVM_EMULATE_H__
#include <linux/kvm_host.h>
#include <asm/debug-monitors.h>
#include <asm/esr.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_hyp.h>
#include <asm/ptrace.h>
#include <asm/cputype.h>
#include <asm/virt.h>
#define CURRENT_EL_SP_EL0_VECTOR 0x0
#define CURRENT_EL_SP_ELx_VECTOR 0x200
#define LOWER_EL_AArch64_VECTOR 0x400
#define LOWER_EL_AArch32_VECTOR 0x600
enum exception_type {
except_type_sync = 0,
except_type_irq = 0x80,
except_type_fiq = 0x100,
except_type_serror = 0x180,
};
bool kvm_condition_valid32(const struct kvm_vcpu *vcpu);
void kvm_skip_instr32(struct kvm_vcpu *vcpu);
void kvm_inject_undefined(struct kvm_vcpu *vcpu);
void kvm_inject_vabt(struct kvm_vcpu *vcpu);
void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr);
void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr);
void kvm_vcpu_wfi(struct kvm_vcpu *vcpu);
#if defined(__KVM_VHE_HYPERVISOR__) || defined(__KVM_NVHE_HYPERVISOR__)
static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
{
return !(vcpu->arch.hcr_el2 & HCR_RW);
}
#else
static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
WARN_ON_ONCE(!test_bit(KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED,
&kvm->arch.flags));
return test_bit(KVM_ARCH_FLAG_EL1_32BIT, &kvm->arch.flags);
}
#endif
static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
if (is_kernel_in_hyp_mode())
vcpu->arch.hcr_el2 |= HCR_E2H;
if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN)) {
/* route synchronous external abort exceptions to EL2 */
vcpu->arch.hcr_el2 |= HCR_TEA;
/* trap error record accesses */
vcpu->arch.hcr_el2 |= HCR_TERR;
}
if (cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) {
vcpu->arch.hcr_el2 |= HCR_FWB;
} else {
/*
* For non-FWB CPUs, we trap VM ops (HCR_EL2.TVM) until M+C
* get set in SCTLR_EL1 such that we can detect when the guest
* MMU gets turned on and do the necessary cache maintenance
* then.
*/
vcpu->arch.hcr_el2 |= HCR_TVM;
}
if (vcpu_el1_is_32bit(vcpu))
vcpu->arch.hcr_el2 &= ~HCR_RW;
else
/*
* TID3: trap feature register accesses that we virtualise.
* For now this is conditional, since no AArch32 feature regs
* are currently virtualised.
*/
vcpu->arch.hcr_el2 |= HCR_TID3;
if (cpus_have_const_cap(ARM64_MISMATCHED_CACHE_TYPE) ||
vcpu_el1_is_32bit(vcpu))
vcpu->arch.hcr_el2 |= HCR_TID2;
if (kvm_has_mte(vcpu->kvm))
vcpu->arch.hcr_el2 |= HCR_ATA;
}
static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu)
{
return (unsigned long *)&vcpu->arch.hcr_el2;
}
static inline void vcpu_clear_wfx_traps(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr_el2 &= ~HCR_TWE;
if (atomic_read(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vlpi_count) ||
vcpu->kvm->arch.vgic.nassgireq)
vcpu->arch.hcr_el2 &= ~HCR_TWI;
else
vcpu->arch.hcr_el2 |= HCR_TWI;
}
static inline void vcpu_set_wfx_traps(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr_el2 |= HCR_TWE;
vcpu->arch.hcr_el2 |= HCR_TWI;
}
static inline void vcpu_ptrauth_enable(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr_el2 |= (HCR_API | HCR_APK);
}
static inline void vcpu_ptrauth_disable(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr_el2 &= ~(HCR_API | HCR_APK);
}
static inline unsigned long vcpu_get_vsesr(struct kvm_vcpu *vcpu)
{
return vcpu->arch.vsesr_el2;
}
static inline void vcpu_set_vsesr(struct kvm_vcpu *vcpu, u64 vsesr)
{
vcpu->arch.vsesr_el2 = vsesr;
}
static __always_inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
{
return (unsigned long *)&vcpu_gp_regs(vcpu)->pc;
}
static __always_inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
{
return (unsigned long *)&vcpu_gp_regs(vcpu)->pstate;
}
static __always_inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu)
{
return !!(*vcpu_cpsr(vcpu) & PSR_MODE32_BIT);
}
static __always_inline bool kvm_condition_valid(const struct kvm_vcpu *vcpu)
{
if (vcpu_mode_is_32bit(vcpu))
return kvm_condition_valid32(vcpu);
return true;
}
static inline void vcpu_set_thumb(struct kvm_vcpu *vcpu)
{
*vcpu_cpsr(vcpu) |= PSR_AA32_T_BIT;
}
/*
* vcpu_get_reg and vcpu_set_reg should always be passed a register number
* coming from a read of ESR_EL2. Otherwise, it may give the wrong result on
* AArch32 with banked registers.
*/
static __always_inline unsigned long vcpu_get_reg(const struct kvm_vcpu *vcpu,
u8 reg_num)
{
return (reg_num == 31) ? 0 : vcpu_gp_regs(vcpu)->regs[reg_num];
}
static __always_inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
unsigned long val)
{
if (reg_num != 31)
vcpu_gp_regs(vcpu)->regs[reg_num] = val;
}
/*
* The layout of SPSR for an AArch32 state is different when observed from an
* AArch64 SPSR_ELx or an AArch32 SPSR_*. This function generates the AArch32
* view given an AArch64 view.
*
* In ARM DDI 0487E.a see:
*
* - The AArch64 view (SPSR_EL2) in section C5.2.18, page C5-426
* - The AArch32 view (SPSR_abt) in section G8.2.126, page G8-6256
* - The AArch32 view (SPSR_und) in section G8.2.132, page G8-6280
*
* Which show the following differences:
*
* | Bit | AA64 | AA32 | Notes |
* +-----+------+------+-----------------------------|
* | 24 | DIT | J | J is RES0 in ARMv8 |
* | 21 | SS | DIT | SS doesn't exist in AArch32 |
*
* ... and all other bits are (currently) common.
*/
static inline unsigned long host_spsr_to_spsr32(unsigned long spsr)
{
const unsigned long overlap = BIT(24) | BIT(21);
unsigned long dit = !!(spsr & PSR_AA32_DIT_BIT);
spsr &= ~overlap;
spsr |= dit << 21;
return spsr;
}
static inline bool vcpu_mode_priv(const struct kvm_vcpu *vcpu)
{
u32 mode;
if (vcpu_mode_is_32bit(vcpu)) {
mode = *vcpu_cpsr(vcpu) & PSR_AA32_MODE_MASK;
return mode > PSR_AA32_MODE_USR;
}
mode = *vcpu_cpsr(vcpu) & PSR_MODE_MASK;
return mode != PSR_MODE_EL0t;
}
static __always_inline u32 kvm_vcpu_get_esr(const struct kvm_vcpu *vcpu)
{
return vcpu->arch.fault.esr_el2;
}
static __always_inline int kvm_vcpu_get_condition(const struct kvm_vcpu *vcpu)
{
u32 esr = kvm_vcpu_get_esr(vcpu);
if (esr & ESR_ELx_CV)
return (esr & ESR_ELx_COND_MASK) >> ESR_ELx_COND_SHIFT;
return -1;
}
static __always_inline unsigned long kvm_vcpu_get_hfar(const struct kvm_vcpu *vcpu)
{
return vcpu->arch.fault.far_el2;
}
static __always_inline phys_addr_t kvm_vcpu_get_fault_ipa(const struct kvm_vcpu *vcpu)
{
return ((phys_addr_t)vcpu->arch.fault.hpfar_el2 & HPFAR_MASK) << 8;
}
static inline u64 kvm_vcpu_get_disr(const struct kvm_vcpu *vcpu)
{
return vcpu->arch.fault.disr_el1;
}
static inline u32 kvm_vcpu_hvc_get_imm(const struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_esr(vcpu) & ESR_ELx_xVC_IMM_MASK;
}
static __always_inline bool kvm_vcpu_dabt_isvalid(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_ISV);
}
static inline unsigned long kvm_vcpu_dabt_iss_nisv_sanitized(const struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_esr(vcpu) & (ESR_ELx_CM | ESR_ELx_WNR | ESR_ELx_FSC);
}
static inline bool kvm_vcpu_dabt_issext(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_SSE);
}
static inline bool kvm_vcpu_dabt_issf(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_SF);
}
static __always_inline int kvm_vcpu_dabt_get_rd(const struct kvm_vcpu *vcpu)
{
return (kvm_vcpu_get_esr(vcpu) & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT;
}
static __always_inline bool kvm_vcpu_abt_iss1tw(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_S1PTW);
}
/* Always check for S1PTW *before* using this. */
static __always_inline bool kvm_vcpu_dabt_iswrite(const struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_esr(vcpu) & ESR_ELx_WNR;
}
static inline bool kvm_vcpu_dabt_is_cm(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_CM);
}
static __always_inline unsigned int kvm_vcpu_dabt_get_as(const struct kvm_vcpu *vcpu)
{
return 1 << ((kvm_vcpu_get_esr(vcpu) & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT);
}
/* This one is not specific to Data Abort */
static __always_inline bool kvm_vcpu_trap_il_is32bit(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_IL);
}
static __always_inline u8 kvm_vcpu_trap_get_class(const struct kvm_vcpu *vcpu)
{
return ESR_ELx_EC(kvm_vcpu_get_esr(vcpu));
}
static inline bool kvm_vcpu_trap_is_iabt(const struct kvm_vcpu *vcpu)
{
return kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_IABT_LOW;
}
static inline bool kvm_vcpu_trap_is_exec_fault(const struct kvm_vcpu *vcpu)
{
return kvm_vcpu_trap_is_iabt(vcpu) && !kvm_vcpu_abt_iss1tw(vcpu);
}
static __always_inline u8 kvm_vcpu_trap_get_fault(const struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC;
}
static __always_inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_TYPE;
}
static __always_inline u8 kvm_vcpu_trap_get_fault_level(const struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_LEVEL;
}
static __always_inline bool kvm_vcpu_abt_issea(const struct kvm_vcpu *vcpu)
{
switch (kvm_vcpu_trap_get_fault(vcpu)) {
case FSC_SEA:
case FSC_SEA_TTW0:
case FSC_SEA_TTW1:
case FSC_SEA_TTW2:
case FSC_SEA_TTW3:
case FSC_SECC:
case FSC_SECC_TTW0:
case FSC_SECC_TTW1:
case FSC_SECC_TTW2:
case FSC_SECC_TTW3:
return true;
default:
return false;
}
}
static __always_inline int kvm_vcpu_sys_get_rt(struct kvm_vcpu *vcpu)
{
u32 esr = kvm_vcpu_get_esr(vcpu);
return ESR_ELx_SYS64_ISS_RT(esr);
}
static inline bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
{
if (kvm_vcpu_abt_iss1tw(vcpu))
return true;
if (kvm_vcpu_trap_is_iabt(vcpu))
return false;
return kvm_vcpu_dabt_iswrite(vcpu);
}
static inline unsigned long kvm_vcpu_get_mpidr_aff(struct kvm_vcpu *vcpu)
{
return vcpu_read_sys_reg(vcpu, MPIDR_EL1) & MPIDR_HWID_BITMASK;
}
static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
{
if (vcpu_mode_is_32bit(vcpu)) {
*vcpu_cpsr(vcpu) |= PSR_AA32_E_BIT;
} else {
u64 sctlr = vcpu_read_sys_reg(vcpu, SCTLR_EL1);
sctlr |= SCTLR_ELx_EE;
vcpu_write_sys_reg(vcpu, sctlr, SCTLR_EL1);
}
}
static inline bool kvm_vcpu_is_be(struct kvm_vcpu *vcpu)
{
if (vcpu_mode_is_32bit(vcpu))
return !!(*vcpu_cpsr(vcpu) & PSR_AA32_E_BIT);
if (vcpu_mode_priv(vcpu))
return !!(vcpu_read_sys_reg(vcpu, SCTLR_EL1) & SCTLR_ELx_EE);
else
return !!(vcpu_read_sys_reg(vcpu, SCTLR_EL1) & SCTLR_EL1_E0E);
}
static inline unsigned long vcpu_data_guest_to_host(struct kvm_vcpu *vcpu,
unsigned long data,
unsigned int len)
{
if (kvm_vcpu_is_be(vcpu)) {
switch (len) {
case 1:
return data & 0xff;
case 2:
return be16_to_cpu(data & 0xffff);
case 4:
return be32_to_cpu(data & 0xffffffff);
default:
return be64_to_cpu(data);
}
} else {
switch (len) {
case 1:
return data & 0xff;
case 2:
return le16_to_cpu(data & 0xffff);
case 4:
return le32_to_cpu(data & 0xffffffff);
default:
return le64_to_cpu(data);
}
}
return data; /* Leave LE untouched */
}
static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,
unsigned long data,
unsigned int len)
{
if (kvm_vcpu_is_be(vcpu)) {
switch (len) {
case 1:
return data & 0xff;
case 2:
return cpu_to_be16(data & 0xffff);
case 4:
return cpu_to_be32(data & 0xffffffff);
default:
return cpu_to_be64(data);
}
} else {
switch (len) {
case 1:
return data & 0xff;
case 2:
return cpu_to_le16(data & 0xffff);
case 4:
return cpu_to_le32(data & 0xffffffff);
default:
return cpu_to_le64(data);
}
}
return data; /* Leave LE untouched */
}
static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu)
{
vcpu->arch.flags |= KVM_ARM64_INCREMENT_PC;
}
static inline bool vcpu_has_feature(struct kvm_vcpu *vcpu, int feature)
{
return test_bit(feature, vcpu->arch.features);
}
#endif /* __ARM64_KVM_EMULATE_H__ */