brain-hackers_pepepper-mirror/linux-brain
1
0
Fork 0
mirror of https://github.com/brain-hackers/linux-brain.git synced 2024-06-09 07:16:21 +09:00
Code Issues Projects Releases Wiki Activity
c9bfb7b4d9
linux-brain/arch/arm64/include/asm/kvm_emulate.h
Marc Zyngier c9bfb7b4d9 KVM: arm64: Assume write fault on S1PTW permission fault on instruction fetch 
commit c4ad98e4b72cb5be30ea282fce935248f2300e62 upstream.

KVM currently assumes that an instruction abort can never be a write.
This is in general true, except when the abort is triggered by
a S1PTW on instruction fetch that tries to update the S1 page tables
(to set AF, for example).

This can happen if the page tables have been paged out and brought
back in without seeing a direct write to them (they are thus marked
read only), and the fault handling code will make the PT executable(!)
instead of writable. The guest gets stuck forever.

In these conditions, the permission fault must be considered as
a write so that the Stage-1 update can take place. This is essentially
the I-side equivalent of the problem fixed by 60e21a0ef5 ("arm64: KVM:
Take S1 walks into account when determining S2 write faults").

Update kvm_is_write_fault() to return true on IABT+S1PTW, and introduce
kvm_vcpu_trap_is_exec_fault() that only return true when no faulting
on a S1 fault. Additionally, kvm_vcpu_dabt_iss1tw() is renamed to
kvm_vcpu_abt_iss1tw(), as the above makes it plain that it isn't
specific to data abort.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Will Deacon <will@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200915104218.1284701-2-maz@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-01 13:18:25 +02:00

517 lines
13 KiB
C
Raw Blame History

/* 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/kvm_mmio.h>
#include <asm/ptrace.h>
#include <asm/cputype.h>
#include <asm/virt.h>
unsigned long *vcpu_reg32(const struct kvm_vcpu *vcpu, u8 reg_num);
unsigned long vcpu_read_spsr32(const struct kvm_vcpu *vcpu);
void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v);
bool kvm_condition_valid32(const struct kvm_vcpu *vcpu);
void kvm_skip_instr32(struct kvm_vcpu *vcpu, bool is_wide_instr);
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_inject_undef32(struct kvm_vcpu *vcpu);
void kvm_inject_dabt32(struct kvm_vcpu *vcpu, unsigned long addr);
void kvm_inject_pabt32(struct kvm_vcpu *vcpu, unsigned long addr);
static inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
{
return !(vcpu->arch.hcr_el2 & HCR_RW);
}
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;
if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features))
vcpu->arch.hcr_el2 &= ~HCR_RW;
/*
* TID3: trap feature register accesses that we virtualise.
* For now this is conditional, since no AArch32 feature regs
* are currently virtualised.
*/
if (!vcpu_el1_is_32bit(vcpu))
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;
}
static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu)
{
return (unsigned long *)&vcpu->arch.hcr_el2;
}
static inline void vcpu_clear_wfe_traps(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr_el2 &= ~HCR_TWE;
}
static inline void vcpu_set_wfe_traps(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr_el2 |= HCR_TWE;
}
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 inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
{
return (unsigned long *)&vcpu_gp_regs(vcpu)->regs.pc;
}
static inline unsigned long *__vcpu_elr_el1(const struct kvm_vcpu *vcpu)
{
return (unsigned long *)&vcpu_gp_regs(vcpu)->elr_el1;
}
static inline unsigned long vcpu_read_elr_el1(const struct kvm_vcpu *vcpu)
{
if (vcpu->arch.sysregs_loaded_on_cpu)
return read_sysreg_el1(SYS_ELR);
else
return *__vcpu_elr_el1(vcpu);
}
static inline void vcpu_write_elr_el1(const struct kvm_vcpu *vcpu, unsigned long v)
{
if (vcpu->arch.sysregs_loaded_on_cpu)
write_sysreg_el1(v, SYS_ELR);
else
*__vcpu_elr_el1(vcpu) = v;
}
static inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
{
return (unsigned long *)&vcpu_gp_regs(vcpu)->regs.pstate;
}
static inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu)
{
return !!(*vcpu_cpsr(vcpu) & PSR_MODE32_BIT);
}
static 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 inline unsigned long vcpu_get_reg(const struct kvm_vcpu *vcpu,
u8 reg_num)
{
return (reg_num == 31) ? 0 : vcpu_gp_regs(vcpu)->regs.regs[reg_num];
}
static inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
unsigned long val)
{
if (reg_num != 31)
vcpu_gp_regs(vcpu)->regs.regs[reg_num] = val;
}
static inline unsigned long vcpu_read_spsr(const struct kvm_vcpu *vcpu)
{
if (vcpu_mode_is_32bit(vcpu))
return vcpu_read_spsr32(vcpu);
if (vcpu->arch.sysregs_loaded_on_cpu)
return read_sysreg_el1(SYS_SPSR);
else
return vcpu_gp_regs(vcpu)->spsr[KVM_SPSR_EL1];
}
static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
{
if (vcpu_mode_is_32bit(vcpu)) {
vcpu_write_spsr32(vcpu, v);
return;
}
if (vcpu->arch.sysregs_loaded_on_cpu)
write_sysreg_el1(v, SYS_SPSR);
else
vcpu_gp_regs(vcpu)->spsr[KVM_SPSR_EL1] = v;
}
/*
* 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 inline u32 kvm_vcpu_get_hsr(const struct kvm_vcpu *vcpu)
{
return vcpu->arch.fault.esr_el2;
}
static inline int kvm_vcpu_get_condition(const struct kvm_vcpu *vcpu)
{
u32 esr = kvm_vcpu_get_hsr(vcpu);
if (esr & ESR_ELx_CV)
return (esr & ESR_ELx_COND_MASK) >> ESR_ELx_COND_SHIFT;
return -1;
}
static inline unsigned long kvm_vcpu_get_hfar(const struct kvm_vcpu *vcpu)
{
return vcpu->arch.fault.far_el2;
}
static 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_hsr(vcpu) & ESR_ELx_xVC_IMM_MASK;
}
static inline bool kvm_vcpu_dabt_isvalid(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_ISV);
}
static inline bool kvm_vcpu_dabt_issext(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_SSE);
}
static inline bool kvm_vcpu_dabt_issf(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_SF);
}
static inline int kvm_vcpu_dabt_get_rd(const struct kvm_vcpu *vcpu)
{
return (kvm_vcpu_get_hsr(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_hsr(vcpu) & ESR_ELx_S1PTW);
}
static inline bool kvm_vcpu_dabt_iswrite(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WNR) ||
kvm_vcpu_abt_iss1tw(vcpu); /* AF/DBM update */
}
static inline bool kvm_vcpu_dabt_is_cm(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_CM);
}
static inline int kvm_vcpu_dabt_get_as(const struct kvm_vcpu *vcpu)
{
return 1 << ((kvm_vcpu_get_hsr(vcpu) & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT);
}
/* This one is not specific to Data Abort */
static inline bool kvm_vcpu_trap_il_is32bit(const struct kvm_vcpu *vcpu)
{
return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_IL);
}
static inline u8 kvm_vcpu_trap_get_class(const struct kvm_vcpu *vcpu)
{
return ESR_ELx_EC(kvm_vcpu_get_hsr(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 inline u8 kvm_vcpu_trap_get_fault(const struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & ESR_ELx_FSC;
}
static inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_hsr(vcpu) & ESR_ELx_FSC_TYPE;
}
static inline bool kvm_vcpu_dabt_isextabt(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 inline int kvm_vcpu_sys_get_rt(struct kvm_vcpu *vcpu)
{
u32 esr = kvm_vcpu_get_hsr(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 bool kvm_arm_get_vcpu_workaround_2_flag(struct kvm_vcpu *vcpu)
{
return vcpu->arch.workaround_flags & VCPU_WORKAROUND_2_FLAG;
}
static inline void kvm_arm_set_vcpu_workaround_2_flag(struct kvm_vcpu *vcpu,
bool flag)
{
if (flag)
vcpu->arch.workaround_flags |= VCPU_WORKAROUND_2_FLAG;
else
vcpu->arch.workaround_flags &= ~VCPU_WORKAROUND_2_FLAG;
}
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 |= (1 << 25);
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);
return !!(vcpu_read_sys_reg(vcpu, SCTLR_EL1) & (1 << 25));
}
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 inline void kvm_skip_instr(struct kvm_vcpu *vcpu, bool is_wide_instr)
{
if (vcpu_mode_is_32bit(vcpu))
kvm_skip_instr32(vcpu, is_wide_instr);
else
*vcpu_pc(vcpu) += 4;
/* advance the singlestep state machine */
*vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS;
}
/*
* Skip an instruction which has been emulated at hyp while most guest sysregs
* are live.
*/
static inline void __hyp_text __kvm_skip_instr(struct kvm_vcpu *vcpu)
{
*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
vcpu->arch.ctxt.gp_regs.regs.pstate = read_sysreg_el2(SYS_SPSR);
kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
write_sysreg_el2(vcpu->arch.ctxt.gp_regs.regs.pstate, SYS_SPSR);
write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);
}
#endif /* __ARM64_KVM_EMULATE_H__ */
Reference in New Issue View Git Blame Copy Permalink