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linux-stable/arch/arm64/kvm/hyp/include/hyp/switch.h

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#ifndef __ARM64_KVM_HYP_SWITCH_H__
#define __ARM64_KVM_HYP_SWITCH_H__
#include <hyp/adjust_pc.h>
#include <hyp/fault.h>
#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <linux/types.h>
#include <linux/jump_label.h>
#include <uapi/linux/psci.h>
#include <kvm/arm_psci.h>
#include <asm/barrier.h>
#include <asm/cpufeature.h>
#include <asm/extable.h>
#include <asm/kprobes.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#include <asm/kvm_nested.h>
#include <asm/fpsimd.h>
#include <asm/debug-monitors.h>
#include <asm/processor.h>
#include <asm/traps.h>
struct kvm_exception_table_entry {
int insn, fixup;
};
extern struct kvm_exception_table_entry __start___kvm_ex_table;
extern struct kvm_exception_table_entry __stop___kvm_ex_table;
/* Check whether the FP regs are owned by the guest */
static inline bool guest_owns_fp_regs(struct kvm_vcpu *vcpu)
{
return vcpu->arch.fp_state == FP_STATE_GUEST_OWNED;
}
/* Save the 32-bit only FPSIMD system register state */
static inline void __fpsimd_save_fpexc32(struct kvm_vcpu *vcpu)
{
if (!vcpu_el1_is_32bit(vcpu))
return;
__vcpu_sys_reg(vcpu, FPEXC32_EL2) = read_sysreg(fpexc32_el2);
}
static inline void __activate_traps_fpsimd32(struct kvm_vcpu *vcpu)
{
/*
* We are about to set CPTR_EL2.TFP to trap all floating point
* register accesses to EL2, however, the ARM ARM clearly states that
* traps are only taken to EL2 if the operation would not otherwise
* trap to EL1. Therefore, always make sure that for 32-bit guests,
* we set FPEXC.EN to prevent traps to EL1, when setting the TFP bit.
* If FP/ASIMD is not implemented, FPEXC is UNDEFINED and any access to
* it will cause an exception.
*/
if (vcpu_el1_is_32bit(vcpu) && system_supports_fpsimd()) {
write_sysreg(1 << 30, fpexc32_el2);
isb();
}
}
#define compute_clr_set(vcpu, reg, clr, set) \
do { \
u64 hfg; \
hfg = __vcpu_sys_reg(vcpu, reg) & ~__ ## reg ## _RES0; \
set |= hfg & __ ## reg ## _MASK; \
clr |= ~hfg & __ ## reg ## _nMASK; \
} while(0)
#define reg_to_fgt_group_id(reg) \
({ \
enum fgt_group_id id; \
switch(reg) { \
case HFGRTR_EL2: \
case HFGWTR_EL2: \
id = HFGxTR_GROUP; \
break; \
case HFGITR_EL2: \
id = HFGITR_GROUP; \
break; \
case HDFGRTR_EL2: \
case HDFGWTR_EL2: \
id = HDFGRTR_GROUP; \
break; \
case HAFGRTR_EL2: \
id = HAFGRTR_GROUP; \
break; \
default: \
BUILD_BUG_ON(1); \
} \
\
id; \
})
#define compute_undef_clr_set(vcpu, kvm, reg, clr, set) \
do { \
u64 hfg = kvm->arch.fgu[reg_to_fgt_group_id(reg)]; \
set |= hfg & __ ## reg ## _MASK; \
clr |= hfg & __ ## reg ## _nMASK; \
} while(0)
#define update_fgt_traps_cs(hctxt, vcpu, kvm, reg, clr, set) \
do { \
u64 c = 0, s = 0; \
\
ctxt_sys_reg(hctxt, reg) = read_sysreg_s(SYS_ ## reg); \
if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) \
compute_clr_set(vcpu, reg, c, s); \
\
compute_undef_clr_set(vcpu, kvm, reg, c, s); \
\
s |= set; \
c |= clr; \
if (c || s) { \
u64 val = __ ## reg ## _nMASK; \
val |= s; \
val &= ~c; \
write_sysreg_s(val, SYS_ ## reg); \
} \
} while(0)
#define update_fgt_traps(hctxt, vcpu, kvm, reg) \
update_fgt_traps_cs(hctxt, vcpu, kvm, reg, 0, 0)
/*
* Validate the fine grain trap masks.
* Check that the masks do not overlap and that all bits are accounted for.
*/
#define CHECK_FGT_MASKS(reg) \
do { \
BUILD_BUG_ON((__ ## reg ## _MASK) & (__ ## reg ## _nMASK)); \
BUILD_BUG_ON(~((__ ## reg ## _RES0) ^ (__ ## reg ## _MASK) ^ \
(__ ## reg ## _nMASK))); \
} while(0)
static inline bool cpu_has_amu(void)
{
u64 pfr0 = read_sysreg_s(SYS_ID_AA64PFR0_EL1);
return cpuid_feature_extract_unsigned_field(pfr0,
ID_AA64PFR0_EL1_AMU_SHIFT);
}
static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
struct kvm *kvm = kern_hyp_va(vcpu->kvm);
CHECK_FGT_MASKS(HFGRTR_EL2);
CHECK_FGT_MASKS(HFGWTR_EL2);
CHECK_FGT_MASKS(HFGITR_EL2);
CHECK_FGT_MASKS(HDFGRTR_EL2);
CHECK_FGT_MASKS(HDFGWTR_EL2);
CHECK_FGT_MASKS(HAFGRTR_EL2);
CHECK_FGT_MASKS(HCRX_EL2);
if (!cpus_have_final_cap(ARM64_HAS_FGT))
return;
update_fgt_traps(hctxt, vcpu, kvm, HFGRTR_EL2);
update_fgt_traps_cs(hctxt, vcpu, kvm, HFGWTR_EL2, 0,
cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38) ?
HFGxTR_EL2_TCR_EL1_MASK : 0);
update_fgt_traps(hctxt, vcpu, kvm, HFGITR_EL2);
update_fgt_traps(hctxt, vcpu, kvm, HDFGRTR_EL2);
update_fgt_traps(hctxt, vcpu, kvm, HDFGWTR_EL2);
if (cpu_has_amu())
update_fgt_traps(hctxt, vcpu, kvm, HAFGRTR_EL2);
}
#define __deactivate_fgt(htcxt, vcpu, kvm, reg) \
do { \
if ((vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) || \
kvm->arch.fgu[reg_to_fgt_group_id(reg)]) \
write_sysreg_s(ctxt_sys_reg(hctxt, reg), \
SYS_ ## reg); \
} while(0)
static inline void __deactivate_traps_hfgxtr(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
struct kvm *kvm = kern_hyp_va(vcpu->kvm);
if (!cpus_have_final_cap(ARM64_HAS_FGT))
return;
__deactivate_fgt(hctxt, vcpu, kvm, HFGRTR_EL2);
if (cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38))
write_sysreg_s(ctxt_sys_reg(hctxt, HFGWTR_EL2), SYS_HFGWTR_EL2);
else
__deactivate_fgt(hctxt, vcpu, kvm, HFGWTR_EL2);
__deactivate_fgt(hctxt, vcpu, kvm, HFGITR_EL2);
__deactivate_fgt(hctxt, vcpu, kvm, HDFGRTR_EL2);
__deactivate_fgt(hctxt, vcpu, kvm, HDFGWTR_EL2);
if (cpu_has_amu())
__deactivate_fgt(hctxt, vcpu, kvm, HAFGRTR_EL2);
}
static inline void __activate_traps_common(struct kvm_vcpu *vcpu)
{
/* Trap on AArch32 cp15 c15 (impdef sysregs) accesses (EL1 or EL0) */
write_sysreg(1 << 15, hstr_el2);
/*
* Make sure we trap PMU access from EL0 to EL2. Also sanitize
* PMSELR_EL0 to make sure it never contains the cycle
* counter, which could make a PMXEVCNTR_EL0 access UNDEF at
* EL1 instead of being trapped to EL2.
*/
if (kvm_arm_support_pmu_v3()) {
struct kvm_cpu_context *hctxt;
write_sysreg(0, pmselr_el0);
hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
ctxt_sys_reg(hctxt, PMUSERENR_EL0) = read_sysreg(pmuserenr_el0);
write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0);
vcpu_set_flag(vcpu, PMUSERENR_ON_CPU);
}
vcpu->arch.mdcr_el2_host = read_sysreg(mdcr_el2);
write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2);
if (cpus_have_final_cap(ARM64_HAS_HCX)) {
u64 hcrx = vcpu->arch.hcrx_el2;
if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) {
u64 clr = 0, set = 0;
compute_clr_set(vcpu, HCRX_EL2, clr, set);
hcrx |= set;
hcrx &= ~clr;
}
write_sysreg_s(hcrx, SYS_HCRX_EL2);
}
__activate_traps_hfgxtr(vcpu);
}
static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu)
{
write_sysreg(vcpu->arch.mdcr_el2_host, mdcr_el2);
write_sysreg(0, hstr_el2);
if (kvm_arm_support_pmu_v3()) {
struct kvm_cpu_context *hctxt;
hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
write_sysreg(ctxt_sys_reg(hctxt, PMUSERENR_EL0), pmuserenr_el0);
vcpu_clear_flag(vcpu, PMUSERENR_ON_CPU);
}
if (cpus_have_final_cap(ARM64_HAS_HCX))
write_sysreg_s(HCRX_HOST_FLAGS, SYS_HCRX_EL2);
__deactivate_traps_hfgxtr(vcpu);
}
static inline void ___activate_traps(struct kvm_vcpu *vcpu)
{
u64 hcr = vcpu->arch.hcr_el2;
if (cpus_have_final_cap(ARM64_WORKAROUND_CAVIUM_TX2_219_TVM))
hcr |= HCR_TVM;
write_sysreg(hcr, hcr_el2);
if (cpus_have_final_cap(ARM64_HAS_RAS_EXTN) && (hcr & HCR_VSE))
write_sysreg_s(vcpu->arch.vsesr_el2, SYS_VSESR_EL2);
}
static inline void ___deactivate_traps(struct kvm_vcpu *vcpu)
{
/*
* If we pended a virtual abort, preserve it until it gets
* cleared. See D1.14.3 (Virtual Interrupts) for details, but
* the crucial bit is "On taking a vSError interrupt,
* HCR_EL2.VSE is cleared to 0."
*/
if (vcpu->arch.hcr_el2 & HCR_VSE) {
vcpu->arch.hcr_el2 &= ~HCR_VSE;
vcpu->arch.hcr_el2 |= read_sysreg(hcr_el2) & HCR_VSE;
}
}
static inline bool __populate_fault_info(struct kvm_vcpu *vcpu)
{
return __get_fault_info(vcpu->arch.fault.esr_el2, &vcpu->arch.fault);
}
static bool kvm_hyp_handle_mops(struct kvm_vcpu *vcpu, u64 *exit_code)
{
*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
arm64_mops_reset_regs(vcpu_gp_regs(vcpu), vcpu->arch.fault.esr_el2);
write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);
/*
* Finish potential single step before executing the prologue
* instruction.
*/
*vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS;
write_sysreg_el2(*vcpu_cpsr(vcpu), SYS_SPSR);
return true;
}
static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu)
{
sve_cond_update_zcr_vq(vcpu_sve_max_vq(vcpu) - 1, SYS_ZCR_EL2);
__sve_restore_state(vcpu_sve_pffr(vcpu),
&vcpu->arch.ctxt.fp_regs.fpsr);
write_sysreg_el1(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR);
}
/*
* We trap the first access to the FP/SIMD to save the host context and
* restore the guest context lazily.
* If FP/SIMD is not implemented, handle the trap and inject an undefined
* instruction exception to the guest. Similarly for trapped SVE accesses.
*/
static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
{
bool sve_guest;
u8 esr_ec;
u64 reg;
if (!system_supports_fpsimd())
return false;
sve_guest = vcpu_has_sve(vcpu);
esr_ec = kvm_vcpu_trap_get_class(vcpu);
/* Only handle traps the vCPU can support here: */
switch (esr_ec) {
case ESR_ELx_EC_FP_ASIMD:
break;
case ESR_ELx_EC_SVE:
if (!sve_guest)
return false;
break;
default:
return false;
}
/* Valid trap. Switch the context: */
/* First disable enough traps to allow us to update the registers */
if (has_vhe() || has_hvhe()) {
reg = CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN;
if (sve_guest)
reg |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN;
sysreg_clear_set(cpacr_el1, 0, reg);
} else {
reg = CPTR_EL2_TFP;
if (sve_guest)
reg |= CPTR_EL2_TZ;
sysreg_clear_set(cptr_el2, reg, 0);
}
isb();
/* Write out the host state if it's in the registers */
if (vcpu->arch.fp_state == FP_STATE_HOST_OWNED)
__fpsimd_save_state(vcpu->arch.host_fpsimd_state);
/* Restore the guest state */
if (sve_guest)
__hyp_sve_restore_guest(vcpu);
else
__fpsimd_restore_state(&vcpu->arch.ctxt.fp_regs);
/* Skip restoring fpexc32 for AArch64 guests */
if (!(read_sysreg(hcr_el2) & HCR_RW))
write_sysreg(__vcpu_sys_reg(vcpu, FPEXC32_EL2), fpexc32_el2);
vcpu->arch.fp_state = FP_STATE_GUEST_OWNED;
return true;
}
static inline bool handle_tx2_tvm(struct kvm_vcpu *vcpu)
{
u32 sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu));
int rt = kvm_vcpu_sys_get_rt(vcpu);
u64 val = vcpu_get_reg(vcpu, rt);
/*
* The normal sysreg handling code expects to see the traps,
* let's not do anything here.
*/
if (vcpu->arch.hcr_el2 & HCR_TVM)
return false;
switch (sysreg) {
case SYS_SCTLR_EL1:
write_sysreg_el1(val, SYS_SCTLR);
break;
case SYS_TTBR0_EL1:
write_sysreg_el1(val, SYS_TTBR0);
break;
case SYS_TTBR1_EL1:
write_sysreg_el1(val, SYS_TTBR1);
break;
case SYS_TCR_EL1:
write_sysreg_el1(val, SYS_TCR);
break;
case SYS_ESR_EL1:
write_sysreg_el1(val, SYS_ESR);
break;
case SYS_FAR_EL1:
write_sysreg_el1(val, SYS_FAR);
break;
case SYS_AFSR0_EL1:
write_sysreg_el1(val, SYS_AFSR0);
break;
case SYS_AFSR1_EL1:
write_sysreg_el1(val, SYS_AFSR1);
break;
case SYS_MAIR_EL1:
write_sysreg_el1(val, SYS_MAIR);
break;
case SYS_AMAIR_EL1:
write_sysreg_el1(val, SYS_AMAIR);
break;
case SYS_CONTEXTIDR_EL1:
write_sysreg_el1(val, SYS_CONTEXTIDR);
break;
default:
return false;
}
__kvm_skip_instr(vcpu);
return true;
}
static inline bool esr_is_ptrauth_trap(u64 esr)
{
switch (esr_sys64_to_sysreg(esr)) {
case SYS_APIAKEYLO_EL1:
case SYS_APIAKEYHI_EL1:
case SYS_APIBKEYLO_EL1:
case SYS_APIBKEYHI_EL1:
case SYS_APDAKEYLO_EL1:
case SYS_APDAKEYHI_EL1:
case SYS_APDBKEYLO_EL1:
case SYS_APDBKEYHI_EL1:
case SYS_APGAKEYLO_EL1:
case SYS_APGAKEYHI_EL1:
return true;
}
return false;
}
#define __ptrauth_save_key(ctxt, key) \
do { \
u64 __val; \
__val = read_sysreg_s(SYS_ ## key ## KEYLO_EL1); \
ctxt_sys_reg(ctxt, key ## KEYLO_EL1) = __val; \
__val = read_sysreg_s(SYS_ ## key ## KEYHI_EL1); \
ctxt_sys_reg(ctxt, key ## KEYHI_EL1) = __val; \
} while(0)
DECLARE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
static bool kvm_hyp_handle_ptrauth(struct kvm_vcpu *vcpu, u64 *exit_code)
{
struct kvm_cpu_context *ctxt;
u64 val;
if (!vcpu_has_ptrauth(vcpu))
return false;
ctxt = this_cpu_ptr(&kvm_hyp_ctxt);
__ptrauth_save_key(ctxt, APIA);
__ptrauth_save_key(ctxt, APIB);
__ptrauth_save_key(ctxt, APDA);
__ptrauth_save_key(ctxt, APDB);
__ptrauth_save_key(ctxt, APGA);
vcpu_ptrauth_enable(vcpu);
val = read_sysreg(hcr_el2);
val |= (HCR_API | HCR_APK);
write_sysreg(val, hcr_el2);
return true;
}
static bool kvm_hyp_handle_cntpct(struct kvm_vcpu *vcpu)
{
struct arch_timer_context *ctxt;
u32 sysreg;
u64 val;
/*
* We only get here for 64bit guests, 32bit guests will hit
* the long and winding road all the way to the standard
* handling. Yes, it sucks to be irrelevant.
*/
sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu));
switch (sysreg) {
case SYS_CNTPCT_EL0:
case SYS_CNTPCTSS_EL0:
if (vcpu_has_nv(vcpu)) {
if (is_hyp_ctxt(vcpu)) {
ctxt = vcpu_hptimer(vcpu);
break;
}
/* Check for guest hypervisor trapping */
val = __vcpu_sys_reg(vcpu, CNTHCTL_EL2);
if (!vcpu_el2_e2h_is_set(vcpu))
val = (val & CNTHCTL_EL1PCTEN) << 10;
if (!(val & (CNTHCTL_EL1PCTEN << 10)))
return false;
}
ctxt = vcpu_ptimer(vcpu);
break;
default:
return false;
}
val = arch_timer_read_cntpct_el0();
if (ctxt->offset.vm_offset)
val -= *kern_hyp_va(ctxt->offset.vm_offset);
if (ctxt->offset.vcpu_offset)
val -= *kern_hyp_va(ctxt->offset.vcpu_offset);
vcpu_set_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu), val);
__kvm_skip_instr(vcpu);
return true;
}
static bool handle_ampere1_tcr(struct kvm_vcpu *vcpu)
{
u32 sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu));
int rt = kvm_vcpu_sys_get_rt(vcpu);
u64 val = vcpu_get_reg(vcpu, rt);
if (sysreg != SYS_TCR_EL1)
return false;
/*
* Affected parts do not advertise support for hardware Access Flag /
* Dirty state management in ID_AA64MMFR1_EL1.HAFDBS, but the underlying
* control bits are still functional. The architecture requires these be
* RES0 on systems that do not implement FEAT_HAFDBS.
*
* Uphold the requirements of the architecture by masking guest writes
* to TCR_EL1.{HA,HD} here.
*/
val &= ~(TCR_HD | TCR_HA);
write_sysreg_el1(val, SYS_TCR);
__kvm_skip_instr(vcpu);
return true;
}
static bool kvm_hyp_handle_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code)
{
if (cpus_have_final_cap(ARM64_WORKAROUND_CAVIUM_TX2_219_TVM) &&
handle_tx2_tvm(vcpu))
return true;
if (cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38) &&
handle_ampere1_tcr(vcpu))
return true;
if (static_branch_unlikely(&vgic_v3_cpuif_trap) &&
__vgic_v3_perform_cpuif_access(vcpu) == 1)
return true;
if (esr_is_ptrauth_trap(kvm_vcpu_get_esr(vcpu)))
return kvm_hyp_handle_ptrauth(vcpu, exit_code);
if (kvm_hyp_handle_cntpct(vcpu))
return true;
return false;
}
static bool kvm_hyp_handle_cp15_32(struct kvm_vcpu *vcpu, u64 *exit_code)
{
if (static_branch_unlikely(&vgic_v3_cpuif_trap) &&
__vgic_v3_perform_cpuif_access(vcpu) == 1)
return true;
return false;
}
static bool kvm_hyp_handle_memory_fault(struct kvm_vcpu *vcpu, u64 *exit_code)
{
if (!__populate_fault_info(vcpu))
return true;
return false;
}
static bool kvm_hyp_handle_iabt_low(struct kvm_vcpu *vcpu, u64 *exit_code)
__alias(kvm_hyp_handle_memory_fault);
static bool kvm_hyp_handle_watchpt_low(struct kvm_vcpu *vcpu, u64 *exit_code)
__alias(kvm_hyp_handle_memory_fault);
static bool kvm_hyp_handle_dabt_low(struct kvm_vcpu *vcpu, u64 *exit_code)
{
if (kvm_hyp_handle_memory_fault(vcpu, exit_code))
return true;
if (static_branch_unlikely(&vgic_v2_cpuif_trap)) {
bool valid;
valid = kvm_vcpu_trap_is_translation_fault(vcpu) &&
kvm_vcpu_dabt_isvalid(vcpu) &&
!kvm_vcpu_abt_issea(vcpu) &&
!kvm_vcpu_abt_iss1tw(vcpu);
if (valid) {
int ret = __vgic_v2_perform_cpuif_access(vcpu);
if (ret == 1)
return true;
/* Promote an illegal access to an SError.*/
if (ret == -1)
*exit_code = ARM_EXCEPTION_EL1_SERROR;
}
}
return false;
}
typedef bool (*exit_handler_fn)(struct kvm_vcpu *, u64 *);
static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu);
static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code);
/*
* Allow the hypervisor to handle the exit with an exit handler if it has one.
*
* Returns true if the hypervisor handled the exit, and control should go back
* to the guest, or false if it hasn't.
*/
static inline bool kvm_hyp_handle_exit(struct kvm_vcpu *vcpu, u64 *exit_code)
{
const exit_handler_fn *handlers = kvm_get_exit_handler_array(vcpu);
exit_handler_fn fn;
fn = handlers[kvm_vcpu_trap_get_class(vcpu)];
if (fn)
return fn(vcpu, exit_code);
return false;
}
static inline void synchronize_vcpu_pstate(struct kvm_vcpu *vcpu, u64 *exit_code)
{
/*
* Check for the conditions of Cortex-A510's #2077057. When these occur
* SPSR_EL2 can't be trusted, but isn't needed either as it is
* unchanged from the value in vcpu_gp_regs(vcpu)->pstate.
* Are we single-stepping the guest, and took a PAC exception from the
* active-not-pending state?
*/
if (cpus_have_final_cap(ARM64_WORKAROUND_2077057) &&
vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP &&
*vcpu_cpsr(vcpu) & DBG_SPSR_SS &&
ESR_ELx_EC(read_sysreg_el2(SYS_ESR)) == ESR_ELx_EC_PAC)
write_sysreg_el2(*vcpu_cpsr(vcpu), SYS_SPSR);
vcpu->arch.ctxt.regs.pstate = read_sysreg_el2(SYS_SPSR);
}
/*
* Return true when we were able to fixup the guest exit and should return to
* the guest, false when we should restore the host state and return to the
* main run loop.
*/
static inline bool fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code)
{
/*
* Save PSTATE early so that we can evaluate the vcpu mode
* early on.
*/
synchronize_vcpu_pstate(vcpu, exit_code);
/*
* Check whether we want to repaint the state one way or
* another.
*/
early_exit_filter(vcpu, exit_code);
if (ARM_EXCEPTION_CODE(*exit_code) != ARM_EXCEPTION_IRQ)
vcpu->arch.fault.esr_el2 = read_sysreg_el2(SYS_ESR);
if (ARM_SERROR_PENDING(*exit_code) &&
ARM_EXCEPTION_CODE(*exit_code) != ARM_EXCEPTION_IRQ) {
u8 esr_ec = kvm_vcpu_trap_get_class(vcpu);
/*
* HVC already have an adjusted PC, which we need to
* correct in order to return to after having injected
* the SError.
*
* SMC, on the other hand, is *trapped*, meaning its
* preferred return address is the SMC itself.
*/
if (esr_ec == ESR_ELx_EC_HVC32 || esr_ec == ESR_ELx_EC_HVC64)
write_sysreg_el2(read_sysreg_el2(SYS_ELR) - 4, SYS_ELR);
}
/*
* We're using the raw exception code in order to only process
* the trap if no SError is pending. We will come back to the
* same PC once the SError has been injected, and replay the
* trapping instruction.
*/
if (*exit_code != ARM_EXCEPTION_TRAP)
goto exit;
/* Check if there's an exit handler and allow it to handle the exit. */
if (kvm_hyp_handle_exit(vcpu, exit_code))
goto guest;
exit:
/* Return to the host kernel and handle the exit */
return false;
guest:
/* Re-enter the guest */
asm(ALTERNATIVE("nop", "dmb sy", ARM64_WORKAROUND_1508412));
return true;
}
static inline void __kvm_unexpected_el2_exception(void)
{
extern char __guest_exit_panic[];
unsigned long addr, fixup;
struct kvm_exception_table_entry *entry, *end;
unsigned long elr_el2 = read_sysreg(elr_el2);
entry = &__start___kvm_ex_table;
end = &__stop___kvm_ex_table;
while (entry < end) {
addr = (unsigned long)&entry->insn + entry->insn;
fixup = (unsigned long)&entry->fixup + entry->fixup;
if (addr != elr_el2) {
entry++;
continue;
}
write_sysreg(fixup, elr_el2);
return;
}
/* Trigger a panic after restoring the hyp context. */
write_sysreg(__guest_exit_panic, elr_el2);
}
#endif /* __ARM64_KVM_HYP_SWITCH_H__ */
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