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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#include <hyp/switch.h>
#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <linux/types.h>
#include <linux/jump_label.h>
#include <linux/percpu.h>
#include <uapi/linux/psci.h>
#include <kvm/arm_psci.h>
#include <asm/barrier.h>
#include <asm/cpufeature.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/fpsimd.h>
#include <asm/debug-monitors.h>
#include <asm/processor.h>
#include <asm/thread_info.h>
#include <asm/vectors.h>
/* VHE specific context */
DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data);
DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
DEFINE_PER_CPU(unsigned long, kvm_hyp_vector);
static void __activate_traps(struct kvm_vcpu *vcpu)
{
u64 val;
___activate_traps(vcpu);
val = read_sysreg(cpacr_el1);
val |= CPACR_ELx_TTA;
val &= ~(CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN |
CPACR_EL1_SMEN_EL0EN | CPACR_EL1_SMEN_EL1EN);
/*
* With VHE (HCR.E2H == 1), accesses to CPACR_EL1 are routed to
* CPTR_EL2. In general, CPACR_EL1 has the same layout as CPTR_EL2,
* except for some missing controls, such as TAM.
* In this case, CPTR_EL2.TAM has the same position with or without
* VHE (HCR.E2H == 1) which allows us to use here the CPTR_EL2.TAM
* shift value for trapping the AMU accesses.
*/
val |= CPTR_EL2_TAM;
if (guest_owns_fp_regs(vcpu)) {
if (vcpu_has_sve(vcpu))
val |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN;
} else {
val &= ~(CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN);
__activate_traps_fpsimd32(vcpu);
}
write_sysreg(val, cpacr_el1);
write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el1);
}
NOKPROBE_SYMBOL(__activate_traps);
static void __deactivate_traps(struct kvm_vcpu *vcpu)
{
const char *host_vectors = vectors;
___deactivate_traps(vcpu);
write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
/*
* ARM errata 1165522 and 1530923 require the actual execution of the
* above before we can switch to the EL2/EL0 translation regime used by
* the host.
*/
asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT));
write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1);
if (!arm64_kernel_unmapped_at_el0())
host_vectors = __this_cpu_read(this_cpu_vector);
write_sysreg(host_vectors, vbar_el1);
}
NOKPROBE_SYMBOL(__deactivate_traps);
void activate_traps_vhe_load(struct kvm_vcpu *vcpu)
{
__activate_traps_common(vcpu);
}
void deactivate_traps_vhe_put(struct kvm_vcpu *vcpu)
{
__deactivate_traps_common(vcpu);
}
static const exit_handler_fn hyp_exit_handlers[] = {
[0 ... ESR_ELx_EC_MAX] = NULL,
[ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32,
[ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg,
[ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd,
[ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd,
[ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low,
[ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low,
[ESR_ELx_EC_WATCHPT_LOW] = kvm_hyp_handle_watchpt_low,
[ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth,
};
static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu)
{
return hyp_exit_handlers;
}
static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code)
{
/*
* If we were in HYP context on entry, adjust the PSTATE view
* so that the usual helpers work correctly.
*/
if (unlikely(vcpu_get_flag(vcpu, VCPU_HYP_CONTEXT))) {
u64 mode = *vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT);
switch (mode) {
case PSR_MODE_EL1t:
mode = PSR_MODE_EL2t;
break;
case PSR_MODE_EL1h:
mode = PSR_MODE_EL2h;
break;
}
*vcpu_cpsr(vcpu) &= ~(PSR_MODE_MASK | PSR_MODE32_BIT);
*vcpu_cpsr(vcpu) |= mode;
}
}
/* Switch to the guest for VHE systems running in EL2 */
static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *host_ctxt;
struct kvm_cpu_context *guest_ctxt;
u64 exit_code;
host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
host_ctxt->__hyp_running_vcpu = vcpu;
guest_ctxt = &vcpu->arch.ctxt;
sysreg_save_host_state_vhe(host_ctxt);
/*
* ARM erratum 1165522 requires us to configure both stage 1 and
* stage 2 translation for the guest context before we clear
* HCR_EL2.TGE.
*
* We have already configured the guest's stage 1 translation in
* kvm_vcpu_load_sysregs_vhe above. We must now call
* __load_stage2 before __activate_traps, because
* __load_stage2 configures stage 2 translation, and
* __activate_traps clear HCR_EL2.TGE (among other things).
*/
__load_stage2(vcpu->arch.hw_mmu, vcpu->arch.hw_mmu->arch);
__activate_traps(vcpu);
__kvm_adjust_pc(vcpu);
sysreg_restore_guest_state_vhe(guest_ctxt);
__debug_switch_to_guest(vcpu);
if (is_hyp_ctxt(vcpu))
vcpu_set_flag(vcpu, VCPU_HYP_CONTEXT);
else
vcpu_clear_flag(vcpu, VCPU_HYP_CONTEXT);
do {
/* Jump in the fire! */
exit_code = __guest_enter(vcpu);
/* And we're baaack! */
} while (fixup_guest_exit(vcpu, &exit_code));
sysreg_save_guest_state_vhe(guest_ctxt);
__deactivate_traps(vcpu);
sysreg_restore_host_state_vhe(host_ctxt);
if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED)
__fpsimd_save_fpexc32(vcpu);
__debug_switch_to_host(vcpu);
return exit_code;
}
NOKPROBE_SYMBOL(__kvm_vcpu_run_vhe);
int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
{
int ret;
local_daif_mask();
/*
* Having IRQs masked via PMR when entering the guest means the GIC
* will not signal the CPU of interrupts of lower priority, and the
* only way to get out will be via guest exceptions.
* Naturally, we want to avoid this.
*
* local_daif_mask() already sets GIC_PRIO_PSR_I_SET, we just need a
* dsb to ensure the redistributor is forwards EL2 IRQs to the CPU.
*/
pmr_sync();
ret = __kvm_vcpu_run_vhe(vcpu);
/*
* local_daif_restore() takes care to properly restore PSTATE.DAIF
* and the GIC PMR if the host is using IRQ priorities.
*/
local_daif_restore(DAIF_PROCCTX_NOIRQ);
/*
* When we exit from the guest we change a number of CPU configuration
* parameters, such as traps. We rely on the isb() in kvm_call_hyp*()
* to make sure these changes take effect before running the host or
* additional guests.
*/
return ret;
}
static void __hyp_call_panic(u64 spsr, u64 elr, u64 par)
{
struct kvm_cpu_context *host_ctxt;
struct kvm_vcpu *vcpu;
host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
vcpu = host_ctxt->__hyp_running_vcpu;
__deactivate_traps(vcpu);
sysreg_restore_host_state_vhe(host_ctxt);
panic("HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n",
spsr, elr,
read_sysreg_el2(SYS_ESR), read_sysreg_el2(SYS_FAR),
read_sysreg(hpfar_el2), par, vcpu);
}
NOKPROBE_SYMBOL(__hyp_call_panic);
void __noreturn hyp_panic(void)
{
u64 spsr = read_sysreg_el2(SYS_SPSR);
u64 elr = read_sysreg_el2(SYS_ELR);
u64 par = read_sysreg_par();
__hyp_call_panic(spsr, elr, par);
unreachable();
}
asmlinkage void kvm_unexpected_el2_exception(void)
{
__kvm_unexpected_el2_exception();
}
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