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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 <hyp/sysreg-sr.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/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>
/* Non-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);
__activate_traps_common(vcpu);
val = CPTR_EL2_DEFAULT;
val |= CPTR_EL2_TTA | CPTR_EL2_TZ | CPTR_EL2_TAM;
if (!update_fp_enabled(vcpu)) {
val |= CPTR_EL2_TFP;
__activate_traps_fpsimd32(vcpu);
}
write_sysreg(val, cptr_el2);
write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el2);
if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt;
isb();
/*
* At this stage, and thanks to the above isb(), S2 is
* configured and enabled. We can now restore the guest's S1
* configuration: SCTLR, and only then TCR.
*/
write_sysreg_el1(ctxt_sys_reg(ctxt, SCTLR_EL1), SYS_SCTLR);
isb();
write_sysreg_el1(ctxt_sys_reg(ctxt, TCR_EL1), SYS_TCR);
}
}
static void __deactivate_traps(struct kvm_vcpu *vcpu)
{
extern char __kvm_hyp_host_vector[];
u64 mdcr_el2;
___deactivate_traps(vcpu);
mdcr_el2 = read_sysreg(mdcr_el2);
if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
u64 val;
/*
* Set the TCR and SCTLR registers in the exact opposite
* sequence as __activate_traps (first prevent walks,
* then force the MMU on). A generous sprinkling of isb()
* ensure that things happen in this exact order.
*/
val = read_sysreg_el1(SYS_TCR);
write_sysreg_el1(val | TCR_EPD1_MASK | TCR_EPD0_MASK, SYS_TCR);
isb();
val = read_sysreg_el1(SYS_SCTLR);
write_sysreg_el1(val | SCTLR_ELx_M, SYS_SCTLR);
isb();
}
__deactivate_traps_common();
mdcr_el2 &= MDCR_EL2_HPMN_MASK;
mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT;
write_sysreg(mdcr_el2, mdcr_el2);
write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2);
write_sysreg(CPTR_EL2_DEFAULT, cptr_el2);
write_sysreg(__kvm_hyp_host_vector, vbar_el2);
}
static void __load_host_stage2(void)
{
write_sysreg(0, vttbr_el2);
}
/* Save VGICv3 state on non-VHE systems */
static void __hyp_vgic_save_state(struct kvm_vcpu *vcpu)
{
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
__vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3);
__vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
}
}
/* Restore VGICv3 state on non_VEH systems */
static void __hyp_vgic_restore_state(struct kvm_vcpu *vcpu)
{
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
__vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
__vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3);
}
}
/**
* Disable host events, enable guest events
*/
static bool __pmu_switch_to_guest(struct kvm_cpu_context *host_ctxt)
{
struct kvm_host_data *host;
struct kvm_pmu_events *pmu;
host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
pmu = &host->pmu_events;
if (pmu->events_host)
write_sysreg(pmu->events_host, pmcntenclr_el0);
if (pmu->events_guest)
write_sysreg(pmu->events_guest, pmcntenset_el0);
return (pmu->events_host || pmu->events_guest);
}
/**
* Disable guest events, enable host events
*/
static void __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt)
{
struct kvm_host_data *host;
struct kvm_pmu_events *pmu;
host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
pmu = &host->pmu_events;
if (pmu->events_guest)
write_sysreg(pmu->events_guest, pmcntenclr_el0);
if (pmu->events_host)
write_sysreg(pmu->events_host, pmcntenset_el0);
}
/* Switch to the guest for legacy non-VHE systems */
int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *host_ctxt;
struct kvm_cpu_context *guest_ctxt;
bool pmu_switch_needed;
u64 exit_code;
/*
* 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.
*/
if (system_uses_irq_prio_masking()) {
gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
pmr_sync();
}
host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
host_ctxt->__hyp_running_vcpu = vcpu;
guest_ctxt = &vcpu->arch.ctxt;
pmu_switch_needed = __pmu_switch_to_guest(host_ctxt);
__sysreg_save_state_nvhe(host_ctxt);
/*
* We must restore the 32-bit state before the sysregs, thanks
* to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
*
* Also, and in order to be able to deal with erratum #1319537 (A57)
* and #1319367 (A72), we must ensure that all VM-related sysreg are
* restored before we enable S2 translation.
*/
__sysreg32_restore_state(vcpu);
__sysreg_restore_state_nvhe(guest_ctxt);
__load_guest_stage2(kern_hyp_va(vcpu->arch.hw_mmu));
__activate_traps(vcpu);
__hyp_vgic_restore_state(vcpu);
__timer_enable_traps(vcpu);
__debug_switch_to_guest(vcpu);
do {
/* Jump in the fire! */
exit_code = __guest_enter(vcpu);
/* And we're baaack! */
} while (fixup_guest_exit(vcpu, &exit_code));
__sysreg_save_state_nvhe(guest_ctxt);
__sysreg32_save_state(vcpu);
__timer_disable_traps(vcpu);
__hyp_vgic_save_state(vcpu);
__deactivate_traps(vcpu);
__load_host_stage2();
__sysreg_restore_state_nvhe(host_ctxt);
if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED)
__fpsimd_save_fpexc32(vcpu);
/*
* This must come after restoring the host sysregs, since a non-VHE
* system may enable SPE here and make use of the TTBRs.
*/
__debug_switch_to_host(vcpu);
if (pmu_switch_needed)
__pmu_switch_to_host(host_ctxt);
/* Returning to host will clear PSR.I, remask PMR if needed */
if (system_uses_irq_prio_masking())
gic_write_pmr(GIC_PRIO_IRQOFF);
host_ctxt->__hyp_running_vcpu = NULL;
return exit_code;
}
void __noreturn hyp_panic(void)
{
u64 spsr = read_sysreg_el2(SYS_SPSR);
u64 elr = read_sysreg_el2(SYS_ELR);
u64 par = read_sysreg(par_el1);
bool restore_host = true;
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;
if (vcpu) {
__timer_disable_traps(vcpu);
__deactivate_traps(vcpu);
__load_host_stage2();
__sysreg_restore_state_nvhe(host_ctxt);
}
__hyp_do_panic(restore_host, spsr, elr, par);
unreachable();
}
asmlinkage void kvm_unexpected_el2_exception(void)
{
return __kvm_unexpected_el2_exception();
}
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