--- /dev/null
- u8 hsr_ec;
+// 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 <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>
+
+extern const char __hyp_panic_string[];
+
+/* Check whether the FP regs were dirtied while in the host-side run loop: */
+static inline bool update_fp_enabled(struct kvm_vcpu *vcpu)
+{
+ /*
+ * When the system doesn't support FP/SIMD, we cannot rely on
+ * the _TIF_FOREIGN_FPSTATE flag. However, we always inject an
+ * abort on the very first access to FP and thus we should never
+ * see KVM_ARM64_FP_ENABLED. For added safety, make sure we always
+ * trap the accesses.
+ */
+ if (!system_supports_fpsimd() ||
+ vcpu->arch.host_thread_info->flags & _TIF_FOREIGN_FPSTATE)
+ vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED |
+ KVM_ARM64_FP_HOST);
+
+ return !!(vcpu->arch.flags & KVM_ARM64_FP_ENABLED);
+}
+
+/* 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();
+ }
+}
+
+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.
+ */
+ write_sysreg(0, pmselr_el0);
+ write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0);
+ write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2);
+}
+
+static inline void __deactivate_traps_common(void)
+{
+ write_sysreg(0, hstr_el2);
+ write_sysreg(0, pmuserenr_el0);
+}
+
+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 void __activate_vm(struct kvm_s2_mmu *mmu)
+{
+ __load_guest_stage2(mmu);
+}
+
+static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar)
+{
+ u64 par, tmp;
+
+ /*
+ * Resolve the IPA the hard way using the guest VA.
+ *
+ * Stage-1 translation already validated the memory access
+ * rights. As such, we can use the EL1 translation regime, and
+ * don't have to distinguish between EL0 and EL1 access.
+ *
+ * We do need to save/restore PAR_EL1 though, as we haven't
+ * saved the guest context yet, and we may return early...
+ */
+ par = read_sysreg(par_el1);
+ asm volatile("at s1e1r, %0" : : "r" (far));
+ isb();
+
+ tmp = read_sysreg(par_el1);
+ write_sysreg(par, par_el1);
+
+ if (unlikely(tmp & SYS_PAR_EL1_F))
+ return false; /* Translation failed, back to guest */
+
+ /* Convert PAR to HPFAR format */
+ *hpfar = PAR_TO_HPFAR(tmp);
+ return true;
+}
+
+static inline bool __populate_fault_info(struct kvm_vcpu *vcpu)
+{
+ u8 ec;
+ u64 esr;
+ u64 hpfar, far;
+
+ esr = vcpu->arch.fault.esr_el2;
+ ec = ESR_ELx_EC(esr);
+
+ if (ec != ESR_ELx_EC_DABT_LOW && ec != ESR_ELx_EC_IABT_LOW)
+ return true;
+
+ far = read_sysreg_el2(SYS_FAR);
+
+ /*
+ * The HPFAR can be invalid if the stage 2 fault did not
+ * happen during a stage 1 page table walk (the ESR_EL2.S1PTW
+ * bit is clear) and one of the two following cases are true:
+ * 1. The fault was due to a permission fault
+ * 2. The processor carries errata 834220
+ *
+ * Therefore, for all non S1PTW faults where we either have a
+ * permission fault or the errata workaround is enabled, we
+ * resolve the IPA using the AT instruction.
+ */
+ if (!(esr & ESR_ELx_S1PTW) &&
+ (cpus_have_final_cap(ARM64_WORKAROUND_834220) ||
+ (esr & ESR_ELx_FSC_TYPE) == FSC_PERM)) {
+ if (!__translate_far_to_hpfar(far, &hpfar))
+ return false;
+ } else {
+ hpfar = read_sysreg(hpfar_el2);
+ }
+
+ vcpu->arch.fault.far_el2 = far;
+ vcpu->arch.fault.hpfar_el2 = hpfar;
+ return true;
+}
+
+/* Check for an FPSIMD/SVE trap and handle as appropriate */
+static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu)
+{
+ bool vhe, sve_guest, sve_host;
- hsr_ec = kvm_vcpu_trap_get_class(vcpu);
- if (hsr_ec != ESR_ELx_EC_FP_ASIMD &&
- hsr_ec != ESR_ELx_EC_SVE)
++ u8 esr_ec;
+
+ if (!system_supports_fpsimd())
+ return false;
+
+ /*
+ * Currently system_supports_sve() currently implies has_vhe(),
+ * so the check is redundant. However, has_vhe() can be determined
+ * statically and helps the compiler remove dead code.
+ */
+ if (has_vhe() && system_supports_sve()) {
+ sve_guest = vcpu_has_sve(vcpu);
+ sve_host = vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE;
+ vhe = true;
+ } else {
+ sve_guest = false;
+ sve_host = false;
+ vhe = has_vhe();
+ }
+
- if (hsr_ec != ESR_ELx_EC_FP_ASIMD)
++ esr_ec = kvm_vcpu_trap_get_class(vcpu);
++ if (esr_ec != ESR_ELx_EC_FP_ASIMD &&
++ esr_ec != ESR_ELx_EC_SVE)
+ return false;
+
+ /* Don't handle SVE traps for non-SVE vcpus here: */
+ if (!sve_guest)
- u32 sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_hsr(vcpu));
++ if (esr_ec != ESR_ELx_EC_FP_ASIMD)
+ return false;
+
+ /* Valid trap. Switch the context: */
+
+ if (vhe) {
+ u64 reg = read_sysreg(cpacr_el1) | CPACR_EL1_FPEN;
+
+ if (sve_guest)
+ reg |= CPACR_EL1_ZEN;
+
+ write_sysreg(reg, cpacr_el1);
+ } else {
+ write_sysreg(read_sysreg(cptr_el2) & ~(u64)CPTR_EL2_TFP,
+ cptr_el2);
+ }
+
+ isb();
+
+ if (vcpu->arch.flags & KVM_ARM64_FP_HOST) {
+ /*
+ * In the SVE case, VHE is assumed: it is enforced by
+ * Kconfig and kvm_arch_init().
+ */
+ if (sve_host) {
+ struct thread_struct *thread = container_of(
+ vcpu->arch.host_fpsimd_state,
+ struct thread_struct, uw.fpsimd_state);
+
+ sve_save_state(sve_pffr(thread),
+ &vcpu->arch.host_fpsimd_state->fpsr);
+ } else {
+ __fpsimd_save_state(vcpu->arch.host_fpsimd_state);
+ }
+
+ vcpu->arch.flags &= ~KVM_ARM64_FP_HOST;
+ }
+
+ if (sve_guest) {
+ sve_load_state(vcpu_sve_pffr(vcpu),
+ &vcpu->arch.ctxt.fp_regs.fpsr,
+ sve_vq_from_vl(vcpu->arch.sve_max_vl) - 1);
+ write_sysreg_s(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR_EL12);
+ } 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.flags |= KVM_ARM64_FP_ENABLED;
+
+ return true;
+}
+
+static inline bool handle_tx2_tvm(struct kvm_vcpu *vcpu)
+{
- !esr_is_ptrauth_trap(kvm_vcpu_get_hsr(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(u32 esr)
+{
+ u32 ec = ESR_ELx_EC(esr);
+
+ if (ec == ESR_ELx_EC_PAC)
+ return true;
+
+ if (ec != ESR_ELx_EC_SYS64)
+ return false;
+
+ 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)
+
+static inline bool __hyp_handle_ptrauth(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpu_context *ctxt;
+ u64 val;
+
+ if (!vcpu_has_ptrauth(vcpu) ||
++ !esr_is_ptrauth_trap(kvm_vcpu_get_esr(vcpu)))
+ return false;
+
+ ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_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;
+}
+
+/*
+ * 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)
+{
+ if (ARM_EXCEPTION_CODE(*exit_code) != ARM_EXCEPTION_IRQ)
+ vcpu->arch.fault.esr_el2 = read_sysreg_el2(SYS_ESR);
+
+ /*
+ * 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;
+
+ if (cpus_have_final_cap(ARM64_WORKAROUND_CAVIUM_TX2_219_TVM) &&
+ kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_SYS64 &&
+ handle_tx2_tvm(vcpu))
+ return true;
+
+ /*
+ * 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.
+ */
+ if (__hyp_handle_fpsimd(vcpu))
+ return true;
+
+ if (__hyp_handle_ptrauth(vcpu))
+ return true;
+
+ if (!__populate_fault_info(vcpu))
+ return true;
+
+ if (static_branch_unlikely(&vgic_v2_cpuif_trap)) {
+ bool valid;
+
+ valid = kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_DABT_LOW &&
+ kvm_vcpu_trap_get_fault_type(vcpu) == FSC_FAULT &&
+ kvm_vcpu_dabt_isvalid(vcpu) &&
+ !kvm_vcpu_dabt_isextabt(vcpu) &&
+ !kvm_vcpu_dabt_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;
+
+ goto exit;
+ }
+ }
+
+ if (static_branch_unlikely(&vgic_v3_cpuif_trap) &&
+ (kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_SYS64 ||
+ kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_CP15_32)) {
+ int ret = __vgic_v3_perform_cpuif_access(vcpu);
+
+ if (ret == 1)
+ return true;
+ }
+
+exit:
+ /* Return to the host kernel and handle the exit */
+ return false;
+}
+
+static inline bool __needs_ssbd_off(struct kvm_vcpu *vcpu)
+{
+ if (!cpus_have_final_cap(ARM64_SSBD))
+ return false;
+
+ return !(vcpu->arch.workaround_flags & VCPU_WORKAROUND_2_FLAG);
+}
+
+static inline void __set_guest_arch_workaround_state(struct kvm_vcpu *vcpu)
+{
+#ifdef CONFIG_ARM64_SSBD
+ /*
+ * The host runs with the workaround always present. If the
+ * guest wants it disabled, so be it...
+ */
+ if (__needs_ssbd_off(vcpu) &&
+ __hyp_this_cpu_read(arm64_ssbd_callback_required))
+ arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 0, NULL);
+#endif
+}
+
+static inline void __set_host_arch_workaround_state(struct kvm_vcpu *vcpu)
+{
+#ifdef CONFIG_ARM64_SSBD
+ /*
+ * If the guest has disabled the workaround, bring it back on.
+ */
+ if (__needs_ssbd_off(vcpu) &&
+ __hyp_this_cpu_read(arm64_ssbd_callback_required))
+ arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 1, NULL);
+#endif
+}
+
+#endif /* __ARM64_KVM_HYP_SWITCH_H__ */
projects / platform / kernel / linux-rpi.git / commitdiff