From 3fb328f76b0f78b27ce9f4c3c1687c2c5bd15134 Mon Sep 17 00:00:00 2001 From: Steffen Eiden Date: Thu, 2 Apr 2026 06:00:00 +0200 Subject: [PATCH] KVM: s390: arm64: Implement required functions Implement the mostly trivial functions that the shared arm64 (kvm) code & headers oblige s390 to implement. MAINTAINERS: Add arch/s390/include/arm64/* to KVM/s390 Implement a very basic smccc handler that (non-compliantly) is just able to stop a vcpu. Signed-off-by: Steffen Eiden Signed-off-by: Christian Borntraeger --- MAINTAINERS | 1 + arch/s390/include/arm64/kvm_emulate.h | 130 ++++++++++++++++++++++++++ arch/s390/include/arm64/kvm_nested.h | 11 +++ arch/s390/include/arm64/ptrace.h | 11 +++ arch/s390/include/arm64/sysreg.h | 13 +++ arch/s390/kvm/arm64/handle_exit.c | 127 +++++++++++++++++++++++++ arch/s390/kvm/arm64/inject_fault.c | 21 +++++ 7 files changed, 314 insertions(+) create mode 100644 arch/s390/include/arm64/kvm_emulate.h create mode 100644 arch/s390/include/arm64/kvm_nested.h create mode 100644 arch/s390/include/arm64/ptrace.h create mode 100644 arch/s390/include/arm64/sysreg.h create mode 100644 arch/s390/kvm/arm64/handle_exit.c create mode 100644 arch/s390/kvm/arm64/inject_fault.c diff --git a/MAINTAINERS b/MAINTAINERS index c2414447892c..1d45ccf863c1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14372,6 +14372,7 @@ L: kvm@vger.kernel.org S: Supported T: git git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git F: Documentation/virt/kvm/s390* +F: arch/s390/include/arm64/* F: arch/s390/include/asm/gmap_helpers.h F: arch/s390/include/asm/kvm* F: arch/s390/include/uapi/asm/kvm* diff --git a/arch/s390/include/arm64/kvm_emulate.h b/arch/s390/include/arm64/kvm_emulate.h new file mode 100644 index 000000000000..416c4f96db05 --- /dev/null +++ b/arch/s390/include/arm64/kvm_emulate.h @@ -0,0 +1,130 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __S390_ARM64_KVM_EMULATE_H__ +#define __S390_ARM64_KVM_EMULATE_H__ + +#include +#include + +#include +#include +#include +#include + +static __always_inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu) +{ + return (unsigned long *)&vcpu->arch.sae_block.pc; +} + +static __always_inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu) +{ + return (unsigned long *)&vcpu->arch.sae_block.pstate; +} + +static __always_inline unsigned long *vcpu_sp_el0(const struct kvm_vcpu *vcpu) +{ + return (unsigned long *)&vcpu->arch.sae_block.sp_el0; +} + +static __always_inline u64 *vcpu_sp_el1(struct kvm_vcpu *vcpu) +{ + return &vcpu->arch.sae_block.sp_el1; +} + +static __always_inline __vector128 *vcpu_vreg(struct kvm_vcpu *vcpu, int off) +{ + return &vcpu->arch.ctxt.vregs[off]; +} + +static __always_inline u32 *vcpu_fpsr(struct kvm_vcpu *vcpu) +{ + return &vcpu->arch.sae_block.fpsr; +} + +static __always_inline u32 *vcpu_fpcr(struct kvm_vcpu *vcpu) +{ + return &vcpu->arch.sae_block.fpcr; +} + +static __always_inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu) +{ + return false; +} + +static __always_inline u64 kvm_vcpu_get_esr(const struct kvm_vcpu *vcpu) +{ + return vcpu->arch.sae_block.hai.esr_el2; +} + +static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu) +{ + return (unsigned long *)&vcpu->arch.hcr_el2; +} + +static __always_inline unsigned long kvm_vcpu_get_hfar(const struct kvm_vcpu *vcpu) +{ + return vcpu->arch.sae_block.hai.far_el2; +} + +static __always_inline phys_addr_t kvm_vcpu_get_fault_ipa(const struct kvm_vcpu *vcpu) +{ + return gfn_to_gpa(vcpu->arch.sae_block.hai.teid.addr); +} + +static inline u16 kvm_vcpu_fault_pic(const struct kvm_vcpu *vcpu) +{ + return vcpu->arch.sae_block.hai.pic & PGM_INT_CODE_MASK; +} + +static __always_inline +bool kvm_vcpu_trap_is_permission_fault(const struct kvm_vcpu *vcpu) +{ + return kvm_vcpu_fault_pic(vcpu) == PGM_PROTECTION; +} + +static __always_inline bool kvm_condition_valid(const struct kvm_vcpu *vcpu) +{ + return true; +} + +static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu) +{ + return false; +} + +static inline bool kvm_vcpu_is_be(struct kvm_vcpu *vcpu) +{ + return false; +} + +static inline int kvm_vcpu_abt_gltl(struct kvm_vcpu *vcpu) +{ + return vcpu->arch.sae_block.hai.gltl; +} + +static inline bool vcpu_mode_priv(const struct kvm_vcpu *vcpu) +{ + u32 mode = *vcpu_cpsr(vcpu) & PSR_MODE_MASK; + + return mode != PSR_MODE_EL0t; +} + +static inline void kvm_skip_instr(struct kvm_vcpu *vcpu) +{ + *vcpu_pc(vcpu) += 4; + *vcpu_cpsr(vcpu) &= ~PSR_BTYPE_MASK; + + /* advance the singlestep state machine */ + *vcpu_cpsr(vcpu) &= ~SPSR_ELx_SS; +} + +static inline void kvm_reset_fpsimd(struct kvm_vcpu *vcpu) +{ + memset(vcpu->arch.ctxt.vregs, 0, sizeof(vcpu->arch.ctxt.vregs)); + vcpu->arch.sae_block.fpsr = 0; + vcpu->arch.sae_block.fpcr = 0; +} + +#include + +#endif /* __S390_ARM64_KVM_EMULATE_H__ */ diff --git a/arch/s390/include/arm64/kvm_nested.h b/arch/s390/include/arm64/kvm_nested.h new file mode 100644 index 000000000000..e950b1a10c41 --- /dev/null +++ b/arch/s390/include/arm64/kvm_nested.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef ASM_KVM_NESTED_H +#define ASM_KVM_NESTED_H + +static inline bool vcpu_has_nv(const struct kvm_vcpu *vcpu) +{ + return false; +} + +#endif /* ASM_KVM_NESTED_H */ diff --git a/arch/s390/include/arm64/ptrace.h b/arch/s390/include/arm64/ptrace.h new file mode 100644 index 000000000000..449b85582c97 --- /dev/null +++ b/arch/s390/include/arm64/ptrace.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __S390_ARM64_PTRACE_H__ +#define __S390_ARM64_PTRACE_H__ + +#include +#include + +#include + +#endif /* __S390_ARM64_PTRACE_H__ */ diff --git a/arch/s390/include/arm64/sysreg.h b/arch/s390/include/arm64/sysreg.h new file mode 100644 index 000000000000..ac6b638fef56 --- /dev/null +++ b/arch/s390/include/arm64/sysreg.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __S390_ARM64_SYSREG_H__ +#define __S390_ARM64_SYSREG_H__ + +#include +#include +#include +#include + +#include + +#endif /* __S390_ARM64_SYSREG_H__ */ diff --git a/arch/s390/kvm/arm64/handle_exit.c b/arch/s390/kvm/arm64/handle_exit.c new file mode 100644 index 000000000000..07d8d7a53702 --- /dev/null +++ b/arch/s390/kvm/arm64/handle_exit.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +#include +#include + +typedef int (*exit_handle_fn)(struct kvm_vcpu *); + +#define PSCI_0_2_FN_SYSTEM_OFF 0x84000008 +#define PSCI_RET_NOT_SUPPORTED -1 +#define PSCI_RET_INTERNAL_FAILURE -6 +/* + * Temporary smc/hvc handler. Non-compliant implementation (features missing). + * Implements only system off so that test programs are able to end their execution. + * Multi-vCPU power state management and KVM_REQ_SLEEP handling are deferred + * to future SMP series. + */ +static int kvm_smccc_call_handler(struct kvm_vcpu *vcpu) +{ + u32 func_id = vcpu_get_reg(vcpu, 0); + u64 val = PSCI_RET_NOT_SUPPORTED; + int ret = 1; + + if (func_id == PSCI_0_2_FN_SYSTEM_OFF) { + scoped_guard(spinlock, &vcpu->arch.mp_state_lock) { + WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED); + } + memset(&vcpu->run->system_event, 0, + sizeof(vcpu->run->system_event)); + vcpu->run->system_event.type = KVM_SYSTEM_EVENT_SHUTDOWN; + vcpu->run->system_event.ndata = 1; + vcpu->run->system_event.data[0] = 0; + vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT; + val = PSCI_RET_INTERNAL_FAILURE; + ret = 0; + } + vcpu_set_reg(vcpu, 0, val); + + return ret; +} + +static int handle_hvc(struct kvm_vcpu *vcpu) +{ + vcpu->stat.hvc_exit_stat++; + return kvm_smccc_call_handler(vcpu); +} + +static int kvm_handle_unknown_ec(struct kvm_vcpu *vcpu) +{ + u64 esr = kvm_vcpu_get_esr(vcpu); + + kvm_pr_unimpl("Unknown exception class: esr: %#016llx -- %s\n", + esr, esr_get_class_string(esr)); + + kvm_inject_undefined(vcpu); + return 1; +} + +static exit_handle_fn arm_exit_handlers[] = { + [0 ... ESR_ELx_EC_MAX] = kvm_handle_unknown_ec, + [ESR_ELx_EC_HVC64] = handle_hvc, +}; + +static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu) +{ + u64 esr = kvm_vcpu_get_esr(vcpu); + u8 esr_ec = ESR_ELx_EC(esr); + + return arm_exit_handlers[esr_ec]; +} + +/* + * We may be single-stepping an emulated instruction. If the emulation + * has been completed in the kernel, we can return to userspace with a + * KVM_EXIT_DEBUG, otherwise userspace needs to complete its + * emulation first. + */ +static int handle_trap_exceptions(struct kvm_vcpu *vcpu) +{ + exit_handle_fn exit_handler; + + exit_handler = kvm_get_exit_handler(vcpu); + return exit_handler(vcpu); +} + +/* manually copied from arch/arm64/kernel/traps.c */ +static const char * const esr_class_str[] = { + [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", + [ESR_ELx_EC_UNKNOWN] = "Unknown/Uncategorized", + [ESR_ELx_EC_WFx] = "WFI/WFE", + [ESR_ELx_EC_FP_ASIMD] = "ASIMD", + [ESR_ELx_EC_PAC] = "PAC", + [ESR_ELx_EC_BTI] = "BTI", + [ESR_ELx_EC_ILL] = "PSTATE.IL", + [ESR_ELx_EC_SVC64] = "SVC (AArch64)", + [ESR_ELx_EC_HVC64] = "HVC (AArch64)", + [ESR_ELx_EC_SMC64] = "SMC (AArch64)", + [ESR_ELx_EC_SYS64] = "MSR/MRS (AArch64)", + [ESR_ELx_EC_SVE] = "SVE", + [ESR_ELx_EC_ERET] = "ERET/ERETAA/ERETAB", + [ESR_ELx_EC_FPAC] = "FPAC", + [ESR_ELx_EC_SME] = "SME", + [ESR_ELx_EC_IMP_DEF] = "EL3 IMP DEF", + [ESR_ELx_EC_IABT_LOW] = "IABT (lower EL)", + [ESR_ELx_EC_IABT_CUR] = "IABT (current EL)", + [ESR_ELx_EC_PC_ALIGN] = "PC Alignment", + [ESR_ELx_EC_DABT_LOW] = "DABT (lower EL)", + [ESR_ELx_EC_DABT_CUR] = "DABT (current EL)", + [ESR_ELx_EC_SP_ALIGN] = "SP Alignment", + [ESR_ELx_EC_MOPS] = "MOPS", + [ESR_ELx_EC_FP_EXC64] = "FP (AArch64)", + [ESR_ELx_EC_GCS] = "Guarded Control Stack", + [ESR_ELx_EC_SERROR] = "SError", + [ESR_ELx_EC_BREAKPT_LOW] = "Breakpoint (lower EL)", + [ESR_ELx_EC_BREAKPT_CUR] = "Breakpoint (current EL)", + [ESR_ELx_EC_SOFTSTP_LOW] = "Software Step (lower EL)", + [ESR_ELx_EC_SOFTSTP_CUR] = "Software Step (current EL)", + [ESR_ELx_EC_WATCHPT_LOW] = "Watchpoint (lower EL)", + [ESR_ELx_EC_WATCHPT_CUR] = "Watchpoint (current EL)", + [ESR_ELx_EC_BRK64] = "BRK (AArch64)", +}; + +const char *esr_get_class_string(unsigned long esr) +{ + return esr_class_str[ESR_ELx_EC(esr)]; +} diff --git a/arch/s390/kvm/arm64/inject_fault.c b/arch/s390/kvm/arm64/inject_fault.c new file mode 100644 index 000000000000..425dbeaa421c --- /dev/null +++ b/arch/s390/kvm/arm64/inject_fault.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +/** + * kvm_inject_undefined - inject an undefined instruction into the guest + * @vcpu: The vCPU in which to inject the exception + * + * It is assumed that this code is called from the VCPU thread and that the + * VCPU therefore is not currently executing guest code. + */ +void kvm_inject_undefined(struct kvm_vcpu *vcpu) +{ + /* Stub until s390 supports arm64 sysregs TODO sysregs*/ +} + +int kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr) +{ + /* Stub until s390 supports arm64 sysregs TODO sysregs*/ + return 1; +}