From: Ashish Kalra <ashish.kalra@xxxxxxx> Construct system vector table and dispatch system vector exceptions through sysvec_table from #HV exception handler instead of explicitly calling each system vector. The system vector table is created dynamically and is placed in a new named ELF section. Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx> --- arch/x86/entry/entry_64.S | 6 +++ arch/x86/kernel/sev.c | 70 +++++++++++++---------------------- arch/x86/kernel/vmlinux.lds.S | 7 ++++ 3 files changed, 38 insertions(+), 45 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index efa56dfde19e..802fb6dec244 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -419,6 +419,12 @@ SYM_CODE_START(\asmsym) _ASM_NOKPROBE(\asmsym) SYM_CODE_END(\asmsym) + .if \vector >= FIRST_SYSTEM_VECTOR && \vector < NR_VECTORS + .section .system_vectors, "aw" + .byte \vector + .quad \cfunc + .previous + .endif .endm /* diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 7fcb3b548215..2c964f7ac7dc 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -151,6 +151,16 @@ struct sev_snp_runtime_data { static DEFINE_PER_CPU(struct sev_snp_runtime_data*, snp_runtime_data); +static void (*sysvec_table[NR_VECTORS - FIRST_SYSTEM_VECTOR]) + (struct pt_regs *regs) __ro_after_init; + +struct sysvec_entry { + unsigned char vector; + void (*sysvec_func)(struct pt_regs *regs); +} __packed; + +extern struct sysvec_entry __system_vectors[], __system_vectors_end[]; + static inline u64 sev_es_rd_ghcb_msr(void) { return __rdmsr(MSR_AMD64_SEV_ES_GHCB); @@ -216,51 +226,11 @@ static void do_exc_hv(struct pt_regs *regs) } else if (pending_events.vector == IA32_SYSCALL_VECTOR) { WARN(1, "syscall shouldn't happen\n"); } else if (pending_events.vector >= FIRST_SYSTEM_VECTOR) { - switch (pending_events.vector) { -#if IS_ENABLED(CONFIG_HYPERV) - case HYPERV_STIMER0_VECTOR: - sysvec_hyperv_stimer0(regs); - break; - case HYPERVISOR_CALLBACK_VECTOR: - sysvec_hyperv_callback(regs); - break; -#endif -#ifdef CONFIG_SMP - case RESCHEDULE_VECTOR: - sysvec_reschedule_ipi(regs); - break; - case IRQ_MOVE_CLEANUP_VECTOR: - sysvec_irq_move_cleanup(regs); - break; - case REBOOT_VECTOR: - sysvec_reboot(regs); - break; - case CALL_FUNCTION_SINGLE_VECTOR: - sysvec_call_function_single(regs); - break; - case CALL_FUNCTION_VECTOR: - sysvec_call_function(regs); - break; -#endif -#ifdef CONFIG_X86_LOCAL_APIC - case ERROR_APIC_VECTOR: - sysvec_error_interrupt(regs); - break; - case SPURIOUS_APIC_VECTOR: - sysvec_spurious_apic_interrupt(regs); - break; - case LOCAL_TIMER_VECTOR: - sysvec_apic_timer_interrupt(regs); - break; - case X86_PLATFORM_IPI_VECTOR: - sysvec_x86_platform_ipi(regs); - break; -#endif - case 0x0: - break; - default: - panic("Unexpected vector %d\n", vector); - unreachable(); + if (!(sysvec_table[pending_events.vector - FIRST_SYSTEM_VECTOR])) { + WARN(1, "system vector entry 0x%x is NULL\n", + pending_events.vector); + } else { + (*sysvec_table[pending_events.vector - FIRST_SYSTEM_VECTOR])(regs); } } else { common_interrupt(regs, pending_events.vector); @@ -383,6 +353,14 @@ static bool sev_restricted_injection_enabled(void) return sev_status & MSR_AMD64_SNP_RESTRICTED_INJ; } +static void __init construct_sysvec_table(void) +{ + struct sysvec_entry *p; + + for (p = __system_vectors; p < __system_vectors_end; p++) + sysvec_table[p->vector - FIRST_SYSTEM_VECTOR] = p->sysvec_func; +} + void __init sev_snp_init_hv_handling(void) { struct sev_es_runtime_data *data; @@ -407,6 +385,8 @@ void __init sev_snp_init_hv_handling(void) apic_set_eoi_write(hv_doorbell_apic_eoi_write); local_irq_restore(flags); + + construct_sysvec_table(); } static int vc_fetch_insn_kernel(struct es_em_ctxt *ctxt, diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 25f155205770..c37165d8e877 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -338,6 +338,13 @@ SECTIONS *(.altinstr_replacement) } + . = ALIGN(8); + .system_vectors : AT(ADDR(.system_vectors) - LOAD_OFFSET) { + __system_vectors = .; + *(.system_vectors) + __system_vectors_end = .; + } + . = ALIGN(8); .apicdrivers : AT(ADDR(.apicdrivers) - LOAD_OFFSET) { __apicdrivers = .; -- 2.25.1