# Commit 37541208f119a9c552c6c6c3246ea61be0d44035 # Date 2024-02-26 18:20:27 +0000 # Author Andrew Cooper # Committer Andrew Cooper x86/entry: Introduce EFRAME_* constants restore_all_guest() does a lot of manipulation of the stack after popping the GPRs, and uses raw %rsp displacements to do so. Also, almost all entrypaths use raw %rsp displacements prior to pushing GPRs. Provide better mnemonics, to aid readability and reduce the chance of errors when editing. No functional change. The resulting binary is identical. Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich --- a/xen/arch/x86/x86_64/asm-offsets.c +++ b/xen/arch/x86/x86_64/asm-offsets.c @@ -55,6 +55,23 @@ void __dummy__(void) DEFINE(UREGS_user_sizeof, sizeof(struct cpu_user_regs)); BLANK(); + /* + * EFRAME_* is for the entry/exit logic where %rsp is pointing at + * UREGS_error_code and GPRs are still/already guest values. + */ +#define OFFSET_EF(sym, mem) \ + DEFINE(sym, offsetof(struct cpu_user_regs, mem) - \ + offsetof(struct cpu_user_regs, error_code)) + + OFFSET_EF(EFRAME_entry_vector, entry_vector); + OFFSET_EF(EFRAME_rip, rip); + OFFSET_EF(EFRAME_cs, cs); + OFFSET_EF(EFRAME_eflags, eflags); + OFFSET_EF(EFRAME_rsp, rsp); + BLANK(); + +#undef OFFSET_EF + OFFSET(irq_caps_offset, struct domain, irq_caps); OFFSET(next_in_list_offset, struct domain, next_in_list); OFFSET(VCPU_processor, struct vcpu, processor); --- a/xen/arch/x86/x86_64/compat/entry.S +++ b/xen/arch/x86/x86_64/compat/entry.S @@ -14,7 +14,7 @@ ENTRY(entry_int82) ASM_CLAC pushq $0 - movl $HYPERCALL_VECTOR, 4(%rsp) + movl $HYPERCALL_VECTOR, EFRAME_entry_vector(%rsp) SAVE_ALL compat=1 /* DPL1 gate, restricted to 32bit PV guests only. */ SPEC_CTRL_ENTRY_FROM_PV /* Req: %rsp=regs/cpuinfo, %rdx=0, Clob: acd */ @@ -213,7 +213,7 @@ ENTRY(cstar_enter) pushq $FLAT_USER_CS32 pushq %rcx pushq $0 - movl $TRAP_syscall, 4(%rsp) + movl $TRAP_syscall, EFRAME_entry_vector(%rsp) SAVE_ALL SPEC_CTRL_ENTRY_FROM_PV /* Req: %rsp=regs/cpuinfo, %rdx=0, Clob: acd */ --- a/xen/arch/x86/x86_64/entry.S +++ b/xen/arch/x86/x86_64/entry.S @@ -196,23 +196,23 @@ restore_all_guest: SPEC_CTRL_EXIT_TO_PV /* Req: a=spec_ctrl %rsp=regs/cpuinfo, Clob: cd */ RESTORE_ALL - testw $TRAP_syscall,4(%rsp) + testw $TRAP_syscall, EFRAME_entry_vector(%rsp) jz iret_exit_to_guest - movq 24(%rsp),%r11 # RFLAGS + mov EFRAME_eflags(%rsp), %r11 andq $~(X86_EFLAGS_IOPL|X86_EFLAGS_NT|X86_EFLAGS_VM),%r11 orq $X86_EFLAGS_IF,%r11 /* Don't use SYSRET path if the return address is not canonical. */ - movq 8(%rsp),%rcx + mov EFRAME_rip(%rsp), %rcx sarq $47,%rcx incl %ecx cmpl $1,%ecx - movq 8(%rsp),%rcx # RIP + mov EFRAME_rip(%rsp), %rcx ja iret_exit_to_guest - cmpw $FLAT_USER_CS32,16(%rsp)# CS - movq 32(%rsp),%rsp # RSP + cmpw $FLAT_USER_CS32, EFRAME_cs(%rsp) + mov EFRAME_rsp(%rsp), %rsp je 1f sysretq 1: sysretl @@ -220,8 +220,8 @@ restore_all_guest: ALIGN /* No special register assumptions. */ iret_exit_to_guest: - andl $~(X86_EFLAGS_IOPL|X86_EFLAGS_NT|X86_EFLAGS_VM),24(%rsp) - orl $X86_EFLAGS_IF,24(%rsp) + andl $~(X86_EFLAGS_IOPL|X86_EFLAGS_NT|X86_EFLAGS_VM), EFRAME_eflags(%rsp) + orl $X86_EFLAGS_IF, EFRAME_eflags(%rsp) addq $8,%rsp .Lft0: iretq _ASM_PRE_EXTABLE(.Lft0, handle_exception) @@ -277,7 +277,7 @@ ENTRY(lstar_enter) pushq $FLAT_KERNEL_CS64 pushq %rcx pushq $0 - movl $TRAP_syscall, 4(%rsp) + movl $TRAP_syscall, EFRAME_entry_vector(%rsp) SAVE_ALL SPEC_CTRL_ENTRY_FROM_PV /* Req: %rsp=regs/cpuinfo, %rdx=0, Clob: acd */ @@ -310,7 +310,7 @@ GLOBAL(sysenter_eflags_saved) pushq $3 /* ring 3 null cs */ pushq $0 /* null rip */ pushq $0 - movl $TRAP_syscall, 4(%rsp) + movl $TRAP_syscall, EFRAME_entry_vector(%rsp) SAVE_ALL SPEC_CTRL_ENTRY_FROM_PV /* Req: %rsp=regs/cpuinfo, %rdx=0, Clob: acd */ @@ -361,7 +361,7 @@ UNLIKELY_END(sysenter_gpf) ENTRY(int80_direct_trap) ASM_CLAC pushq $0 - movl $0x80, 4(%rsp) + movl $0x80, EFRAME_entry_vector(%rsp) SAVE_ALL SPEC_CTRL_ENTRY_FROM_PV /* Req: %rsp=regs/cpuinfo, %rdx=0, Clob: acd */ @@ -584,7 +584,7 @@ ENTRY(common_interrupt) jmp ret_from_intr ENTRY(page_fault) - movl $TRAP_page_fault,4(%rsp) + movl $TRAP_page_fault, EFRAME_entry_vector(%rsp) /* No special register assumptions. */ GLOBAL(handle_exception) SAVE_ALL CLAC @@ -714,71 +714,71 @@ FATAL_exception_with_ints_disabled: ENTRY(divide_error) pushq $0 - movl $TRAP_divide_error,4(%rsp) + movl $TRAP_divide_error, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(coprocessor_error) pushq $0 - movl $TRAP_copro_error,4(%rsp) + movl $TRAP_copro_error, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(simd_coprocessor_error) pushq $0 - movl $TRAP_simd_error,4(%rsp) + movl $TRAP_simd_error, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(device_not_available) pushq $0 - movl $TRAP_no_device,4(%rsp) + movl $TRAP_no_device, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(debug) pushq $0 - movl $TRAP_debug,4(%rsp) + movl $TRAP_debug, EFRAME_entry_vector(%rsp) jmp handle_ist_exception ENTRY(int3) pushq $0 - movl $TRAP_int3,4(%rsp) + movl $TRAP_int3, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(overflow) pushq $0 - movl $TRAP_overflow,4(%rsp) + movl $TRAP_overflow, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(bounds) pushq $0 - movl $TRAP_bounds,4(%rsp) + movl $TRAP_bounds, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(invalid_op) pushq $0 - movl $TRAP_invalid_op,4(%rsp) + movl $TRAP_invalid_op, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(invalid_TSS) - movl $TRAP_invalid_tss,4(%rsp) + movl $TRAP_invalid_tss, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(segment_not_present) - movl $TRAP_no_segment,4(%rsp) + movl $TRAP_no_segment, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(stack_segment) - movl $TRAP_stack_error,4(%rsp) + movl $TRAP_stack_error, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(general_protection) - movl $TRAP_gp_fault,4(%rsp) + movl $TRAP_gp_fault, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(alignment_check) - movl $TRAP_alignment_check,4(%rsp) + movl $TRAP_alignment_check, EFRAME_entry_vector(%rsp) jmp handle_exception ENTRY(double_fault) - movl $TRAP_double_fault,4(%rsp) + movl $TRAP_double_fault, EFRAME_entry_vector(%rsp) /* Set AC to reduce chance of further SMAP faults */ SAVE_ALL STAC @@ -801,7 +801,7 @@ ENTRY(double_fault) .pushsection .init.text, "ax", @progbits ENTRY(early_page_fault) - movl $TRAP_page_fault,4(%rsp) + movl $TRAP_page_fault, EFRAME_entry_vector(%rsp) SAVE_ALL movq %rsp,%rdi call do_early_page_fault @@ -810,7 +810,7 @@ ENTRY(early_page_fault) ENTRY(nmi) pushq $0 - movl $TRAP_nmi,4(%rsp) + movl $TRAP_nmi, EFRAME_entry_vector(%rsp) handle_ist_exception: SAVE_ALL CLAC @@ -876,7 +876,7 @@ handle_ist_exception: ENTRY(machine_check) pushq $0 - movl $TRAP_machine_check,4(%rsp) + movl $TRAP_machine_check, EFRAME_entry_vector(%rsp) jmp handle_ist_exception .pushsection .rodata, "a", @progbits @@ -928,7 +928,7 @@ autogen_stubs: /* Automatically generate ALIGN 1: pushq $0 - movb $vec,4(%rsp) + movb $vec, EFRAME_entry_vector(%rsp) jmp common_interrupt entrypoint 1b @@ -939,7 +939,7 @@ autogen_stubs: /* Automatically generate 1: test $8,%spl /* 64bit exception frames are 16 byte aligned, but the word */ jz 2f /* size is 8 bytes. Check whether the processor gave us an */ pushq $0 /* error code, and insert an empty one if not. */ -2: movb $vec,4(%rsp) +2: movb $vec, EFRAME_entry_vector(%rsp) jmp handle_exception entrypoint 1b