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| author |   Sean Christopherson <seanjc@google.com> | 2022-12-13 06:09:11 +0000 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-01-24 10:36:41 -0800 |
| commit | 4f76e86f7e0dc33af14256d30177bf65de2f9cab (patch) | |
| tree | 2b2eed8c95f88e3734774deccfd418327966c22b /arch/x86/kvm/vmx/vmenter.S | |
| parent | x86/entry: KVM: Use dedicated VMX NMI entry for 32-bit kernels too (diff) | |
| download | wireguard-linux-4f76e86f7e0dc33af14256d30177bf65de2f9cab.tar.xz wireguard-linux-4f76e86f7e0dc33af14256d30177bf65de2f9cab.zip | |
KVM: VMX: Provide separate subroutines for invoking NMI vs. IRQ handlers
Split the asm subroutines for handling NMIs versus IRQs that occur in the
guest so that the NMI handler can be called from a noinstr section. As a
bonus, the NMI path doesn't need an indirect branch.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221213060912.654668-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/vmx/vmenter.S')
| -rw-r--r-- | arch/x86/kvm/vmx/vmenter.S | 70 |
1 files changed, 39 insertions, 31 deletions
diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S index cd2f75360bf3..f0519f0f738c 100644 --- a/arch/x86/kvm/vmx/vmenter.S +++ b/arch/x86/kvm/vmx/vmenter.S @@ -31,6 +31,39 @@ #define VCPU_R15 __VCPU_REGS_R15 * WORD_SIZE #endif +.macro VMX_DO_EVENT_IRQOFF call_insn call_target + /* + * Unconditionally create a stack frame, getting the correct RSP on the + * stack (for x86-64) would take two instructions anyways, and RBP can + * be used to restore RSP to make objtool happy (see below). + */ + push %_ASM_BP + mov %_ASM_SP, %_ASM_BP + +#ifdef CONFIG_X86_64 + /* + * Align RSP to a 16-byte boundary (to emulate CPU behavior) before + * creating the synthetic interrupt stack frame for the IRQ/NMI. + */ + and $-16, %rsp + push $__KERNEL_DS + push %rbp +#endif + pushf + push $__KERNEL_CS + \call_insn \call_target + + /* + * "Restore" RSP from RBP, even though IRET has already unwound RSP to + * the correct value. objtool doesn't know the callee will IRET and, + * without the explicit restore, thinks the stack is getting walloped. + * Using an unwind hint is problematic due to x86-64's dynamic alignment. + */ + mov %_ASM_BP, %_ASM_SP + pop %_ASM_BP + RET +.endm + .section .noinstr.text, "ax" /** @@ -320,35 +353,10 @@ SYM_FUNC_START(vmread_error_trampoline) SYM_FUNC_END(vmread_error_trampoline) #endif -SYM_FUNC_START(vmx_do_interrupt_nmi_irqoff) - /* - * Unconditionally create a stack frame, getting the correct RSP on the - * stack (for x86-64) would take two instructions anyways, and RBP can - * be used to restore RSP to make objtool happy (see below). - */ - push %_ASM_BP - mov %_ASM_SP, %_ASM_BP +SYM_FUNC_START(vmx_do_nmi_irqoff) + VMX_DO_EVENT_IRQOFF call asm_exc_nmi_kvm_vmx +SYM_FUNC_END(vmx_do_nmi_irqoff) -#ifdef CONFIG_X86_64 - /* - * Align RSP to a 16-byte boundary (to emulate CPU behavior) before - * creating the synthetic interrupt stack frame for the IRQ/NMI. - */ - and $-16, %rsp - push $__KERNEL_DS - push %rbp -#endif - pushf - push $__KERNEL_CS - CALL_NOSPEC _ASM_ARG1 - - /* - * "Restore" RSP from RBP, even though IRET has already unwound RSP to - * the correct value. objtool doesn't know the callee will IRET and, - * without the explicit restore, thinks the stack is getting walloped. - * Using an unwind hint is problematic due to x86-64's dynamic alignment. - */ - mov %_ASM_BP, %_ASM_SP - pop %_ASM_BP - RET -SYM_FUNC_END(vmx_do_interrupt_nmi_irqoff) +SYM_FUNC_START(vmx_do_interrupt_irqoff) + VMX_DO_EVENT_IRQOFF CALL_NOSPEC _ASM_ARG1 +SYM_FUNC_END(vmx_do_interrupt_irqoff) |