KVM: VMX: Improve handle_external_interrupt_irqoff inline assembly

Improve handle_external_interrupt_irqoff inline assembly in several ways:
- remove unneeded %c operand modifiers and "$" prefixes
- use %rsp instead of _ASM_SP, since we are in CONFIG_X86_64 part
- use $-16 immediate to align %rsp
- remove unneeded use of __ASM_SIZE macro
- define "ss" named operand only for X86_64

The patch introduces no functional changes.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Message-Id: <20200504155706.2516956-1-ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 30faae5..9ce182d 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6382,13 +6382,13 @@ static void handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu)
 
        asm volatile(
 #ifdef CONFIG_X86_64
-               "mov %%" _ASM_SP ", %[sp]\n\t"
-               "and $0xfffffffffffffff0, %%" _ASM_SP "\n\t"
-               "push $%c[ss]\n\t"
+               "mov %%rsp, %[sp]\n\t"
+               "and $-16, %%rsp\n\t"
+               "push %[ss]\n\t"
                "push %[sp]\n\t"
 #endif
                "pushf\n\t"
-               __ASM_SIZE(push) " $%c[cs]\n\t"
+               "push %[cs]\n\t"
                CALL_NOSPEC
                :
 #ifdef CONFIG_X86_64
@@ -6397,7 +6397,9 @@ static void handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu)
                ASM_CALL_CONSTRAINT
                :
                [thunk_target]"r"(entry),
+#ifdef CONFIG_X86_64
                [ss]"i"(__KERNEL_DS),
+#endif
                [cs]"i"(__KERNEL_CS)
        );