KVM: x86: Dedup fastpath MSR post-handling logic

Now that the WRMSR fastpath for x2APIC_ICR and TSC_DEADLINE are identical,
ignoring the backend MSR handling, consolidate the common bits of skipping
the instruction and setting the return value.

No functional change intended.

Link: https://lore.kernel.org/r/20240802195120.325560-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0c97dd5a01971f99554b68825bd5d52b627b3b74..d392e9097d63347f53521f73f2ad76931557a91f 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2186,31 +2186,32 @@ fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu)
 {
        u32 msr = kvm_rcx_read(vcpu);
        u64 data;
-       fastpath_t ret = EXIT_FASTPATH_NONE;
+       fastpath_t ret;
+       bool handled;
 
        kvm_vcpu_srcu_read_lock(vcpu);
 
        switch (msr) {
        case APIC_BASE_MSR + (APIC_ICR >> 4):
                data = kvm_read_edx_eax(vcpu);
-               if (!handle_fastpath_set_x2apic_icr_irqoff(vcpu, data)) {
-                       kvm_skip_emulated_instruction(vcpu);
-                       ret = EXIT_FASTPATH_REENTER_GUEST;
-               }
+               handled = !handle_fastpath_set_x2apic_icr_irqoff(vcpu, data);
                break;
        case MSR_IA32_TSC_DEADLINE:
                data = kvm_read_edx_eax(vcpu);
-               if (!handle_fastpath_set_tscdeadline(vcpu, data)) {
-                       kvm_skip_emulated_instruction(vcpu);
-                       ret = EXIT_FASTPATH_REENTER_GUEST;
-               }
+               handled = !handle_fastpath_set_tscdeadline(vcpu, data);
                break;
        default:
+               handled = false;
                break;
        }
 
-       if (ret != EXIT_FASTPATH_NONE)
+       if (handled) {
+               kvm_skip_emulated_instruction(vcpu);
+               ret = EXIT_FASTPATH_REENTER_GUEST;
                trace_kvm_msr_write(msr, data);
+       } else {
+               ret = EXIT_FASTPATH_NONE;
+       }
 
        kvm_vcpu_srcu_read_unlock(vcpu);