KVM: VMX: Dedup code for removing MSR from VMCS's auto-load list

Add a helper to remove an MSR from an auto-{load,store} list to dedup the
msr_autoload code, and in anticipation of adding similar functionality for
msr_autostore.

No functional change intended.

Tested-by: Manali Shukla <manali.shukla@amd.com>
Link: https://patch.msgid.link/20251206001720.468579-38-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 52bcb817cc157863fbbcce25bcc50424ab543d7a..a51f66d1b20122870ea0f46be3b12dda49906c3b 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1040,9 +1040,22 @@ static int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr)
        return -ENOENT;
 }
 
-static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
+static void vmx_remove_auto_msr(struct vmx_msrs *m, u32 msr,
+                               unsigned long vmcs_count_field)
 {
        int i;
+
+       i = vmx_find_loadstore_msr_slot(m, msr);
+       if (i < 0)
+               return;
+
+       --m->nr;
+       m->val[i] = m->val[m->nr];
+       vmcs_write32(vmcs_count_field, m->nr);
+}
+
+static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
+{
        struct msr_autoload *m = &vmx->msr_autoload;
 
        switch (msr) {
@@ -1063,21 +1076,9 @@ static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
                }
                break;
        }
-       i = vmx_find_loadstore_msr_slot(&m->guest, msr);
-       if (i < 0)
-               goto skip_guest;
-       --m->guest.nr;
-       m->guest.val[i] = m->guest.val[m->guest.nr];
-       vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->guest.nr);
-
-skip_guest:
-       i = vmx_find_loadstore_msr_slot(&m->host, msr);
-       if (i < 0)
-               return;
 
-       --m->host.nr;
-       m->host.val[i] = m->host.val[m->host.nr];
-       vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->host.nr);
+       vmx_remove_auto_msr(&m->guest, msr, VM_ENTRY_MSR_LOAD_COUNT);
+       vmx_remove_auto_msr(&m->host, msr, VM_EXIT_MSR_LOAD_COUNT);
 }
 
 static __always_inline void add_atomic_switch_msr_special(struct vcpu_vmx *vmx,