[PATCH v6 37/44] KVM: VMX: Dedup code for removing MSR from VMCS's auto-load list

Sean Christopherson seanjc at google.com
Fri Dec 5 16:17:13 PST 2025


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.

Signed-off-by: Sean Christopherson <seanjc at google.com>
---
 arch/x86/kvm/vmx/vmx.c | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 52bcb817cc15..a51f66d1b201 100644
--- 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 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)
 {
-	int i;
 	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,
-- 
2.52.0.223.gf5cc29aaa4-goog




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