KVM: SEV: Extract loading of guest-provided VMSA to a separate helper

commit 0060569e4f18a7dee2dd8728595e909f19a23c24 upstream.

Extract the loading/retrieval of a guest-provided VMSA to a separate helper
so that KVM can reuse the core logic when refreshing the VMSA after an MMU
invalidation from guest_memfd.

No functional change intended.

Cc: stable@vger.kernel.org # 6.12.x
Reviewed-by: Michael Roth <michael.roth@amd.com>
Link: https://patch.msgid.link/20260709204948.1988414-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index b7596d7a29d3202dfc2a5cfb01906186c99392dd..8fda50829c2865108de666635764f7c2b937d394 100644 (file)
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -4013,29 +4013,17 @@ next_range:
        BUG();
 }
 
-/*
- * Invoked as part of svm_vcpu_reset() processing of an init event.
- */
-static void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
+static void sev_snp_reload_vmsa(struct kvm_vcpu *vcpu, gpa_t gpa)
 {
        struct vcpu_svm *svm = to_svm(vcpu);
        struct kvm_memory_slot *slot;
+       gfn_t gfn = gpa_to_gfn(gpa);
        struct page *page;
        kvm_pfn_t pfn;
-       gfn_t gfn;
-
-       guard(mutex)(&svm->sev_es.snp_vmsa_mutex);
-
-       if (!svm->sev_es.snp_ap_waiting_for_reset)
-               return;
 
-       svm->sev_es.snp_ap_waiting_for_reset = false;
-
-       /* Mark the vCPU as offline and not runnable */
-       vcpu->arch.pv.pv_unhalted = false;
-       kvm_set_mp_state(vcpu, KVM_MP_STATE_HALTED);
+       lockdep_assert_held(&svm->sev_es.snp_vmsa_mutex);
 
-       /* Clear use of the VMSA */
+       /* Clear use of the VMSA. */
        svm->vmcb->control.vmsa_pa = INVALID_PAGE;
        svm->sev_es.snp_guest_vmsa_gpa = INVALID_PAGE;
 
@@ -4045,12 +4033,9 @@ static void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
         */
        vmcb_mark_all_dirty(svm->vmcb);
 
-       if (!VALID_PAGE(svm->sev_es.snp_pending_vmsa_gpa))
+       if (!VALID_PAGE(gpa))
                return;
 
-       gfn = gpa_to_gfn(svm->sev_es.snp_pending_vmsa_gpa);
-       svm->sev_es.snp_pending_vmsa_gpa = INVALID_PAGE;
-
        slot = gfn_to_memslot(vcpu->kvm, gfn);
        if (!slot)
                return;
@@ -4074,7 +4059,7 @@ static void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
        svm->sev_es.snp_has_guest_vmsa = true;
 
        /* Use the new VMSA */
-       svm->sev_es.snp_guest_vmsa_gpa = gfn_to_gpa(gfn);
+       svm->sev_es.snp_guest_vmsa_gpa = gpa;
        svm->vmcb->control.vmsa_pa = pfn_to_hpa(pfn);
 
        /* Mark the vCPU as runnable */
@@ -4088,6 +4073,31 @@ static void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
        kvm_release_page_clean(page);
 }
 
+/*
+ * Invoked as part of svm_vcpu_reset() processing of an init event.
+ */
+static void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
+{
+       struct vcpu_svm *svm = to_svm(vcpu);
+       gpa_t gpa;
+
+       guard(mutex)(&svm->sev_es.snp_vmsa_mutex);
+
+       if (!svm->sev_es.snp_ap_waiting_for_reset)
+               return;
+
+       svm->sev_es.snp_ap_waiting_for_reset = false;
+
+       /* Mark the vCPU as offline and not runnable */
+       vcpu->arch.pv.pv_unhalted = false;
+       kvm_set_mp_state(vcpu, KVM_MP_STATE_HALTED);
+
+       gpa = svm->sev_es.snp_pending_vmsa_gpa;
+       svm->sev_es.snp_pending_vmsa_gpa = INVALID_PAGE;
+
+       sev_snp_reload_vmsa(vcpu, gpa);
+}
+
 static int sev_snp_ap_creation(struct vcpu_svm *svm)
 {
        struct kvm_sev_info *sev = to_kvm_sev_info(svm->vcpu.kvm);