From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 19 Mar 2025 13:10:44 +0000 (-0400)
Subject: Merge tag 'kvm-x86-svm-6.15' of https://github.com/kvm-x86/linux into HEAD
X-Git-Tag: v6.15-rc1~195^2~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9b093f5b86fb0bfd4d819dd2741893de69f111d9;p=thirdparty%2Fkernel%2Flinux.git

Merge tag 'kvm-x86-svm-6.15' of https://github.com/kvm-x86/linux into HEAD

KVM SVM changes for 6.15

 - Ensure the PSP driver is initialized when both the PSP and KVM modules are
   built-in (the initcall framework doesn't handle dependencies).

 - Use long-term pins when registering encrypted memory regions, so that the
   pages are migrated out of MIGRATE_CMA/ZONE_MOVABLE and don't lead to
   excessive fragmentation.

 - Add macros and helpers for setting GHCB return/error codes.

 - Add support for Idle HLT interception, which elides interception if the vCPU
   has a pending, unmasked virtual IRQ when HLT is executed.

 - Fix a bug in INVPCID emulation where KVM fails to check for a non-canonical
   address.

 - Don't attempt VMRUN for SEV-ES+ guests if the vCPU's VMSA is invalid, e.g.
   because the vCPU was "destroyed" via SNP's AP Creation hypercall.

 - Reject SNP AP Creation if the requested SEV features for the vCPU don't
   match the VM's configured set of features.

 - Misc cleanups
---

9b093f5b86fb0bfd4d819dd2741893de69f111d9
diff --cc arch/x86/kvm/svm/sev.c
index 596167d335443,ea50f44a22394..0bc708ee27887
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@@ -3911,33 -3876,47 +3876,46 @@@ void sev_snp_init_protected_guest_state
  	 */
  	vmcb_mark_all_dirty(svm->vmcb);
  
- 	return 0;
- }
+ 	if (!VALID_PAGE(svm->sev_es.snp_vmsa_gpa))
+ 		return;
  
- /*
-  * Invoked as part of svm_vcpu_reset() processing of an init event.
-  */
- void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
- {
- 	struct vcpu_svm *svm = to_svm(vcpu);
- 	int ret;
+ 	gfn = gpa_to_gfn(svm->sev_es.snp_vmsa_gpa);
+ 	svm->sev_es.snp_vmsa_gpa = INVALID_PAGE;
  
- 	if (!sev_snp_guest(vcpu->kvm))
+ 	slot = gfn_to_memslot(vcpu->kvm, gfn);
+ 	if (!slot)
  		return;
  
- 	mutex_lock(&svm->sev_es.snp_vmsa_mutex);
+ 	/*
+ 	 * The new VMSA will be private memory guest memory, so retrieve the
+ 	 * PFN from the gmem backend.
+ 	 */
+ 	if (kvm_gmem_get_pfn(vcpu->kvm, slot, gfn, &pfn, &page, NULL))
+ 		return;
  
- 	if (!svm->sev_es.snp_ap_waiting_for_reset)
- 		goto unlock;
+ 	/*
+ 	 * From this point forward, the VMSA will always be a guest-mapped page
+ 	 * rather than the initial one allocated by KVM in svm->sev_es.vmsa. In
+ 	 * theory, svm->sev_es.vmsa could be free'd and cleaned up here, but
+ 	 * that involves cleanups like wbinvd_on_all_cpus() which would ideally
+ 	 * be handled during teardown rather than guest boot.  Deferring that
+ 	 * also allows the existing logic for SEV-ES VMSAs to be re-used with
+ 	 * minimal SNP-specific changes.
+ 	 */
+ 	svm->sev_es.snp_has_guest_vmsa = true;
  
- 	svm->sev_es.snp_ap_waiting_for_reset = false;
+ 	/* Use the new VMSA */
+ 	svm->vmcb->control.vmsa_pa = pfn_to_hpa(pfn);
  
- 	ret = __sev_snp_update_protected_guest_state(vcpu);
- 	if (ret)
- 		vcpu_unimpl(vcpu, "snp: AP state update on init failed\n");
+ 	/* Mark the vCPU as runnable */
 -	vcpu->arch.pv.pv_unhalted = false;
 -	vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
++	kvm_set_mp_state(vcpu, KVM_MP_STATE_RUNNABLE);
  
- unlock:
- 	mutex_unlock(&svm->sev_es.snp_vmsa_mutex);
+ 	/*
+ 	 * gmem pages aren't currently migratable, but if this ever changes
+ 	 * then care should be taken to ensure svm->sev_es.vmsa is pinned
+ 	 * through some other means.
+ 	 */
+ 	kvm_release_page_clean(page);
  }
  
  static int sev_snp_ap_creation(struct vcpu_svm *svm)