Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "Arm:

   - Only adjust the ID registers when no irqchip has been created once
     per VM run, instead of doing it once per vcpu, as this otherwise
     triggers a pretty bad conbsistency check failure in the sysreg code

   - Make sure the per-vcpu Fine Grain Traps are computed before we load
     the system registers on the HW, as we otherwise start running
     without anything set until the first preemption of the vcpu

  x86:

   - Fix selftests failure on AMD, checking for an optimization that was
     not happening anymore"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: SVM: Fix redundant updates of LBR MSR intercepts
  KVM: arm64: VHE: Compute fgt traps before activating them
  KVM: arm64: Finalize ID registers only once per VM

Author: torvalds

arch/arm64/kvm/arm.c

@@ -624,6 +624,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	kvm_timer_vcpu_load(vcpu);
 	kvm_vgic_load(vcpu);
 	kvm_vcpu_load_debug(vcpu);
+	kvm_vcpu_load_fgt(vcpu);
 	if (has_vhe())
 		kvm_vcpu_load_vhe(vcpu);
 	kvm_arch_vcpu_load_fp(vcpu);
@@ -642,7 +643,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 		vcpu->arch.hcr_el2 |= HCR_TWI;
 
 	vcpu_set_pauth_traps(vcpu);
-	kvm_vcpu_load_fgt(vcpu);
 
 	if (is_protected_kvm_enabled()) {
 		kvm_call_hyp_nvhe(__pkvm_vcpu_load,

arch/arm64/kvm/sys_regs.c

@@ -5609,7 +5609,11 @@ int kvm_finalize_sys_regs(struct kvm_vcpu *vcpu)
 
 	guard(mutex)(&kvm->arch.config_lock);
 
-	if (!irqchip_in_kernel(kvm)) {
+	/*
+	 * This hacks into the ID registers, so only perform it when the
+	 * first vcpu runs, or the kvm_set_vm_id_reg() helper will scream.
+	 */
+	if (!irqchip_in_kernel(kvm) && !kvm_vm_has_ran_once(kvm)) {
 		u64 val;
 
 		val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;

arch/x86/kvm/svm/svm.c

@@ -705,7 +705,11 @@ void *svm_alloc_permissions_map(unsigned long size, gfp_t gfp_mask)
 
 static void svm_recalc_lbr_msr_intercepts(struct kvm_vcpu *vcpu)
 {
-	bool intercept = !(to_svm(vcpu)->vmcb->control.virt_ext & LBR_CTL_ENABLE_MASK);
+	struct vcpu_svm *svm = to_svm(vcpu);
+	bool intercept = !(svm->vmcb->control.virt_ext & LBR_CTL_ENABLE_MASK);
+
+	if (intercept == svm->lbr_msrs_intercepted)
+		return;
 
 	svm_set_intercept_for_msr(vcpu, MSR_IA32_LASTBRANCHFROMIP, MSR_TYPE_RW, intercept);
 	svm_set_intercept_for_msr(vcpu, MSR_IA32_LASTBRANCHTOIP, MSR_TYPE_RW, intercept);
@@ -714,6 +718,8 @@ static void svm_recalc_lbr_msr_intercepts(struct kvm_vcpu *vcpu)
 
 	if (sev_es_guest(vcpu->kvm))
 		svm_set_intercept_for_msr(vcpu, MSR_IA32_DEBUGCTLMSR, MSR_TYPE_RW, intercept);
+
+	svm->lbr_msrs_intercepted = intercept;
 }
 
 void svm_vcpu_free_msrpm(void *msrpm)
@@ -1221,6 +1227,7 @@ static int svm_vcpu_create(struct kvm_vcpu *vcpu)
 	}
 
 	svm->x2avic_msrs_intercepted = true;
+	svm->lbr_msrs_intercepted = true;
 
 	svm->vmcb01.ptr = page_address(vmcb01_page);
 	svm->vmcb01.pa = __sme_set(page_to_pfn(vmcb01_page) << PAGE_SHIFT);

arch/x86/kvm/svm/svm.h

@@ -336,6 +336,7 @@ struct vcpu_svm {
 	bool guest_state_loaded;
 
 	bool x2avic_msrs_intercepted;
+	bool lbr_msrs_intercepted;
 
 	/* Guest GIF value, used when vGIF is not enabled */
 	bool guest_gif;