linux-kernel - [PATCH v2 44/59] KVM: SVM: WARN if (de)activating guest mode in IOMMU fails

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250523010004.3240643-45-seanjc@google.com>
Date: Thu, 22 May 2025 17:59:49 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>, 
	Joerg Roedel <joro@...tes.org>, David Woodhouse <dwmw2@...radead.org>, 
	Lu Baolu <baolu.lu@...ux.intel.com>
Cc: kvm@...r.kernel.org, iommu@...ts.linux.dev, linux-kernel@...r.kernel.org, 
	Sairaj Kodilkar <sarunkod@....com>, Vasant Hegde <vasant.hegde@....com>, 
	Maxim Levitsky <mlevitsk@...hat.com>, Joao Martins <joao.m.martins@...cle.com>, 
	Francesco Lavra <francescolavra.fl@...il.com>, David Matlack <dmatlack@...gle.com>
Subject: [PATCH v2 44/59] KVM: SVM: WARN if (de)activating guest mode in IOMMU fails

WARN if (de)activating "guest mode" for an IRTE entry fails as modifying
an IRTE should only fail if KVM is buggy, e.g. has stale metadata.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/svm/avic.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index ab7fb8950cc0..6048cd90e731 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -724,10 +724,9 @@ void avic_apicv_post_state_restore(struct kvm_vcpu *vcpu)
 	avic_handle_ldr_update(vcpu);
 }
 
-static int avic_set_pi_irte_mode(struct kvm_vcpu *vcpu, bool activate)
+static void avic_set_pi_irte_mode(struct kvm_vcpu *vcpu, bool activate)
 {
 	int apic_id = kvm_cpu_get_apicid(vcpu->cpu);
-	int ret = 0;
 	unsigned long flags;
 	struct vcpu_svm *svm = to_svm(vcpu);
 	struct kvm_kernel_irqfd *irqfd;
@@ -742,16 +741,15 @@ static int avic_set_pi_irte_mode(struct kvm_vcpu *vcpu, bool activate)
 		goto out;
 
 	list_for_each_entry(irqfd, &svm->ir_list, vcpu_list) {
+		void *data = irqfd->irq_bypass_data;
+
 		if (activate)
-			ret = amd_iommu_activate_guest_mode(irqfd->irq_bypass_data, apic_id);
+			WARN_ON_ONCE(amd_iommu_activate_guest_mode(data, apic_id));
 		else
-			ret = amd_iommu_deactivate_guest_mode(irqfd->irq_bypass_data);
-		if (ret)
-			break;
+			WARN_ON_ONCE(amd_iommu_deactivate_guest_mode(data));
 	}
 out:
 	spin_unlock_irqrestore(&svm->ir_list_lock, flags);
-	return ret;
 }
 
 static void svm_ir_list_del(struct kvm_kernel_irqfd *irqfd)
-- 
2.49.0.1151.ga128411c76-goog