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AJvYcCX8HioN/UUzqm+87DEfg26Wc2qRt6oawCgI7lc1a/m+veDu3W1umCOVI5jfsHmMNkSqXuU=@vger.kernel.org X-Gm-Message-State: AOJu0YwLG605ZCo9YjidSSadQB9IC7RojMtWrZzWTKYM0wRktcjSRHH2 avRkx+jGVmRWDJZLHRBB89dz5GyRQ+F90kEI1MbjMBC7lH1+l9ClbGudl7P8pArUY+3biLFYpBz 3KSaVMA== X-Google-Smtp-Source: AGHT+IFtBQrCrRoK6BL9Dz+IQ2aeYDyw9D2RNz8zXlEmSFnG0/dQfadG1s0WIBiR2YE1o9tnTCGC7rDXtkk= X-Received: from pjbpq18.prod.google.com ([2002:a17:90b:3d92:b0:2e0:915d:d594]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:1c08:b0:312:db8:dbd1 with SMTP id 98e67ed59e1d1-313c0667c29mr974887a91.5.1749682109408; Wed, 11 Jun 2025 15:48:29 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 11 Jun 2025 15:45:57 -0700 In-Reply-To: <20250611224604.313496-2-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250611224604.313496-2-seanjc@google.com> X-Mailer: git-send-email 2.50.0.rc1.591.g9c95f17f64-goog Message-ID: <20250611224604.313496-56-seanjc@google.com> Subject: [PATCH v3 54/62] KVM: VMX: WARN if VT-d Posted IRQs aren't possible when starting IRQ bypass From: Sean Christopherson To: Marc Zyngier , Oliver Upton , Sean Christopherson , Paolo Bonzini , Joerg Roedel , David Woodhouse , Lu Baolu Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Sairaj Kodilkar , Vasant Hegde , Maxim Levitsky , Joao Martins , Francesco Lavra , David Matlack Content-Type: text/plain; charset="UTF-8" WARN if KVM attempts to "start" IRQ bypass when VT-d Posted IRQs are disabled, to make it obvious that the logic is a sanity check, and so that a bug related to nr_possible_bypass_irqs is more like to cause noisy failures, e.g. so that KVM doesn't silently fail to wake blocking vCPUs. Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/posted_intr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c index 5671d59a6b6d..4a6d9a17da23 100644 --- a/arch/x86/kvm/vmx/posted_intr.c +++ b/arch/x86/kvm/vmx/posted_intr.c @@ -296,7 +296,7 @@ bool pi_has_pending_interrupt(struct kvm_vcpu *vcpu) */ void vmx_pi_start_bypass(struct kvm *kvm) { - if (!kvm_arch_has_irq_bypass()) + if (WARN_ON_ONCE(!vmx_can_use_vtd_pi(kvm))) return; kvm_make_all_cpus_request(kvm, KVM_REQ_UNBLOCK); -- 2.50.0.rc1.591.g9c95f17f64-goog