From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D11082DB7BE for ; Wed, 10 Jun 2026 00:53:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781052840; cv=none; b=gXr+CD+LpHqCwmioLWUofO0yvkh9wN2e3kuWMm134VQjp0tnnyFdbbYDQjulVt3QT7qU7uTrnaagecytl5ZLZZfyc5ZjhZZ7c6z8BuqNn6OZXSkBP0VZfvWWuex5rX+AwPNHIkdsIBymwp23m+OOVKv9RPp9YkVq1LmHtSi7zNw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781052840; c=relaxed/simple; bh=b2x4shEy924lZqBZs0VEmqx1TKq80ADVagm5ZmIqKhg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=OWEK8890P1PSEgQJjmXBgJ82nqkwZpfcVhlUcmbTDQYXS77JcLMHRN/+xEtHgyISZm3bIq+Ybb7xjLdga2kKxfUW+nDzWmU+3w6jT83ykJVVm/wkxAKN9kNikhP893CLf93l6cCKWROyrgRN2mE2NgCPPeAdj03PxOMEktkGOnw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=uZy6cB3d; arc=none smtp.client-ip=209.85.210.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="uZy6cB3d" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-84238e83851so3837033b3a.1 for ; Tue, 09 Jun 2026 17:53:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1781052837; x=1781657637; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=GUYNx7RZ8mYUz0pjgPg+HKHfepMmoInSE1YhyqLiL7U=; b=uZy6cB3dB6ZhDBW2N/uYuM/rQwRZPLHXd88dAlMpL+WiLyH9St+ccikdMzjPP7DkhN VObG8IMafyffzFXeHtcm4CUzrkSuy7MgwKNzOC4w/mU89VytLuJRrT+8pxEE+sm4g6O9 U5jFV2AWGwCJaSmhFe5oUkjvv4Eo7pvym9uNsaUJt54zyz0znoJNNMD+3TCLqGBhmmWs PPePbpQlloKcUzWcu2HcZ1KOTqbL8pV6LL5pNmD4W5I7Xorm8ii1/lEQhuHp9JITJpGt tvVVmU9+FCG94ikaJ0YwU+VMMHN5dA2JP16XrjdCGmMj9L+B3jSD8R0AnpzHbRzUOwIt HGeA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781052837; x=1781657637; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=GUYNx7RZ8mYUz0pjgPg+HKHfepMmoInSE1YhyqLiL7U=; b=ah/APEg46BbgrVAMYozGQh7VnYbxr72qwikmLAV9Ic34rEbuTgDhMEZ9LYZPwD2P/j ZXHC1kJKJDoKXzOt0dd7AbdU04PNb6rbdPMqXgOijpftxKYajuuP5nNYHc4exOZ+tXuN ny39PsmUafVv7a0w2ItyliS2NwIdlWUZyJPssRvjF45QKeUfdKrIkRf/6iB3e1Ncjg4S CokL1XSzqwNjmun3gtA76UKkFmbtuDzGX1KeOOB6ZRPTqHPtKHQPW3dZ74LIwWPgC71i eCwa9s3QQ/1kg8cC+qR86sWbEO+V71J+xyQ3iGnZ+zhyYz+gfU7lfxED12LktBiiBzo3 Ylcg== X-Forwarded-Encrypted: i=1; AFNElJ//Z84EOHpuESQe4tOMA0QxPPUe9Tow851GiNAo0PUY/xg5Hn0XflHw/PAt6WjgI5xlXQz8ogoFotUwpdY=@vger.kernel.org X-Gm-Message-State: AOJu0Ywo8m8p+1As9fhvxvZIKwUV1ITF/FSub+YE+iEouWCLu5qEh0fH 45pIlbMUdYs07dJiK8GRWEKgtqjhUeK2OxC21hL4ZIi6m7+FP+CW6KF0IpmAQSTcUVgDBJxQP5P vyGjeUw== X-Received: from pfbhx1.prod.google.com ([2002:a05:6a00:8981:b0:842:5a44:a83c]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:90a7:b0:842:5634:3c1d with SMTP id d2e1a72fcca58-842b0e835d1mr22690620b3a.19.1781052836923; Tue, 09 Jun 2026 17:53:56 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 9 Jun 2026 17:53:32 -0700 In-Reply-To: <20260610005338.2967132-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260610005338.2967132-1-seanjc@google.com> X-Mailer: git-send-email 2.54.0.1099.g489fc7bff1-goog Message-ID: <20260610005338.2967132-13-seanjc@google.com> Subject: [PATCH v6 12/18] KVM: selftests: Verify non-postable IRQ remapping in IRQ test From: Sean Christopherson To: Paolo Bonzini , Marc Zyngier , Oliver Upton , Sean Christopherson Cc: Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, David Matlack , Josh Hilke Content-Type: text/plain; charset="UTF-8" From: David Matlack Extend the eventfd IRQ test with an '-n' flag to route a subset of device interrupts as NMIs (Non-Maskable Interrupts) into the guest using an alternating pattern of 4 NMIs followed by 4 regular interrupts. While this adds coverage for NMI injection, the primary goal is to validate KVM's handling of non-postable interrupt delivery (AMD and Intel IOMMUs only support posting fixed IRQs targeting a single vCPU). KVM has historically bungled handling transitions between posted and remapped modes. Use NMIs to stress the transitions, because they are a reliable, architectural way to force these code paths. Signed-off-by: David Matlack Co-developed-by: Josh Hilke Signed-off-by: Josh Hilke [sean: add GUEST_RECEIVED_INTERRUPT(), massage changelog] Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/irq_test.c | 48 ++++++++++++++++++++------ 1 file changed, 37 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/kvm/irq_test.c b/tools/testing/selftests/kvm/irq_test.c index 15791ba0a2f9..3fed76c553dd 100644 --- a/tools/testing/selftests/kvm/irq_test.c +++ b/tools/testing/selftests/kvm/irq_test.c @@ -17,11 +17,17 @@ static u64 timeout_ns = 2ULL * 1000 * 1000 * 1000; static bool guest_ready_for_irqs[KVM_MAX_VCPUS]; static bool guest_received_irq[KVM_MAX_VCPUS]; +static bool guest_received_nmi[KVM_MAX_VCPUS]; static bool irq_affinity; static bool done; #define GUEST_RECEIVED_IRQ(__vcpu) \ SYNC_FROM_GUEST_AND_READ((__vcpu)->vm, guest_received_irq[(__vcpu)->id]) +#define GUEST_RECEIVED_NMI(__vcpu) \ + SYNC_FROM_GUEST_AND_READ((__vcpu)->vm, guest_received_nmi[(__vcpu)->id]) + +#define GUEST_RECEIVED_INTERRUPT(__vcpu, __nmi) \ + ((__nmi) ? GUEST_RECEIVED_NMI(__vcpu) : GUEST_RECEIVED_IRQ(__vcpu)) static u32 guest_get_vcpu_id(void) { @@ -35,6 +41,11 @@ static void guest_irq_handler(struct ex_regs *regs) x2apic_write_reg(APIC_EOI, 0); } +static void guest_nmi_handler(struct ex_regs *regs) +{ + WRITE_ONCE(guest_received_nmi[guest_get_vcpu_id()], true); +} + static void guest_code(void) { x2apic_enable(); @@ -91,7 +102,7 @@ static void trigger_interrupt(struct vfio_pci_device *device, int eventfd) static void kvm_route_msi(struct kvm_vm *vm, u32 gsi, struct kvm_vcpu *vcpu, - u8 vector) + u8 vector, bool use_nmi) { struct { struct kvm_irq_routing header; @@ -102,7 +113,7 @@ static void kvm_route_msi(struct kvm_vm *vm, u32 gsi, struct kvm_vcpu *vcpu, .gsi = gsi, .type = KVM_IRQ_ROUTING_MSI, .u.msi.address_lo = 0xFEE00000 | (vcpu->id << 12), - .u.msi.data = vector, + .u.msi.data = use_nmi ? NMI_VECTOR | (4 << 8) : vector, }, }; @@ -134,13 +145,14 @@ static const char *probe_iommu_type(void) static void help(const char *name) { - printf("Usage: %s [-a] [-d ] [-e] [-h] [-i nr_irqs] [-t iommu_type]\n", name); + printf("Usage: %s [-a] [-d ] [-e] [-h] [-i nr_irqs] [-n] [-t iommu_type]\n", name); printf("\n"); printf("Tests KVM interrupt routing and delivery via irqfd.\n"); printf("-a Affine the device's host IRQ to a random physical CPU\n"); printf("-d Use a VFIO device to send MSI-X interrupts instead of manually signaling the eventfd\n"); printf("-e Set empty GSI routing in-between some interrupts\n"); printf("-i The number of IRQs to generate during the test\n"); + printf("-n Deliver 50 percent of IRQs as non-maskable interrupts\n"); printf("-t Override the IOMMU type to use (vfio_type1_iommu or iommufd)\n"); printf("\n"); exit(KSFT_FAIL); @@ -171,11 +183,12 @@ int main(int argc, char **argv) const char *device_bdf = NULL; const char *iommu_type = NULL; int i, j, c, msix, eventfd; + bool use_nmi = false; struct iommu *iommu; struct kvm_vm *vm; int irq, irq_cpu; - while ((c = getopt(argc, argv, "ad:ehi:t:")) != -1) { + while ((c = getopt(argc, argv, "ad:ehi:nt:")) != -1) { switch (c) { case 'a': irq_affinity = true; @@ -189,6 +202,9 @@ int main(int argc, char **argv) case 'i': nr_irqs = atoi_positive("Number of IRQs", optarg); break; + case 'n': + use_nmi = true; + break; case 't': iommu_type = optarg; break; @@ -202,6 +218,7 @@ int main(int argc, char **argv) vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus); vm_install_exception_handler(vm, vector, guest_irq_handler); + vm_install_exception_handler(vm, NMI_VECTOR, guest_nmi_handler); if (device_bdf) { if (!iommu_type) @@ -239,36 +256,45 @@ int main(int argc, char **argv) for (i = 0; i < nr_irqs; i++) { const bool do_set_empty_routing = set_empty_routing && (i & BIT(3)); + const bool do_use_nmi = use_nmi && (i & BIT(2)); struct kvm_vcpu *vcpu = vcpus[i % nr_vcpus]; struct timespec start; if (do_set_empty_routing) kvm_set_empty_gsi_routing(vm); - kvm_route_msi(vm, gsi, vcpu, vector); + kvm_route_msi(vm, gsi, vcpu, vector, do_use_nmi); if (irq_affinity) { irq_cpu = kvm_random_u64(&kvm_rng) % get_nprocs(); proc_irq_set_smp_affinity(irq, irq_cpu); } - for (j = 0; j < nr_vcpus; j++) + for (j = 0; j < nr_vcpus; j++) { TEST_ASSERT(!GUEST_RECEIVED_IRQ(vcpus[j]), "IRQ flag for vCPU %d not clear prior to test", vcpus[j]->id); + TEST_ASSERT(!GUEST_RECEIVED_NMI(vcpus[j]), + "NMI flag for vCPU %d not clear prior to test", + vcpus[j]->id); + } trigger_interrupt(device, eventfd); clock_gettime(CLOCK_MONOTONIC, &start); - while (!GUEST_RECEIVED_IRQ(vcpu) && + while (!GUEST_RECEIVED_INTERRUPT(vcpu, do_use_nmi) && timespec_to_ns(timespec_elapsed(start)) <= timeout_ns) cpu_relax(); - TEST_ASSERT(GUEST_RECEIVED_IRQ(vcpu), - "vCPU %d timed out waiting for IRQ (vector 0x%x) from GSI %d (via CPU %d)\n", - vcpu->id, vector, gsi, irq_cpu); + TEST_ASSERT(GUEST_RECEIVED_INTERRUPT(vcpu, do_use_nmi), + "vCPU %d timed out waiting for %s (vector 0x%x) from GSI %d (via CPU %d)\n", + vcpu->id, do_use_nmi ? "NMI" : "IRQ", + do_use_nmi ? NMI_VECTOR : vector, gsi, irq_cpu); - WRITE_AND_SYNC_TO_GUEST(vm, guest_received_irq[vcpu->id], false); + if (do_use_nmi) + WRITE_AND_SYNC_TO_GUEST(vm, guest_received_nmi[vcpu->id], false); + else + WRITE_AND_SYNC_TO_GUEST(vm, guest_received_irq[vcpu->id], false); } WRITE_AND_SYNC_TO_GUEST(vm, done, true); -- 2.54.0.1099.g489fc7bff1-goog