From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (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 6C8D83C4B94 for ; Fri, 26 Jun 2026 21:35:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782509750; cv=none; b=YCXgo0RVe+phPTjdN2Po1Qp2dLWl9nyWLywkfFSnhvvYrxixHUDJ5lY+A0yaEjog4guOWfbejJE/vLClMSBXmnuGID/jsa7OtbSzPbbrNBUuYSjS3rpUYMJdeQVTZ/SVwsFcfk8y86SqL8m4VxUzlJ3AeVuYftAvMC1wnl/EgLM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782509750; c=relaxed/simple; bh=qB0d72ez1NHl3UqKmCwxaCkrkHi0KCAo7LAgN3ooies=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=kLXaNdzE+b5WLsTmg+OhD8IS8Jhsbhs86+GJn4FtMGAF7TvkLppNeOvZvZC9tIcu22tQTROjYAJnvTnaeV/sXUXmENuEVHLFah+PcKC6yRKafISHbpHwkDBR9uZyXTVZq92pKD6aLVlh5cQ4aOb6euIlnK9j+Q5vVaDoMMKz8Dg= 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=Qg1vy/uR; arc=none smtp.client-ip=209.85.215.201 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="Qg1vy/uR" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-c8895156101so742527a12.1 for ; Fri, 26 Jun 2026 14:35:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782509748; x=1783114548; darn=lists.linux.dev; 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=2XjP7ltNePjDS5cnt47gmPWCN7JEd91hh65v72L1LY8=; b=Qg1vy/uR5k3lEQWsq7838ApVvvimvaNwOoLH/Cr2aohz+iibl1FUaD2orwxwSt7mHM +WjuzzVRr+YMvOc6w7Pl1OenA4hosRO8ehAUAVpqV65IVnaddO4i+cxMjnZDxfApjUoT BrwZYprZC5+dSQbQRFvFB/pBiEoDHf90EHeJgK/6mtKpUBdApzGugqax7PdyxOI8aC7y BdLMz95ocbYKHRFJ6+ud6rB21SpVc1OU0IhwZeHA0xtNuCqw/4sbcSoWT3ouES4JfCrK ssH7V7xzDT4sJSeKx/Cs0XmARyt+lCQaOMMzfMtpAs1qw1RPEbtiYkDv+0CcDKGh2wxq rfAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782509748; x=1783114548; 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=2XjP7ltNePjDS5cnt47gmPWCN7JEd91hh65v72L1LY8=; b=hYFVI5JqnZfN4YI9RorpvdZGd/uQZgkg6RNIfJpPNxII05XZOv5byn4QJNLZtcLa3j MsBtoufUAFu7UQQfIfq5c3ik0McymrxPZz5q51lSz1QvpygRUtaMwGvtdtUgHOHa4wMz ZcHS3DqE3JNsrZvn/AvPMLyfk3Ca9WhhSsOyN3saKdksprb/Ll358L6F2LH3HRa88Yus sc5F5xkfc8FcfbLZUM+9I5jAbGmFEFsKWJQVcvAuiqF9RpqWvxcnFxoaUgl42cB2DKrE JTjLSW8UQwfrWcfxXNVUPEqNYWtWgtuyClCw7PVRmqqgofNpSXTS4DzRiy2s0ccY1Iz1 QaGA== X-Forwarded-Encrypted: i=1; AFNElJ+0IK5mOJ9j4aTVwlUi3PFpnKHuqKdVamWF6I/y4QBxJCH9XgbwAa6grGobKN9Th7KbPyDrQHs=@lists.linux.dev X-Gm-Message-State: AOJu0YzZPSVY7IIjf0BxawN1u6/Kn73FMdlmwDJ6dYJYbNLzZ61Io0/r XFWPxeMfdKNI21kMcN5wLDvhf7I81COWVrLaGhevWPeiroDSRcrrtSP8Z0R16ilWBjjVajOiLyn S17y15Q== X-Received: from pgcv18.prod.google.com ([2002:a05:6a02:5312:b0:c8c:6076:b4a5]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:1bc1:b0:39f:24a5:3065 with SMTP id adf61e73a8af0-3bd4aee9d34mr9183524637.7.1782509747404; Fri, 26 Jun 2026 14:35:47 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 26 Jun 2026 14:35:22 -0700 In-Reply-To: <20260626213534.3866178-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260626213534.3866178-1-seanjc@google.com> X-Mailer: git-send-email 2.55.0.rc0.799.gd6f94ed593-goog Message-ID: <20260626213534.3866178-10-seanjc@google.com> Subject: [PATCH v8 09/20] KVM: selftests: Add VFIO device support to eventfd 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 a '-d' argument that takes a BDF (in the format segment:bus:device.function) of an interrupt-capable PCI(e) device bound to VFIO, and use said device to trigger interrupts instead of always synthesizing interrupts via direct writes to the eventfd. Using a VFIO device to trigger interrupts validates the end-to-end delivery of IRQs for "real" devices, and when supported by hardware (and KVM), also validates interrupt delivery via IRQ bypass, i.e. via device posted IRQs. Now that IOMMUFD is a thing, auto-probe IOMMUFD vs. "legacy" VFIO by temporarily opening /dev/iommufd, and skip the test if neither IOMMUFD nor legacy VFIO is available. Add a '-t' option to the user override the probe logic, e.g. in case IOMMUFD is available but the system is configured for legacy usage. Note, the device must have a VFIO selftest driver in order to work with the test. A helper script to list supported devices will hopefully be available in the near future at tools/testing/selftests/vfio/scripts/list_supported_devices.sh[1]. Example: $ ./tools/testing/selftests/kvm/irq_test -d 0000:06:0a.1 Link: https://lore.kernel.org/all/20260602222941.3133236-1-jrhilke%40google.com [1] Signed-off-by: David Matlack Co-developed-by: Josh Hilke Signed-off-by: Josh Hilke Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/irq_test.c | 98 ++++++++++++++++++++++++-- 1 file changed, 92 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/kvm/irq_test.c b/tools/testing/selftests/kvm/irq_test.c index 9f8895b89821..70b2c9cac279 100644 --- a/tools/testing/selftests/kvm/irq_test.c +++ b/tools/testing/selftests/kvm/irq_test.c @@ -3,7 +3,10 @@ #include "test_util.h" #include "apic.h" #include "processor.h" +#include "proc_util.h" +#include +#include #include #include #include @@ -55,6 +58,48 @@ static void *vcpu_thread_main(void *arg) return NULL; } +static int vfio_setup_msi(struct vfio_pci_device *device) +{ + const int flags = MAP_SHARED | MAP_ANONYMOUS; + const int prot = PROT_READ | PROT_WRITE; + struct iova_allocator *allocator; + struct dma_region *region; + + /* Sanity check that the device+driver can actually send MSIs. */ + TEST_REQUIRE(device->driver.ops); + TEST_REQUIRE(device->driver.ops->send_msi); + + /* + * Set up a DMA-able region for the driver to use. Very few devices + * provide a way to arbitrarily send interrupts (MSIs), e.g. by writing + * an MMIO register. Instead, most devices send MSIs when an action is + * completed, and practically all actions involve DMA of some form. + */ + allocator = iova_allocator_init(device->iommu); + + region = &device->driver.region; + region->size = SZ_2M; + region->iova = iova_allocator_alloc(allocator, region->size); + region->vaddr = kvm_mmap(region->size, prot, flags, -1); + TEST_ASSERT(region->vaddr != MAP_FAILED, "mmap() failed\n"); + iommu_map(device->iommu, region); + + iova_allocator_cleanup(allocator); + + vfio_pci_driver_init(device); + + return device->driver.msi; +} + +static void trigger_interrupt(struct vfio_pci_device *device, int eventfd) +{ + if (device) + vfio_pci_driver_send_msi(device); + else + eventfd_write(eventfd, 1); +} + + static void kvm_route_msi(struct kvm_vm *vm, u32 gsi, struct kvm_vcpu *vcpu, u8 vector) { @@ -74,11 +119,29 @@ static void kvm_route_msi(struct kvm_vm *vm, u32 gsi, struct kvm_vcpu *vcpu, vm_ioctl(vm, KVM_SET_GSI_ROUTING, &routing.header); } +static const char *probe_iommu_type(void) +{ + int io_fd; + + io_fd = open("/dev/iommu", O_RDONLY); + if (io_fd >= 0) { + close(io_fd); + return MODE_IOMMUFD; + } + + io_fd = __open_path_or_exit("/dev/vfio/vfio", O_RDONLY, + "Is VFIO (or IOMMUFD) loaded and enabled?"); + close(io_fd); + return MODE_VFIO_TYPE1_IOMMU; +} + static void help(const char *name) { - printf("Usage: %s [-h]\n", name); + printf("Usage: %s [-d ] [-h] [-t iommu_type]\n", name); printf("\n"); printf("Tests KVM interrupt routing and delivery via irqfd.\n"); + printf("-d Use a VFIO device to send MSI-X interrupts instead of manually signaling the eventfd\n"); + printf("-t Override the IOMMU type to use (vfio_type1_iommu or iommufd)\n"); printf("\n"); exit(KSFT_FAIL); } @@ -100,14 +163,25 @@ int main(int argc, char **argv) u32 gsi = kvm_random_u64_in_range(&kvm_rng, 24, KVM_MAX_IRQ_ROUTES - 1); u8 vector = kvm_random_u64_in_range(&kvm_rng, 32, UINT8_MAX); - struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; pthread_t vcpu_threads[KVM_MAX_VCPUS]; + struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; + struct vfio_pci_device *device = NULL; int nr_irqs = 1000, nr_vcpus = 1; - int i, j, c, eventfd; + const char *device_bdf = NULL; + const char *iommu_type = NULL; + int i, j, c, msix, eventfd; + struct iommu *iommu; struct kvm_vm *vm; + int irq; - while ((c = getopt(argc, argv, "h")) != -1) { + while ((c = getopt(argc, argv, "d:ht:")) != -1) { switch (c) { + case 'd': + device_bdf = optarg; + break; + case 't': + iommu_type = optarg; + break; case 'h': default: help(argv[0]); @@ -119,7 +193,19 @@ 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); - eventfd = kvm_new_eventfd(); + if (device_bdf) { + if (!iommu_type) + iommu_type = probe_iommu_type(); + iommu = iommu_init(iommu_type); + device = vfio_pci_device_init(device_bdf, iommu); + msix = vfio_setup_msi(device); + irq = vfio_msix_to_host_irq(device_bdf, msix); + eventfd = device->msi_eventfds[msix]; + printf("Using device %s MSI-X[%d] (IRQ-%u)\n", device_bdf, msix, + irq); + } else { + eventfd = kvm_new_eventfd(); + } pr_info("Injecting interrupts for GSI %d (guest vector 0x%x) %d times\n", gsi, vector, nr_irqs); @@ -147,7 +233,7 @@ int main(int argc, char **argv) "IRQ flag for vCPU %d not clear prior to test", vcpus[j]->id); - eventfd_write(eventfd, 1); + trigger_interrupt(device, eventfd); clock_gettime(CLOCK_MONOTONIC, &start); while (!GUEST_RECEIVED_IRQ(vcpu) && -- 2.55.0.rc0.799.gd6f94ed593-goog