Use real device MSIs to deliver interrupts into the guest in
vfio_pci_device_irq_test (when possible). If the device has a driver, we
can use the driver to make the device send a physical MSI, rather than
synthesizing an eventfd notification in software. This allows this test
to exercise IRQ Bypass (e.g. VT-d device-posted interrupts in Intel).
Signed-off-by: David Matlack <dmatl...@google.com>
---
.../selftests/kvm/vfio_pci_device_irq_test.c | 66 +++++++++++++++----
1 file changed, 55 insertions(+), 11 deletions(-)
diff --git a/tools/testing/selftests/kvm/vfio_pci_device_irq_test.c
b/tools/testing/selftests/kvm/vfio_pci_device_irq_test.c
index c792fc169028..8cbaf38357c4 100644
--- a/tools/testing/selftests/kvm/vfio_pci_device_irq_test.c
+++ b/tools/testing/selftests/kvm/vfio_pci_device_irq_test.c
@@ -7,6 +7,8 @@
#include <pthread.h>
#include <time.h>
#include <linux/vfio.h>
+#include <linux/sizes.h>
+
#include <vfio_util.h>
static bool guest_ready_for_irq;
@@ -60,11 +62,54 @@ void *vcpu_thread_main(void *arg)
static void help(const char *name)
{
- printf("Usage: %s [-i iommu_mode] segment:bus:device.function\n", name);
+ printf("Usage: %s [-i iommu_mode] [-d] segment:bus:device.function\n",
name);
+ printf(" -d: Send a real MSI from the device, rather than
synthesizing\n"
+ " an eventfd signal from VFIO. Note that this option
requires\n"
+ " a VFIO selftests driver that supports the device.\n");
iommu_mode_help("-i");
exit(1);
}
+static int setup_msi(struct vfio_pci_device *device, bool use_device_msi)
+{
+ const int flags = MAP_SHARED | MAP_ANONYMOUS;
+ const int prot = PROT_READ | PROT_WRITE;
+ struct vfio_dma_region *region;
+
+ if (use_device_msi) {
+ /* A driver is required to generate an MSI. */
+ TEST_REQUIRE(device->driver.ops);
+
+ /* Set up a DMA-able region for the driver to use. */
+ region = &device->driver.region;
+ region->iova = 0;
+ region->size = SZ_2M;
+ region->vaddr = mmap(NULL, region->size, prot, flags, -1, 0);
+ TEST_ASSERT(region->vaddr != MAP_FAILED, "mmap() failed\n");
+ vfio_pci_dma_map(device, region);
+
+ vfio_pci_driver_init(device);
+
+ return device->driver.msi;
+ }
+
+ TEST_REQUIRE(device->msix_info.count > 0);
+ vfio_pci_msix_enable(device, 0, 1);
+ return 0;
+}
+
+static void send_msi(struct vfio_pci_device *device, bool use_device_msi, int
msi)
+{
+ if (use_device_msi) {
+ printf("Sending MSI %d from the device\n", msi);
+ TEST_ASSERT_EQ(msi, device->driver.msi);
+ vfio_pci_driver_send_msi(device);
+ } else {
+ printf("Notifying the eventfd for MSI %d from VFIO\n", msi);
+ vfio_pci_irq_trigger(device, VFIO_PCI_MSIX_IRQ_INDEX, msi);
+ }
+}
+
int main(int argc, char **argv)
{
/* Random non-reserved vector and GSI to use for the device IRQ */
@@ -74,16 +119,21 @@ int main(int argc, char **argv)
struct timespec start, elapsed;
struct vfio_pci_device *device;
const char *iommu_mode = NULL;
+ bool use_device_msi = false;
struct kvm_vcpu *vcpu;
pthread_t vcpu_thread;
struct kvm_vm *vm;
+ int msi;
int c;
- while ((c = getopt(argc, argv, "i:")) != -1) {
+ while ((c = getopt(argc, argv, "i:d")) != -1) {
switch (c) {
case 'i':
iommu_mode = optarg;
break;
+ case 'd':
+ use_device_msi = true;
+ break;
default:
help(argv[0]);
}
@@ -96,10 +146,9 @@ int main(int argc, char **argv)
vm_install_exception_handler(vm, vector, guest_irq_handler);
device = vfio_pci_device_init(argv[optind], iommu_mode);
- TEST_REQUIRE(device->msix_info.count > 0);
+ msi = setup_msi(device, use_device_msi);
- vfio_pci_msix_enable(device, 0, 1);
- kvm_add_irqfd(vm, gsi, device->msi_eventfds[0]);
+ kvm_add_irqfd(vm, gsi, device->msi_eventfds[msi]);
kvm_route_msi(vm, gsi, vcpu, vector);
pthread_create(&vcpu_thread, NULL, vcpu_thread_main, vcpu);
@@ -107,12 +156,7 @@ int main(int argc, char **argv)
while (!READ_ONCE(guest_ready_for_irq))
sync_global_from_guest(vm, guest_ready_for_irq);
- /*
- * TODO: Get the device to send a physical MSI to exercise IRQ Bypass
- * (e.g. VT-d on Intel), rather than manually synthesizing a
- * notification from VFIO.
- */
- vfio_pci_irq_trigger(device, VFIO_PCI_MSIX_IRQ_INDEX, 0);
+ send_msi(device, use_device_msi, msi);
clock_gettime(CLOCK_MONOTONIC, &start);
--
2.49.0.1151.ga128411c76-goog
