Allow drivers that cannot trigger MSI interrupts to leave the send_msi
callback NULL. Add an fcntl_set_msi_nonblock() wrapper that only sets
nonblocking mode when send_msi is available, and update ASSERT_NO_MSI()
to skip when the driver lacks MSI support. The send_msi test SKIPs and
mix_and_match skips the MSI portion per iteration.

Signed-off-by: Rubin Du <rubind@nvidia.com>
---
 .../selftests/vfio/vfio_pci_driver_test.c     | 39 ++++++++++++-------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/vfio/vfio_pci_driver_test.c b/tools/testing/selftests/vfio/vfio_pci_driver_test.c
index 44aa90ee113a..761bf117d624 100644
--- a/tools/testing/selftests/vfio/vfio_pci_driver_test.c
+++ b/tools/testing/selftests/vfio/vfio_pci_driver_test.c
@@ -11,11 +11,18 @@
 
 static const char *device_bdf;
 
-#define ASSERT_NO_MSI(_eventfd) do {			\
-	u64 __value;					\
-							\
-	ASSERT_EQ(-1, read(_eventfd, &__value, 8));	\
-	ASSERT_EQ(EAGAIN, errno);			\
+#define fcntl_set_msi_nonblock(_self) do {				\
+	if (_self->device->driver.ops->send_msi)			\
+		fcntl_set_nonblock(_self->msi_fd);			\
+} while (0)
+
+#define ASSERT_NO_MSI(_self) do {					\
+	u64 __value;							\
+									\
+	if (!_self->device->driver.ops->send_msi)			\
+		break;							\
+	ASSERT_EQ(-1, read(_self->msi_fd, &__value, 8));		\
+	ASSERT_EQ(EAGAIN, errno);					\
 } while (0)
 
 static void region_setup(struct iommu *iommu,
@@ -129,7 +136,7 @@ TEST_F(vfio_pci_driver_test, init_remove)
 
 TEST_F(vfio_pci_driver_test, memcpy_success)
 {
-	fcntl_set_nonblock(self->msi_fd);
+	fcntl_set_msi_nonblock(self);
 
 	memset(self->src, 'x', self->size);
 	memset(self->dst, 'y', self->size);
@@ -140,12 +147,12 @@ TEST_F(vfio_pci_driver_test, memcpy_success)
 					    self->size));
 
 	ASSERT_EQ(0, memcmp(self->src, self->dst, self->size));
-	ASSERT_NO_MSI(self->msi_fd);
+	ASSERT_NO_MSI(self);
 }
 
 TEST_F(vfio_pci_driver_test, memcpy_from_unmapped_iova)
 {
-	fcntl_set_nonblock(self->msi_fd);
+	fcntl_set_msi_nonblock(self);
 
 	/*
 	 * Ignore the return value since not all devices will detect and report
@@ -154,12 +161,12 @@ TEST_F(vfio_pci_driver_test, memcpy_from_unmapped_iova)
 	vfio_pci_driver_memcpy(self->device, self->unmapped_iova,
 			       self->dst_iova, self->size);
 
-	ASSERT_NO_MSI(self->msi_fd);
+	ASSERT_NO_MSI(self);
 }
 
 TEST_F(vfio_pci_driver_test, memcpy_to_unmapped_iova)
 {
-	fcntl_set_nonblock(self->msi_fd);
+	fcntl_set_msi_nonblock(self);
 
 	/*
 	 * Ignore the return value since not all devices will detect and report
@@ -168,13 +175,16 @@ TEST_F(vfio_pci_driver_test, memcpy_to_unmapped_iova)
 	vfio_pci_driver_memcpy(self->device, self->src_iova,
 			       self->unmapped_iova, self->size);
 
-	ASSERT_NO_MSI(self->msi_fd);
+	ASSERT_NO_MSI(self);
 }
 
 TEST_F(vfio_pci_driver_test, send_msi)
 {
 	u64 value;
 
+	if (!self->device->driver.ops->send_msi)
+		SKIP(return, "Driver does not support send_msi()\n");
+
 	vfio_pci_driver_send_msi(self->device);
 	ASSERT_EQ(8, read(self->msi_fd, &value, 8));
 	ASSERT_EQ(1, value);
@@ -201,6 +211,9 @@ TEST_F(vfio_pci_driver_test, mix_and_match)
 				       self->dst_iova,
 				       self->size);
 
+		if (!self->device->driver.ops->send_msi)
+			continue;
+
 		vfio_pci_driver_send_msi(self->device);
 		ASSERT_EQ(8, read(self->msi_fd, &value, 8));
 		ASSERT_EQ(1, value);
@@ -214,7 +227,7 @@ TEST_F_TIMEOUT(vfio_pci_driver_test, memcpy_storm, 60)
 	u64 size;
 	u64 count;
 
-	fcntl_set_nonblock(self->msi_fd);
+	fcntl_set_msi_nonblock(self);
 
 	/*
 	 * Perform up to 250GiB worth of DMA reads and writes across several
@@ -232,7 +245,7 @@ TEST_F_TIMEOUT(vfio_pci_driver_test, memcpy_storm, 60)
 				     size, count);
 
 	ASSERT_EQ(0, vfio_pci_driver_memcpy_wait(self->device));
-	ASSERT_NO_MSI(self->msi_fd);
+	ASSERT_NO_MSI(self);
 }
 
 static bool device_has_selftests_driver(const char *bdf)
-- 
2.43.0