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authorStefan Hajnoczi <stefanha@redhat.com>2014-09-29 16:40:11 +0100
committerPeter Maydell <peter.maydell@linaro.org>2014-09-29 17:31:08 +0100
commite8c81b4d8a5a2fd125e559cb02b8a87598419041 (patch)
treea7fc7c59c24b280e203d4b5b1694c5df1c770aa4 /tests/libqos/virtio.c
parented9114356b587b362f5ed10e75366a4f07ed32af (diff)
libqos: improve event_index test with timeout
The virtio event_index feature lets the device driver tell the device how many requests to process before raising the next interrupt. virtio-blk-test.c tries to verify that the device does not raise an interrupt unnecessarily. Unfortunately the test has a race condition. It spins checking for an interrupt up to 100 times and then assumes the request has finished. On a slow host the I/O request could still be in flight and the test would fail. This patch waits for the request to complete, or until a 30-second timeout is reached. If an interrupt is raised while waiting the test fails since the device was not supposed to raise interrupts. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'tests/libqos/virtio.c')
-rw-r--r--tests/libqos/virtio.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/tests/libqos/virtio.c b/tests/libqos/virtio.c
index 9b6de2c0a7..009325dd02 100644
--- a/tests/libqos/virtio.c
+++ b/tests/libqos/virtio.c
@@ -91,6 +91,28 @@ bool qvirtio_wait_queue_isr(const QVirtioBus *bus, QVirtioDevice *d,
return timeout != 0;
}
+/* Wait for the status byte at given guest memory address to be set
+ *
+ * The virtqueue interrupt must not be raised, making this useful for testing
+ * event_index functionality.
+ */
+uint8_t qvirtio_wait_status_byte_no_isr(const QVirtioBus *bus,
+ QVirtioDevice *d,
+ QVirtQueue *vq,
+ uint64_t addr,
+ gint64 timeout_us)
+{
+ gint64 start_time = g_get_monotonic_time();
+ uint8_t val;
+
+ while ((val = readb(addr)) == 0xff) {
+ clock_step(100);
+ g_assert(!bus->get_queue_isr_status(d, vq));
+ g_assert(g_get_monotonic_time() - start_time <= timeout_us);
+ }
+ return val;
+}
+
bool qvirtio_wait_config_isr(const QVirtioBus *bus, QVirtioDevice *d,
uint64_t timeout)
{