qemu-e2k/tests/libqos/virtio.c
Stefan Hajnoczi 70556264a8 libqos: use microseconds instead of iterations for virtio timeout
Some hosts are slow or overloaded so test execution takes a long time.
Test cases use timeouts to protect against an infinite loop stalling the
test forever (especially important in automated test setups).

Commit 6cd14054b6 ("libqos virtio:
Increase ISR timeout") increased the clock_step() value in an attempt to
lengthen the virtio interrupt wait timeout, but timeout failures are
still occuring on the Travis automated testing platform.

This is because clock_step() only affects the guest's virtual time.
Virtio requests can be bottlenecked on host disk I/O latency - which
cannot be improved by stepping the clock, so the fix was ineffective.

This patch changes the qvirtio_wait_queue_isr() and
qvirtio_wait_config_isr() timeout mechanism from loop iterations to
microseconds.  This way the test case can specify an absolute 30 second
timeout.  Number of loop iterations is not a reliable timeout mechanism
since the speed depends on many factors including host performance.

Tests should no longer timeout on overloaded Travis instances.

Cc: Marc Marí <marc.mari.barcelo@gmail.com>
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2014-09-29 17:31:11 +01:00

282 lines
8.4 KiB
C

/*
* libqos virtio driver
*
* Copyright (c) 2014 Marc Marí
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include <glib.h>
#include "libqtest.h"
#include "libqos/virtio.h"
uint8_t qvirtio_config_readb(const QVirtioBus *bus, QVirtioDevice *d,
void *addr)
{
return bus->config_readb(d, addr);
}
uint16_t qvirtio_config_readw(const QVirtioBus *bus, QVirtioDevice *d,
void *addr)
{
return bus->config_readw(d, addr);
}
uint32_t qvirtio_config_readl(const QVirtioBus *bus, QVirtioDevice *d,
void *addr)
{
return bus->config_readl(d, addr);
}
uint64_t qvirtio_config_readq(const QVirtioBus *bus, QVirtioDevice *d,
void *addr)
{
return bus->config_readq(d, addr);
}
uint32_t qvirtio_get_features(const QVirtioBus *bus, QVirtioDevice *d)
{
return bus->get_features(d);
}
void qvirtio_set_features(const QVirtioBus *bus, QVirtioDevice *d,
uint32_t features)
{
bus->set_features(d, features);
}
QVirtQueue *qvirtqueue_setup(const QVirtioBus *bus, QVirtioDevice *d,
QGuestAllocator *alloc, uint16_t index)
{
return bus->virtqueue_setup(d, alloc, index);
}
void qvirtio_reset(const QVirtioBus *bus, QVirtioDevice *d)
{
bus->set_status(d, QVIRTIO_RESET);
g_assert_cmphex(bus->get_status(d), ==, QVIRTIO_RESET);
}
void qvirtio_set_acknowledge(const QVirtioBus *bus, QVirtioDevice *d)
{
bus->set_status(d, bus->get_status(d) | QVIRTIO_ACKNOWLEDGE);
g_assert_cmphex(bus->get_status(d), ==, QVIRTIO_ACKNOWLEDGE);
}
void qvirtio_set_driver(const QVirtioBus *bus, QVirtioDevice *d)
{
bus->set_status(d, bus->get_status(d) | QVIRTIO_DRIVER);
g_assert_cmphex(bus->get_status(d), ==,
QVIRTIO_DRIVER | QVIRTIO_ACKNOWLEDGE);
}
void qvirtio_set_driver_ok(const QVirtioBus *bus, QVirtioDevice *d)
{
bus->set_status(d, bus->get_status(d) | QVIRTIO_DRIVER_OK);
g_assert_cmphex(bus->get_status(d), ==,
QVIRTIO_DRIVER_OK | QVIRTIO_DRIVER | QVIRTIO_ACKNOWLEDGE);
}
void qvirtio_wait_queue_isr(const QVirtioBus *bus, QVirtioDevice *d,
QVirtQueue *vq, gint64 timeout_us)
{
gint64 start_time = g_get_monotonic_time();
for (;;) {
clock_step(100);
if (bus->get_queue_isr_status(d, vq)) {
return;
}
g_assert(g_get_monotonic_time() - start_time <= timeout_us);
}
}
/* 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;
}
void qvirtio_wait_config_isr(const QVirtioBus *bus, QVirtioDevice *d,
gint64 timeout_us)
{
gint64 start_time = g_get_monotonic_time();
for (;;) {
clock_step(100);
if (bus->get_config_isr_status(d)) {
return;
}
g_assert(g_get_monotonic_time() - start_time <= timeout_us);
}
}
void qvring_init(const QGuestAllocator *alloc, QVirtQueue *vq, uint64_t addr)
{
int i;
vq->desc = addr;
vq->avail = vq->desc + vq->size*sizeof(QVRingDesc);
vq->used = (uint64_t)((vq->avail + sizeof(uint16_t) * (3 + vq->size)
+ vq->align - 1) & ~(vq->align - 1));
for (i = 0; i < vq->size - 1; i++) {
/* vq->desc[i].addr */
writew(vq->desc + (16 * i), 0);
/* vq->desc[i].next */
writew(vq->desc + (16 * i) + 14, i + 1);
}
/* vq->avail->flags */
writew(vq->avail, 0);
/* vq->avail->idx */
writew(vq->avail + 2, 0);
/* vq->avail->used_event */
writew(vq->avail + 4 + (2 * vq->size), 0);
/* vq->used->flags */
writew(vq->used, 0);
/* vq->used->avail_event */
writew(vq->used+2+(sizeof(struct QVRingUsedElem)*vq->size), 0);
}
QVRingIndirectDesc *qvring_indirect_desc_setup(QVirtioDevice *d,
QGuestAllocator *alloc, uint16_t elem)
{
int i;
QVRingIndirectDesc *indirect = g_malloc(sizeof(*indirect));
indirect->index = 0;
indirect->elem = elem;
indirect->desc = guest_alloc(alloc, sizeof(QVRingDesc)*elem);
for (i = 0; i < elem - 1; ++i) {
/* indirect->desc[i].addr */
writeq(indirect->desc + (16 * i), 0);
/* indirect->desc[i].flags */
writew(indirect->desc + (16 * i) + 12, QVRING_DESC_F_NEXT);
/* indirect->desc[i].next */
writew(indirect->desc + (16 * i) + 14, i + 1);
}
return indirect;
}
void qvring_indirect_desc_add(QVRingIndirectDesc *indirect, uint64_t data,
uint32_t len, bool write)
{
uint16_t flags;
g_assert_cmpint(indirect->index, <, indirect->elem);
flags = readw(indirect->desc + (16 * indirect->index) + 12);
if (write) {
flags |= QVRING_DESC_F_WRITE;
}
/* indirect->desc[indirect->index].addr */
writeq(indirect->desc + (16 * indirect->index), data);
/* indirect->desc[indirect->index].len */
writel(indirect->desc + (16 * indirect->index) + 8, len);
/* indirect->desc[indirect->index].flags */
writew(indirect->desc + (16 * indirect->index) + 12, flags);
indirect->index++;
}
uint32_t qvirtqueue_add(QVirtQueue *vq, uint64_t data, uint32_t len, bool write,
bool next)
{
uint16_t flags = 0;
vq->num_free--;
if (write) {
flags |= QVRING_DESC_F_WRITE;
}
if (next) {
flags |= QVRING_DESC_F_NEXT;
}
/* vq->desc[vq->free_head].addr */
writeq(vq->desc + (16 * vq->free_head), data);
/* vq->desc[vq->free_head].len */
writel(vq->desc + (16 * vq->free_head) + 8, len);
/* vq->desc[vq->free_head].flags */
writew(vq->desc + (16 * vq->free_head) + 12, flags);
return vq->free_head++; /* Return and increase, in this order */
}
uint32_t qvirtqueue_add_indirect(QVirtQueue *vq, QVRingIndirectDesc *indirect)
{
g_assert(vq->indirect);
g_assert_cmpint(vq->size, >=, indirect->elem);
g_assert_cmpint(indirect->index, ==, indirect->elem);
vq->num_free--;
/* vq->desc[vq->free_head].addr */
writeq(vq->desc + (16 * vq->free_head), indirect->desc);
/* vq->desc[vq->free_head].len */
writel(vq->desc + (16 * vq->free_head) + 8,
sizeof(QVRingDesc) * indirect->elem);
/* vq->desc[vq->free_head].flags */
writew(vq->desc + (16 * vq->free_head) + 12, QVRING_DESC_F_INDIRECT);
return vq->free_head++; /* Return and increase, in this order */
}
void qvirtqueue_kick(const QVirtioBus *bus, QVirtioDevice *d, QVirtQueue *vq,
uint32_t free_head)
{
/* vq->avail->idx */
uint16_t idx = readl(vq->avail + 2);
/* vq->used->flags */
uint16_t flags;
/* vq->used->avail_event */
uint16_t avail_event;
/* vq->avail->ring[idx % vq->size] */
writel(vq->avail + 4 + (2 * (idx % vq->size)), free_head);
/* vq->avail->idx */
writel(vq->avail + 2, idx + 1);
/* Must read after idx is updated */
flags = readw(vq->avail);
avail_event = readw(vq->used + 4 +
(sizeof(struct QVRingUsedElem) * vq->size));
/* < 1 because we add elements to avail queue one by one */
if ((flags & QVRING_USED_F_NO_NOTIFY) == 0 &&
(!vq->event || (uint16_t)(idx-avail_event) < 1)) {
bus->virtqueue_kick(d, vq);
}
}
void qvirtqueue_set_used_event(QVirtQueue *vq, uint16_t idx)
{
g_assert(vq->event);
/* vq->avail->used_event */
writew(vq->avail + 4 + (2 * vq->size), idx);
}