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virtio: use u32, not bitmap for features

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It seemed like a good idea to use bitmap for features
in struct virtio_device, but it's actually a pain,
and seems to become even more painful when we get more
than 32 feature bits.  Just change it to a u32 for now.

Based on patch by Rusty.

Suggested-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This commit is contained in:
Michael S. Tsirkin 2014-10-07 16:39:42 +02:00
parent d4024af56f
commit e16e12be34
16 changed files with 42 additions and 74 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/char/virtio_console.c
View File

@ -355,7 +355,7 @@ static inline bool use_multiport(struct ports_device *portdev)
*/
if (!portdev->vdev)
return 0;
return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
return __virtio_test_bit(portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT);
}
static DEFINE_SPINLOCK(dma_bufs_lock);

8
drivers/lguest/lguest_device.c
View File

@ -137,14 +137,14 @@ static void lg_finalize_features(struct virtio_device *vdev)
vring_transport_features(vdev);
/*
* The vdev->feature array is a Linux bitmask: this isn't the same as a
* the simple array of bits used by lguest devices for features. So we
* do this slow, manual conversion which is completely general.
* Since lguest is currently x86-only, we're little-endian. That
* means we could just memcpy. But it's not time critical, and in
* case someone copies this code, we do it the slow, obvious way.
*/
memset(out_features, 0, desc->feature_len);
bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8;
for (i = 0; i < bits; i++) {
if (test_bit(i, vdev->features))
if (__virtio_test_bit(vdev, i))
out_features[i / 8] |= (1 << (i % 8));
}

2
drivers/misc/mic/card/mic_virtio.c
View File

@ -101,7 +101,7 @@ static void mic_finalize_features(struct virtio_device *vdev)
bits = min_t(unsigned, feature_len,
sizeof(vdev->features)) * 8;
for (i = 0; i < bits; i++) {
if (test_bit(i, vdev->features))
if (__virtio_test_bit(vdev, i))
iowrite8(ioread8(&out_features[i / 8]) | (1 << (i % 8)),
&out_features[i / 8]);
}

2
drivers/remoteproc/remoteproc_virtio.c
View File

@ -231,7 +231,7 @@ static void rproc_virtio_finalize_features(struct virtio_device *vdev)
* Remember the finalized features of our vdev, and provide it
* to the remote processor once it is powered on.
*/
rsc->gfeatures = vdev->features[0];
rsc->gfeatures = vdev->features;
}
static void rproc_virtio_get(struct virtio_device *vdev, unsigned offset,

2
drivers/s390/kvm/kvm_virtio.c
View File

@ -106,7 +106,7 @@ static void kvm_finalize_features(struct virtio_device *vdev)
memset(out_features, 0, desc->feature_len);
bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8;
for (i = 0; i < bits; i++) {
if (test_bit(i, vdev->features))
if (__virtio_test_bit(vdev, i))
out_features[i / 8] |= (1 << (i % 8));
}
}

23
drivers/s390/kvm/virtio_ccw.c
View File

@ -701,7 +701,6 @@ static void virtio_ccw_finalize_features(struct virtio_device *vdev)
{
struct virtio_ccw_device *vcdev = to_vc_device(vdev);
struct virtio_feature_desc *features;
int i;
struct ccw1 *ccw;
ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
@ -715,19 +714,15 @@ static void virtio_ccw_finalize_features(struct virtio_device *vdev)
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
for (i = 0; i < sizeof(*vdev->features) / sizeof(features->features);
i++) {
int highbits = i % 2 ? 32 : 0;
features->index = i;
features->features = cpu_to_le32(vdev->features[i / 2]
>> highbits);
/* Write the feature bits to the host. */
ccw->cmd_code = CCW_CMD_WRITE_FEAT;
ccw->flags = 0;
ccw->count = sizeof(*features);
ccw->cda = (__u32)(unsigned long)features;
ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
}
features->index = 0;
features->features = cpu_to_le32(vdev->features);
/* Write the feature bits to the host. */
ccw->cmd_code = CCW_CMD_WRITE_FEAT;
ccw->flags = 0;
ccw->count = sizeof(*features);
ccw->cda = (__u32)(unsigned long)features;
ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
out_free:
kfree(features);
kfree(ccw);

10
drivers/virtio/virtio.c
View File

@ -49,9 +49,9 @@ static ssize_t features_show(struct device *_d,
/* We actually represent this as a bitstring, as it could be
* arbitrary length in future. */
for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++)
for (i = 0; i < sizeof(dev->features)*8; i++)
len += sprintf(buf+len, "%c",
test_bit(i, dev->features) ? '1' : '0');
__virtio_test_bit(dev, i) ? '1' : '0');
len += sprintf(buf+len, "\n");
return len;
}
@ -168,18 +168,18 @@ static int virtio_dev_probe(struct device *_d)
device_features = dev->config->get_features(dev);
/* Features supported by both device and driver into dev->features. */
memset(dev->features, 0, sizeof(dev->features));
dev->features = 0;
for (i = 0; i < drv->feature_table_size; i++) {
unsigned int f = drv->feature_table[i];
BUG_ON(f >= 32);
if (device_features & (1 << f))
set_bit(f, dev->features);
__virtio_set_bit(dev, f);
}
/* Transport features always preserved to pass to finalize_features. */
for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
if (device_features & (1 << i))
set_bit(i, dev->features);
__virtio_set_bit(dev, i);
dev->config->finalize_features(dev);

8
drivers/virtio/virtio_mmio.c
View File

@ -155,16 +155,12 @@ static u32 vm_get_features(struct virtio_device *vdev)
static void vm_finalize_features(struct virtio_device *vdev)
{
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
int i;
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
for (i = 0; i < ARRAY_SIZE(vdev->features); i++) {
writel(i, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL);
writel(vdev->features[i],
vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
}
writel(0, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL);
writel(vdev->features, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
}
static void vm_get(struct virtio_device *vdev, unsigned offset,

3
drivers/virtio/virtio_pci.c
View File

@ -120,8 +120,7 @@ static void vp_finalize_features(struct virtio_device *vdev)
vring_transport_features(vdev);
/* We only support 32 feature bits. */
BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
iowrite32(vdev->features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
}
/* virtio config->get() implementation */

2
drivers/virtio/virtio_ring.c
View File

@ -781,7 +781,7 @@ void vring_transport_features(struct virtio_device *vdev)
break;
default:
/* We don't understand this bit. */
clear_bit(i, vdev->features);
__virtio_clear_bit(vdev, i);
}
}
}

3
include/linux/virtio.h
View File

@ -101,8 +101,7 @@ struct virtio_device {
const struct virtio_config_ops *config;
const struct vringh_config_ops *vringh_config;
struct list_head vqs;
/* Note that this is a Linux set_bit-style bitmap. */
unsigned long features[1];
u32 features;
void *priv;
};

6
include/linux/virtio_config.h
View File

@ -92,7 +92,7 @@ static inline bool __virtio_test_bit(const struct virtio_device *vdev,
else
BUG_ON(fbit >= 32);
return test_bit(fbit, vdev->features);
return vdev->features & BIT(fbit);
}
/**
@ -109,7 +109,7 @@ static inline void __virtio_set_bit(struct virtio_device *vdev,
else
BUG_ON(fbit >= 32);
set_bit(fbit, vdev->features);
vdev->features |= BIT(fbit);
}
/**
@ -126,7 +126,7 @@ static inline void __virtio_clear_bit(struct virtio_device *vdev,
else
BUG_ON(fbit >= 32);
clear_bit(fbit, vdev->features);
vdev->features &= ~BIT(fbit);
}
/**

22
tools/virtio/linux/virtio.h
View File

@ -6,31 +6,11 @@
/* TODO: empty stubs for now. Broken but enough for virtio_ring.c */
#define list_add_tail(a, b) do {} while (0)
#define list_del(a) do {} while (0)
#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
#define BITS_PER_BYTE 8
#define BITS_PER_LONG (sizeof(long) * BITS_PER_BYTE)
#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
/* TODO: Not atomic as it should be:
* we don't use this for anything important. */
static inline void clear_bit(int nr, volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
*p &= ~mask;
}
static inline int test_bit(int nr, const volatile unsigned long *addr)
{
return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
}
/* end of stubs */
struct virtio_device {
void *dev;
unsigned long features[1];
u32 features;
};
struct virtqueue {

2
tools/virtio/linux/virtio_config.h
View File

@ -2,5 +2,5 @@
#define VIRTIO_TRANSPORT_F_END 32
#define virtio_has_feature(dev, feature) \
test_bit((feature), (dev)->features)
(__virtio_test_bit((dev), feature))

5
tools/virtio/virtio_test.c
View File

@ -60,7 +60,7 @@ void vhost_vq_setup(struct vdev_info *dev, struct vq_info *info)
{
struct vhost_vring_state state = { .index = info->idx };
struct vhost_vring_file file = { .index = info->idx };
unsigned long long features = dev->vdev.features[0];
unsigned long long features = dev->vdev.features;
struct vhost_vring_addr addr = {
.index = info->idx,
.desc_user_addr = (uint64_t)(unsigned long)info->vring.desc,
@ -113,8 +113,7 @@ static void vdev_info_init(struct vdev_info* dev, unsigned long long features)
{
int r;
memset(dev, 0, sizeof *dev);
dev->vdev.features[0] = features;
dev->vdev.features[1] = features >> 32;
dev->vdev.features = features;
dev->buf_size = 1024;
dev->buf = malloc(dev->buf_size);
assert(dev->buf);

16
tools/virtio/vringh_test.c
View File

@ -304,7 +304,7 @@ static int parallel_test(unsigned long features,
close(to_guest[1]);
close(to_host[0]);
gvdev.vdev.features[0] = features;
gvdev.vdev.features = features;
gvdev.to_host_fd = to_host[1];
gvdev.notifies = 0;
@ -449,13 +449,13 @@ int main(int argc, char *argv[])
bool fast_vringh = false, parallel = false;
getrange = getrange_iov;
vdev.features[0] = 0;
vdev.features = 0;
while (argv[1]) {
if (strcmp(argv[1], "--indirect") == 0)
vdev.features[0] |= (1 << VIRTIO_RING_F_INDIRECT_DESC);
__virtio_set_bit(&vdev, VIRTIO_RING_F_INDIRECT_DESC);
else if (strcmp(argv[1], "--eventidx") == 0)
vdev.features[0] |= (1 << VIRTIO_RING_F_EVENT_IDX);
__virtio_set_bit(&vdev, VIRTIO_RING_F_EVENT_IDX);
else if (strcmp(argv[1], "--slow-range") == 0)
getrange = getrange_slow;
else if (strcmp(argv[1], "--fast-vringh") == 0)
@ -468,7 +468,7 @@ int main(int argc, char *argv[])
}
if (parallel)
return parallel_test(vdev.features[0], getrange, fast_vringh);
return parallel_test(vdev.features, getrange, fast_vringh);
if (posix_memalign(&__user_addr_min, PAGE_SIZE, USER_MEM) != 0)
abort();
@ -483,7 +483,7 @@ int main(int argc, char *argv[])
/* Set up host side. */
vring_init(&vrh.vring, RINGSIZE, __user_addr_min, ALIGN);
vringh_init_user(&vrh, vdev.features[0], RINGSIZE, true,
vringh_init_user(&vrh, vdev.features, RINGSIZE, true,
vrh.vring.desc, vrh.vring.avail, vrh.vring.used);
/* No descriptor to get yet... */
@ -652,13 +652,13 @@ int main(int argc, char *argv[])
}
/* Test weird (but legal!) indirect. */
if (vdev.features[0] & (1 << VIRTIO_RING_F_INDIRECT_DESC)) {
if (__virtio_test_bit(&vdev, VIRTIO_RING_F_INDIRECT_DESC)) {
char *data = __user_addr_max - USER_MEM/4;
struct vring_desc *d = __user_addr_max - USER_MEM/2;
struct vring vring;
/* Force creation of direct, which we modify. */
vdev.features[0] &= ~(1 << VIRTIO_RING_F_INDIRECT_DESC);
__virtio_clear_bit(&vdev, VIRTIO_RING_F_INDIRECT_DESC);
vq = vring_new_virtqueue(0, RINGSIZE, ALIGN, &vdev, true,
__user_addr_min,
never_notify_host,