[PATCH v3 02/41] virtio: add support for 64 bit features.

From: Michael S. Tsirkin
Date: Mon Nov 24 2014 - 07:09:28 EST


From: Rusty Russell <rusty@xxxxxxxxxxxxxxx>

Change the u32 to a u64, and make sure to use 1ULL everywhere!

Cc: Brian Swetland <swetland@xxxxxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
[Thomas Huth: fix up virtio-ccw get_features]
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
Acked-by: Pawel Moll <pawel.moll@xxxxxxx>
Acked-by: Ohad Ben-Cohen <ohad@xxxxxxxxxx>

Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
include/linux/virtio.h | 2 +-
include/linux/virtio_config.h | 8 ++++----
tools/virtio/linux/virtio.h | 2 +-
tools/virtio/linux/virtio_config.h | 2 +-
drivers/char/virtio_console.c | 2 +-
drivers/lguest/lguest_device.c | 10 +++++-----
drivers/remoteproc/remoteproc_virtio.c | 5 ++++-
drivers/s390/kvm/kvm_virtio.c | 10 +++++-----
drivers/s390/kvm/virtio_ccw.c | 29 ++++++++++++++++++++++++-----
drivers/virtio/virtio.c | 12 ++++++------
drivers/virtio/virtio_mmio.c | 14 +++++++++-----
drivers/virtio/virtio_pci.c | 5 ++---
drivers/virtio/virtio_ring.c | 2 +-
13 files changed, 64 insertions(+), 39 deletions(-)

diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 7828a7f..149284e 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -101,7 +101,7 @@ struct virtio_device {
const struct virtio_config_ops *config;
const struct vringh_config_ops *vringh_config;
struct list_head vqs;
- u32 features;
+ u64 features;
void *priv;
};

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index aa84d0e..022d904 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -66,7 +66,7 @@ struct virtio_config_ops {
vq_callback_t *callbacks[],
const char *names[]);
void (*del_vqs)(struct virtio_device *);
- u32 (*get_features)(struct virtio_device *vdev);
+ u64 (*get_features)(struct virtio_device *vdev);
void (*finalize_features)(struct virtio_device *vdev);
const char *(*bus_name)(struct virtio_device *vdev);
int (*set_vq_affinity)(struct virtqueue *vq, int cpu);
@@ -86,14 +86,14 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev,
{
/* Did you forget to fix assumptions on max features? */
if (__builtin_constant_p(fbit))
- BUILD_BUG_ON(fbit >= 32);
+ BUILD_BUG_ON(fbit >= 64);
else
- BUG_ON(fbit >= 32);
+ BUG_ON(fbit >= 64);

if (fbit < VIRTIO_TRANSPORT_F_START)
virtio_check_driver_offered_feature(vdev, fbit);

- return vdev->features & (1 << fbit);
+ return vdev->features & (1ULL << fbit);
}

static inline
diff --git a/tools/virtio/linux/virtio.h b/tools/virtio/linux/virtio.h
index 72bff70..8eb6421 100644
--- a/tools/virtio/linux/virtio.h
+++ b/tools/virtio/linux/virtio.h
@@ -10,7 +10,7 @@

struct virtio_device {
void *dev;
- u32 features;
+ u64 features;
};

struct virtqueue {
diff --git a/tools/virtio/linux/virtio_config.h b/tools/virtio/linux/virtio_config.h
index 1f1636b..a254c2b 100644
--- a/tools/virtio/linux/virtio_config.h
+++ b/tools/virtio/linux/virtio_config.h
@@ -2,5 +2,5 @@
#define VIRTIO_TRANSPORT_F_END 32

#define virtio_has_feature(dev, feature) \
- ((dev)->features & (1 << feature))
+ ((dev)->features & (1ULL << feature))

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 0074f9b..fda9a75 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -355,7 +355,7 @@ static inline bool use_multiport(struct ports_device *portdev)
*/
if (!portdev->vdev)
return 0;
- return portdev->vdev->features & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
+ return portdev->vdev->features & (1ULL << VIRTIO_CONSOLE_F_MULTIPORT);
}

static DEFINE_SPINLOCK(dma_bufs_lock);
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
index c831c47..4d29bcd 100644
--- a/drivers/lguest/lguest_device.c
+++ b/drivers/lguest/lguest_device.c
@@ -94,17 +94,17 @@ static unsigned desc_size(const struct lguest_device_desc *desc)
}

/* This gets the device's feature bits. */
-static u32 lg_get_features(struct virtio_device *vdev)
+static u64 lg_get_features(struct virtio_device *vdev)
{
unsigned int i;
- u32 features = 0;
+ u64 features = 0;
struct lguest_device_desc *desc = to_lgdev(vdev)->desc;
u8 *in_features = lg_features(desc);

/* We do this the slow but generic way. */
- for (i = 0; i < min(desc->feature_len * 8, 32); i++)
+ for (i = 0; i < min(desc->feature_len * 8, 64); i++)
if (in_features[i / 8] & (1 << (i % 8)))
- features |= (1 << i);
+ features |= (1ULL << i);

return features;
}
@@ -144,7 +144,7 @@ static void lg_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 (vdev->features & (1 << i))
+ if (vdev->features & (1ULL << i))
out_features[i / 8] |= (1 << (i % 8));
}

diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
index dafaf38..627737e 100644
--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -207,7 +207,7 @@ static void rproc_virtio_reset(struct virtio_device *vdev)
}

/* provide the vdev features as retrieved from the firmware */
-static u32 rproc_virtio_get_features(struct virtio_device *vdev)
+static u64 rproc_virtio_get_features(struct virtio_device *vdev)
{
struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
struct fw_rsc_vdev *rsc;
@@ -227,6 +227,9 @@ static void rproc_virtio_finalize_features(struct virtio_device *vdev)
/* Give virtio_ring a chance to accept features */
vring_transport_features(vdev);

+ /* Make sure we don't have any features > 32 bits! */
+ BUG_ON((u32)vdev->features != vdev->features);
+
/*
* Remember the finalized features of our vdev, and provide it
* to the remote processor once it is powered on.
diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c
index ac79a09..c78251d 100644
--- a/drivers/s390/kvm/kvm_virtio.c
+++ b/drivers/s390/kvm/kvm_virtio.c
@@ -80,16 +80,16 @@ static unsigned desc_size(const struct kvm_device_desc *desc)
}

/* This gets the device's feature bits. */
-static u32 kvm_get_features(struct virtio_device *vdev)
+static u64 kvm_get_features(struct virtio_device *vdev)
{
unsigned int i;
- u32 features = 0;
+ u64 features = 0;
struct kvm_device_desc *desc = to_kvmdev(vdev)->desc;
u8 *in_features = kvm_vq_features(desc);

- for (i = 0; i < min(desc->feature_len * 8, 32); i++)
+ for (i = 0; i < min(desc->feature_len * 8, 64); i++)
if (in_features[i / 8] & (1 << (i % 8)))
- features |= (1 << i);
+ features |= (1ULL << i);
return features;
}

@@ -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 (vdev->features & (1 << i))
+ if (vdev->features & (1ULL << i))
out_features[i / 8] |= (1 << (i % 8));
}
}
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index 1dbee95..abba04d 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -660,11 +660,12 @@ static void virtio_ccw_reset(struct virtio_device *vdev)
kfree(ccw);
}

-static u32 virtio_ccw_get_features(struct virtio_device *vdev)
+static u64 virtio_ccw_get_features(struct virtio_device *vdev)
{
struct virtio_ccw_device *vcdev = to_vc_device(vdev);
struct virtio_feature_desc *features;
- int ret, rc;
+ int ret;
+ u64 rc;
struct ccw1 *ccw;

ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
@@ -677,7 +678,6 @@ static u32 virtio_ccw_get_features(struct virtio_device *vdev)
goto out_free;
}
/* Read the feature bits from the host. */
- /* TODO: Features > 32 bits */
features->index = 0;
ccw->cmd_code = CCW_CMD_READ_FEAT;
ccw->flags = 0;
@@ -691,6 +691,16 @@ static u32 virtio_ccw_get_features(struct virtio_device *vdev)

rc = le32_to_cpu(features->features);

+ /* Read second half feature bits from the host. */
+ features->index = 1;
+ ccw->cmd_code = CCW_CMD_READ_FEAT;
+ ccw->flags = 0;
+ ccw->count = sizeof(*features);
+ ccw->cda = (__u32)(unsigned long)features;
+ ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
+ if (ret == 0)
+ rc |= (u64)le32_to_cpu(features->features) << 32;
+
out_free:
kfree(features);
kfree(ccw);
@@ -715,8 +725,17 @@ static void virtio_ccw_finalize_features(struct virtio_device *vdev)
vring_transport_features(vdev);

features->index = 0;
- features->features = cpu_to_le32(vdev->features);
- /* Write the feature bits to the host. */
+ features->features = cpu_to_le32((u32)vdev->features);
+ /* Write the first half of 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 = 1;
+ features->features = cpu_to_le32(vdev->features >> 32);
+ /* Write the second half of the feature bits to the host. */
ccw->cmd_code = CCW_CMD_WRITE_FEAT;
ccw->flags = 0;
ccw->count = sizeof(*features);
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 7814b1f..d213567 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -159,7 +159,7 @@ static int virtio_dev_probe(struct device *_d)
int err, i;
struct virtio_device *dev = dev_to_virtio(_d);
struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
- u32 device_features;
+ u64 device_features;

/* We have a driver! */
add_status(dev, VIRTIO_CONFIG_S_DRIVER);
@@ -171,15 +171,15 @@ static int virtio_dev_probe(struct device *_d)
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))
- dev->features |= (1 << f);
+ BUG_ON(f >= 64);
+ if (device_features & (1ULL << f))
+ dev->features |= (1ULL << 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))
- dev->features |= (1 << i);
+ if (device_features & (1ULL << i))
+ dev->features |= (1ULL << i);

dev->config->finalize_features(dev);

diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index eb5b0e2..fd01c6d 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -142,14 +142,16 @@ struct virtio_mmio_vq_info {

/* Configuration interface */

-static u32 vm_get_features(struct virtio_device *vdev)
+static u64 vm_get_features(struct virtio_device *vdev)
{
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+ u64 features;

- /* TODO: Features > 32 bits */
writel(0, vm_dev->base + VIRTIO_MMIO_HOST_FEATURES_SEL);
-
- return readl(vm_dev->base + VIRTIO_MMIO_HOST_FEATURES);
+ features = readl(vm_dev->base + VIRTIO_MMIO_HOST_FEATURES);
+ writel(1, vm_dev->base + VIRTIO_MMIO_HOST_FEATURES_SEL);
+ features |= ((u64)readl(vm_dev->base + VIRTIO_MMIO_HOST_FEATURES) << 32);
+ return features;
}

static void vm_finalize_features(struct virtio_device *vdev)
@@ -160,7 +162,9 @@ static void vm_finalize_features(struct virtio_device *vdev)
vring_transport_features(vdev);

writel(0, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL);
- writel(vdev->features, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
+ writel((u32)vdev->features, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
+ writel(1, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL);
+ writel(vdev->features >> 32, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
}

static void vm_get(struct virtio_device *vdev, unsigned offset,
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index ab95a4c..68c0711 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -102,12 +102,11 @@ static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
}

/* virtio config->get_features() implementation */
-static u32 vp_get_features(struct virtio_device *vdev)
+static u64 vp_get_features(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);

- /* When someone needs more than 32 feature bits, we'll need to
- * steal a bit to indicate that the rest are somewhere else. */
+ /* We only support 32 feature bits. */
return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
}

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 15a8a05..61a1fe1 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -781,7 +781,7 @@ void vring_transport_features(struct virtio_device *vdev)
break;
default:
/* We don't understand this bit. */
- vdev->features &= ~(1 << i);
+ vdev->features &= ~(1ULL << i);
}
}
}
--
MST

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