* [PATCH 2/3] vringh: initial virtio 1.0 support
[not found] <1418678019-31629-1-git-send-email-mst@redhat.com>
2014-12-15 21:14 ` [PATCH 1/3] vringh: 64 bit features Michael S. Tsirkin
@ 2014-12-15 21:14 ` Michael S. Tsirkin
1 sibling, 0 replies; 2+ messages in thread
From: Michael S. Tsirkin @ 2014-12-15 21:14 UTC (permalink / raw)
To: linux-kernel; +Cc: netdev, kvm, virtualization
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
include/linux/vringh.h | 33 ++++++++++++++
drivers/vhost/vringh.c | 121 ++++++++++++++++++++++++++++++-------------------
2 files changed, 107 insertions(+), 47 deletions(-)
diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index f696dd0..a3fa537 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -24,12 +24,16 @@
#ifndef _LINUX_VRINGH_H
#define _LINUX_VRINGH_H
#include <uapi/linux/virtio_ring.h>
+#include <linux/virtio_byteorder.h>
#include <linux/uio.h>
#include <linux/slab.h>
#include <asm/barrier.h>
/* virtio_ring with information needed for host access. */
struct vringh {
+ /* Everything is little endian */
+ bool little_endian;
+
/* Guest publishes used event idx (note: we always do). */
bool event_indices;
@@ -222,4 +226,33 @@ static inline void vringh_notify(struct vringh *vrh)
vrh->notify(vrh);
}
+static inline u16 vringh16_to_cpu(const struct vringh *vrh, __virtio16 val)
+{
+ return __virtio16_to_cpu(vrh->little_endian, val);
+}
+
+static inline __virtio16 cpu_to_vringh16(const struct vringh *vrh, u16 val)
+{
+ return __cpu_to_virtio16(vrh->little_endian, val);
+}
+
+static inline u32 vringh32_to_cpu(const struct vringh *vrh, __virtio32 val)
+{
+ return __virtio32_to_cpu(vrh->little_endian, val);
+}
+
+static inline __virtio32 cpu_to_vringh32(const struct vringh *vrh, u32 val)
+{
+ return __cpu_to_virtio32(vrh->little_endian, val);
+}
+
+static inline u64 vringh64_to_cpu(const struct vringh *vrh, __virtio64 val)
+{
+ return __virtio64_to_cpu(vrh->little_endian, val);
+}
+
+static inline __virtio64 cpu_to_vringh64(const struct vringh *vrh, u64 val)
+{
+ return __cpu_to_virtio64(vrh->little_endian, val);
+}
#endif /* _LINUX_VRINGH_H */
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index ac3fe27..3bb02c6 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -11,6 +11,7 @@
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/export.h>
+#include <uapi/linux/virtio_config.h>
static __printf(1,2) __cold void vringh_bad(const char *fmt, ...)
{
@@ -28,13 +29,14 @@ static __printf(1,2) __cold void vringh_bad(const char *fmt, ...)
/* Returns vring->num if empty, -ve on error. */
static inline int __vringh_get_head(const struct vringh *vrh,
- int (*getu16)(u16 *val, const u16 *p),
+ int (*getu16)(const struct vringh *vrh,
+ u16 *val, const __virtio16 *p),
u16 *last_avail_idx)
{
u16 avail_idx, i, head;
int err;
- err = getu16(&avail_idx, &vrh->vring.avail->idx);
+ err = getu16(vrh, &avail_idx, &vrh->vring.avail->idx);
if (err) {
vringh_bad("Failed to access avail idx at %p",
&vrh->vring.avail->idx);
@@ -49,7 +51,7 @@ static inline int __vringh_get_head(const struct vringh *vrh,
i = *last_avail_idx & (vrh->vring.num - 1);
- err = getu16(&head, &vrh->vring.avail->ring[i]);
+ err = getu16(vrh, &head, &vrh->vring.avail->ring[i]);
if (err) {
vringh_bad("Failed to read head: idx %d address %p",
*last_avail_idx, &vrh->vring.avail->ring[i]);
@@ -144,28 +146,32 @@ static inline bool no_range_check(struct vringh *vrh, u64 addr, size_t *len,
}
/* No reason for this code to be inline. */
-static int move_to_indirect(int *up_next, u16 *i, void *addr,
+static int move_to_indirect(const struct vringh *vrh,
+ int *up_next, u16 *i, void *addr,
const struct vring_desc *desc,
struct vring_desc **descs, int *desc_max)
{
+ u32 len;
+
/* Indirect tables can't have indirect. */
if (*up_next != -1) {
vringh_bad("Multilevel indirect %u->%u", *up_next, *i);
return -EINVAL;
}
- if (unlikely(desc->len % sizeof(struct vring_desc))) {
+ len = vringh32_to_cpu(vrh, desc->len);
+ if (unlikely(len % sizeof(struct vring_desc))) {
vringh_bad("Strange indirect len %u", desc->len);
return -EINVAL;
}
/* We will check this when we follow it! */
- if (desc->flags & VRING_DESC_F_NEXT)
- *up_next = desc->next;
+ if (desc->flags & cpu_to_vringh16(vrh, VRING_DESC_F_NEXT))
+ *up_next = vringh16_to_cpu(vrh, desc->next);
else
*up_next = -2;
*descs = addr;
- *desc_max = desc->len / sizeof(struct vring_desc);
+ *desc_max = len / sizeof(struct vring_desc);
/* Now, start at the first indirect. */
*i = 0;
@@ -287,22 +293,25 @@ __vringh_iov(struct vringh *vrh, u16 i,
if (unlikely(err))
goto fail;
- if (unlikely(desc.flags & VRING_DESC_F_INDIRECT)) {
+ if (unlikely(desc.flags &
+ cpu_to_vringh16(vrh, VRING_DESC_F_INDIRECT))) {
+ u64 a = vringh64_to_cpu(vrh, desc.addr);
+
/* Make sure it's OK, and get offset. */
- len = desc.len;
- if (!rcheck(vrh, desc.addr, &len, &range, getrange)) {
+ len = vringh32_to_cpu(vrh, desc.len);
+ if (!rcheck(vrh, a, &len, &range, getrange)) {
err = -EINVAL;
goto fail;
}
- if (unlikely(len != desc.len)) {
+ if (unlikely(len != vringh32_to_cpu(vrh, desc.len))) {
slow = true;
/* We need to save this range to use offset */
slowrange = range;
}
- addr = (void *)(long)(desc.addr + range.offset);
- err = move_to_indirect(&up_next, &i, addr, &desc,
+ addr = (void *)(long)(a + range.offset);
+ err = move_to_indirect(vrh, &up_next, &i, addr, &desc,
&descs, &desc_max);
if (err)
goto fail;
@@ -315,7 +324,7 @@ __vringh_iov(struct vringh *vrh, u16 i,
goto fail;
}
- if (desc.flags & VRING_DESC_F_WRITE)
+ if (desc.flags & cpu_to_vringh16(vrh, VRING_DESC_F_WRITE))
iov = wiov;
else {
iov = riov;
@@ -336,12 +345,14 @@ __vringh_iov(struct vringh *vrh, u16 i,
again:
/* Make sure it's OK, and get offset. */
- len = desc.len;
- if (!rcheck(vrh, desc.addr, &len, &range, getrange)) {
+ len = vringh32_to_cpu(vrh, desc.len);
+ if (!rcheck(vrh, vringh64_to_cpu(vrh, desc.addr), &len, &range,
+ getrange)) {
err = -EINVAL;
goto fail;
}
- addr = (void *)(unsigned long)(desc.addr + range.offset);
+ addr = (void *)(unsigned long)(vringh64_to_cpu(vrh, desc.addr) +
+ range.offset);
if (unlikely(iov->used == (iov->max_num & ~VRINGH_IOV_ALLOCATED))) {
err = resize_iovec(iov, gfp);
@@ -353,14 +364,16 @@ __vringh_iov(struct vringh *vrh, u16 i,
iov->iov[iov->used].iov_len = len;
iov->used++;
- if (unlikely(len != desc.len)) {
- desc.len -= len;
- desc.addr += len;
+ if (unlikely(len != vringh32_to_cpu(vrh, desc.len))) {
+ desc.len = cpu_to_vringh32(vrh,
+ vringh32_to_cpu(vrh, desc.len) - len);
+ desc.addr = cpu_to_vringh64(vrh,
+ vringh64_to_cpu(vrh, desc.addr) + len);
goto again;
}
- if (desc.flags & VRING_DESC_F_NEXT) {
- i = desc.next;
+ if (desc.flags & cpu_to_vringh16(vrh, VRING_DESC_F_NEXT)) {
+ i = vringh16_to_cpu(vrh, desc.next);
} else {
/* Just in case we need to finish traversing above. */
if (unlikely(up_next > 0)) {
@@ -387,7 +400,8 @@ fail:
static inline int __vringh_complete(struct vringh *vrh,
const struct vring_used_elem *used,
unsigned int num_used,
- int (*putu16)(u16 *p, u16 val),
+ int (*putu16)(const struct vringh *vrh,
+ __virtio16 *p, u16 val),
int (*putused)(struct vring_used_elem *dst,
const struct vring_used_elem
*src, unsigned num))
@@ -420,7 +434,7 @@ static inline int __vringh_complete(struct vringh *vrh,
/* Make sure buffer is written before we update index. */
virtio_wmb(vrh->weak_barriers);
- err = putu16(&vrh->vring.used->idx, used_idx + num_used);
+ err = putu16(vrh, &vrh->vring.used->idx, used_idx + num_used);
if (err) {
vringh_bad("Failed to update used index at %p",
&vrh->vring.used->idx);
@@ -433,7 +447,9 @@ static inline int __vringh_complete(struct vringh *vrh,
static inline int __vringh_need_notify(struct vringh *vrh,
- int (*getu16)(u16 *val, const u16 *p))
+ int (*getu16)(const struct vringh *vrh,
+ u16 *val,
+ const __virtio16 *p))
{
bool notify;
u16 used_event;
@@ -447,7 +463,7 @@ static inline int __vringh_need_notify(struct vringh *vrh,
/* Old-style, without event indices. */
if (!vrh->event_indices) {
u16 flags;
- err = getu16(&flags, &vrh->vring.avail->flags);
+ err = getu16(vrh, &flags, &vrh->vring.avail->flags);
if (err) {
vringh_bad("Failed to get flags at %p",
&vrh->vring.avail->flags);
@@ -457,7 +473,7 @@ static inline int __vringh_need_notify(struct vringh *vrh,
}
/* Modern: we know when other side wants to know. */
- err = getu16(&used_event, &vring_used_event(&vrh->vring));
+ err = getu16(vrh, &used_event, &vring_used_event(&vrh->vring));
if (err) {
vringh_bad("Failed to get used event idx at %p",
&vring_used_event(&vrh->vring));
@@ -478,20 +494,22 @@ static inline int __vringh_need_notify(struct vringh *vrh,
}
static inline bool __vringh_notify_enable(struct vringh *vrh,
- int (*getu16)(u16 *val, const u16 *p),
- int (*putu16)(u16 *p, u16 val))
+ int (*getu16)(const struct vringh *vrh,
+ u16 *val, const __virtio16 *p),
+ int (*putu16)(const struct vringh *vrh,
+ __virtio16 *p, u16 val))
{
u16 avail;
if (!vrh->event_indices) {
/* Old-school; update flags. */
- if (putu16(&vrh->vring.used->flags, 0) != 0) {
+ if (putu16(vrh, &vrh->vring.used->flags, 0) != 0) {
vringh_bad("Clearing used flags %p",
&vrh->vring.used->flags);
return true;
}
} else {
- if (putu16(&vring_avail_event(&vrh->vring),
+ if (putu16(vrh, &vring_avail_event(&vrh->vring),
vrh->last_avail_idx) != 0) {
vringh_bad("Updating avail event index %p",
&vring_avail_event(&vrh->vring));
@@ -503,7 +521,7 @@ static inline bool __vringh_notify_enable(struct vringh *vrh,
* sure it's written, then check again. */
virtio_mb(vrh->weak_barriers);
- if (getu16(&avail, &vrh->vring.avail->idx) != 0) {
+ if (getu16(vrh, &avail, &vrh->vring.avail->idx) != 0) {
vringh_bad("Failed to check avail idx at %p",
&vrh->vring.avail->idx);
return true;
@@ -516,11 +534,13 @@ static inline bool __vringh_notify_enable(struct vringh *vrh,
}
static inline void __vringh_notify_disable(struct vringh *vrh,
- int (*putu16)(u16 *p, u16 val))
+ int (*putu16)(const struct vringh *vrh,
+ __virtio16 *p, u16 val))
{
if (!vrh->event_indices) {
/* Old-school; update flags. */
- if (putu16(&vrh->vring.used->flags, VRING_USED_F_NO_NOTIFY)) {
+ if (putu16(vrh, &vrh->vring.used->flags,
+ VRING_USED_F_NO_NOTIFY)) {
vringh_bad("Setting used flags %p",
&vrh->vring.used->flags);
}
@@ -528,14 +548,18 @@ static inline void __vringh_notify_disable(struct vringh *vrh,
}
/* Userspace access helpers: in this case, addresses are really userspace. */
-static inline int getu16_user(u16 *val, const u16 *p)
+static inline int getu16_user(const struct vringh *vrh, u16 *val, const __virtio16 *p)
{
- return get_user(*val, (__force u16 __user *)p);
+ __virtio16 v = 0;
+ int rc = get_user(v, (__force __virtio16 __user *)p);
+ *val = vringh16_to_cpu(vrh, v);
+ return rc;
}
-static inline int putu16_user(u16 *p, u16 val)
+static inline int putu16_user(const struct vringh *vrh, __virtio16 *p, u16 val)
{
- return put_user(val, (__force u16 __user *)p);
+ __virtio16 v = cpu_to_vringh16(vrh, val);
+ return put_user(v, (__force __virtio16 __user *)p);
}
static inline int copydesc_user(void *dst, const void *src, size_t len)
@@ -589,6 +613,7 @@ int vringh_init_user(struct vringh *vrh, u64 features,
return -EINVAL;
}
+ vrh->little_endian = (features & (1ULL << VIRTIO_F_VERSION_1));
vrh->event_indices = (features & (1 << VIRTIO_RING_F_EVENT_IDX));
vrh->weak_barriers = weak_barriers;
vrh->completed = 0;
@@ -729,8 +754,8 @@ int vringh_complete_user(struct vringh *vrh, u16 head, u32 len)
{
struct vring_used_elem used;
- used.id = head;
- used.len = len;
+ used.id = cpu_to_vringh32(vrh, head);
+ used.len = cpu_to_vringh32(vrh, len);
return __vringh_complete(vrh, &used, 1, putu16_user, putused_user);
}
EXPORT_SYMBOL(vringh_complete_user);
@@ -792,15 +817,16 @@ int vringh_need_notify_user(struct vringh *vrh)
EXPORT_SYMBOL(vringh_need_notify_user);
/* Kernelspace access helpers. */
-static inline int getu16_kern(u16 *val, const u16 *p)
+static inline int getu16_kern(const struct vringh *vrh,
+ u16 *val, const __virtio16 *p)
{
- *val = ACCESS_ONCE(*p);
+ *val = vringh16_to_cpu(vrh, ACCESS_ONCE(*p));
return 0;
}
-static inline int putu16_kern(u16 *p, u16 val)
+static inline int putu16_kern(const struct vringh *vrh, __virtio16 *p, u16 val)
{
- ACCESS_ONCE(*p) = val;
+ ACCESS_ONCE(*p) = cpu_to_vringh16(vrh, val);
return 0;
}
@@ -848,6 +874,7 @@ int vringh_init_kern(struct vringh *vrh, u64 features,
return -EINVAL;
}
+ vrh->little_endian = (features & (1ULL << VIRTIO_F_VERSION_1));
vrh->event_indices = (features & (1 << VIRTIO_RING_F_EVENT_IDX));
vrh->weak_barriers = weak_barriers;
vrh->completed = 0;
@@ -962,8 +989,8 @@ int vringh_complete_kern(struct vringh *vrh, u16 head, u32 len)
{
struct vring_used_elem used;
- used.id = head;
- used.len = len;
+ used.id = cpu_to_vringh32(vrh, head);
+ used.len = cpu_to_vringh32(vrh, len);
return __vringh_complete(vrh, &used, 1, putu16_kern, putused_kern);
}
--
MST
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