From bedbef8ad3e75a304af6361af235302bcc61d06b Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 14 May 2024 06:39:01 +0000
Subject: [PATCH] 修改内核路径
---
kernel/drivers/vhost/vringh.c | 450 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 421 insertions(+), 29 deletions(-)
diff --git a/kernel/drivers/vhost/vringh.c b/kernel/drivers/vhost/vringh.c
index 97aa9b8..48f4ec2 100644
--- a/kernel/drivers/vhost/vringh.c
+++ b/kernel/drivers/vhost/vringh.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Helpers for the host side of a virtio ring.
*
@@ -12,6 +13,11 @@
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/export.h>
+#if IS_REACHABLE(CONFIG_VHOST_IOTLB)
+#include <linux/bvec.h>
+#include <linux/highmem.h>
+#include <linux/vhost_iotlb.h>
+#endif
#include <uapi/linux/virtio_config.h>
static __printf(1,2) __cold void vringh_bad(const char *fmt, ...)
@@ -70,9 +76,11 @@
}
/* Copy some bytes to/from the iovec. Returns num copied. */
-static inline ssize_t vringh_iov_xfer(struct vringh_kiov *iov,
+static inline ssize_t vringh_iov_xfer(struct vringh *vrh,
+ struct vringh_kiov *iov,
void *ptr, size_t len,
- int (*xfer)(void *addr, void *ptr,
+ int (*xfer)(const struct vringh *vrh,
+ void *addr, void *ptr,
size_t len))
{
int err, done = 0;
@@ -81,7 +89,7 @@
size_t partlen;
partlen = min(iov->iov[iov->i].iov_len, len);
- err = xfer(iov->iov[iov->i].iov_base, ptr, partlen);
+ err = xfer(vrh, iov->iov[iov->i].iov_base, ptr, partlen);
if (err)
return err;
done += partlen;
@@ -95,6 +103,7 @@
/* Fix up old iov element then increment. */
iov->iov[iov->i].iov_len = iov->consumed;
iov->iov[iov->i].iov_base -= iov->consumed;
+
iov->consumed = 0;
iov->i++;
@@ -226,7 +235,8 @@
u64 addr,
struct vringh_range *r),
struct vringh_range *range,
- int (*copy)(void *dst, const void *src, size_t len))
+ int (*copy)(const struct vringh *vrh,
+ void *dst, const void *src, size_t len))
{
size_t part, len = sizeof(struct vring_desc);
@@ -240,7 +250,7 @@
if (!rcheck(vrh, addr, &part, range, getrange))
return -EINVAL;
- err = copy(dst, src, part);
+ err = copy(vrh, dst, src, part);
if (err)
return err;
@@ -261,9 +271,10 @@
struct vringh_range *)),
bool (*getrange)(struct vringh *, u64, struct vringh_range *),
gfp_t gfp,
- int (*copy)(void *dst, const void *src, size_t len))
+ int (*copy)(const struct vringh *vrh,
+ void *dst, const void *src, size_t len))
{
- int err, count = 0, up_next, desc_max;
+ int err, count = 0, indirect_count = 0, up_next, desc_max;
struct vring_desc desc, *descs;
struct vringh_range range = { -1ULL, 0 }, slowrange;
bool slow = false;
@@ -291,7 +302,7 @@
err = slow_copy(vrh, &desc, &descs[i], rcheck, getrange,
&slowrange, copy);
else
- err = copy(&desc, &descs[i], sizeof(desc));
+ err = copy(vrh, &desc, &descs[i], sizeof(desc));
if (unlikely(err))
goto fail;
@@ -320,7 +331,12 @@
continue;
}
- if (count++ == vrh->vring.num) {
+ if (up_next == -1)
+ count++;
+ else
+ indirect_count++;
+
+ if (count > vrh->vring.num || indirect_count > desc_max) {
vringh_bad("Descriptor loop in %p", descs);
err = -ELOOP;
goto fail;
@@ -382,6 +398,7 @@
i = return_from_indirect(vrh, &up_next,
&descs, &desc_max);
slow = false;
+ indirect_count = 0;
} else
break;
}
@@ -404,7 +421,8 @@
unsigned int num_used,
int (*putu16)(const struct vringh *vrh,
__virtio16 *p, u16 val),
- int (*putused)(struct vring_used_elem *dst,
+ int (*putused)(const struct vringh *vrh,
+ struct vring_used_elem *dst,
const struct vring_used_elem
*src, unsigned num))
{
@@ -420,12 +438,12 @@
/* Compiler knows num_used == 1 sometimes, hence extra check */
if (num_used > 1 && unlikely(off + num_used >= vrh->vring.num)) {
u16 part = vrh->vring.num - off;
- err = putused(&used_ring->ring[off], used, part);
+ err = putused(vrh, &used_ring->ring[off], used, part);
if (!err)
- err = putused(&used_ring->ring[0], used + part,
+ err = putused(vrh, &used_ring->ring[0], used + part,
num_used - part);
} else
- err = putused(&used_ring->ring[off], used, num_used);
+ err = putused(vrh, &used_ring->ring[off], used, num_used);
if (err) {
vringh_bad("Failed to write %u used entries %u at %p",
@@ -564,13 +582,15 @@
return put_user(v, (__force __virtio16 __user *)p);
}
-static inline int copydesc_user(void *dst, const void *src, size_t len)
+static inline int copydesc_user(const struct vringh *vrh,
+ void *dst, const void *src, size_t len)
{
return copy_from_user(dst, (__force void __user *)src, len) ?
-EFAULT : 0;
}
-static inline int putused_user(struct vring_used_elem *dst,
+static inline int putused_user(const struct vringh *vrh,
+ struct vring_used_elem *dst,
const struct vring_used_elem *src,
unsigned int num)
{
@@ -578,13 +598,15 @@
sizeof(*dst) * num) ? -EFAULT : 0;
}
-static inline int xfer_from_user(void *src, void *dst, size_t len)
+static inline int xfer_from_user(const struct vringh *vrh, void *src,
+ void *dst, size_t len)
{
return copy_from_user(dst, (__force void __user *)src, len) ?
-EFAULT : 0;
}
-static inline int xfer_to_user(void *dst, void *src, size_t len)
+static inline int xfer_to_user(const struct vringh *vrh,
+ void *dst, void *src, size_t len)
{
return copy_to_user((__force void __user *)dst, src, len) ?
-EFAULT : 0;
@@ -605,9 +627,9 @@
*/
int vringh_init_user(struct vringh *vrh, u64 features,
unsigned int num, bool weak_barriers,
- struct vring_desc __user *desc,
- struct vring_avail __user *avail,
- struct vring_used __user *used)
+ vring_desc_t __user *desc,
+ vring_avail_t __user *avail,
+ vring_used_t __user *used)
{
/* Sane power of 2 please! */
if (!num || num > 0xffff || (num & (num - 1))) {
@@ -706,7 +728,7 @@
*/
ssize_t vringh_iov_pull_user(struct vringh_iov *riov, void *dst, size_t len)
{
- return vringh_iov_xfer((struct vringh_kiov *)riov,
+ return vringh_iov_xfer(NULL, (struct vringh_kiov *)riov,
dst, len, xfer_from_user);
}
EXPORT_SYMBOL(vringh_iov_pull_user);
@@ -714,7 +736,7 @@
/**
* vringh_iov_push_user - copy bytes into vring_iov.
* @wiov: the wiov as passed to vringh_getdesc_user() (updated as we consume)
- * @dst: the place to copy.
+ * @src: the place to copy from.
* @len: the maximum length to copy.
*
* Returns the bytes copied <= len or a negative errno.
@@ -722,7 +744,7 @@
ssize_t vringh_iov_push_user(struct vringh_iov *wiov,
const void *src, size_t len)
{
- return vringh_iov_xfer((struct vringh_kiov *)wiov,
+ return vringh_iov_xfer(NULL, (struct vringh_kiov *)wiov,
(void *)src, len, xfer_to_user);
}
EXPORT_SYMBOL(vringh_iov_push_user);
@@ -832,13 +854,15 @@
return 0;
}
-static inline int copydesc_kern(void *dst, const void *src, size_t len)
+static inline int copydesc_kern(const struct vringh *vrh,
+ void *dst, const void *src, size_t len)
{
memcpy(dst, src, len);
return 0;
}
-static inline int putused_kern(struct vring_used_elem *dst,
+static inline int putused_kern(const struct vringh *vrh,
+ struct vring_used_elem *dst,
const struct vring_used_elem *src,
unsigned int num)
{
@@ -846,7 +870,15 @@
return 0;
}
-static inline int xfer_kern(void *src, void *dst, size_t len)
+static inline int xfer_kern(const struct vringh *vrh, void *src,
+ void *dst, size_t len)
+{
+ memcpy(dst, src, len);
+ return 0;
+}
+
+static inline int kern_xfer(const struct vringh *vrh, void *dst,
+ void *src, size_t len)
{
memcpy(dst, src, len);
return 0;
@@ -943,14 +975,14 @@
*/
ssize_t vringh_iov_pull_kern(struct vringh_kiov *riov, void *dst, size_t len)
{
- return vringh_iov_xfer(riov, dst, len, xfer_kern);
+ return vringh_iov_xfer(NULL, riov, dst, len, xfer_kern);
}
EXPORT_SYMBOL(vringh_iov_pull_kern);
/**
* vringh_iov_push_kern - copy bytes into vring_iov.
* @wiov: the wiov as passed to vringh_getdesc_kern() (updated as we consume)
- * @dst: the place to copy.
+ * @src: the place to copy from.
* @len: the maximum length to copy.
*
* Returns the bytes copied <= len or a negative errno.
@@ -958,7 +990,7 @@
ssize_t vringh_iov_push_kern(struct vringh_kiov *wiov,
const void *src, size_t len)
{
- return vringh_iov_xfer(wiov, (void *)src, len, xfer_kern);
+ return vringh_iov_xfer(NULL, wiov, (void *)src, len, kern_xfer);
}
EXPORT_SYMBOL(vringh_iov_push_kern);
@@ -1036,4 +1068,364 @@
}
EXPORT_SYMBOL(vringh_need_notify_kern);
+#if IS_REACHABLE(CONFIG_VHOST_IOTLB)
+
+static int iotlb_translate(const struct vringh *vrh,
+ u64 addr, u64 len, struct bio_vec iov[],
+ int iov_size, u32 perm)
+{
+ struct vhost_iotlb_map *map;
+ struct vhost_iotlb *iotlb = vrh->iotlb;
+ int ret = 0;
+ u64 s = 0, last = addr + len - 1;
+
+ while (len > s) {
+ u64 size, pa, pfn;
+
+ if (unlikely(ret >= iov_size)) {
+ ret = -ENOBUFS;
+ break;
+ }
+
+ map = vhost_iotlb_itree_first(iotlb, addr, last);
+ if (!map || map->start > addr) {
+ ret = -EINVAL;
+ break;
+ } else if (!(map->perm & perm)) {
+ ret = -EPERM;
+ break;
+ }
+
+ size = map->size - addr + map->start;
+ pa = map->addr + addr - map->start;
+ pfn = pa >> PAGE_SHIFT;
+ iov[ret].bv_page = pfn_to_page(pfn);
+ iov[ret].bv_len = min(len - s, size);
+ iov[ret].bv_offset = pa & (PAGE_SIZE - 1);
+ s += size;
+ addr += size;
+ ++ret;
+ }
+
+ return ret;
+}
+
+static inline int copy_from_iotlb(const struct vringh *vrh, void *dst,
+ void *src, size_t len)
+{
+ struct iov_iter iter;
+ struct bio_vec iov[16];
+ int ret;
+
+ ret = iotlb_translate(vrh, (u64)(uintptr_t)src,
+ len, iov, 16, VHOST_MAP_RO);
+ if (ret < 0)
+ return ret;
+
+ iov_iter_bvec(&iter, READ, iov, ret, len);
+
+ ret = copy_from_iter(dst, len, &iter);
+
+ return ret;
+}
+
+static inline int copy_to_iotlb(const struct vringh *vrh, void *dst,
+ void *src, size_t len)
+{
+ struct iov_iter iter;
+ struct bio_vec iov[16];
+ int ret;
+
+ ret = iotlb_translate(vrh, (u64)(uintptr_t)dst,
+ len, iov, 16, VHOST_MAP_WO);
+ if (ret < 0)
+ return ret;
+
+ iov_iter_bvec(&iter, WRITE, iov, ret, len);
+
+ return copy_to_iter(src, len, &iter);
+}
+
+static inline int getu16_iotlb(const struct vringh *vrh,
+ u16 *val, const __virtio16 *p)
+{
+ struct bio_vec iov;
+ void *kaddr, *from;
+ int ret;
+
+ /* Atomic read is needed for getu16 */
+ ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p),
+ &iov, 1, VHOST_MAP_RO);
+ if (ret < 0)
+ return ret;
+
+ kaddr = kmap_atomic(iov.bv_page);
+ from = kaddr + iov.bv_offset;
+ *val = vringh16_to_cpu(vrh, READ_ONCE(*(__virtio16 *)from));
+ kunmap_atomic(kaddr);
+
+ return 0;
+}
+
+static inline int putu16_iotlb(const struct vringh *vrh,
+ __virtio16 *p, u16 val)
+{
+ struct bio_vec iov;
+ void *kaddr, *to;
+ int ret;
+
+ /* Atomic write is needed for putu16 */
+ ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p),
+ &iov, 1, VHOST_MAP_WO);
+ if (ret < 0)
+ return ret;
+
+ kaddr = kmap_atomic(iov.bv_page);
+ to = kaddr + iov.bv_offset;
+ WRITE_ONCE(*(__virtio16 *)to, cpu_to_vringh16(vrh, val));
+ kunmap_atomic(kaddr);
+
+ return 0;
+}
+
+static inline int copydesc_iotlb(const struct vringh *vrh,
+ void *dst, const void *src, size_t len)
+{
+ int ret;
+
+ ret = copy_from_iotlb(vrh, dst, (void *)src, len);
+ if (ret != len)
+ return -EFAULT;
+
+ return 0;
+}
+
+static inline int xfer_from_iotlb(const struct vringh *vrh, void *src,
+ void *dst, size_t len)
+{
+ int ret;
+
+ ret = copy_from_iotlb(vrh, dst, src, len);
+ if (ret != len)
+ return -EFAULT;
+
+ return 0;
+}
+
+static inline int xfer_to_iotlb(const struct vringh *vrh,
+ void *dst, void *src, size_t len)
+{
+ int ret;
+
+ ret = copy_to_iotlb(vrh, dst, src, len);
+ if (ret != len)
+ return -EFAULT;
+
+ return 0;
+}
+
+static inline int putused_iotlb(const struct vringh *vrh,
+ struct vring_used_elem *dst,
+ const struct vring_used_elem *src,
+ unsigned int num)
+{
+ int size = num * sizeof(*dst);
+ int ret;
+
+ ret = copy_to_iotlb(vrh, dst, (void *)src, num * sizeof(*dst));
+ if (ret != size)
+ return -EFAULT;
+
+ return 0;
+}
+
+/**
+ * vringh_init_iotlb - initialize a vringh for a ring with IOTLB.
+ * @vrh: the vringh to initialize.
+ * @features: the feature bits for this ring.
+ * @num: the number of elements.
+ * @weak_barriers: true if we only need memory barriers, not I/O.
+ * @desc: the userpace descriptor pointer.
+ * @avail: the userpace avail pointer.
+ * @used: the userpace used pointer.
+ *
+ * Returns an error if num is invalid.
+ */
+int vringh_init_iotlb(struct vringh *vrh, u64 features,
+ unsigned int num, bool weak_barriers,
+ struct vring_desc *desc,
+ struct vring_avail *avail,
+ struct vring_used *used)
+{
+ return vringh_init_kern(vrh, features, num, weak_barriers,
+ desc, avail, used);
+}
+EXPORT_SYMBOL(vringh_init_iotlb);
+
+/**
+ * vringh_set_iotlb - initialize a vringh for a ring with IOTLB.
+ * @vrh: the vring
+ * @iotlb: iotlb associated with this vring
+ */
+void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb)
+{
+ vrh->iotlb = iotlb;
+}
+EXPORT_SYMBOL(vringh_set_iotlb);
+
+/**
+ * vringh_getdesc_iotlb - get next available descriptor from ring with
+ * IOTLB.
+ * @vrh: the kernelspace vring.
+ * @riov: where to put the readable descriptors (or NULL)
+ * @wiov: where to put the writable descriptors (or NULL)
+ * @head: head index we received, for passing to vringh_complete_iotlb().
+ * @gfp: flags for allocating larger riov/wiov.
+ *
+ * Returns 0 if there was no descriptor, 1 if there was, or -errno.
+ *
+ * Note that on error return, you can tell the difference between an
+ * invalid ring and a single invalid descriptor: in the former case,
+ * *head will be vrh->vring.num. You may be able to ignore an invalid
+ * descriptor, but there's not much you can do with an invalid ring.
+ *
+ * Note that you may need to clean up riov and wiov, even on error!
+ */
+int vringh_getdesc_iotlb(struct vringh *vrh,
+ struct vringh_kiov *riov,
+ struct vringh_kiov *wiov,
+ u16 *head,
+ gfp_t gfp)
+{
+ int err;
+
+ err = __vringh_get_head(vrh, getu16_iotlb, &vrh->last_avail_idx);
+ if (err < 0)
+ return err;
+
+ /* Empty... */
+ if (err == vrh->vring.num)
+ return 0;
+
+ *head = err;
+ err = __vringh_iov(vrh, *head, riov, wiov, no_range_check, NULL,
+ gfp, copydesc_iotlb);
+ if (err)
+ return err;
+
+ return 1;
+}
+EXPORT_SYMBOL(vringh_getdesc_iotlb);
+
+/**
+ * vringh_iov_pull_iotlb - copy bytes from vring_iov.
+ * @vrh: the vring.
+ * @riov: the riov as passed to vringh_getdesc_iotlb() (updated as we consume)
+ * @dst: the place to copy.
+ * @len: the maximum length to copy.
+ *
+ * Returns the bytes copied <= len or a negative errno.
+ */
+ssize_t vringh_iov_pull_iotlb(struct vringh *vrh,
+ struct vringh_kiov *riov,
+ void *dst, size_t len)
+{
+ return vringh_iov_xfer(vrh, riov, dst, len, xfer_from_iotlb);
+}
+EXPORT_SYMBOL(vringh_iov_pull_iotlb);
+
+/**
+ * vringh_iov_push_iotlb - copy bytes into vring_iov.
+ * @vrh: the vring.
+ * @wiov: the wiov as passed to vringh_getdesc_iotlb() (updated as we consume)
+ * @src: the place to copy from.
+ * @len: the maximum length to copy.
+ *
+ * Returns the bytes copied <= len or a negative errno.
+ */
+ssize_t vringh_iov_push_iotlb(struct vringh *vrh,
+ struct vringh_kiov *wiov,
+ const void *src, size_t len)
+{
+ return vringh_iov_xfer(vrh, wiov, (void *)src, len, xfer_to_iotlb);
+}
+EXPORT_SYMBOL(vringh_iov_push_iotlb);
+
+/**
+ * vringh_abandon_iotlb - we've decided not to handle the descriptor(s).
+ * @vrh: the vring.
+ * @num: the number of descriptors to put back (ie. num
+ * vringh_get_iotlb() to undo).
+ *
+ * The next vringh_get_iotlb() will return the old descriptor(s) again.
+ */
+void vringh_abandon_iotlb(struct vringh *vrh, unsigned int num)
+{
+ /* We only update vring_avail_event(vr) when we want to be notified,
+ * so we haven't changed that yet.
+ */
+ vrh->last_avail_idx -= num;
+}
+EXPORT_SYMBOL(vringh_abandon_iotlb);
+
+/**
+ * vringh_complete_iotlb - we've finished with descriptor, publish it.
+ * @vrh: the vring.
+ * @head: the head as filled in by vringh_getdesc_iotlb.
+ * @len: the length of data we have written.
+ *
+ * You should check vringh_need_notify_iotlb() after one or more calls
+ * to this function.
+ */
+int vringh_complete_iotlb(struct vringh *vrh, u16 head, u32 len)
+{
+ struct vring_used_elem used;
+
+ used.id = cpu_to_vringh32(vrh, head);
+ used.len = cpu_to_vringh32(vrh, len);
+
+ return __vringh_complete(vrh, &used, 1, putu16_iotlb, putused_iotlb);
+}
+EXPORT_SYMBOL(vringh_complete_iotlb);
+
+/**
+ * vringh_notify_enable_iotlb - we want to know if something changes.
+ * @vrh: the vring.
+ *
+ * This always enables notifications, but returns false if there are
+ * now more buffers available in the vring.
+ */
+bool vringh_notify_enable_iotlb(struct vringh *vrh)
+{
+ return __vringh_notify_enable(vrh, getu16_iotlb, putu16_iotlb);
+}
+EXPORT_SYMBOL(vringh_notify_enable_iotlb);
+
+/**
+ * vringh_notify_disable_iotlb - don't tell us if something changes.
+ * @vrh: the vring.
+ *
+ * This is our normal running state: we disable and then only enable when
+ * we're going to sleep.
+ */
+void vringh_notify_disable_iotlb(struct vringh *vrh)
+{
+ __vringh_notify_disable(vrh, putu16_iotlb);
+}
+EXPORT_SYMBOL(vringh_notify_disable_iotlb);
+
+/**
+ * vringh_need_notify_iotlb - must we tell the other side about used buffers?
+ * @vrh: the vring we've called vringh_complete_iotlb() on.
+ *
+ * Returns -errno or 0 if we don't need to tell the other side, 1 if we do.
+ */
+int vringh_need_notify_iotlb(struct vringh *vrh)
+{
+ return __vringh_need_notify(vrh, getu16_iotlb);
+}
+EXPORT_SYMBOL(vringh_need_notify_iotlb);
+
+#endif
+
MODULE_LICENSE("GPL");
--
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