Shunsuke Mie
2022-Dec-27 02:25 UTC
[RFC PATCH 2/9] vringh: remove vringh_iov and unite to vringh_kiov
struct vringh_iov is defined to hold userland addresses. However, to use
common function, __vring_iov, finally the vringh_iov converts to the
vringh_kiov with simple cast. It includes compile time check code to make
sure it can be cast correctly.
To simplify the code, this patch removes the struct vringh_iov and unifies
APIs to struct vringh_kiov.
Signed-off-by: Shunsuke Mie <mie at igel.co.jp>
---
drivers/vhost/vringh.c | 32 ++++++------------------------
include/linux/vringh.h | 45 ++++--------------------------------------
2 files changed, 10 insertions(+), 67 deletions(-)
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 828c29306565..aa3cd27d2384 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -691,8 +691,8 @@ EXPORT_SYMBOL(vringh_init_user);
* calling vringh_iov_cleanup() to release the memory, even on error!
*/
int vringh_getdesc_user(struct vringh *vrh,
- struct vringh_iov *riov,
- struct vringh_iov *wiov,
+ struct vringh_kiov *riov,
+ struct vringh_kiov *wiov,
bool (*getrange)(struct vringh *vrh,
u64 addr, struct vringh_range *r),
u16 *head)
@@ -708,26 +708,6 @@ int vringh_getdesc_user(struct vringh *vrh,
if (err == vrh->vring.num)
return 0;
- /* We need the layouts to be the identical for this to work */
- BUILD_BUG_ON(sizeof(struct vringh_kiov) != sizeof(struct vringh_iov));
- BUILD_BUG_ON(offsetof(struct vringh_kiov, iov) !- offsetof(struct
vringh_iov, iov));
- BUILD_BUG_ON(offsetof(struct vringh_kiov, i) !- offsetof(struct
vringh_iov, i));
- BUILD_BUG_ON(offsetof(struct vringh_kiov, used) !- offsetof(struct
vringh_iov, used));
- BUILD_BUG_ON(offsetof(struct vringh_kiov, max_num) !- offsetof(struct
vringh_iov, max_num));
- BUILD_BUG_ON(sizeof(struct iovec) != sizeof(struct kvec));
- BUILD_BUG_ON(offsetof(struct iovec, iov_base) !- offsetof(struct kvec,
iov_base));
- BUILD_BUG_ON(offsetof(struct iovec, iov_len) !- offsetof(struct kvec,
iov_len));
- BUILD_BUG_ON(sizeof(((struct iovec *)NULL)->iov_base)
- != sizeof(((struct kvec *)NULL)->iov_base));
- BUILD_BUG_ON(sizeof(((struct iovec *)NULL)->iov_len)
- != sizeof(((struct kvec *)NULL)->iov_len));
-
*head = err;
err = __vringh_iov(vrh, *head, (struct vringh_kiov *)riov,
(struct vringh_kiov *)wiov,
@@ -740,14 +720,14 @@ int vringh_getdesc_user(struct vringh *vrh,
EXPORT_SYMBOL(vringh_getdesc_user);
/**
- * vringh_iov_pull_user - copy bytes from vring_iov.
+ * vringh_iov_pull_user - copy bytes from vring_kiov.
* @riov: the riov as passed to vringh_getdesc_user() (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_user(struct vringh_iov *riov, void *dst, size_t len)
+ssize_t vringh_iov_pull_user(struct vringh_kiov *riov, void *dst, size_t len)
{
return vringh_iov_xfer(NULL, (struct vringh_kiov *)riov,
dst, len, xfer_from_user);
@@ -755,14 +735,14 @@ ssize_t vringh_iov_pull_user(struct vringh_iov *riov, void
*dst, size_t len)
EXPORT_SYMBOL(vringh_iov_pull_user);
/**
- * vringh_iov_push_user - copy bytes into vring_iov.
+ * vringh_iov_push_user - copy bytes into vring_kiov.
* @wiov: the wiov as passed to vringh_getdesc_user() (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_user(struct vringh_iov *wiov,
+ssize_t vringh_iov_push_user(struct vringh_kiov *wiov,
const void *src, size_t len)
{
return vringh_iov_xfer(NULL, (struct vringh_kiov *)wiov,
diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index 1991a02c6431..733d948e8123 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -79,18 +79,6 @@ struct vringh_range {
u64 offset;
};
-/**
- * struct vringh_iov - iovec mangler.
- *
- * Mangles iovec in place, and restores it.
- * Remaining data is iov + i, of used - i elements.
- */
-struct vringh_iov {
- struct iovec *iov;
- size_t consumed; /* Within iov[i] */
- unsigned i, used, max_num;
-};
-
/**
* struct vringh_kiov - kvec mangler.
*
@@ -113,44 +101,19 @@ int vringh_init_user(struct vringh *vrh, u64 features,
vring_avail_t __user *avail,
vring_used_t __user *used);
-static inline void vringh_iov_init(struct vringh_iov *iov,
- struct iovec *iovec, unsigned num)
-{
- iov->used = iov->i = 0;
- iov->consumed = 0;
- iov->max_num = num;
- iov->iov = iovec;
-}
-
-static inline void vringh_iov_reset(struct vringh_iov *iov)
-{
- iov->iov[iov->i].iov_len += iov->consumed;
- iov->iov[iov->i].iov_base -= iov->consumed;
- iov->consumed = 0;
- iov->i = 0;
-}
-
-static inline void vringh_iov_cleanup(struct vringh_iov *iov)
-{
- if (iov->max_num & VRINGH_IOV_ALLOCATED)
- kfree(iov->iov);
- iov->max_num = iov->used = iov->i = iov->consumed = 0;
- iov->iov = NULL;
-}
-
/* Convert a descriptor into iovecs. */
int vringh_getdesc_user(struct vringh *vrh,
- struct vringh_iov *riov,
- struct vringh_iov *wiov,
+ struct vringh_kiov *riov,
+ struct vringh_kiov *wiov,
bool (*getrange)(struct vringh *vrh,
u64 addr, struct vringh_range *r),
u16 *head);
/* Copy bytes from readable vsg, consuming it (and incrementing wiov->i). */
-ssize_t vringh_iov_pull_user(struct vringh_iov *riov, void *dst, size_t len);
+ssize_t vringh_iov_pull_user(struct vringh_kiov *riov, void *dst, size_t len);
/* Copy bytes into writable vsg, consuming it (and incrementing wiov->i). */
-ssize_t vringh_iov_push_user(struct vringh_iov *wiov,
+ssize_t vringh_iov_push_user(struct vringh_kiov *wiov,
const void *src, size_t len);
/* Mark a descriptor as used. */
--
2.25.1
Jason Wang
2022-Dec-27 06:04 UTC
[RFC PATCH 2/9] vringh: remove vringh_iov and unite to vringh_kiov
On Tue, Dec 27, 2022 at 10:25 AM Shunsuke Mie <mie at igel.co.jp> wrote:> > struct vringh_iov is defined to hold userland addresses. However, to use > common function, __vring_iov, finally the vringh_iov converts to the > vringh_kiov with simple cast. It includes compile time check code to make > sure it can be cast correctly. > > To simplify the code, this patch removes the struct vringh_iov and unifies > APIs to struct vringh_kiov. > > Signed-off-by: Shunsuke Mie <mie at igel.co.jp>While at this, I wonder if we need to go further, that is, switch to using an iov iterator instead of a vringh customized one. Thanks> --- > drivers/vhost/vringh.c | 32 ++++++------------------------ > include/linux/vringh.h | 45 ++++-------------------------------------- > 2 files changed, 10 insertions(+), 67 deletions(-) > > diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c > index 828c29306565..aa3cd27d2384 100644 > --- a/drivers/vhost/vringh.c > +++ b/drivers/vhost/vringh.c > @@ -691,8 +691,8 @@ EXPORT_SYMBOL(vringh_init_user); > * calling vringh_iov_cleanup() to release the memory, even on error! > */ > int vringh_getdesc_user(struct vringh *vrh, > - struct vringh_iov *riov, > - struct vringh_iov *wiov, > + struct vringh_kiov *riov, > + struct vringh_kiov *wiov, > bool (*getrange)(struct vringh *vrh, > u64 addr, struct vringh_range *r), > u16 *head) > @@ -708,26 +708,6 @@ int vringh_getdesc_user(struct vringh *vrh, > if (err == vrh->vring.num) > return 0; > > - /* We need the layouts to be the identical for this to work */ > - BUILD_BUG_ON(sizeof(struct vringh_kiov) != sizeof(struct vringh_iov)); > - BUILD_BUG_ON(offsetof(struct vringh_kiov, iov) !> - offsetof(struct vringh_iov, iov)); > - BUILD_BUG_ON(offsetof(struct vringh_kiov, i) !> - offsetof(struct vringh_iov, i)); > - BUILD_BUG_ON(offsetof(struct vringh_kiov, used) !> - offsetof(struct vringh_iov, used)); > - BUILD_BUG_ON(offsetof(struct vringh_kiov, max_num) !> - offsetof(struct vringh_iov, max_num)); > - BUILD_BUG_ON(sizeof(struct iovec) != sizeof(struct kvec)); > - BUILD_BUG_ON(offsetof(struct iovec, iov_base) !> - offsetof(struct kvec, iov_base)); > - BUILD_BUG_ON(offsetof(struct iovec, iov_len) !> - offsetof(struct kvec, iov_len)); > - BUILD_BUG_ON(sizeof(((struct iovec *)NULL)->iov_base) > - != sizeof(((struct kvec *)NULL)->iov_base)); > - BUILD_BUG_ON(sizeof(((struct iovec *)NULL)->iov_len) > - != sizeof(((struct kvec *)NULL)->iov_len)); > - > *head = err; > err = __vringh_iov(vrh, *head, (struct vringh_kiov *)riov, > (struct vringh_kiov *)wiov, > @@ -740,14 +720,14 @@ int vringh_getdesc_user(struct vringh *vrh, > EXPORT_SYMBOL(vringh_getdesc_user); > > /** > - * vringh_iov_pull_user - copy bytes from vring_iov. > + * vringh_iov_pull_user - copy bytes from vring_kiov. > * @riov: the riov as passed to vringh_getdesc_user() (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_user(struct vringh_iov *riov, void *dst, size_t len) > +ssize_t vringh_iov_pull_user(struct vringh_kiov *riov, void *dst, size_t len) > { > return vringh_iov_xfer(NULL, (struct vringh_kiov *)riov, > dst, len, xfer_from_user); > @@ -755,14 +735,14 @@ ssize_t vringh_iov_pull_user(struct vringh_iov *riov, void *dst, size_t len) > EXPORT_SYMBOL(vringh_iov_pull_user); > > /** > - * vringh_iov_push_user - copy bytes into vring_iov. > + * vringh_iov_push_user - copy bytes into vring_kiov. > * @wiov: the wiov as passed to vringh_getdesc_user() (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_user(struct vringh_iov *wiov, > +ssize_t vringh_iov_push_user(struct vringh_kiov *wiov, > const void *src, size_t len) > { > return vringh_iov_xfer(NULL, (struct vringh_kiov *)wiov, > diff --git a/include/linux/vringh.h b/include/linux/vringh.h > index 1991a02c6431..733d948e8123 100644 > --- a/include/linux/vringh.h > +++ b/include/linux/vringh.h > @@ -79,18 +79,6 @@ struct vringh_range { > u64 offset; > }; > > -/** > - * struct vringh_iov - iovec mangler. > - * > - * Mangles iovec in place, and restores it. > - * Remaining data is iov + i, of used - i elements. > - */ > -struct vringh_iov { > - struct iovec *iov; > - size_t consumed; /* Within iov[i] */ > - unsigned i, used, max_num; > -}; > - > /** > * struct vringh_kiov - kvec mangler. > * > @@ -113,44 +101,19 @@ int vringh_init_user(struct vringh *vrh, u64 features, > vring_avail_t __user *avail, > vring_used_t __user *used); > > -static inline void vringh_iov_init(struct vringh_iov *iov, > - struct iovec *iovec, unsigned num) > -{ > - iov->used = iov->i = 0; > - iov->consumed = 0; > - iov->max_num = num; > - iov->iov = iovec; > -} > - > -static inline void vringh_iov_reset(struct vringh_iov *iov) > -{ > - iov->iov[iov->i].iov_len += iov->consumed; > - iov->iov[iov->i].iov_base -= iov->consumed; > - iov->consumed = 0; > - iov->i = 0; > -} > - > -static inline void vringh_iov_cleanup(struct vringh_iov *iov) > -{ > - if (iov->max_num & VRINGH_IOV_ALLOCATED) > - kfree(iov->iov); > - iov->max_num = iov->used = iov->i = iov->consumed = 0; > - iov->iov = NULL; > -} > - > /* Convert a descriptor into iovecs. */ > int vringh_getdesc_user(struct vringh *vrh, > - struct vringh_iov *riov, > - struct vringh_iov *wiov, > + struct vringh_kiov *riov, > + struct vringh_kiov *wiov, > bool (*getrange)(struct vringh *vrh, > u64 addr, struct vringh_range *r), > u16 *head); > > /* Copy bytes from readable vsg, consuming it (and incrementing wiov->i). */ > -ssize_t vringh_iov_pull_user(struct vringh_iov *riov, void *dst, size_t len); > +ssize_t vringh_iov_pull_user(struct vringh_kiov *riov, void *dst, size_t len); > > /* Copy bytes into writable vsg, consuming it (and incrementing wiov->i). */ > -ssize_t vringh_iov_push_user(struct vringh_iov *wiov, > +ssize_t vringh_iov_push_user(struct vringh_kiov *wiov, > const void *src, size_t len); > > /* Mark a descriptor as used. */ > -- > 2.25.1 >