search for: vring_used_align_size

...1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index eec2f11..080422f 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -819,7 +819,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp) BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || - (a.log_guest_addr & (sizeof(u64) - 1))) { + (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) { r = -EINVAL; break; } -- MST

...1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index eec2f11..080422f 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -819,7 +819,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp) BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || - (a.log_guest_addr & (sizeof(u64) - 1))) { + (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) { r = -EINVAL; break; } -- MST

...propriate Reported-by: kbuild test robot <lkp at intel.com> All errors (new ones prefixed by >>): In file included from <command-line>:32:0: ./usr/include/linux/virtio_ring.h:91:31: error: expected declaration specifiers or '...' before numeric constant #define VRING_USED_ALIGN_SIZE 4 ^ ./usr/include/linux/virtio_ring.h:120:42: note: in expansion of macro 'VRING_USED_ALIGN_SIZE' typedef struct vring_used_elem __aligned(VRING_USED_ALIGN_SIZE) ^~~~~~~~~~~~~~~~~~~~~ >> ./usr/includ...

...@@ -86,6 +86,13 @@ * at the end of the used ring. Guest should ignore the used->flags field. */ #define VIRTIO_RING_F_EVENT_IDX 29 +/* Alignment requirements for vring elements. + * When using pre-virtio 1.0 layout, these fall out naturally. + */ +#define VRING_AVAIL_ALIGN_SIZE 2 +#define VRING_USED_ALIGN_SIZE 4 +#define VRING_DESC_ALIGN_SIZE 16 + /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ struct vring_desc { /* Address (guest-physical). */ @@ -112,29 +119,43 @@ struct vring_used_elem { __virtio32 len; }; +typedef struct vring_used_elem __aligned(VRI...

...@@ -86,6 +86,13 @@ * at the end of the used ring. Guest should ignore the used->flags field. */ #define VIRTIO_RING_F_EVENT_IDX 29 +/* Alignment requirements for vring elements. + * When using pre-virtio 1.0 layout, these fall out naturally. + */ +#define VRING_AVAIL_ALIGN_SIZE 2 +#define VRING_USED_ALIGN_SIZE 4 +#define VRING_DESC_ALIGN_SIZE 16 + /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ struct vring_desc { /* Address (guest-physical). */ @@ -112,29 +119,43 @@ struct vring_used_elem { __virtio32 len; }; +typedef struct vring_used_elem __aligned(VRI...

...@@ -86,6 +86,13 @@ * at the end of the used ring. Guest should ignore the used->flags field. */ #define VIRTIO_RING_F_EVENT_IDX 29 +/* Alignment requirements for vring elements. + * When using pre-virtio 1.0 layout, these fall out naturally. + */ +#define VRING_AVAIL_ALIGN_SIZE 2 +#define VRING_USED_ALIGN_SIZE 4 +#define VRING_DESC_ALIGN_SIZE 16 + /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ struct vring_desc { /* Address (guest-physical). */ @@ -112,29 +119,46 @@ struct vring_used_elem { __virtio32 len; }; +typedef struct vring_used_elem __attribute__...

...@@ -86,6 +86,13 @@ * at the end of the used ring. Guest should ignore the used->flags field. */ #define VIRTIO_RING_F_EVENT_IDX 29 +/* Alignment requirements for vring elements. + * When using pre-virtio 1.0 layout, these fall out naturally. + */ +#define VRING_AVAIL_ALIGN_SIZE 2 +#define VRING_USED_ALIGN_SIZE 4 +#define VRING_DESC_ALIGN_SIZE 16 + /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ struct vring_desc { /* Address (guest-physical). */ @@ -112,29 +119,46 @@ struct vring_used_elem { __virtio32 len; }; +typedef struct vring_used_elem __attribute__...

...the used ring. Guest should ignore the used->flags field. */ > #define VIRTIO_RING_F_EVENT_IDX 29 > > +/* Alignment requirements for vring elements. > + * When using pre-virtio 1.0 layout, these fall out naturally. > + */ > +#define VRING_AVAIL_ALIGN_SIZE 2 > +#define VRING_USED_ALIGN_SIZE 4 > +#define VRING_DESC_ALIGN_SIZE 16 > + > /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ > struct vring_desc { > /* Address (guest-physical). */ > @@ -112,29 +119,43 @@ struct vring_used_elem { > __virtio32 len; > }; &g...

...the used ring. Guest should ignore the used->flags field. */ > #define VIRTIO_RING_F_EVENT_IDX 29 > > +/* Alignment requirements for vring elements. > + * When using pre-virtio 1.0 layout, these fall out naturally. > + */ > +#define VRING_AVAIL_ALIGN_SIZE 2 > +#define VRING_USED_ALIGN_SIZE 4 > +#define VRING_DESC_ALIGN_SIZE 16 > + > /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ > struct vring_desc { > /* Address (guest-physical). */ > @@ -112,29 +119,46 @@ struct vring_used_elem { > __virtio32 len; > }; &g...

...amp; (sizeof *vq->used->ring - 1)) || - (a.log_guest_addr & (sizeof *vq->used->ring - 1))) { + + /* Make sure it's safe to cast pointers to vring types. */ + BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE); + BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); + if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || + (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || + (a.log_guest_addr & (sizeof(u64) - 1))) { r = -EINVAL; break; } -- MST

...amp; (sizeof *vq->used->ring - 1)) || - (a.log_guest_addr & (sizeof *vq->used->ring - 1))) { + + /* Make sure it's safe to cast pointers to vring types. */ + BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE); + BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); + if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || + (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || + (a.log_guest_addr & (sizeof(u64) - 1))) { r = -EINVAL; break; } -- MST

...; }; -struct vring { - unsigned int num; - - struct vring_desc *desc; - - struct vring_avail *avail; - - struct vring_used *used; -}; - /* Alignment requirements for vring elements. * When using pre-virtio 1.0 layout, these fall out naturally. */ @@ -135,6 +125,34 @@ struct vring { #define VRING_USED_ALIGN_SIZE 4 #define VRING_DESC_ALIGN_SIZE 16 +/* + * The ring element addresses are passed between components with different + * alignments assumptions. Thus, we might need to decrease the compiler-selected + * alignment, and so must use a typedef to make sure the __aligned attribute + * actually takes ho...

...:41PM +0800, Tiwei Bie wrote: > Introduce VIRTIO_RING_NO_LEGACY to support disabling legacy > macros and layout definitions. > > Suggested-by: Michael S. Tsirkin <mst at redhat.com> > Signed-off-by: Tiwei Bie <tiwei.bie at intel.com> > --- > VRING_AVAIL_ALIGN_SIZE, VRING_USED_ALIGN_SIZE and VRING_DESC_ALIGN_SIZE > are not pre-virtio 1.0, but can also be disabled by VIRTIO_RING_NO_LEGACY > in this patch, because their names are not consistent with other names. > Not sure whether this is a good idea. If we want this, we may also want > to define _SPLIT_ version for them....

...nd specifying the packed + * attribute generates a warning. + */ +typedef struct vring_desc __attribute__((aligned(VRING_DESC_ALIGN_SIZE))) + vring_desc_t; +typedef struct vring_avail __attribute__((aligned(VRING_AVAIL_ALIGN_SIZE))) + vring_avail_t; +typedef struct vring_used __attribute__((aligned(VRING_USED_ALIGN_SIZE))) + vring_used_t; + +struct vring { + unsigned int num; + + vring_desc_t *desc; + + vring_avail_t *avail; + + vring_used_t *used; +}; + static inline void vring_init(struct vring *vr, unsigned int num, void *p, unsigned long align) { -- MST

...nd specifying the packed + * attribute generates a warning. + */ +typedef struct vring_desc __attribute__((aligned(VRING_DESC_ALIGN_SIZE))) + vring_desc_t; +typedef struct vring_avail __attribute__((aligned(VRING_AVAIL_ALIGN_SIZE))) + vring_avail_t; +typedef struct vring_used __attribute__((aligned(VRING_USED_ALIGN_SIZE))) + vring_used_t; + +struct vring { + unsigned int num; + + vring_desc_t *desc; + + vring_avail_t *avail; + + vring_used_t *used; +}; + static inline void vring_init(struct vring *vr, unsigned int num, void *p, unsigned long align) { -- MST

...; }; -struct vring { - unsigned int num; - - struct vring_desc *desc; - - struct vring_avail *avail; - - struct vring_used *used; -}; - /* Alignment requirements for vring elements. * When using pre-virtio 1.0 layout, these fall out naturally. */ @@ -135,6 +125,34 @@ struct vring { #define VRING_USED_ALIGN_SIZE 4 #define VRING_DESC_ALIGN_SIZE 16 +/* + * The ring element addresses are passed between components with different + * alignments assumptions. Thus, we might need to decrease the compiler-selected + * alignment, and so must use a typedef to make sure the __aligned attribute + * actually takes ho...

...> > + */ > > +typedef struct vring_desc __attribute__((aligned(VRING_DESC_ALIGN_SIZE))) > > + vring_desc_t; > > +typedef struct vring_avail __attribute__((aligned(VRING_AVAIL_ALIGN_SIZE))) > > + vring_avail_t; > > +typedef struct vring_used __attribute__((aligned(VRING_USED_ALIGN_SIZE))) > > + vring_used_t; > > + > > +struct vring { > > + unsigned int num; > > + > > + vring_desc_t *desc; > > + > > + vring_avail_t *avail; > > + > > + vring_used_t *used; > > +}; > > + > > static inline void vring_init(...

...> > + */ > > +typedef struct vring_desc __attribute__((aligned(VRING_DESC_ALIGN_SIZE))) > > + vring_desc_t; > > +typedef struct vring_avail __attribute__((aligned(VRING_AVAIL_ALIGN_SIZE))) > > + vring_avail_t; > > +typedef struct vring_used __attribute__((aligned(VRING_USED_ALIGN_SIZE))) > > + vring_used_t; > > + > > +struct vring { > > + unsigned int num; > > + > > + vring_desc_t *desc; > > + > > + vring_avail_t *avail; > > + > > + vring_used_t *used; > > +}; > > + > > static inline void vring_init(...

This series tries to access virtqueue metadata through kernel virtual address instead of copy_user() friends since they had too much overheads like checks, spec barriers or even hardware feature toggling. This is done through setup kernel address through direct mapping and co-opreate VM management with MMU notifiers. Test shows about 23% improvement on TX PPS. TCP_STREAM doesn't see obvious

Hi: This series tries to access virtqueue metadata through kernel virtual address instead of copy_user() friends since they had too much overheads like checks, spec barriers or even hardware feature toggling like SMAP. This is done through setup kernel address through direct mapping and co-opreate VM management with MMU notifiers. Test shows about 23% improvement on TX PPS. TCP_STREAM