search for: iotlb_iov

...OTLB performance is bad for dynamic mapping since it will be reset each time a new updating is coming. We can optimize this by only reset the metadata IOTLB when the updating is for metdata. Want to try this? Thanks > > - ret = translate_desc(vq, (u64)(uintptr_t)from, size, vq->iotlb_iov, > - ARRAY_SIZE(vq->iotlb_iov), > - VHOST_ACCESS_RO); > - if (ret < 0) { > - vq_err(vq, "IOTLB translation failure: uaddr " > - "%p size 0x%llx\n", from, > - (unsigned long long) size); > - goto out; > - } &gt...

...se. */ - /* TODO: more fast path */ struct iov_iter t; + void __user *uaddr = vhost_vq_meta_fetch(vq, + (u64)(uintptr_t)to, size, + VHOST_ADDR_DESC); + + if (uaddr) + return __copy_to_user(uaddr, from, size); + ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, ARRAY_SIZE(vq->iotlb_iov), VHOST_ACCESS_WO); @@ -761,8 +796,14 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, * could be access through iotlb. So -EAGAIN should * not happen in this case. */ - /* TODO: more fast path */ + void __user *...

...se. */ - /* TODO: more fast path */ struct iov_iter t; + void __user *uaddr = vhost_vq_meta_fetch(vq, + (u64)(uintptr_t)to, size, + VHOST_ADDR_DESC); + + if (uaddr) + return __copy_to_user(uaddr, from, size); + ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, ARRAY_SIZE(vq->iotlb_iov), VHOST_ACCESS_WO); @@ -761,8 +796,14 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, * could be access through iotlb. So -EAGAIN should * not happen in this case. */ - /* TODO: more fast path */ + void __user *...

...se. */ - /* TODO: more fast path */ struct iov_iter t; + void __user *uaddr = vhost_vq_meta_fetch(vq, + (u64)(uintptr_t)to, size, + VHOST_ADDR_DESC); + + if (uaddr) + return __copy_to_user(uaddr, from, size); + ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, ARRAY_SIZE(vq->iotlb_iov), VHOST_ACCESS_WO); @@ -761,8 +796,14 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, * could be access through iotlb. So -EAGAIN should * not happen in this case. */ - /* TODO: more fast path */ + void __user *...

...se. */ - /* TODO: more fast path */ struct iov_iter t; + void __user *uaddr = vhost_vq_meta_fetch(vq, + (u64)(uintptr_t)to, size, + VHOST_ADDR_DESC); + + if (uaddr) + return __copy_to_user(uaddr, from, size); + ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, ARRAY_SIZE(vq->iotlb_iov), VHOST_ACCESS_WO); @@ -761,8 +796,14 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, * could be access through iotlb. So -EAGAIN should * not happen in this case. */ - /* TODO: more fast path */ + void __user *...

...+ /* This function should be called after iotlb + * prefetch, which means we're sure that all vq + * could be access through iotlb. So -EAGAIN should + * not happen in this case. + */ + /* TODO: more fast path */ + struct iov_iter t; + ret = translate_desc(vq, (u64)to, size, vq->iotlb_iov, + ARRAY_SIZE(vq->iotlb_iov), + VHOST_ACCESS_WO); + if (ret < 0) + goto out; + iov_iter_init(&t, WRITE, vq->iotlb_iov, ret, size); + ret = copy_to_iter(from, size, &t); + if (ret == size) + ret = 0; + } +out: + return ret; +} static int vhost_copy_from_us...

This patch tries to implement an device IOTLB for vhost. This could be used with for co-operation with userspace IOMMU implementation (qemu) for a secure DMA environment (DMAR) in guest. The idea is simple. When vhost meets an IOTLB miss, it will request the assistance of userspace to do the translation, this is done through: - when there's a IOTLB miss, it will notify userspace through

This patch tries to implement an device IOTLB for vhost. This could be used with for co-operation with userspace IOMMU implementation (qemu) for a secure DMA environment (DMAR) in guest. The idea is simple. When vhost meets an IOTLB miss, it will request the assistance of userspace to do the translation, this is done through: - when there's a IOTLB miss, it will notify userspace through

This patch tries to implement an device IOTLB for vhost. This could be used with for co-operation with userspace IOMMU implementation (qemu) for a secure DMA environment (DMAR) in guest. The idea is simple. When vhost meets an IOTLB miss, it will request the assistance of userspace to do the translation, this is done through: - when there's a IOTLB miss, it will notify userspace through

This patch tries to implement an device IOTLB for vhost. This could be used with for co-operation with userspace IOMMU implementation (qemu) for a secure DMA environment (DMAR) in guest. The idea is simple. When vhost meets an IOTLB miss, it will request the assistance of userspace to do the translation, this is done through: - when there's a IOTLB miss, it will notify userspace through

...v_length(vq->iov, out); diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 042030e5a035..6730735d31c7 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -802,9 +802,8 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, ARRAY_SIZE(vq->iotlb_iov), VHOST_ACCESS_RO); if (ret < 0) { - vq_err(vq, "IOTLB translation failure: uaddr " - "%p size 0x%llx\n", from, - (unsigned long long) size); + vq_err(vq, "IOTLB translation failure: uaddr %p size 0x%llx\n", + from, (unsig...

...v_length(vq->iov, out); diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 042030e5a035..6730735d31c7 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -802,9 +802,8 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, ARRAY_SIZE(vq->iotlb_iov), VHOST_ACCESS_RO); if (ret < 0) { - vq_err(vq, "IOTLB translation failure: uaddr " - "%p size 0x%llx\n", from, - (unsigned long long) size); + vq_err(vq, "IOTLB translation failure: uaddr %p size 0x%llx\n", + from, (unsig...

This patch tries to implement an device IOTLB for vhost. This could be used with for co-operation with userspace IOMMU implementation (qemu) for a secure DMA environment (DMAR) in guest. The idea is simple. When vhost meets an IOTLB miss, it will request the assistance of userspace to do the translation, this is done through: - when there's a IOTLB miss, it will notify userspace through

This patch tries to implement an device IOTLB for vhost. This could be used with for co-operation with userspace IOMMU implementation (qemu) for a secure DMA environment (DMAR) in guest. The idea is simple. When vhost meets an IOTLB miss, it will request the assistance of userspace to do the translation, this is done through: - when there's a IOTLB miss, it will notify userspace through

...*/ - u16 used_flags; - - /* Last used index value we have signalled on */ - u16 signalled_used; - - /* Last used index value we have signalled on */ - bool signalled_used_valid; - - /* Log writes to used structure. */ - bool log_used; - u64 log_addr; - - struct iovec iov[UIO_MAXIOV]; - struct iovec iotlb_iov[64]; - struct iovec *indirect; - struct vring_used_elem *heads; - /* Protected by virtqueue mutex. */ - struct vhost_umem *umem; - struct vhost_umem *iotlb; - void *private_data; - u64 acked_features; - /* Log write descriptors */ - void __user *log_base; - struct vhost_log *log; - - /* Ring endian...

...*/ - u16 used_flags; - - /* Last used index value we have signalled on */ - u16 signalled_used; - - /* Last used index value we have signalled on */ - bool signalled_used_valid; - - /* Log writes to used structure. */ - bool log_used; - u64 log_addr; - - struct iovec iov[UIO_MAXIOV]; - struct iovec iotlb_iov[64]; - struct iovec *indirect; - struct vring_used_elem *heads; - /* Protected by virtqueue mutex. */ - struct vhost_umem *umem; - struct vhost_umem *iotlb; - void *private_data; - u64 acked_features; - /* Log write descriptors */ - void __user *log_base; - struct vhost_log *log; - - /* Ring endian...

...ve signalled on */ > - u16 signalled_used; > - > - /* Last used index value we have signalled on */ > - bool signalled_used_valid; > - > - /* Log writes to used structure. */ > - bool log_used; > - u64 log_addr; > - > - struct iovec iov[UIO_MAXIOV]; > - struct iovec iotlb_iov[64]; > - struct iovec *indirect; > - struct vring_used_elem *heads; > - /* Protected by virtqueue mutex. */ > - struct vhost_umem *umem; > - struct vhost_umem *iotlb; > - void *private_data; > - u64 acked_features; > - /* Log write descriptors */ > - void __user *log_base...

Hi all: This RFC implement packed ring layout. The code were tested with Tiwei's RFC V3 ahttps://lkml.org/lkml/2018/4/25/34. Some fixups and tweaks were needed on top of Tiwei's code to make it run for event index. Pktgen reports about 20% improvement on PPS (event index is off). More testing is ongoing. Notes for tester: - Start from this version, vhost need qemu co-operation to work

Hi all: This RFC implement packed ring layout. The code were tested with Tiwei's RFC V3 ahttps://lkml.org/lkml/2018/4/25/34. Some fixups and tweaks were needed on top of Tiwei's code to make it run for event index. Pktgen reports about 20% improvement on PPS (event index is off). More testing is ongoing. Notes for tester: - Start from this version, vhost need qemu co-operation to work

Hi all: This RFC implement packed ring layout. The code were tested with Tiwei's RFC V5 at https://lkml.org/lkml/2018/5/22/138. Some fixups and tweaks were needed on top of Tiwei's code to make it run for event index. Pktgen reports about 20% improvement on TX PPS when doing pktgen from guest to host. No ovbious improvement on RX PPS. We can do lots of optimizations on top but for simple