Message ID | 20241205203430.76251-2-sahilcdq@proton.me (mailing list archive) |
---|---|
State | New |
Headers | show |
Series | Add packed virtqueue to shadow virtqueue | expand |
On Thu, Dec 5, 2024 at 9:35 PM Sahil Siddiq <icegambit91@gmail.com> wrote: > > This commit refactors vhost_svq_add_split and > vhost_svq_add to simplify their implementation > and prepare for the addition of packed vqs in > following commits. > Acked-by: Eugenio Pérez <eperezma@redhat.com> > Signed-off-by: Sahil Siddiq <sahilcdq@proton.me> > --- > Changes v3 -> v4: > - Split commit #1 in v3 into 2 commits. > - Changes related to "vhost_svq_add_packed" are > now in commit #2. > > hw/virtio/vhost-shadow-virtqueue.c | 102 ++++++++++++----------------- > 1 file changed, 41 insertions(+), 61 deletions(-) > > diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c > index 37aca8b431..bb7cf6d5db 100644 > --- a/hw/virtio/vhost-shadow-virtqueue.c > +++ b/hw/virtio/vhost-shadow-virtqueue.c > @@ -124,83 +124,48 @@ static bool vhost_svq_translate_addr(const VhostShadowVirtqueue *svq, > } > > /** > - * Write descriptors to SVQ vring > + * Write descriptors to SVQ split vring > * > * @svq: The shadow virtqueue > - * @sg: Cache for hwaddr > - * @iovec: The iovec from the guest > - * @num: iovec length > - * @more_descs: True if more descriptors come in the chain > - * @write: True if they are writeable descriptors > - * > - * Return true if success, false otherwise and print error. > + * @out_sg: The iovec to the guest > + * @out_num: Outgoing iovec length > + * @in_sg: The iovec from the guest > + * @in_num: Incoming iovec length > + * @sgs: Cache for hwaddr > + * @head: Saves current free_head > */ > -static bool vhost_svq_vring_write_descs(VhostShadowVirtqueue *svq, hwaddr *sg, > - const struct iovec *iovec, size_t num, > - bool more_descs, bool write) > +static void vhost_svq_add_split(VhostShadowVirtqueue *svq, > + const struct iovec *out_sg, size_t out_num, > + const struct iovec *in_sg, size_t in_num, > + hwaddr *sgs, unsigned *head) > { > + unsigned avail_idx, n; > uint16_t i = svq->free_head, last = svq->free_head; > - unsigned n; > - uint16_t flags = write ? cpu_to_le16(VRING_DESC_F_WRITE) : 0; > + vring_avail_t *avail = svq->vring.avail; > vring_desc_t *descs = svq->vring.desc; > - bool ok; > - > - if (num == 0) { > - return true; > - } > + size_t num = in_num + out_num; > > - ok = vhost_svq_translate_addr(svq, sg, iovec, num); > - if (unlikely(!ok)) { > - return false; > - } > + *head = svq->free_head; > > for (n = 0; n < num; n++) { > - if (more_descs || (n + 1 < num)) { > - descs[i].flags = flags | cpu_to_le16(VRING_DESC_F_NEXT); > + descs[i].flags = cpu_to_le16(n < out_num ? 0 : VRING_DESC_F_WRITE); > + if (n + 1 < num) { > + descs[i].flags |= cpu_to_le16(VRING_DESC_F_NEXT); > descs[i].next = cpu_to_le16(svq->desc_next[i]); > + } > + > + descs[i].addr = cpu_to_le64(sgs[n]); > + if (n < out_num) { > + descs[i].len = cpu_to_le32(out_sg[n].iov_len); > } else { > - descs[i].flags = flags; > + descs[i].len = cpu_to_le32(in_sg[n - out_num].iov_len); > } > - descs[i].addr = cpu_to_le64(sg[n]); > - descs[i].len = cpu_to_le32(iovec[n].iov_len); > > last = i; > i = cpu_to_le16(svq->desc_next[i]); > } > > svq->free_head = le16_to_cpu(svq->desc_next[last]); > - return true; > -} > - > -static bool vhost_svq_add_split(VhostShadowVirtqueue *svq, > - const struct iovec *out_sg, size_t out_num, > - const struct iovec *in_sg, size_t in_num, > - unsigned *head) > -{ > - unsigned avail_idx; > - vring_avail_t *avail = svq->vring.avail; > - bool ok; > - g_autofree hwaddr *sgs = g_new(hwaddr, MAX(out_num, in_num)); > - > - *head = svq->free_head; > - > - /* We need some descriptors here */ > - if (unlikely(!out_num && !in_num)) { > - qemu_log_mask(LOG_GUEST_ERROR, > - "Guest provided element with no descriptors"); > - return false; > - } > - > - ok = vhost_svq_vring_write_descs(svq, sgs, out_sg, out_num, in_num > 0, > - false); > - if (unlikely(!ok)) { > - return false; > - } > - > - ok = vhost_svq_vring_write_descs(svq, sgs, in_sg, in_num, false, true); > - if (unlikely(!ok)) { > - return false; > - } > > /* > * Put the entry in the available array (but don't update avail->idx until > @@ -214,7 +179,6 @@ static bool vhost_svq_add_split(VhostShadowVirtqueue *svq, > smp_wmb(); > avail->idx = cpu_to_le16(svq->shadow_avail_idx); > > - return true; > } > > static void vhost_svq_kick(VhostShadowVirtqueue *svq) > @@ -254,15 +218,31 @@ int vhost_svq_add(VhostShadowVirtqueue *svq, const struct iovec *out_sg, > unsigned ndescs = in_num + out_num; > bool ok; > > + /* We need some descriptors here */ > + if (unlikely(!ndescs)) { > + qemu_log_mask(LOG_GUEST_ERROR, > + "Guest provided element with no descriptors"); > + return -EINVAL; > + } > + > if (unlikely(ndescs > vhost_svq_available_slots(svq))) { > return -ENOSPC; > } > > - ok = vhost_svq_add_split(svq, out_sg, out_num, in_sg, in_num, &qemu_head); > + g_autofree hwaddr *sgs = g_new(hwaddr, ndescs); > + ok = vhost_svq_translate_addr(svq, sgs, out_sg, out_num); > if (unlikely(!ok)) { > return -EINVAL; > } > > + ok = vhost_svq_translate_addr(svq, sgs + out_num, in_sg, in_num); > + if (unlikely(!ok)) { > + return -EINVAL; > + } > + > + vhost_svq_add_split(svq, out_sg, out_num, in_sg, > + in_num, sgs, &qemu_head); > + > svq->num_free -= ndescs; > svq->desc_state[qemu_head].elem = elem; > svq->desc_state[qemu_head].ndescs = ndescs; > -- > 2.47.0 >
diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index 37aca8b431..bb7cf6d5db 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -124,83 +124,48 @@ static bool vhost_svq_translate_addr(const VhostShadowVirtqueue *svq, } /** - * Write descriptors to SVQ vring + * Write descriptors to SVQ split vring * * @svq: The shadow virtqueue - * @sg: Cache for hwaddr - * @iovec: The iovec from the guest - * @num: iovec length - * @more_descs: True if more descriptors come in the chain - * @write: True if they are writeable descriptors - * - * Return true if success, false otherwise and print error. + * @out_sg: The iovec to the guest + * @out_num: Outgoing iovec length + * @in_sg: The iovec from the guest + * @in_num: Incoming iovec length + * @sgs: Cache for hwaddr + * @head: Saves current free_head */ -static bool vhost_svq_vring_write_descs(VhostShadowVirtqueue *svq, hwaddr *sg, - const struct iovec *iovec, size_t num, - bool more_descs, bool write) +static void vhost_svq_add_split(VhostShadowVirtqueue *svq, + const struct iovec *out_sg, size_t out_num, + const struct iovec *in_sg, size_t in_num, + hwaddr *sgs, unsigned *head) { + unsigned avail_idx, n; uint16_t i = svq->free_head, last = svq->free_head; - unsigned n; - uint16_t flags = write ? cpu_to_le16(VRING_DESC_F_WRITE) : 0; + vring_avail_t *avail = svq->vring.avail; vring_desc_t *descs = svq->vring.desc; - bool ok; - - if (num == 0) { - return true; - } + size_t num = in_num + out_num; - ok = vhost_svq_translate_addr(svq, sg, iovec, num); - if (unlikely(!ok)) { - return false; - } + *head = svq->free_head; for (n = 0; n < num; n++) { - if (more_descs || (n + 1 < num)) { - descs[i].flags = flags | cpu_to_le16(VRING_DESC_F_NEXT); + descs[i].flags = cpu_to_le16(n < out_num ? 0 : VRING_DESC_F_WRITE); + if (n + 1 < num) { + descs[i].flags |= cpu_to_le16(VRING_DESC_F_NEXT); descs[i].next = cpu_to_le16(svq->desc_next[i]); + } + + descs[i].addr = cpu_to_le64(sgs[n]); + if (n < out_num) { + descs[i].len = cpu_to_le32(out_sg[n].iov_len); } else { - descs[i].flags = flags; + descs[i].len = cpu_to_le32(in_sg[n - out_num].iov_len); } - descs[i].addr = cpu_to_le64(sg[n]); - descs[i].len = cpu_to_le32(iovec[n].iov_len); last = i; i = cpu_to_le16(svq->desc_next[i]); } svq->free_head = le16_to_cpu(svq->desc_next[last]); - return true; -} - -static bool vhost_svq_add_split(VhostShadowVirtqueue *svq, - const struct iovec *out_sg, size_t out_num, - const struct iovec *in_sg, size_t in_num, - unsigned *head) -{ - unsigned avail_idx; - vring_avail_t *avail = svq->vring.avail; - bool ok; - g_autofree hwaddr *sgs = g_new(hwaddr, MAX(out_num, in_num)); - - *head = svq->free_head; - - /* We need some descriptors here */ - if (unlikely(!out_num && !in_num)) { - qemu_log_mask(LOG_GUEST_ERROR, - "Guest provided element with no descriptors"); - return false; - } - - ok = vhost_svq_vring_write_descs(svq, sgs, out_sg, out_num, in_num > 0, - false); - if (unlikely(!ok)) { - return false; - } - - ok = vhost_svq_vring_write_descs(svq, sgs, in_sg, in_num, false, true); - if (unlikely(!ok)) { - return false; - } /* * Put the entry in the available array (but don't update avail->idx until @@ -214,7 +179,6 @@ static bool vhost_svq_add_split(VhostShadowVirtqueue *svq, smp_wmb(); avail->idx = cpu_to_le16(svq->shadow_avail_idx); - return true; } static void vhost_svq_kick(VhostShadowVirtqueue *svq) @@ -254,15 +218,31 @@ int vhost_svq_add(VhostShadowVirtqueue *svq, const struct iovec *out_sg, unsigned ndescs = in_num + out_num; bool ok; + /* We need some descriptors here */ + if (unlikely(!ndescs)) { + qemu_log_mask(LOG_GUEST_ERROR, + "Guest provided element with no descriptors"); + return -EINVAL; + } + if (unlikely(ndescs > vhost_svq_available_slots(svq))) { return -ENOSPC; } - ok = vhost_svq_add_split(svq, out_sg, out_num, in_sg, in_num, &qemu_head); + g_autofree hwaddr *sgs = g_new(hwaddr, ndescs); + ok = vhost_svq_translate_addr(svq, sgs, out_sg, out_num); if (unlikely(!ok)) { return -EINVAL; } + ok = vhost_svq_translate_addr(svq, sgs + out_num, in_sg, in_num); + if (unlikely(!ok)) { + return -EINVAL; + } + + vhost_svq_add_split(svq, out_sg, out_num, in_sg, + in_num, sgs, &qemu_head); + svq->num_free -= ndescs; svq->desc_state[qemu_head].elem = elem; svq->desc_state[qemu_head].ndescs = ndescs;
This commit refactors vhost_svq_add_split and vhost_svq_add to simplify their implementation and prepare for the addition of packed vqs in following commits. Signed-off-by: Sahil Siddiq <sahilcdq@proton.me> --- Changes v3 -> v4: - Split commit #1 in v3 into 2 commits. - Changes related to "vhost_svq_add_packed" are now in commit #2. hw/virtio/vhost-shadow-virtqueue.c | 102 ++++++++++++----------------- 1 file changed, 41 insertions(+), 61 deletions(-)