| Message ID | 20200730140731.32912-3-mhartmay@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Enable virtio-fs on s390x | expand |
On Thu, Jul 30, 2020 at 04:07:31PM +0200, Marc Hartmayer wrote: > Since virtio existed even before it got standardized, the virtio > standard defines the following types of virtio devices: > > + legacy device (pre-virtio 1.0) > + non-legacy or VIRTIO 1.0 device > + transitional device (which can act both as legacy and non-legacy) > > Virtio 1.0 defines the fields of the virtqueues as little endian, > while legacy uses guest's native endian [1]. Currently libvhost-user > does not handle virtio endianness at all, i.e. it works only if the > native endianness matches with whatever is actually needed. That means > things break spectacularly on big-endian targets. Let us handle virtio > endianness for non-legacy as required by the virtio specification > [1]. The fencing of legacy virtio devices is done in > `vu_set_features_exec`. > > [1] https://docs.oasis-open.org/virtio/virtio/v1.1/cs01/virtio-v1.1-cs01.html#x1-210003 > > Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> > --- > contrib/libvhost-user/libvhost-user.c | 77 +++++++++++++++------------ > 1 file changed, 43 insertions(+), 34 deletions(-) > > diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c > index 53f16bdf082c..e2238a0400c9 100644 > --- a/contrib/libvhost-user/libvhost-user.c > +++ b/contrib/libvhost-user/libvhost-user.c > @@ -42,6 +42,7 @@ > > #include "qemu/atomic.h" > #include "qemu/osdep.h" > +#include "qemu/bswap.h" > #include "qemu/memfd.h" > > #include "libvhost-user.h" > @@ -539,6 +540,14 @@ vu_set_features_exec(VuDev *dev, VhostUserMsg *vmsg) > DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64); > > dev->features = vmsg->payload.u64; > + if (!vu_has_feature(dev, VIRTIO_F_VERSION_1)) { > + /* > + * We only support devices conforming to VIRTIO 1.0 or > + * later > + */ > + vu_panic(dev, "virtio legacy devices aren't supported by libvhost-user"); > + return false; > + } > > if (!(dev->features & VHOST_USER_F_PROTOCOL_FEATURES)) { > vu_set_enable_all_rings(dev, true); > @@ -1074,7 +1083,7 @@ vu_set_vring_addr_exec(VuDev *dev, VhostUserMsg *vmsg) > return false; > } > > - vq->used_idx = vq->vring.used->idx; > + vq->used_idx = lduw_le_p(&vq->vring.used->idx); > > if (vq->last_avail_idx != vq->used_idx) { > bool resume = dev->iface->queue_is_processed_in_order && > @@ -1191,7 +1200,7 @@ vu_check_queue_inflights(VuDev *dev, VuVirtq *vq) > return 0; > } > > - vq->used_idx = vq->vring.used->idx; > + vq->used_idx = lduw_le_p(&vq->vring.used->idx); > vq->resubmit_num = 0; > vq->resubmit_list = NULL; > vq->counter = 0; > @@ -2021,13 +2030,13 @@ vu_queue_started(const VuDev *dev, const VuVirtq *vq) > static inline uint16_t > vring_avail_flags(VuVirtq *vq) > { > - return vq->vring.avail->flags; > + return lduw_le_p(&vq->vring.avail->flags); > } > > static inline uint16_t > vring_avail_idx(VuVirtq *vq) > { > - vq->shadow_avail_idx = vq->vring.avail->idx; > + vq->shadow_avail_idx = lduw_le_p(&vq->vring.avail->idx); > > return vq->shadow_avail_idx; > } > @@ -2035,7 +2044,7 @@ vring_avail_idx(VuVirtq *vq) > static inline uint16_t > vring_avail_ring(VuVirtq *vq, int i) > { > - return vq->vring.avail->ring[i]; > + return lduw_le_p(&vq->vring.avail->ring[i]); > } > > static inline uint16_t > @@ -2123,12 +2132,12 @@ virtqueue_read_next_desc(VuDev *dev, struct vring_desc *desc, > int i, unsigned int max, unsigned int *next) > { > /* If this descriptor says it doesn't chain, we're done. */ > - if (!(desc[i].flags & VRING_DESC_F_NEXT)) { > + if (!(lduw_le_p(&desc[i].flags) & VRING_DESC_F_NEXT)) { > return VIRTQUEUE_READ_DESC_DONE; > } > > /* Check they're not leading us off end of descriptors. */ > - *next = desc[i].next; > + *next = lduw_le_p(&desc[i].next); > /* Make sure compiler knows to grab that: we don't want it changing! */ > smp_wmb(); > > @@ -2171,8 +2180,8 @@ vu_queue_get_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int *in_bytes, > } > desc = vq->vring.desc; > > - if (desc[i].flags & VRING_DESC_F_INDIRECT) { > - if (desc[i].len % sizeof(struct vring_desc)) { > + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_INDIRECT) { > + if (ldl_le_p(&desc[i].len) % sizeof(struct vring_desc)) { > vu_panic(dev, "Invalid size for indirect buffer table"); > goto err; > } > @@ -2185,8 +2194,8 @@ vu_queue_get_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int *in_bytes, > > /* loop over the indirect descriptor table */ > indirect = 1; > - desc_addr = desc[i].addr; > - desc_len = desc[i].len; > + desc_addr = ldq_le_p(&desc[i].addr); > + desc_len = ldl_le_p(&desc[i].len); > max = desc_len / sizeof(struct vring_desc); > read_len = desc_len; > desc = vu_gpa_to_va(dev, &read_len, desc_addr); > @@ -2213,10 +2222,10 @@ vu_queue_get_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int *in_bytes, > goto err; > } > > - if (desc[i].flags & VRING_DESC_F_WRITE) { > - in_total += desc[i].len; > + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_WRITE) { > + in_total += ldl_le_p(&desc[i].len); > } else { > - out_total += desc[i].len; > + out_total += ldl_le_p(&desc[i].len); > } > if (in_total >= max_in_bytes && out_total >= max_out_bytes) { > goto done; > @@ -2367,7 +2376,7 @@ vring_used_flags_set_bit(VuVirtq *vq, int mask) > > flags = (uint16_t *)((char*)vq->vring.used + > offsetof(struct vring_used, flags)); > - *flags |= mask; > + stw_le_p(flags, lduw_le_p(flags) | mask); > } > > static inline void > @@ -2377,7 +2386,7 @@ vring_used_flags_unset_bit(VuVirtq *vq, int mask) > > flags = (uint16_t *)((char*)vq->vring.used + > offsetof(struct vring_used, flags)); > - *flags &= ~mask; > + stw_le_p(flags, lduw_le_p(flags) & ~mask); > } > > static inline void > @@ -2387,7 +2396,7 @@ vring_set_avail_event(VuVirtq *vq, uint16_t val) > return; > } > > - *((uint16_t *) &vq->vring.used->ring[vq->vring.num]) = val; > + stw_le_p(&vq->vring.used->ring[vq->vring.num], val); > } > > void > @@ -2476,14 +2485,14 @@ vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int idx, size_t sz) > struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE]; > int rc; > > - if (desc[i].flags & VRING_DESC_F_INDIRECT) { > - if (desc[i].len % sizeof(struct vring_desc)) { > + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_INDIRECT) { > + if (ldl_le_p(&desc[i].len) % sizeof(struct vring_desc)) { > vu_panic(dev, "Invalid size for indirect buffer table"); > } > > /* loop over the indirect descriptor table */ > - desc_addr = desc[i].addr; > - desc_len = desc[i].len; > + desc_addr = ldq_le_p(&desc[i].addr); > + desc_len = ldl_le_p(&desc[i].len); > max = desc_len / sizeof(struct vring_desc); > read_len = desc_len; > desc = vu_gpa_to_va(dev, &read_len, desc_addr); > @@ -2505,10 +2514,10 @@ vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int idx, size_t sz) > > /* Collect all the descriptors */ > do { > - if (desc[i].flags & VRING_DESC_F_WRITE) { > + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_WRITE) { > virtqueue_map_desc(dev, &in_num, iov + out_num, > VIRTQUEUE_MAX_SIZE - out_num, true, > - desc[i].addr, desc[i].len); > + ldq_le_p(&desc[i].addr), ldl_le_p(&desc[i].len)); > } else { > if (in_num) { > vu_panic(dev, "Incorrect order for descriptors"); > @@ -2516,7 +2525,7 @@ vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int idx, size_t sz) > } > virtqueue_map_desc(dev, &out_num, iov, > VIRTQUEUE_MAX_SIZE, false, > - desc[i].addr, desc[i].len); > + ldq_le_p(&desc[i].addr), ldl_le_p(&desc[i].len)); > } > > /* If we've got too many, that implies a descriptor loop. */ > @@ -2712,14 +2721,14 @@ vu_log_queue_fill(VuDev *dev, VuVirtq *vq, > max = vq->vring.num; > i = elem->index; > > - if (desc[i].flags & VRING_DESC_F_INDIRECT) { > - if (desc[i].len % sizeof(struct vring_desc)) { > + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_INDIRECT) { > + if (ldl_le_p(&desc[i].len) % sizeof(struct vring_desc)) { > vu_panic(dev, "Invalid size for indirect buffer table"); > } > > /* loop over the indirect descriptor table */ > - desc_addr = desc[i].addr; > - desc_len = desc[i].len; > + desc_addr = ldq_le_p(&desc[i].addr); > + desc_len = ldl_le_p(&desc[i].len); > max = desc_len / sizeof(struct vring_desc); > read_len = desc_len; > desc = vu_gpa_to_va(dev, &read_len, desc_addr); > @@ -2745,9 +2754,9 @@ vu_log_queue_fill(VuDev *dev, VuVirtq *vq, > return; > } > > - if (desc[i].flags & VRING_DESC_F_WRITE) { > - min = MIN(desc[i].len, len); > - vu_log_write(dev, desc[i].addr, min); > + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_WRITE) { > + min = MIN(ldl_le_p(&desc[i].len), len); > + vu_log_write(dev, ldq_le_p(&desc[i].addr), min); > len -= min; > } > > @@ -2772,15 +2781,15 @@ vu_queue_fill(VuDev *dev, VuVirtq *vq, > > idx = (idx + vq->used_idx) % vq->vring.num; > > - uelem.id = elem->index; > - uelem.len = len; > + stl_le_p(&uelem.id, elem->index); > + stl_le_p(&uelem.len, len); > vring_used_write(dev, vq, &uelem, idx); > } > > static inline > void vring_used_idx_set(VuDev *dev, VuVirtq *vq, uint16_t val) > { > - vq->vring.used->idx = val; > + stw_le_p(&vq->vring.used->idx, val); > vu_log_write(dev, > vq->vring.log_guest_addr + offsetof(struct vring_used, idx), > sizeof(vq->vring.used->idx)); > -- > 2.25.4
On Thu, 30 Jul 2020 16:07:31 +0200 Marc Hartmayer <mhartmay@linux.ibm.com> wrote: > Since virtio existed even before it got standardized, the virtio > standard defines the following types of virtio devices: > > + legacy device (pre-virtio 1.0) > + non-legacy or VIRTIO 1.0 device > + transitional device (which can act both as legacy and non-legacy) > > Virtio 1.0 defines the fields of the virtqueues as little endian, > while legacy uses guest's native endian [1]. Currently libvhost-user > does not handle virtio endianness at all, i.e. it works only if the > native endianness matches with whatever is actually needed. That means > things break spectacularly on big-endian targets. Let us handle virtio > endianness for non-legacy as required by the virtio specification > [1]. Maybe add "and fence legacy virtio, as there is no safe way to figure out the needed endianness conversions for all cases." > The fencing of legacy virtio devices is done in > `vu_set_features_exec`. Not that I disagree with fencing legacy virtio, but looking at some vhost-user* drivers, I'm not sure everything will work as desired for those (I might be missing something, though.) - vhost-user-blk lists VERSION_1 in the supported features, but vhost-user-scsi doesn't... is there some inheritance going on that I'm missing? - vhost-user-gpu-pci inherits from virtio-gpu-pci, so I guess it's fine - vhost-user-input should also always have been virtio-1 So, has anybody been using vhost-user-scsi and can confirm that it still works, or at least can be made to work? > > [1] https://docs.oasis-open.org/virtio/virtio/v1.1/cs01/virtio-v1.1-cs01.html#x1-210003 > > Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com> > --- > contrib/libvhost-user/libvhost-user.c | 77 +++++++++++++++------------ > 1 file changed, 43 insertions(+), 34 deletions(-) The code change per se LGTM.
On Sun, Aug 02, 2020 at 01:13 AM -0400, "Michael S. Tsirkin" <mst@redhat.com> wrote: > On Thu, Jul 30, 2020 at 04:07:31PM +0200, Marc Hartmayer wrote: >> Since virtio existed even before it got standardized, the virtio >> standard defines the following types of virtio devices: >> >> + legacy device (pre-virtio 1.0) >> + non-legacy or VIRTIO 1.0 device >> + transitional device (which can act both as legacy and non-legacy) >> >> Virtio 1.0 defines the fields of the virtqueues as little endian, >> while legacy uses guest's native endian [1]. Currently libvhost-user >> does not handle virtio endianness at all, i.e. it works only if the >> native endianness matches with whatever is actually needed. That means >> things break spectacularly on big-endian targets. Let us handle virtio >> endianness for non-legacy as required by the virtio specification >> [1]. The fencing of legacy virtio devices is done in >> `vu_set_features_exec`. >> >> [1] https://docs.oasis-open.org/virtio/virtio/v1.1/cs01/virtio-v1.1-cs01.html#x1-210003 >> >> Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com> > > > Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Thanks. […snip]
On Mon, Aug 03, 2020 at 11:26 AM +0200, Cornelia Huck <cohuck@redhat.com> wrote: > On Thu, 30 Jul 2020 16:07:31 +0200 > Marc Hartmayer <mhartmay@linux.ibm.com> wrote: > >> Since virtio existed even before it got standardized, the virtio >> standard defines the following types of virtio devices: >> >> + legacy device (pre-virtio 1.0) >> + non-legacy or VIRTIO 1.0 device >> + transitional device (which can act both as legacy and non-legacy) >> >> Virtio 1.0 defines the fields of the virtqueues as little endian, >> while legacy uses guest's native endian [1]. Currently libvhost-user >> does not handle virtio endianness at all, i.e. it works only if the >> native endianness matches with whatever is actually needed. That means >> things break spectacularly on big-endian targets. Let us handle virtio >> endianness for non-legacy as required by the virtio specification >> [1]. > > Maybe add > > "and fence legacy virtio, as there is no safe way to figure out the > needed endianness conversions for all cases." Okay. > >> The fencing of legacy virtio devices is done in >> `vu_set_features_exec`. > > Not that I disagree with fencing legacy virtio, but looking at some > vhost-user* drivers, I'm not sure everything will work as desired for > those (I might be missing something, though.) > > - vhost-user-blk lists VERSION_1 in the supported features, but > vhost-user-scsi doesn't... is there some inheritance going on that > I'm missing? > - vhost-user-gpu-pci inherits from virtio-gpu-pci, so I guess it's fine > - vhost-user-input should also always have been virtio-1 > > So, has anybody been using vhost-user-scsi and can confirm that it > still works, or at least can be made to work? Unfortunately, I don’t have the required hardware :/ Can please anybody verify this? > >> >> [1] https://docs.oasis-open.org/virtio/virtio/v1.1/cs01/virtio-v1.1-cs01.html#x1-210003 >> >> Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com> >> --- >> contrib/libvhost-user/libvhost-user.c | 77 +++++++++++++++------------ >> 1 file changed, 43 insertions(+), 34 deletions(-) > > The code change per se LGTM. Thanks for the feedback! >
diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c index 53f16bdf082c..e2238a0400c9 100644 --- a/contrib/libvhost-user/libvhost-user.c +++ b/contrib/libvhost-user/libvhost-user.c @@ -42,6 +42,7 @@ #include "qemu/atomic.h" #include "qemu/osdep.h" +#include "qemu/bswap.h" #include "qemu/memfd.h" #include "libvhost-user.h" @@ -539,6 +540,14 @@ vu_set_features_exec(VuDev *dev, VhostUserMsg *vmsg) DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64); dev->features = vmsg->payload.u64; + if (!vu_has_feature(dev, VIRTIO_F_VERSION_1)) { + /* + * We only support devices conforming to VIRTIO 1.0 or + * later + */ + vu_panic(dev, "virtio legacy devices aren't supported by libvhost-user"); + return false; + } if (!(dev->features & VHOST_USER_F_PROTOCOL_FEATURES)) { vu_set_enable_all_rings(dev, true); @@ -1074,7 +1083,7 @@ vu_set_vring_addr_exec(VuDev *dev, VhostUserMsg *vmsg) return false; } - vq->used_idx = vq->vring.used->idx; + vq->used_idx = lduw_le_p(&vq->vring.used->idx); if (vq->last_avail_idx != vq->used_idx) { bool resume = dev->iface->queue_is_processed_in_order && @@ -1191,7 +1200,7 @@ vu_check_queue_inflights(VuDev *dev, VuVirtq *vq) return 0; } - vq->used_idx = vq->vring.used->idx; + vq->used_idx = lduw_le_p(&vq->vring.used->idx); vq->resubmit_num = 0; vq->resubmit_list = NULL; vq->counter = 0; @@ -2021,13 +2030,13 @@ vu_queue_started(const VuDev *dev, const VuVirtq *vq) static inline uint16_t vring_avail_flags(VuVirtq *vq) { - return vq->vring.avail->flags; + return lduw_le_p(&vq->vring.avail->flags); } static inline uint16_t vring_avail_idx(VuVirtq *vq) { - vq->shadow_avail_idx = vq->vring.avail->idx; + vq->shadow_avail_idx = lduw_le_p(&vq->vring.avail->idx); return vq->shadow_avail_idx; } @@ -2035,7 +2044,7 @@ vring_avail_idx(VuVirtq *vq) static inline uint16_t vring_avail_ring(VuVirtq *vq, int i) { - return vq->vring.avail->ring[i]; + return lduw_le_p(&vq->vring.avail->ring[i]); } static inline uint16_t @@ -2123,12 +2132,12 @@ virtqueue_read_next_desc(VuDev *dev, struct vring_desc *desc, int i, unsigned int max, unsigned int *next) { /* If this descriptor says it doesn't chain, we're done. */ - if (!(desc[i].flags & VRING_DESC_F_NEXT)) { + if (!(lduw_le_p(&desc[i].flags) & VRING_DESC_F_NEXT)) { return VIRTQUEUE_READ_DESC_DONE; } /* Check they're not leading us off end of descriptors. */ - *next = desc[i].next; + *next = lduw_le_p(&desc[i].next); /* Make sure compiler knows to grab that: we don't want it changing! */ smp_wmb(); @@ -2171,8 +2180,8 @@ vu_queue_get_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int *in_bytes, } desc = vq->vring.desc; - if (desc[i].flags & VRING_DESC_F_INDIRECT) { - if (desc[i].len % sizeof(struct vring_desc)) { + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_INDIRECT) { + if (ldl_le_p(&desc[i].len) % sizeof(struct vring_desc)) { vu_panic(dev, "Invalid size for indirect buffer table"); goto err; } @@ -2185,8 +2194,8 @@ vu_queue_get_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int *in_bytes, /* loop over the indirect descriptor table */ indirect = 1; - desc_addr = desc[i].addr; - desc_len = desc[i].len; + desc_addr = ldq_le_p(&desc[i].addr); + desc_len = ldl_le_p(&desc[i].len); max = desc_len / sizeof(struct vring_desc); read_len = desc_len; desc = vu_gpa_to_va(dev, &read_len, desc_addr); @@ -2213,10 +2222,10 @@ vu_queue_get_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int *in_bytes, goto err; } - if (desc[i].flags & VRING_DESC_F_WRITE) { - in_total += desc[i].len; + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_WRITE) { + in_total += ldl_le_p(&desc[i].len); } else { - out_total += desc[i].len; + out_total += ldl_le_p(&desc[i].len); } if (in_total >= max_in_bytes && out_total >= max_out_bytes) { goto done; @@ -2367,7 +2376,7 @@ vring_used_flags_set_bit(VuVirtq *vq, int mask) flags = (uint16_t *)((char*)vq->vring.used + offsetof(struct vring_used, flags)); - *flags |= mask; + stw_le_p(flags, lduw_le_p(flags) | mask); } static inline void @@ -2377,7 +2386,7 @@ vring_used_flags_unset_bit(VuVirtq *vq, int mask) flags = (uint16_t *)((char*)vq->vring.used + offsetof(struct vring_used, flags)); - *flags &= ~mask; + stw_le_p(flags, lduw_le_p(flags) & ~mask); } static inline void @@ -2387,7 +2396,7 @@ vring_set_avail_event(VuVirtq *vq, uint16_t val) return; } - *((uint16_t *) &vq->vring.used->ring[vq->vring.num]) = val; + stw_le_p(&vq->vring.used->ring[vq->vring.num], val); } void @@ -2476,14 +2485,14 @@ vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int idx, size_t sz) struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE]; int rc; - if (desc[i].flags & VRING_DESC_F_INDIRECT) { - if (desc[i].len % sizeof(struct vring_desc)) { + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_INDIRECT) { + if (ldl_le_p(&desc[i].len) % sizeof(struct vring_desc)) { vu_panic(dev, "Invalid size for indirect buffer table"); } /* loop over the indirect descriptor table */ - desc_addr = desc[i].addr; - desc_len = desc[i].len; + desc_addr = ldq_le_p(&desc[i].addr); + desc_len = ldl_le_p(&desc[i].len); max = desc_len / sizeof(struct vring_desc); read_len = desc_len; desc = vu_gpa_to_va(dev, &read_len, desc_addr); @@ -2505,10 +2514,10 @@ vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int idx, size_t sz) /* Collect all the descriptors */ do { - if (desc[i].flags & VRING_DESC_F_WRITE) { + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_WRITE) { virtqueue_map_desc(dev, &in_num, iov + out_num, VIRTQUEUE_MAX_SIZE - out_num, true, - desc[i].addr, desc[i].len); + ldq_le_p(&desc[i].addr), ldl_le_p(&desc[i].len)); } else { if (in_num) { vu_panic(dev, "Incorrect order for descriptors"); @@ -2516,7 +2525,7 @@ vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int idx, size_t sz) } virtqueue_map_desc(dev, &out_num, iov, VIRTQUEUE_MAX_SIZE, false, - desc[i].addr, desc[i].len); + ldq_le_p(&desc[i].addr), ldl_le_p(&desc[i].len)); } /* If we've got too many, that implies a descriptor loop. */ @@ -2712,14 +2721,14 @@ vu_log_queue_fill(VuDev *dev, VuVirtq *vq, max = vq->vring.num; i = elem->index; - if (desc[i].flags & VRING_DESC_F_INDIRECT) { - if (desc[i].len % sizeof(struct vring_desc)) { + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_INDIRECT) { + if (ldl_le_p(&desc[i].len) % sizeof(struct vring_desc)) { vu_panic(dev, "Invalid size for indirect buffer table"); } /* loop over the indirect descriptor table */ - desc_addr = desc[i].addr; - desc_len = desc[i].len; + desc_addr = ldq_le_p(&desc[i].addr); + desc_len = ldl_le_p(&desc[i].len); max = desc_len / sizeof(struct vring_desc); read_len = desc_len; desc = vu_gpa_to_va(dev, &read_len, desc_addr); @@ -2745,9 +2754,9 @@ vu_log_queue_fill(VuDev *dev, VuVirtq *vq, return; } - if (desc[i].flags & VRING_DESC_F_WRITE) { - min = MIN(desc[i].len, len); - vu_log_write(dev, desc[i].addr, min); + if (lduw_le_p(&desc[i].flags) & VRING_DESC_F_WRITE) { + min = MIN(ldl_le_p(&desc[i].len), len); + vu_log_write(dev, ldq_le_p(&desc[i].addr), min); len -= min; } @@ -2772,15 +2781,15 @@ vu_queue_fill(VuDev *dev, VuVirtq *vq, idx = (idx + vq->used_idx) % vq->vring.num; - uelem.id = elem->index; - uelem.len = len; + stl_le_p(&uelem.id, elem->index); + stl_le_p(&uelem.len, len); vring_used_write(dev, vq, &uelem, idx); } static inline void vring_used_idx_set(VuDev *dev, VuVirtq *vq, uint16_t val) { - vq->vring.used->idx = val; + stw_le_p(&vq->vring.used->idx, val); vu_log_write(dev, vq->vring.log_guest_addr + offsetof(struct vring_used, idx), sizeof(vq->vring.used->idx));
Since virtio existed even before it got standardized, the virtio standard defines the following types of virtio devices: + legacy device (pre-virtio 1.0) + non-legacy or VIRTIO 1.0 device + transitional device (which can act both as legacy and non-legacy) Virtio 1.0 defines the fields of the virtqueues as little endian, while legacy uses guest's native endian [1]. Currently libvhost-user does not handle virtio endianness at all, i.e. it works only if the native endianness matches with whatever is actually needed. That means things break spectacularly on big-endian targets. Let us handle virtio endianness for non-legacy as required by the virtio specification [1]. The fencing of legacy virtio devices is done in `vu_set_features_exec`. [1] https://docs.oasis-open.org/virtio/virtio/v1.1/cs01/virtio-v1.1-cs01.html#x1-210003 Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com> --- contrib/libvhost-user/libvhost-user.c | 77 +++++++++++++++------------ 1 file changed, 43 insertions(+), 34 deletions(-)