On Thu, Jan 15, 2026 at 12:59 PM Jason Wang <[email protected]> wrote: > > On Thu, Jan 15, 2026 at 4:44 PM Michael S. Tsirkin <[email protected]> wrote: > > > > On Thu, Jan 15, 2026 at 04:22:49PM +0800, Jason Wang wrote: > > > On Thu, Jan 15, 2026 at 2:49 AM Eugenio Pérez <[email protected]> wrote: > > > > > > > > The function vduse_dev_alloc_coherent will be called under rwlock in > > > > next patches. Make it out of the lock to avoid increasing its fail > > > > rate. > > > > > > > > Signed-off-by: Eugenio Pérez <[email protected]> > > > > --- > > > > v12: > > > > * Avoid free_pages_exact(NULL, size) in case vduse_domain_alloc_coherent > > > > fails (MST). > > > > > > > > v11: Remove duplicated call to free_pages_exact (Jason). > > > > --- > > > > drivers/vdpa/vdpa_user/iova_domain.c | 24 +++++++----------------- > > > > drivers/vdpa/vdpa_user/iova_domain.h | 5 ++--- > > > > drivers/vdpa/vdpa_user/vduse_dev.c | 17 +++++++++++------ > > > > 3 files changed, 20 insertions(+), 26 deletions(-) > > > > > > > > diff --git a/drivers/vdpa/vdpa_user/iova_domain.c > > > > b/drivers/vdpa/vdpa_user/iova_domain.c > > > > index 309cd5a039d1..0a9f668467a8 100644 > > > > --- a/drivers/vdpa/vdpa_user/iova_domain.c > > > > +++ b/drivers/vdpa/vdpa_user/iova_domain.c > > > > @@ -493,17 +493,15 @@ void vduse_domain_unmap_page(struct > > > > vduse_iova_domain *domain, > > > > vduse_domain_free_iova(iovad, dma_addr, size); > > > > } > > > > > > > > -void *vduse_domain_alloc_coherent(struct vduse_iova_domain *domain, > > > > - size_t size, dma_addr_t *dma_addr, > > > > - gfp_t flag) > > > > +dma_addr_t vduse_domain_alloc_coherent(struct vduse_iova_domain > > > > *domain, > > > > + size_t size, void *orig) > > > > { > > > > struct iova_domain *iovad = &domain->consistent_iovad; > > > > unsigned long limit = domain->iova_limit; > > > > dma_addr_t iova = vduse_domain_alloc_iova(iovad, size, limit); > > > > - void *orig = alloc_pages_exact(size, flag); > > > > > > > > - if (!iova || !orig) > > > > - goto err; > > > > + if (!iova) > > > > + return DMA_MAPPING_ERROR; > > > > > > > > spin_lock(&domain->iotlb_lock); > > > > if (vduse_iotlb_add_range(domain, (u64)iova, (u64)iova + size - > > > > 1, > > > > @@ -514,17 +512,12 @@ void *vduse_domain_alloc_coherent(struct > > > > vduse_iova_domain *domain, > > > > } > > > > spin_unlock(&domain->iotlb_lock); > > > > > > > > - *dma_addr = iova; > > > > + return iova; > > > > > > > > - return orig; > > > > err: > > > > - *dma_addr = DMA_MAPPING_ERROR; > > > > - if (orig) > > > > - free_pages_exact(orig, size); > > > > - if (iova) > > > > - vduse_domain_free_iova(iovad, iova, size); > > > > + vduse_domain_free_iova(iovad, iova, size); > > > > > > > > - return NULL; > > > > + return DMA_MAPPING_ERROR; > > > > } > > > > > > > > void vduse_domain_free_coherent(struct vduse_iova_domain *domain, > > > > size_t size, > > > > @@ -533,7 +526,6 @@ void vduse_domain_free_coherent(struct > > > > vduse_iova_domain *domain, size_t size, > > > > struct iova_domain *iovad = &domain->consistent_iovad; > > > > struct vhost_iotlb_map *map; > > > > struct vdpa_map_file *map_file; > > > > - phys_addr_t pa; > > > > > > > > spin_lock(&domain->iotlb_lock); > > > > map = vhost_iotlb_itree_first(domain->iotlb, (u64)dma_addr, > > > > @@ -545,12 +537,10 @@ void vduse_domain_free_coherent(struct > > > > vduse_iova_domain *domain, size_t size, > > > > map_file = (struct vdpa_map_file *)map->opaque; > > > > fput(map_file->file); > > > > kfree(map_file); > > > > - pa = map->addr; > > > > vhost_iotlb_map_free(domain->iotlb, map); > > > > spin_unlock(&domain->iotlb_lock); > > > > > > > > vduse_domain_free_iova(iovad, dma_addr, size); > > > > - free_pages_exact(phys_to_virt(pa), size); > > > > } > > > > > > > > static vm_fault_t vduse_domain_mmap_fault(struct vm_fault *vmf) > > > > diff --git a/drivers/vdpa/vdpa_user/iova_domain.h > > > > b/drivers/vdpa/vdpa_user/iova_domain.h > > > > index 081f06c52cdc..e50e55d1396f 100644 > > > > --- a/drivers/vdpa/vdpa_user/iova_domain.h > > > > +++ b/drivers/vdpa/vdpa_user/iova_domain.h > > > > @@ -65,9 +65,8 @@ void vduse_domain_unmap_page(struct vduse_iova_domain > > > > *domain, > > > > dma_addr_t dma_addr, size_t size, > > > > enum dma_data_direction dir, unsigned long > > > > attrs); > > > > > > > > -void *vduse_domain_alloc_coherent(struct vduse_iova_domain *domain, > > > > - size_t size, dma_addr_t *dma_addr, > > > > - gfp_t flag); > > > > +dma_addr_t vduse_domain_alloc_coherent(struct vduse_iova_domain > > > > *domain, > > > > + size_t size, void *orig); > > > > > > > > void vduse_domain_free_coherent(struct vduse_iova_domain *domain, > > > > size_t size, > > > > dma_addr_t dma_addr, unsigned long > > > > attrs); > > > > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c > > > > b/drivers/vdpa/vdpa_user/vduse_dev.c > > > > index 0e3cf5128ad0..6dba1f3224d9 100644 > > > > --- a/drivers/vdpa/vdpa_user/vduse_dev.c > > > > +++ b/drivers/vdpa/vdpa_user/vduse_dev.c > > > > @@ -916,23 +916,27 @@ static void *vduse_dev_alloc_coherent(union > > > > virtio_map token, size_t size, > > > > { > > > > struct vduse_dev *vdev; > > > > struct vduse_iova_domain *domain; > > > > - unsigned long iova; > > > > void *addr; > > > > > > > > *dma_addr = DMA_MAPPING_ERROR; > > > > if (!token.group) > > > > return NULL; > > > > > > > > - vdev = token.group->dev; > > > > - domain = vdev->domain; > > > > - addr = vduse_domain_alloc_coherent(domain, size, > > > > - (dma_addr_t *)&iova, flag); > > > > + addr = alloc_pages_exact(size, flag); > > > > if (!addr) > > > > return NULL; > > > > > > > > - *dma_addr = (dma_addr_t)iova; > > > > + vdev = token.group->dev; > > > > + domain = vdev->domain; > > > > + *dma_addr = vduse_domain_alloc_coherent(domain, size, addr); > > > > + if (*dma_addr == DMA_MAPPING_ERROR) > > > > + goto err; > > > > > > > > return addr; > > > > + > > > > +err: > > > > + free_pages_exact(addr, size); > > > > + return NULL; > > > > } > > > > > > I think the code tries to hide the iova domain specific things (e.g > > > mappings and DMA_MAPPING_ERROR) from vduse core. Could we find a way > > > to stick to that? > > > > > > Thanks > > > > > > what do you suggest more spefically though? > > I think it would be better to move the dma/map stuffs to the iova_domain.c >
I'm not sure, DMA_MAPPING_ERROR was returned by parameter already before this series and virtio_ring.c uses it in other functions too. I guess we could divert more from the HW DMA and trust in return value in virtion_ring.c conditionals checking if vring_use_dma_api, but I think to include it here is trying to add too much to this series to be honest. Would that work to do it on top in the future? > Thanks > > > > > > > > > > > static void vduse_dev_free_coherent(union virtio_map token, size_t > > > > size, > > > > @@ -949,6 +953,7 @@ static void vduse_dev_free_coherent(union > > > > virtio_map token, size_t size, > > > > domain = vdev->domain; > > > > > > > > vduse_domain_free_coherent(domain, size, dma_addr, attrs); > > > > + free_pages_exact(vaddr, size); > > > > } > > > > > > > > static bool vduse_dev_need_sync(union virtio_map token, dma_addr_t > > > > dma_addr) > > > > -- > > > > 2.52.0 > > > > > > >
