| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <CACGkMEuMsz8ao0btTixZ=Lh7GadyxdOtu4HQeF=c7=TTirmV+A@mail.gmail.com>
Date: Thu, 15 Jan 2026 16:22:49 +0800
From: Jason Wang <jasowang@...hat.com>
To: Eugenio Pérez <eperezma@...hat.com>
Cc: "Michael S . Tsirkin" <mst@...hat.com>, Maxime Coquelin <mcoqueli@...hat.com>,
Xuan Zhuo <xuanzhuo@...ux.alibaba.com>, virtualization@...ts.linux.dev,
Stefano Garzarella <sgarzare@...hat.com>, Yongji Xie <xieyongji@...edance.com>,
linux-kernel@...r.kernel.org, Cindy Lu <lulu@...hat.com>,
Laurent Vivier <lvivier@...hat.com>
Subject: Re: [PATCH v12 09/13] vduse: take out allocations from vduse_dev_alloc_coherent
On Thu, Jan 15, 2026 at 2:49 AM Eugenio Pérez <eperezma@...hat.com> 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 <eperezma@...hat.com>
> ---
> 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
>
> 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
>
Powered by blists - more mailing lists