[PATCH v11 09/12] vduse: take out allocations from vduse_dev_alloc_coherent

From: Eugenio Pérez

Date: Fri Jan 09 2026 - 10:28:14 EST


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@xxxxxxxxxx>
---
v11: Remove duplicated call to free_pages_exact (Jason).
---
drivers/vdpa/vdpa_user/iova_domain.c | 10 ++--------
drivers/vdpa/vdpa_user/iova_domain.h | 2 +-
drivers/vdpa/vdpa_user/vduse_dev.c | 13 +++++++++++--
3 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/vdpa/vdpa_user/iova_domain.c b/drivers/vdpa/vdpa_user/iova_domain.c
index 309cd5a039d1..3955690696fe 100644
--- a/drivers/vdpa/vdpa_user/iova_domain.c
+++ b/drivers/vdpa/vdpa_user/iova_domain.c
@@ -495,14 +495,13 @@ void vduse_domain_unmap_page(struct vduse_iova_domain *domain,

void *vduse_domain_alloc_coherent(struct vduse_iova_domain *domain,
size_t size, dma_addr_t *dma_addr,
- gfp_t flag)
+ 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)
+ if (!iova)
goto err;

spin_lock(&domain->iotlb_lock);
@@ -519,8 +518,6 @@ void *vduse_domain_alloc_coherent(struct vduse_iova_domain *domain,
return orig;
err:
*dma_addr = DMA_MAPPING_ERROR;
- if (orig)
- free_pages_exact(orig, size);
if (iova)
vduse_domain_free_iova(iovad, iova, size);

@@ -533,7 +530,6 @@ 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 +541,10 @@ 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..1854fdc25597 100644
--- a/drivers/vdpa/vdpa_user/iova_domain.h
+++ b/drivers/vdpa/vdpa_user/iova_domain.h
@@ -67,7 +67,7 @@ void vduse_domain_unmap_page(struct vduse_iova_domain *domain,

void *vduse_domain_alloc_coherent(struct vduse_iova_domain *domain,
size_t size, dma_addr_t *dma_addr,
- gfp_t flag);
+ 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 82ee476d45e0..675da1465e0e 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -923,16 +923,24 @@ static void *vduse_dev_alloc_coherent(union virtio_map token, size_t size,
if (!token.group)
return NULL;

+ addr = alloc_pages_exact(size, flag);
+ if (!addr)
+ return NULL;
+
vdev = token.group->dev;
domain = vdev->domain;
addr = vduse_domain_alloc_coherent(domain, size,
- (dma_addr_t *)&iova, flag);
+ (dma_addr_t *)&iova, addr);
if (!addr)
- return NULL;
+ goto err;

*dma_addr = (dma_addr_t)iova;

return addr;
+
+err:
+ free_pages_exact(addr, size);
+ return NULL;
}

static void vduse_dev_free_coherent(union virtio_map token, size_t size,
@@ -949,6 +957,7 @@ 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