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vfio/pds: Only use a single SGL for both seq and ack

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Since the seq/ack operations never happen in parallel there
is no need for multiple scatter gather lists per region.
The current implementation is wasting memory. Fix this by
only using a single scatter-gather list for both the seq
and ack operations.

Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231117001207.2793-3-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Brett Creeley 2023-11-16 16:12:03 -08:00 committed by Alex Williamson
parent 4004497cec
commit 3b8f7a24d1
2 changed files with 28 additions and 46 deletions
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68
drivers/vfio/pci/pds/dirty.c
View File

@ -100,35 +100,35 @@ static void pds_vfio_dirty_free_bitmaps(struct pds_vfio_dirty *dirty)
}
static void __pds_vfio_dirty_free_sgl(struct pds_vfio_pci_device *pds_vfio,
struct pds_vfio_bmp_info *bmp_info)
struct pds_vfio_dirty *dirty)
{
struct pci_dev *pdev = pds_vfio->vfio_coredev.pdev;
struct device *pdsc_dev = &pci_physfn(pdev)->dev;
dma_unmap_single(pdsc_dev, bmp_info->sgl_addr,
bmp_info->num_sge * sizeof(struct pds_lm_sg_elem),
dma_unmap_single(pdsc_dev, dirty->sgl_addr,
dirty->num_sge * sizeof(struct pds_lm_sg_elem),
DMA_BIDIRECTIONAL);
kfree(bmp_info->sgl);
kfree(dirty->sgl);
bmp_info->num_sge = 0;
bmp_info->sgl = NULL;
bmp_info->sgl_addr = 0;
dirty->num_sge = 0;
dirty->sgl = NULL;
dirty->sgl_addr = 0;
}
static void pds_vfio_dirty_free_sgl(struct pds_vfio_pci_device *pds_vfio)
{
if (pds_vfio->dirty.host_seq.sgl)
__pds_vfio_dirty_free_sgl(pds_vfio, &pds_vfio->dirty.host_seq);
if (pds_vfio->dirty.host_ack.sgl)
__pds_vfio_dirty_free_sgl(pds_vfio, &pds_vfio->dirty.host_ack);
struct pds_vfio_dirty *dirty = &pds_vfio->dirty;
if (dirty->sgl)
__pds_vfio_dirty_free_sgl(pds_vfio, dirty);
}
static int __pds_vfio_dirty_alloc_sgl(struct pds_vfio_pci_device *pds_vfio,
struct pds_vfio_bmp_info *bmp_info,
u32 page_count)
static int pds_vfio_dirty_alloc_sgl(struct pds_vfio_pci_device *pds_vfio,
u32 page_count)
{
struct pci_dev *pdev = pds_vfio->vfio_coredev.pdev;
struct device *pdsc_dev = &pci_physfn(pdev)->dev;
struct pds_vfio_dirty *dirty = &pds_vfio->dirty;
struct pds_lm_sg_elem *sgl;
dma_addr_t sgl_addr;
size_t sgl_size;
@ -147,30 +147,9 @@ static int __pds_vfio_dirty_alloc_sgl(struct pds_vfio_pci_device *pds_vfio,
return -EIO;
}
bmp_info->sgl = sgl;
bmp_info->num_sge = max_sge;
bmp_info->sgl_addr = sgl_addr;
return 0;
}
static int pds_vfio_dirty_alloc_sgl(struct pds_vfio_pci_device *pds_vfio,
u32 page_count)
{
struct pds_vfio_dirty *dirty = &pds_vfio->dirty;
int err;
err = __pds_vfio_dirty_alloc_sgl(pds_vfio, &dirty->host_seq,
page_count);
if (err)
return err;
err = __pds_vfio_dirty_alloc_sgl(pds_vfio, &dirty->host_ack,
page_count);
if (err) {
__pds_vfio_dirty_free_sgl(pds_vfio, &dirty->host_seq);
return err;
}
dirty->sgl = sgl;
dirty->num_sge = max_sge;
dirty->sgl_addr = sgl_addr;
return 0;
}
@ -328,6 +307,8 @@ static int pds_vfio_dirty_seq_ack(struct pds_vfio_pci_device *pds_vfio,
u8 dma_dir = read_seq ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
struct pci_dev *pdev = pds_vfio->vfio_coredev.pdev;
struct device *pdsc_dev = &pci_physfn(pdev)->dev;
struct pds_vfio_dirty *dirty = &pds_vfio->dirty;
struct pds_lm_sg_elem *sgl;
unsigned long long npages;
struct sg_table sg_table;
struct scatterlist *sg;
@ -374,8 +355,9 @@ static int pds_vfio_dirty_seq_ack(struct pds_vfio_pci_device *pds_vfio,
if (err)
goto out_free_sg_table;
sgl = pds_vfio->dirty.sgl;
for_each_sgtable_dma_sg(&sg_table, sg, i) {
struct pds_lm_sg_elem *sg_elem = &bmp_info->sgl[i];
struct pds_lm_sg_elem *sg_elem = &sgl[i];
sg_elem->addr = cpu_to_le64(sg_dma_address(sg));
sg_elem->len = cpu_to_le32(sg_dma_len(sg));
@ -383,15 +365,15 @@ static int pds_vfio_dirty_seq_ack(struct pds_vfio_pci_device *pds_vfio,
num_sge = sg_table.nents;
size = num_sge * sizeof(struct pds_lm_sg_elem);
dma_sync_single_for_device(pdsc_dev, bmp_info->sgl_addr, size, dma_dir);
err = pds_vfio_dirty_seq_ack_cmd(pds_vfio, bmp_info->sgl_addr, num_sge,
dma_sync_single_for_device(pdsc_dev, dirty->sgl_addr, size, dma_dir);
err = pds_vfio_dirty_seq_ack_cmd(pds_vfio, dirty->sgl_addr, num_sge,
offset, bmp_bytes, read_seq);
if (err)
dev_err(&pdev->dev,
"Dirty bitmap %s failed offset %u bmp_bytes %u num_sge %u DMA 0x%llx: %pe\n",
bmp_type_str, offset, bmp_bytes,
num_sge, bmp_info->sgl_addr, ERR_PTR(err));
dma_sync_single_for_cpu(pdsc_dev, bmp_info->sgl_addr, size, dma_dir);
num_sge, dirty->sgl_addr, ERR_PTR(err));
dma_sync_single_for_cpu(pdsc_dev, dirty->sgl_addr, size, dma_dir);
dma_unmap_sgtable(pdsc_dev, &sg_table, dma_dir, 0);
out_free_sg_table:

6
drivers/vfio/pci/pds/dirty.h
View File

@ -7,9 +7,6 @@
struct pds_vfio_bmp_info {
unsigned long *bmp;
u32 bmp_bytes;
struct pds_lm_sg_elem *sgl;
dma_addr_t sgl_addr;
u16 num_sge;
};
struct pds_vfio_dirty {
@ -18,6 +15,9 @@ struct pds_vfio_dirty {
u64 region_size;
u64 region_start;
u64 region_page_size;
struct pds_lm_sg_elem *sgl;
dma_addr_t sgl_addr;
u16 num_sge;
bool is_enabled;
};