From 3b8f7a24d1fe79cc3fa1da9be5610b9c3aedbc2a Mon Sep 17 00:00:00 2001 From: Brett Creeley Date: Thu, 16 Nov 2023 16:12:03 -0800 Subject: vfio/pds: Only use a single SGL for both seq and ack 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 Signed-off-by: Shannon Nelson Link: https://lore.kernel.org/r/20231117001207.2793-3-brett.creeley@amd.com Signed-off-by: Alex Williamson --- drivers/vfio/pci/pds/dirty.c | 68 ++++++++++++++++---------------------------- drivers/vfio/pci/pds/dirty.h | 6 ++-- 2 files changed, 28 insertions(+), 46 deletions(-) (limited to 'drivers/vfio') diff --git a/drivers/vfio/pci/pds/dirty.c b/drivers/vfio/pci/pds/dirty.c index 27607d7b9030..4462f6edb0ed 100644 --- a/drivers/vfio/pci/pds/dirty.c +++ b/drivers/vfio/pci/pds/dirty.c @@ -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: diff --git a/drivers/vfio/pci/pds/dirty.h b/drivers/vfio/pci/pds/dirty.h index f78da25d75ca..9de5aac58190 100644 --- a/drivers/vfio/pci/pds/dirty.h +++ b/drivers/vfio/pci/pds/dirty.h @@ -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; }; -- cgit