From 358b1c992ec04c296b959b59c178a5d426c730a5 Mon Sep 17 00:00:00 2001 From: Brett Creeley Date: Thu, 16 Nov 2023 16:12:02 -0800 Subject: [PATCH] vfio/pds: Fix calculations in pds_vfio_dirty_sync [ Upstream commit 4004497cec3093d7b0087bc70709b45969fa07b6 ] The incorrect check is being done for comparing the iova/length being requested to sync. This can cause the dirty sync operation to fail. Fix this by making sure the iova offset added to the requested sync length doesn't exceed the region_size. Also, the region_start is assumed to always be at 0. This can cause dirty tracking to fail because the device/driver bitmap offset always starts at 0, however, the region_start/iova may not. Fix this by determining the iova offset from region_start to determine the bitmap offset. Fixes: f232836a9152 ("vfio/pds: Add support for dirty page tracking") Signed-off-by: Brett Creeley Signed-off-by: Shannon Nelson Link: https://lore.kernel.org/r/20231117001207.2793-2-brett.creeley@amd.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin --- drivers/vfio/pci/pds/dirty.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/vfio/pci/pds/dirty.c b/drivers/vfio/pci/pds/dirty.c index c937aa6..27607d7 100644 --- a/drivers/vfio/pci/pds/dirty.c +++ b/drivers/vfio/pci/pds/dirty.c @@ -478,8 +478,7 @@ static int pds_vfio_dirty_sync(struct pds_vfio_pci_device *pds_vfio, pds_vfio->vf_id, iova, length, pds_vfio->dirty.region_page_size, pages, bitmap_size); - if (!length || ((dirty->region_start + iova + length) > - (dirty->region_start + dirty->region_size))) { + if (!length || ((iova - dirty->region_start + length) > dirty->region_size)) { dev_err(dev, "Invalid iova 0x%lx and/or length 0x%lx to sync\n", iova, length); return -EINVAL; @@ -496,7 +495,8 @@ static int pds_vfio_dirty_sync(struct pds_vfio_pci_device *pds_vfio, return -EINVAL; } - bmp_offset = DIV_ROUND_UP(iova / dirty->region_page_size, sizeof(u64)); + bmp_offset = DIV_ROUND_UP((iova - dirty->region_start) / + dirty->region_page_size, sizeof(u64)); dev_dbg(dev, "Syncing dirty bitmap, iova 0x%lx length 0x%lx, bmp_offset %llu bmp_bytes %llu\n", -- 2.7.4