Reduce overhead when unmapping large memory regions by batching GPA unmap operations in 2MB-aligned chunks.
Use a dedicated constant for batch size to improve code clarity and maintainability. Signed-off-by: Stanislav Kinsburskii <[email protected]> --- drivers/hv/mshv_root.h | 2 ++ drivers/hv/mshv_root_hv_call.c | 2 +- drivers/hv/mshv_root_main.c | 28 +++++++++++++++++++++++++--- 3 files changed, 28 insertions(+), 4 deletions(-) diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h index e3931b0f12693..97e64d5341b6e 100644 --- a/drivers/hv/mshv_root.h +++ b/drivers/hv/mshv_root.h @@ -32,6 +32,8 @@ static_assert(HV_HYP_PAGE_SIZE == MSHV_HV_PAGE_SIZE); #define MSHV_PIN_PAGES_BATCH_SIZE (0x10000000ULL / HV_HYP_PAGE_SIZE) +#define MSHV_MAX_UNMAP_GPA_PAGES 512 + struct mshv_vp { u32 vp_index; struct mshv_partition *vp_partition; diff --git a/drivers/hv/mshv_root_hv_call.c b/drivers/hv/mshv_root_hv_call.c index c9c274f29c3c6..0696024ccfe31 100644 --- a/drivers/hv/mshv_root_hv_call.c +++ b/drivers/hv/mshv_root_hv_call.c @@ -17,7 +17,7 @@ /* Determined empirically */ #define HV_INIT_PARTITION_DEPOSIT_PAGES 208 #define HV_MAP_GPA_DEPOSIT_PAGES 256 -#define HV_UMAP_GPA_PAGES 512 +#define HV_UMAP_GPA_PAGES MSHV_MAX_UNMAP_GPA_PAGES #define HV_PAGE_COUNT_2M_ALIGNED(pg_count) (!((pg_count) & (0x200 - 1))) diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index 97e322f3c6b5e..b61bef6b9c132 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -1378,6 +1378,7 @@ mshv_map_user_memory(struct mshv_partition *partition, static void mshv_partition_destroy_region(struct mshv_mem_region *region) { struct mshv_partition *partition = region->partition; + u64 gfn, gfn_count, start_gfn, end_gfn; u32 unmap_flags = 0; int ret; @@ -1396,9 +1397,30 @@ static void mshv_partition_destroy_region(struct mshv_mem_region *region) if (region->flags.large_pages) unmap_flags |= HV_UNMAP_GPA_LARGE_PAGE; - /* ignore unmap failures and continue as process may be exiting */ - hv_call_unmap_gpa_pages(partition->pt_id, region->start_gfn, - region->nr_pages, unmap_flags); + start_gfn = region->start_gfn; + end_gfn = region->start_gfn + region->nr_pages; + + for (gfn = start_gfn; gfn < end_gfn; gfn += gfn_count) { + if (gfn % MSHV_MAX_UNMAP_GPA_PAGES) + gfn_count = ALIGN(gfn, MSHV_MAX_UNMAP_GPA_PAGES) - gfn; + else + gfn_count = MSHV_MAX_UNMAP_GPA_PAGES; + + if (gfn + gfn_count > end_gfn) + gfn_count = end_gfn - gfn; + + /* Skip if all pages in this range if none is mapped */ + if (!memchr_inv(region->pages + (gfn - start_gfn), 0, + gfn_count * sizeof(struct page *))) + continue; + + ret = hv_call_unmap_gpa_pages(partition->pt_id, gfn, + gfn_count, unmap_flags); + if (ret) + pt_err(partition, + "Failed to unmap GPA pages %#llx-%#llx: %d\n", + gfn, gfn + gfn_count - 1, ret); + } mshv_region_invalidate(region);
