On Thu, Apr 30, 2026 at 02:52:17PM +0000, Stanislav Kinsburskii wrote: > Clean up hv_do_map_gpa_hcall() and hv_call_unmap_gpa_pages() after the > preceding bug-fix patches: > > Move "done += completed" before the status checks so that pages mapped > by a partially-successful batch are included in the error cleanup unmap. > Previously these mappings were leaked on failure. > > While here, improve type safety and readability: > - Change "int done" to "u64 done" to match the u64 page_count it is > compared against, avoiding signed/unsigned comparison hazards. > - Use u64 for loop iteration and batch size variables consistently. > - Add proper braces to the for-loop body in hv_do_map_gpa_hcall(). > - Remove unnecessary "ret" variable from hv_call_unmap_gpa_pages(). > - Simplify the error-path unmap to use "done << large_shift" directly > instead of mutating done in place. > > v3: aligned changes by 80 colons > v2: replaced min with min_t
This part describing the changes in various version should be placed after the "---" line below. This way it won't appear in the final commit log. https://www.kernel.org/doc/html/latest/process/submitting-patches.html#commentary Thanks, Anirudh. > > Fixes: 621191d709b14 ("Drivers: hv: Introduce mshv_root module to expose > /dev/mshv to VMMs") > Signed-off-by: Stanislav Kinsburskii <[email protected]> > --- > drivers/hv/mshv_root_hv_call.c | 56 > +++++++++++++++------------------------- > 1 file changed, 21 insertions(+), 35 deletions(-) > > diff --git a/drivers/hv/mshv_root_hv_call.c b/drivers/hv/mshv_root_hv_call.c > index e5992c324904a..e1f9e28d5a19b 100644 > --- a/drivers/hv/mshv_root_hv_call.c > +++ b/drivers/hv/mshv_root_hv_call.c > @@ -195,8 +195,8 @@ static int hv_do_map_gpa_hcall(u64 partition_id, u64 gfn, > u64 page_struct_count, > struct hv_input_map_gpa_pages *input_page; > u64 status, *pfnlist; > unsigned long irq_flags, large_shift = 0; > - int ret = 0, done = 0; > - u64 page_count = page_struct_count; > + u64 done = 0, page_count = page_struct_count; > + int ret = 0; > > if (page_count == 0 || (pages && mmio_spa)) > return -EINVAL; > @@ -213,8 +213,8 @@ static int hv_do_map_gpa_hcall(u64 partition_id, u64 gfn, > u64 page_struct_count, > } > > while (done < page_count) { > - ulong i, completed, remain = page_count - done; > - int rep_count = min(remain, HV_MAP_GPA_BATCH_SIZE); > + u64 i, completed, remain = page_count - done; > + u64 rep_count = min_t(u64, remain, HV_MAP_GPA_BATCH_SIZE); > > local_irq_save(irq_flags); > input_page = *this_cpu_ptr(hyperv_pcpu_input_arg); > @@ -224,23 +224,14 @@ static int hv_do_map_gpa_hcall(u64 partition_id, u64 > gfn, u64 page_struct_count, > input_page->map_flags = flags; > pfnlist = input_page->source_gpa_page_list; > > - for (i = 0; i < rep_count; i++) > - if (flags & HV_MAP_GPA_NO_ACCESS) { > + for (i = 0; i < rep_count; i++) { > + if (flags & HV_MAP_GPA_NO_ACCESS) > pfnlist[i] = 0; > - } else if (pages) { > - u64 index = (done + i) << large_shift; > - > - if (index >= page_struct_count) { > - ret = -EINVAL; > - break; > - } > - pfnlist[i] = page_to_pfn(pages[index]); > - } else { > + else if (pages) > + pfnlist[i] = page_to_pfn(pages[(done + i) << > + large_shift]); > + else > pfnlist[i] = mmio_spa + done + i; > - } > - if (ret) { > - local_irq_restore(irq_flags); > - break; > } > > status = hv_do_rep_hypercall(HVCALL_MAP_GPA_PAGES, rep_count, 0, > @@ -248,29 +239,26 @@ static int hv_do_map_gpa_hcall(u64 partition_id, u64 > gfn, u64 page_struct_count, > local_irq_restore(irq_flags); > > completed = hv_repcomp(status); > + done += completed; > > if (hv_result_needs_memory(status)) { > ret = hv_call_deposit_pages(NUMA_NO_NODE, partition_id, > HV_MAP_GPA_DEPOSIT_PAGES); > if (ret) > break; > - > } else if (!hv_result_success(status)) { > ret = hv_result_to_errno(status); > break; > } > - > - done += completed; > } > > if (ret && done) { > u32 unmap_flags = 0; > > - if (flags & HV_MAP_GPA_LARGE_PAGE) { > + if (flags & HV_MAP_GPA_LARGE_PAGE) > unmap_flags |= HV_UNMAP_GPA_LARGE_PAGE; > - done <<= large_shift; > - } > - hv_call_unmap_gpa_pages(partition_id, gfn, done, unmap_flags); > + hv_call_unmap_gpa_pages(partition_id, gfn, > + done << large_shift, unmap_flags); > } > > return ret; > @@ -305,7 +293,7 @@ int hv_call_unmap_gpa_pages(u64 partition_id, u64 gfn, > u64 page_count_4k, > struct hv_input_unmap_gpa_pages *input_page; > u64 status, page_count = page_count_4k; > unsigned long irq_flags, large_shift = 0; > - int ret = 0, done = 0; > + u64 done = 0; > > if (page_count == 0) > return -EINVAL; > @@ -319,8 +307,8 @@ int hv_call_unmap_gpa_pages(u64 partition_id, u64 gfn, > u64 page_count_4k, > } > > while (done < page_count) { > - ulong completed, remain = page_count - done; > - int rep_count = min(remain, HV_UMAP_GPA_PAGES); > + u64 completed, remain = page_count - done; > + u64 rep_count = min_t(u64, remain, HV_UMAP_GPA_PAGES); > > local_irq_save(irq_flags); > input_page = *this_cpu_ptr(hyperv_pcpu_input_arg); > @@ -333,15 +321,13 @@ int hv_call_unmap_gpa_pages(u64 partition_id, u64 gfn, > u64 page_count_4k, > local_irq_restore(irq_flags); > > completed = hv_repcomp(status); > - if (!hv_result_success(status)) { > - ret = hv_result_to_errno(status); > - break; > - } > - > done += completed; > + > + if (!hv_result_success(status)) > + return hv_result_to_errno(status); > } > > - return ret; > + return 0; > } > > int hv_call_get_gpa_access_states(u64 partition_id, u32 count, u64 > gpa_base_pfn, > >
