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.
Fixes: 621191d709b14 ("Drivers: hv: Introduce mshv_root module to expose
/dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <[email protected]>
---
v4: Removed redundant "completed" variable
---
drivers/hv/mshv_root_hv_call.c | 58 ++++++++++++++--------------------------
1 file changed, 21 insertions(+), 37 deletions(-)
diff --git a/drivers/hv/mshv_root_hv_call.c b/drivers/hv/mshv_root_hv_call.c
index e5992c324904a..7509709f079fc 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, 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);
@@ -224,53 +224,40 @@ 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,
input_page, NULL);
local_irq_restore(irq_flags);
- completed = hv_repcomp(status);
+ done += hv_repcomp(status);
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 +292,7 @@ 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 +306,8 @@ 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 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);
@@ -332,16 +319,13 @@ int hv_call_unmap_gpa_pages(u64 partition_id, u64 gfn,
u64 page_count_4k,
0, input_page, NULL);
local_irq_restore(irq_flags);
- completed = hv_repcomp(status);
- if (!hv_result_success(status)) {
- ret = hv_result_to_errno(status);
- break;
- }
+ done += hv_repcomp(status);
- 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,
