On 12/3/2025 10:58 AM, Nuno Das Neves wrote: > On 11/25/2025 6:09 PM, Stanislav Kinsburskii wrote: >> Refactor region overlap check in mshv_partition_create_region to use >> mshv_partition_region_by_gfn for both start and end guest PFNs, replacing >> manual iteration. >> >> This is a cleaner approach that leverages existing functionality to >> accurately detect overlapping memory regions. >> >> Signed-off-by: Stanislav Kinsburskii <[email protected]> >> --- >> drivers/hv/mshv_root_main.c | 8 ++------ >> 1 file changed, 2 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c >> index 5dfb933da981..ae600b927f49 100644 >> --- a/drivers/hv/mshv_root_main.c >> +++ b/drivers/hv/mshv_root_main.c >> @@ -1086,13 +1086,9 @@ static int mshv_partition_create_region(struct >> mshv_partition *partition, >> u64 nr_pages = HVPFN_DOWN(mem->size); >> >> /* Reject overlapping regions */ >> - hlist_for_each_entry(rg, &partition->pt_mem_regions, hnode) { >> - if (mem->guest_pfn + nr_pages <= rg->start_gfn || >> - rg->start_gfn + rg->nr_pages <= mem->guest_pfn) >> - continue; >> - >> + if (mshv_partition_region_by_gfn(partition, mem->guest_pfn) || >> + mshv_partition_region_by_gfn(partition, mem->guest_pfn + nr_pages - >> 1)) >> return -EEXIST; > > This logic does not work. I fixed this check in > ba9eb9b86d23 mshv: Fix create memory region overlap check > > This change would just be reverting that fix. > > Consider an existing region at 0x2000 of size 0x1000. The user > tries to map a new region at 0x1000 of size 0x3000. Since the new region > starts before and ends after the existing region, the overlap would not > be detected by this logic. It just checks if an existing region contains > 0x1000 or 0x4000 - 1 which it does not. This is why a manual iteration > here is needed. >
Apologies, after sending this I realized you already dropped the patch. >> - } >> >> rg = mshv_region_create(mem->guest_pfn, nr_pages, >> mem->userspace_addr, mem->flags, >> >> >
