linux-kernel - [PATCH v7 5/7] Drivers: hv: Improve region overlap detection in partition create

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Message-ID: 
 <176412295734.447063.5692907557041244468.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net>
Date: Wed, 26 Nov 2025 02:09:17 +0000
From: Stanislav Kinsburskii <skinsburskii@...ux.microsoft.com>
To: kys@...rosoft.com, haiyangz@...rosoft.com, wei.liu@...nel.org,
 decui@...rosoft.com
Cc: linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v7 5/7] Drivers: hv: Improve region overlap detection in
 partition create

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 <skinsburskii@...ux.microsoft.com>
---
 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;
-	}
 
 	rg = mshv_region_create(mem->guest_pfn, nr_pages,
 				mem->userspace_addr, mem->flags,