Re: [PATCH v2 2/3] receiver: Remove dependencies on HVM_MAX_VCPUS

[Owen Smith <owen.smith@xxxxxxxxxx>]

Reviewed-by: Owen Smith <owen.smith@xxxxxxxxxx>

________________________________________
From: win-pv-devel <win-pv-devel-bounces@xxxxxxxxxxxxxxxxxxxx> on behalf of Tu 
Dinh <ngoc-tu.dinh@xxxxxxxxxx>
Sent: 15 October 2026 2:16 PM
To: win-pv-devel@xxxxxxxxxxxxxxxxxxxx
Cc: Tu Dinh
Subject: [PATCH v2 2/3] receiver: Remove dependencies on HVM_MAX_VCPUS

For Receiver->GetList, XenNet can use KeQueryMaximumProcessorCountEx(
ALL_PROCESSOR_GROUPS) instead.

PutList is only used to replace the per-CPU GetList, so keep it as is.

Queue is indexed not by CPU index but by queue index, so allocate it
using the max count returned by QueryRingCount V11 instead.

Signed-off-by: Tu Dinh <ngoc-tu.dinh@xxxxxxxxxx>
---
v2: Set ProcessorCount and RingCount to 0 on cleanup.
---
 src/xennet/receiver.c | 61 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 55 insertions(+), 6 deletions(-)

diff --git a/src/xennet/receiver.c b/src/xennet/receiver.c
index 565d31b..7fb3ed2 100644
--- a/src/xennet/receiver.c
+++ b/src/xennet/receiver.c
@@ -33,7 +33,6 @@
 #include <ndis.h>
 #include <procgrp.h>
 #include <tcpip.h>
-#include <xen.h>
 #include <ethernet.h>

 #include "util.h"
@@ -52,9 +51,11 @@ typedef struct _XENNET_RECEIVER_QUEUE {
 struct _XENNET_RECEIVER {
     PXENNET_ADAPTER             Adapter;
     NDIS_HANDLE                 NetBufferListPool;
+    ULONG                       ProcessorCount;
+    ULONG                       RingCount;
     PNET_BUFFER_LIST            PutList;
-    PNET_BUFFER_LIST            GetList[HVM_MAX_VCPUS];
-    XENNET_RECEIVER_QUEUE       Queue[HVM_MAX_VCPUS];
+    PNET_BUFFER_LIST            *GetList;
+    XENNET_RECEIVER_QUEUE       *Queue;
     LONG                        Indicated;
     LONG                        Returned;
     XENVIF_VIF_OFFLOAD_OPTIONS  OffloadOptions;
@@ -500,6 +501,24 @@ ReceiverInitialize(
     RtlZeroMemory(*Receiver, sizeof(XENNET_RECEIVER));
     (*Receiver)->Adapter = Adapter;

+    (*Receiver)->ProcessorCount = 
KeQueryMaximumProcessorCountEx(ALL_PROCESSOR_GROUPS);
+    XENVIF_VIF(QueryRingCount,
+               AdapterGetVifInterface(Adapter),
+               NULL,
+               &(*Receiver)->RingCount);
+
+    (*Receiver)->GetList = __AllocatePoolWithTag(NonPagedPool,
+                                                 (*Receiver)->ProcessorCount * 
sizeof(PNET_BUFFER_LIST),
+                                                 RECEIVER_POOL_TAG);
+    if ((*Receiver)->GetList == NULL)
+        goto fail2;
+
+    (*Receiver)->Queue = __AllocatePoolWithTag(NonPagedPool,
+                                               (*Receiver)->RingCount * 
sizeof(XENNET_RECEIVER_QUEUE),
+                                               RECEIVER_POOL_TAG);
+    if ((*Receiver)->Queue == NULL)
+        goto fail3;
+
     RtlZeroMemory(&Params, sizeof(NET_BUFFER_LIST_POOL_PARAMETERS));
     Params.Header.Type = NDIS_OBJECT_TYPE_DEFAULT;
     Params.Header.Revision = NET_BUFFER_LIST_POOL_PARAMETERS_REVISION_1;
@@ -514,9 +533,9 @@ ReceiverInitialize(

     status = NDIS_STATUS_RESOURCES;
     if ((*Receiver)->NetBufferListPool == NULL)
-        goto fail2;
+        goto fail4;

-    for (Index = 0; Index < HVM_MAX_VCPUS; Index++) {
+    for (Index = 0; Index < (*Receiver)->RingCount; Index++) {
         PXENNET_RECEIVER_QUEUE  Queue = &(*Receiver)->Queue[Index];

         KeInitializeSpinLock(&Queue->Lock);
@@ -524,8 +543,29 @@ ReceiverInitialize(

     return NDIS_STATUS_SUCCESS;

+fail4:
+    Error("fail4\n");
+
+    __FreePoolWithTag((*Receiver)->Queue, RECEIVER_POOL_TAG);
+    (*Receiver)->Queue = NULL;
+
+fail3:
+    Error("fail3\n");
+
+    __FreePoolWithTag((*Receiver)->GetList, RECEIVER_POOL_TAG);
+    (*Receiver)->GetList = NULL;
+
 fail2:
+    Error("fail2\n");
+
+    (*Receiver)->ProcessorCount = 0;
+    (*Receiver)->RingCount = 0;
+    __FreePoolWithTag(*Receiver, RECEIVER_POOL_TAG);
+    *Receiver = NULL;
+
 fail1:
+    Error("fail1 (%08x)\n", status);
+
     return status;
 }

@@ -541,7 +581,7 @@ ReceiverTeardown(

     ASSERT3U(Receiver->Returned, ==, Receiver->Indicated);

-    for (Index = 0; Index < HVM_MAX_VCPUS; Index++) {
+    for (Index = 0; Index < Receiver->ProcessorCount; Index++) {
         NetBufferList = Receiver->GetList[Index];

         while (NetBufferList != NULL) {
@@ -571,6 +611,15 @@ ReceiverTeardown(
     NdisFreeNetBufferListPool(Receiver->NetBufferListPool);
     Receiver->NetBufferListPool = NULL;

+    __FreePoolWithTag(Receiver->Queue, RECEIVER_POOL_TAG);
+    Receiver->Queue = NULL;
+
+    __FreePoolWithTag(Receiver->GetList, RECEIVER_POOL_TAG);
+    Receiver->GetList = NULL;
+
+    Receiver->RingCount = 0;
+    Receiver->ProcessorCount = 0;
+
     Receiver->Adapter = NULL;

     __FreePoolWithTag(Receiver, RECEIVER_POOL_TAG);
--
2.55.0.windows.3


--
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