From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id EAADC4689F; Thu, 12 Jun 2025 13:39:11 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 056A940ECF; Thu, 12 Jun 2025 13:39:09 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mails.dpdk.org (Postfix) with ESMTP id 540394021F for ; Thu, 12 Jun 2025 13:39:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1749728347; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=1GX5v8HG/OEp61BEm13eO8kFiaDTrTJtYtE3Y6FZAuU=; b=Ec2a8mM3JUAxmLlI3Na9/tchKf194WhEA48JSssHIyWRqlSb6H1HyLcRkzHm+QyL6r0tIl 2NRruvJsiUlmE2H0cUqs/s19Fmi/gNdufaDx3IcE/wCmgvcTc355kYtkxTcwpyIiPZ7MCh jciMq8KM4A6OseoQs7veS0B7jeNUJ90= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-196-iSa-kP7yOUmVdd1zNKJntA-1; Thu, 12 Jun 2025 07:39:06 -0400 X-MC-Unique: iSa-kP7yOUmVdd1zNKJntA-1 X-Mimecast-MFC-AGG-ID: iSa-kP7yOUmVdd1zNKJntA_1749728345 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D3AF2195609E; Thu, 12 Jun 2025 11:39:02 +0000 (UTC) Received: from [10.44.22.28] (unknown [10.44.22.28]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D674C18003FC; Thu, 12 Jun 2025 11:38:56 +0000 (UTC) Message-ID: Date: Thu, 12 Jun 2025 13:38:53 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 1/1] vhost: handle virtqueue locking for memory hotplug To: Danylo Vodopianov , "thomas@monjalon.net" , "aman.deep.singh@intel.com" , "yuying.zhang@intel.com" , "orika@nvidia.com" , "mcoqueli@redhat.com" , Christian Koue Muf , "matan@mellanox.com" , "david.marchand@redhat.com" , Mykola Kostenok , Serhii Iliushyk Cc: "stephen@networkplumber.org" , "dev@dpdk.org" , Chenbo Xia References: <20250602084025.1881768-2-dvo-plv@napatech.com> <20250602085005.1882499-1-dvo-plv@napatech.com> <20250602085005.1882499-2-dvo-plv@napatech.com> <6ee82aef-dbb1-4e5f-8a53-6a956161c1db@redhat.com> From: Maxime Coquelin Autocrypt: addr=maxime.coquelin@redhat.com; keydata= xsFNBFOEQQIBEADjNLYZZqghYuWv1nlLisptPJp+TSxE/KuP7x47e1Gr5/oMDJ1OKNG8rlNg kLgBQUki3voWhUbMb69ybqdMUHOl21DGCj0BTU3lXwapYXOAnsh8q6RRM+deUpasyT+Jvf3a gU35dgZcomRh5HPmKMU4KfeA38cVUebsFec1HuJAWzOb/UdtQkYyZR4rbzw8SbsOemtMtwOx YdXodneQD7KuRU9IhJKiEfipwqk2pufm2VSGl570l5ANyWMA/XADNhcEXhpkZ1Iwj3TWO7XR uH4xfvPl8nBsLo/EbEI7fbuUULcAnHfowQslPUm6/yaGv6cT5160SPXT1t8U9QDO6aTSo59N jH519JS8oeKZB1n1eLDslCfBpIpWkW8ZElGkOGWAN0vmpLfdyiqBNNyS3eGAfMkJ6b1A24un /TKc6j2QxM0QK4yZGfAxDxtvDv9LFXec8ENJYsbiR6WHRHq7wXl/n8guyh5AuBNQ3LIK44x0 KjGXP1FJkUhUuruGyZsMrDLBRHYi+hhDAgRjqHgoXi5XGETA1PAiNBNnQwMf5aubt+mE2Q5r qLNTgwSo2dpTU3+mJ3y3KlsIfoaxYI7XNsPRXGnZi4hbxmeb2NSXgdCXhX3nELUNYm4ArKBP LugOIT/zRwk0H0+RVwL2zHdMO1Tht1UOFGfOZpvuBF60jhMzbQARAQABzSxNYXhpbWUgQ29x dWVsaW4gPG1heGltZS5jb3F1ZWxpbkByZWRoYXQuY29tPsLBeAQTAQIAIgUCV3u/5QIbAwYL CQgHAwIGFQgCCQoLBBYCAwECHgECF4AACgkQyjiNKEaHD4ma2g/+P+Hg9WkONPaY1J4AR7Uf kBneosS4NO3CRy0x4WYmUSLYMLx1I3VH6SVjqZ6uBoYy6Fs6TbF6SHNc7QbB6Qjo3neqnQR1 71Ua1MFvIob8vUEl3jAR/+oaE1UJKrxjWztpppQTukIk4oJOmXbL0nj3d8dA2QgHdTyttZ1H xzZJWWz6vqxCrUqHU7RSH9iWg9R2iuTzii4/vk1oi4Qz7y/q8ONOq6ffOy/t5xSZOMtZCspu Mll2Szzpc/trFO0pLH4LZZfz/nXh2uuUbk8qRIJBIjZH3ZQfACffgfNefLe2PxMqJZ8mFJXc RQO0ONZvwoOoHL6CcnFZp2i0P5ddduzwPdGsPq1bnIXnZqJSl3dUfh3xG5ArkliZ/++zGF1O wvpGvpIuOgLqjyCNNRoR7cP7y8F24gWE/HqJBXs1qzdj/5Hr68NVPV1Tu/l2D1KMOcL5sOrz 2jLXauqDWn1Okk9hkXAP7+0Cmi6QwAPuBT3i6t2e8UdtMtCE4sLesWS/XohnSFFscZR6Vaf3 gKdWiJ/fW64L6b9gjkWtHd4jAJBAIAx1JM6xcA1xMbAFsD8gA2oDBWogHGYcScY/4riDNKXi lw92d6IEHnSf6y7KJCKq8F+Jrj2BwRJiFKTJ6ChbOpyyR6nGTckzsLgday2KxBIyuh4w+hMq TGDSp2rmWGJjASrOwU0EVPSbkwEQAMkaNc084Qvql+XW+wcUIY+Dn9A2D1gMr2BVwdSfVDN7 0ZYxo9PvSkzh6eQmnZNQtl8WSHl3VG3IEDQzsMQ2ftZn2sxjcCadexrQQv3Lu60Tgj7YVYRM H+fLYt9W5YuWduJ+FPLbjIKynBf6JCRMWr75QAOhhhaI0tsie3eDsKQBA0w7WCuPiZiheJaL 4MDe9hcH4rM3ybnRW7K2dLszWNhHVoYSFlZGYh+MGpuODeQKDS035+4H2rEWgg+iaOwqD7bg CQXwTZ1kSrm8NxIRVD3MBtzp9SZdUHLfmBl/tLVwDSZvHZhhvJHC6Lj6VL4jPXF5K2+Nn/Su CQmEBisOmwnXZhhu8ulAZ7S2tcl94DCo60ReheDoPBU8PR2TLg8rS5f9w6mLYarvQWL7cDtT d2eX3Z6TggfNINr/RTFrrAd7NHl5h3OnlXj7PQ1f0kfufduOeCQddJN4gsQfxo/qvWVB7PaE 1WTIggPmWS+Xxijk7xG6x9McTdmGhYaPZBpAxewK8ypl5+yubVsE9yOOhKMVo9DoVCjh5To5 aph7CQWfQsV7cd9PfSJjI2lXI0dhEXhQ7lRCFpf3V3mD6CyrhpcJpV6XVGjxJvGUale7+IOp sQIbPKUHpB2F+ZUPWds9yyVxGwDxD8WLqKKy0WLIjkkSsOb9UBNzgRyzrEC9lgQ/ABEBAAHC wV8EGAECAAkFAlT0m5MCGwwACgkQyjiNKEaHD4nU8hAAtt0xFJAy0sOWqSmyxTc7FUcX+pbD KVyPlpl6urKKMk1XtVMUPuae/+UwvIt0urk1mXi6DnrAN50TmQqvdjcPTQ6uoZ8zjgGeASZg jj0/bJGhgUr9U7oG7Hh2F8vzpOqZrdd65MRkxmc7bWj1k81tOU2woR/Gy8xLzi0k0KUa8ueB iYOcZcIGTcs9CssVwQjYaXRoeT65LJnTxYZif2pfNxfINFzCGw42s3EtZFteczClKcVSJ1+L +QUY/J24x0/ocQX/M1PwtZbB4c/2Pg/t5FS+s6UB1Ce08xsJDcwyOPIH6O3tccZuriHgvqKP yKz/Ble76+NFlTK1mpUlfM7PVhD5XzrDUEHWRTeTJSvJ8TIPL4uyfzhjHhlkCU0mw7Pscyxn DE8G0UYMEaNgaZap8dcGMYH/96EfE5s/nTX0M6MXV0yots7U2BDb4soLCxLOJz4tAFDtNFtA wLBhXRSvWhdBJZiig/9CG3dXmKfi2H+wdUCSvEFHRpgo7GK8/Kh3vGhgKmnnxhl8ACBaGy9n fxjSxjSO6rj4/MeenmlJw1yebzkX8ZmaSi8BHe+n6jTGEFNrbiOdWpJgc5yHIZZnwXaW54QT UhhSjDL1rV2B4F28w30jYmlRmm2RdN7iCZfbyP3dvFQTzQ4ySquuPkIGcOOHrvZzxbRjzMx1 Mwqu3GQ= In-Reply-To: X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: FolAvQ-joX8P0fNMc76ilu4xX86SAX6dd0XcoiQxBY0_1749728345 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Hi Danylo, On 6/4/25 10:32 AM, Danylo Vodopianov wrote: > Hello, Maxime > > Thank you for your review. > If I understand correctly, you propose modifying the | > VHOST_USER_ASSERT_LOCK()| macro so that a |VHOST_USER_SET_MEM_TABLE| >  request does not trigger an assertion. > However, I believe such modification would not be appropriate, as it > would revert the logic introduced in commit |5e8fcc60b59d| ("vhost: > enhance virtqueue access lock asserts"). With this approach, we would be > performing memory hotplug without queue locking, which could lead to > unintended consequences. > Regarding VDPA device regression. We faced with this issue when we > request the number of lcores that the default amount of memory on the > socket cannot handle it. > So, regression occurred during the startup part, during device > configuration when it creates pkt mbuf pool. > > Let me know your thoughts regarding this. No, my point was to modify VHOST_USER_ASSERT_LOCK() to no trigger an assertion in case vDPA is configured, as we don't want to lock in this case. Regards, Maxime > ------------------------------------------------------------------------ > *От:* Maxime Coquelin > *Отправлено:* 3 июня 2025 г. 15:30 > *Кому:* Danylo Vodopianov ; thomas@monjalon.net > ; aman.deep.singh@intel.com > ; yuying.zhang@intel.com > ; orika@nvidia.com ; > mcoqueli@redhat.com ; Christian Koue Muf > ; matan@mellanox.com ; > david.marchand@redhat.com ; Mykola Kostenok > ; Serhii Iliushyk > *Копия:* stephen@networkplumber.org ; > dev@dpdk.org ; Chenbo Xia > *Тема:* Re: [PATCH v4 1/1] vhost: handle virtqueue locking for memory > hotplug > Hello Danylo, > > On 6/2/25 10:50 AM, Danylo Vodopianov wrote: >> For vDPA devices, virtqueues are not locked once the device has been >> configured. In the >> commit 5e8fcc60b59d ("vhost: enhance virtqueue access lock asserts"), >> the asserts were enhanced to trigger rte_panic functionality, preventing >> access to virtqueues without locking. However, this change introduced >> an issue where the memory hotplug mechanism, added in the >> commit 127f9c6f7b78 ("vhost: handle memory hotplug with vDPA devices"), >> no longer works. Since it expects for all queues are locked. >> >> During the initialization of a vDPA device, the driver sets the >> VIRTIO_DEV_VDPA_CONFIGURED flag, which prevents the >> vhost_user_lock_all_queue_pairs function from locking the >> virtqueues. This leads to the error: the VIRTIO_DEV_VDPA_CONFIGURED >> flag allows the use of the hotplug mechanism, but it fails >> because the virtqueues are not locked, while it expects to be locked >> for VHOST_USER_SET_MEM_TABLE in the table VHOST_MESSAGE_HANDLERS. >> >> This patch addresses the issue by enhancing the conditional statement >> to include a new condition. Specifically, when the device receives the >> VHOST_USER_SET_MEM_TABLE request, the virtqueues are locked to update >> the basic configurations and hotplug the guest memory. >> >> This fix does not impact access lock when vDPA driver is configured >> for other unnecessary message handlers. >> >> Manual memory configuring with "--socket-mem" option allows to avoid >> hotplug mechanism using. > > s/using/use/ > > It needs a fixes tag, and stable@dpdk.org should be cc'ed, so that it > gets backported to LTS branches. > >> >> Signed-off-by: Danylo Vodopianov >> --- >>   lib/vhost/vhost_user.c | 8 +++++++- >>   1 file changed, 7 insertions(+), 1 deletion(-) >> >> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c >> index ec950acf97..16d03e1033 100644 >> --- a/lib/vhost/vhost_user.c >> +++ b/lib/vhost/vhost_user.c >> @@ -3178,7 +3178,13 @@ vhost_user_msg_handler(int vid, int fd) >>         * would cause a dead lock. >>         */ >>        if (msg_handler != NULL && msg_handler->lock_all_qps) { >> -             if (!(dev->flags & VIRTIO_DEV_VDPA_CONFIGURED)) { >> +             /* Lock all queue pairs if the device is not configured for vDPA, >> +              * or if it is configured for vDPA but the request is VHOST_USER_SET_MEM_TABLE. >> +              * This ensures proper queue locking for memory table updates and guest >> +              * memory hotplug. >> +              */ >> +             if (!(dev->flags & VIRTIO_DEV_VDPA_CONFIGURED) || >> +                     request == VHOST_USER_SET_MEM_TABLE) { > > It looks like a workaround, and I'm afraid it could cause regression > with some vDPA devices, or that it would not be enough and we would have > to add other requests as exception. > > > Wouldn't it better to modify VHOST_USER_ASSERT_LOCK() so that it takes > into account the VIRTIO_DEV_VDPA_CONFIGURED flag? > > Thanks, > Maxime > >>                        vhost_user_lock_all_queue_pairs(dev); >>                        unlock_required = 1; >>                } >