From nobody Mon Mar 20 20:10:38 2023 X-Original-To: freebsd-xen@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4PgQpT3qj3z409yn for ; Mon, 20 Mar 2023 20:10:41 +0000 (UTC) (envelope-from abj.dev@gmx.com) Received: from mout.gmx.net (mout.gmx.net [212.227.15.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass Class 2 CA" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4PgQpS1MKlz3GsY for ; Mon, 20 Mar 2023 20:10:40 +0000 (UTC) (envelope-from abj.dev@gmx.com) Authentication-Results: mx1.freebsd.org; dkim=none; spf=pass (mx1.freebsd.org: domain of abj.dev@gmx.com designates 212.227.15.18 as permitted sender) smtp.mailfrom=abj.dev@gmx.com; dmarc=pass (policy=none) header.from=gmx.com Received: from [213.110.65.3] ([213.110.65.3]) by web-mail.gmx.net (3c-app-mailcom-bs03.server.lan [172.19.170.169]) (via HTTP); Mon, 20 Mar 2023 21:10:38 +0100 List-Id: Discussion List-Archive: https://lists.freebsd.org/archives/freebsd-xen List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-xen@freebsd.org X-BeenThere: freebsd-xen@freebsd.org MIME-Version: 1.0 Message-ID: From: Janis Abens To: Xen FreeBSD Subject: Kernel panic due to netback.c Content-Type: text/html; charset=UTF-8 Date: Mon, 20 Mar 2023 21:10:38 +0100 Importance: normal Sensitivity: Normal X-Priority: 3 X-Provags-ID: V03:K1:o1T0efVcXSgnQurqgDW5uCTRmw0iXUphg9QjznKMNLvpDOQfEXo6Sl5OTkcUjVOsQjpEr OoxQ5nnY8MApYD1uhQHsREoSNLBTTIGd52UobmiPBjDj1pCIGhcp0+3EmBN61TUaOLqdY4A2WzlG QQAO5qLgQatz9xygR0C7+9+TJdXW25ntmj77T+JPklqZlWaO+u0njr0AnefkNesnKKN7QdjxgXns i6bo0nfUf5k7UQy0K8xNWwNa1GKW1A4fKADoIlDO00tkLFjCTsWo5g34nyWJ7HXOtHPanxpjwnt+ ac= X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:IDlihw+6vck=;m/IFVLpiqvAZSEEektLwa7BNrYQ 6wgfP287m1W5WKkNKKtHJJVBh1oqqja/Gj+AVVoGrz3xBGvYKLbnZ8G41OWdZjoL8mNl49xpJ y6UklL4j/ZTF/d36kLv+dVonuqBhHFRLtIWx+Qedb7P8gwLsUZ3DLGqG4iGUvr/+qhziJ2vVR 1T0MtKsx1jwLcOJCOfIDSu1nt5M5wvg68zOMV6LYTlm/zHPLKYLIqpYtl9RSxrIHFSdcRUS6/ i2QaET1em8nYw8Sq+aC0IuyiNe4OqEQtdL+BElE/qawBDP/J+WRjlHHHftVVN/gSGyJNLScGE gS4giP1Yznw4SF1lyOoUXT5RZGh6tmK9/8fSsRfc1hWZGVPo3RYAWLBTdCy9PW21ZVPfUZdmy b6JoTLgjefZatNEH/7stEyu1gtr8FTQEv41JJfK4/h8fBXk1EARyAscAmNhZs/sYwfq2egAHm QwfB+eoCLjnJ7sb02Wbh/iL29NLUYFdmEmYWWAgvcwVYl84ICi2Grnytw/fMXHli1VmtozYnP spp2T/MksB9RehbxdsvjqFw34qMP8TREFy4ecN/YUOfgKXIi7hcsNJVQ5u28gBpFFqsbSRjA/ okTSId1oUfkAIVERT853upIRZc99vx9Va9IvRZjTrvEKjKgme3GSki5yZqgRK9XM7+/O92SKC nYOVaraNgvdgQlneFZzrkoA+WcrP6Bq2CF5pyE6CJ9N62NTy6yl5Ja/x9hrFpxcvwGvsrqAMf m+hHNTRSiSx7bSsa728e4/okZ6igasQjxKNRtPt58ayo0rh7LXtQECNjDM8xRApemejOwl08J 1sDVugYY0MC82yPkZWVbnnMt7+WDEqSNFOlwNsrqTsxkU= X-Spamd-Result: default: False [1.05 / 15.00]; NEURAL_SPAM_MEDIUM(1.00)[0.999]; NEURAL_SPAM_SHORT(0.95)[0.954]; NEURAL_HAM_LONG(-0.80)[-0.804]; DMARC_POLICY_ALLOW(-0.50)[gmx.com,none]; MID_RHS_NOT_FQDN(0.50)[]; MIME_HTML_ONLY(0.20)[]; R_SPF_ALLOW(-0.20)[+ip4:212.227.15.0/24:c]; RCVD_IN_DNSWL_LOW(-0.10)[212.227.15.18:from]; MLMMJ_DEST(0.00)[freebsd-xen@FreeBSD.org]; FROM_EQ_ENVFROM(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmx.com]; R_DKIM_NA(0.00)[]; ASN(0.00)[asn:8560, ipnet:212.227.0.0/16, country:DE]; RCVD_COUNT_TWO(0.00)[2]; HAS_X_PRIO_THREE(0.00)[3]; RCVD_TLS_LAST(0.00)[]; RCPT_COUNT_ONE(0.00)[1]; RWL_MAILSPIKE_POSSIBLE(0.00)[212.227.15.18:from]; TO_MATCH_ENVRCPT_ALL(0.00)[]; TO_DN_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; MIME_TRACE(0.00)[0:~]; FREEMAIL_FROM(0.00)[gmx.com]; ARC_NA(0.00)[] X-Rspamd-Queue-Id: 4PgQpS1MKlz3GsY X-Spamd-Bar: + X-ThisMailContainsUnwantedMimeParts: N
Hello,
 
From time to time a kernel panic occurs. Xen-kernel-4.15, dom0, FreeBSD 13.0-RELEASE.
 
"Fatal trap 12: page fault while in kernel mode"
 
I can not repeat it reliably, but eventually it happens. I have captured a stack trace (always the same on crash), relevant part is:
..
#9  xnb_txpkt2gnttab (pkt=<optimized out>, pkt@entry=0xfffffe00c49fdac8, mbufc=<optimized out>, mbufc@entry=0xfffff8002f958500, gnttab=gnttab@entry=0xfffffe019ae94a70,
    txb=txb@entry=0xfffffe019ae95480, otherend_id=6) at /usr/src/sys/dev/xen/netback/netback.c:1715
#10 0xffffffff80a8d72a in xnb_recv (txb=0xfffffe019ae95480, otherend=6, mbufc=<optimized out>, ifnet=0xfffff80170f81000, gnttab=0xfffffe019ae94a70)
    at /usr/src/sys/dev/xen/netback/netback.c:1851
#11 xnb_intr (arg=0xfffffe019ae94000) at /usr/src/sys/dev/xen/netback/netback.c:1446
..
 
It seems netback.c has not changed in ages, same lines are valid in 13.2 RC3 as well.
 
relevant code around /usr/src/sys/dev/xen/netback/netback.c:1715
..
xnb_txpkt2gnttab(const struct xnb_pkt *pkt, struct mbuf *mbufc,
..
  while (size_remaining > 0) {
    const netif_tx_request_t *txq = RING_GET_REQUEST(txb, r_idx);
    const size_t mbuf_space = M_TRAILINGSPACE(mbuf) - m_ofs; /* PANIC happens here! */
..
 
By analyzing the trace i've come to conclusion that mbuf is NULL, thus macro:
#define M_TRAILINGSPACE(m) ((m)->m_maxlen - (m)->m_len)
introduces panic.
 
The only way mbuf can become NULL is within this same loop at line:1751 mbuf = mbuf->m_next;
it can not be NULL at the function call, because xnb_recv ensures that it is not NULL, before call.
 
The problem definiteley is because "while condition" is on size_remaining, but contents are accessed based on mbuf->m_next;
 
So my questions are:
1) would it be possible to add some function before the PANIC line (or mbuf->m_next) that dumps offending packet in error logs or something similar? The goal for this would be to find a way to reliably repeat this case and understand what is the cause? If there is no such a function, which variables would be relevant and hellpful in this case?
2) How could this code be modified so that it does not panic in this case, but just drops offending packet instead?
A code snippet in xnb_recv has caught my eye:
  if (*mbufc == NULL) {
    /*
     * Couldn't allocate mbufs.  Respond and drop the packet.  Do
     * not consume the requests
     */
    xnb_txpkt2rsp(&pkt, txb, 1);
    DPRINTF("xnb_intr: Couldn't allocate mbufs, num_consumed=%d\n",
        num_consumed);
    if_inc_counter(ifnet, IFCOUNTER_IQDROPS, 1);
    return ENOMEM;
  }
Could it be used in function xnb_txpkt2gnttab to avoid panic in this particular case as well?

Thank you!
Janis Abens
 
From nobody Mon Mar 20 20:25:17 2023 X-Original-To: freebsd-xen@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4PgR7N0Xysz40C44 for ; Mon, 20 Mar 2023 20:25:20 +0000 (UTC) (envelope-from abj.dev@gmx.com) Received: from mout.gmx.net (mout.gmx.net [212.227.15.19]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass Class 2 CA" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4PgR7L6S2qz3Nch for ; Mon, 20 Mar 2023 20:25:18 +0000 (UTC) (envelope-from abj.dev@gmx.com) Authentication-Results: mx1.freebsd.org; dkim=none; spf=pass (mx1.freebsd.org: domain of abj.dev@gmx.com designates 212.227.15.19 as permitted sender) smtp.mailfrom=abj.dev@gmx.com; dmarc=pass (policy=none) header.from=gmx.com Received: from [213.110.65.3] ([213.110.65.3]) by web-mail.gmx.net (3c-app-mailcom-bs03.server.lan [172.19.170.169]) (via HTTP); Mon, 20 Mar 2023 21:25:17 +0100 List-Id: Discussion List-Archive: https://lists.freebsd.org/archives/freebsd-xen List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-xen@freebsd.org X-BeenThere: freebsd-xen@freebsd.org MIME-Version: 1.0 Message-ID: From: Janis Abens To: Xen FreeBSD Subject: Re: Kernel panic due to netback.c Content-Type: text/plain; charset=UTF-8 Date: Mon, 20 Mar 2023 21:25:17 +0100 Importance: normal Sensitivity: Normal Content-Transfer-Encoding: quoted-printable X-Priority: 3 X-Provags-ID: V03:K1:5iVW0tOCEPy0+jlF1kWth/QWCqFUnYz9k7/vZWDyKYfzX/ED0SLFI6N4rNERNmp5FGxVF PX331Ph/dhlSJVd8btZqhAkz4xh0cG/rDjasZir2/cMtYN/i+luBDxlKF/IiVUD3VoXr4UlFlFB8 FlrgjjeuZuFdJFMRx4UrpcbSGFJr/fyuokD+y7Poq3kZwaS5dMnkoA5qCqxf/9myEDYrfsqxXIi4 tXLTd1c1MONS3lL5qOiJS+W22uBIZGz4NUmbz1Ju7w62mvUKFgex4PwDmTxP34p+WS2kIqZwK3+Y CY= X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:GNFlJOr7oSQ=;hHO/lYzhelC/c0DvMnNzb6EDVa+ ic5dZZLCl5MpVTW4dBdD7AeF/Y2B0dcVjLzrB5FVOxZe4m1BaQ7N42CwQjoyJugtPwRiC+OFV MpBlEiwQVdp1eHVSVzDqPPGFp2Hb9+UAn1sQLrxx/BeuDnIS+c/hFKYztIwib9kON4m1sppBW ROiRoGnUqjLVtYoRWfdeB6TOKNCtfTi0xiY2MiOy0ywaBlB1JG84WuMm/tNjMGBs5Ijj3s2fu Bc95HXg5qfxg5E5/Vx4kRRzsL1hw0gwut5qDecAgDpfSFrf1REwPiOG5TkfY/WPPVfqMP0F3M 5k29mSxkRpoS93Vj1RiQ22EBKwhhxaNLibMx9l1THyge5Q37676OLkXJXJ2uDPCcTWjm9ey7V CYySAC7R8D7CZZ1+EpmEfrHucKpSo0ZDuGEQBzHhKP03uWytubrt0M8foSfNJtqf5P3W0wrEZ ZmZvYecLCbVrwOOj0vfCDl1XLYGCrsGBbKLL0uwAPrpRKTW3x2e5JALiyjbD7c3Wyxw4vvIO3 oh5WzGiWS3wtu1oaKSwvG2LN8zvIFwd56nc/rB+06VMDJ+Wk+Cq9HoKOtfe1kcv0EtfJJDpkF V88oxx5NnYrCNhoFH5jrbslFsx3T/lD+2zumu2dQnZjm9vSxJFqJNgMpjygZXy1iZmDV8ucov iO/Fw9RKV60sDbLconVO53l3fvydA637izI6fJ2zUHETN39BWh3VFu4KD0pLgsgmrRYFRpNP4 z1+jp9T4a8cNlZxiAsZBUkOqDf6JCjz2qdrRUGtUVOVHt5WSGRLk5O2dbhtU9d3b4xb5jQbY/ GHNjjnwfaWzf6ZoePKu6R39gr+R6dq9SNcJbgjrunBs/Y= X-Spamd-Result: default: False [-0.44 / 15.00]; FAKE_REPLY(1.00)[]; NEURAL_HAM_MEDIUM(-0.96)[-0.957]; DMARC_POLICY_ALLOW(-0.50)[gmx.com,none]; MID_RHS_NOT_FQDN(0.50)[]; NEURAL_HAM_LONG(-0.29)[-0.286]; NEURAL_SPAM_SHORT(0.20)[0.203]; R_SPF_ALLOW(-0.20)[+ip4:212.227.15.0/24:c]; MIME_GOOD(-0.10)[text/plain]; RCVD_IN_DNSWL_LOW(-0.10)[212.227.15.19:from]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[gmx.com]; MLMMJ_DEST(0.00)[freebsd-xen@FreeBSD.org]; ASN(0.00)[asn:8560, ipnet:212.227.0.0/16, country:DE]; FROM_EQ_ENVFROM(0.00)[]; HAS_X_PRIO_THREE(0.00)[3]; RCVD_TLS_LAST(0.00)[]; RWL_MAILSPIKE_POSSIBLE(0.00)[212.227.15.19:from]; FROM_HAS_DN(0.00)[]; ARC_NA(0.00)[]; TO_DN_ALL(0.00)[]; FREEMAIL_FROM(0.00)[gmx.com]; RCPT_COUNT_ONE(0.00)[1]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-Rspamd-Queue-Id: 4PgR7L6S2qz3Nch X-Spamd-Bar: / X-ThisMailContainsUnwantedMimeParts: N I'm sorry, it's unreadable=2E I sen't it from the new webmail, that has a d= efault setting to HTML=2E Fixing my error and resending previous message as= text=2E =C2=A0 Hello, >From time to time a kernel panic occurs=2E Xen-kernel-4=2E15, dom0, FreeBS= D 13=2E0-RELEASE=2E "Fatal trap 12: page fault while in kernel mode" I can not repeat it reliably, but eventually it happens=2E I have captured= a stack trace (always the same on crash), relevant part is: =2E=2E #9 xnb_txpkt2gnttab (pkt=3D, pkt@entry=3D0xfffffe00c49fdac= 8, mbufc=3D, mbufc@entry=3D0xfffff8002f958500, gnttab=3Dgntt= ab@entry=3D0xfffffe019ae94a70, txb=3Dtxb@entry=3D0xfffffe019ae95480, otherend_id=3D6) at /usr/src/sys= /dev/xen/netback/netback=2Ec:1715 #10 0xffffffff80a8d72a in xnb_recv (txb=3D0xfffffe019ae95480, otherend=3D6= , mbufc=3D, ifnet=3D0xfffff80170f81000, gnttab=3D0xfffffe019= ae94a70) at /usr/src/sys/dev/xen/netback/netback=2Ec:1851 #11 xnb_intr (arg=3D0xfffffe019ae94000) at /usr/src/sys/dev/xen/netback/ne= tback=2Ec:1446 =2E=2E It seems netback=2Ec has not changed in ages, same lines are valid in 13= =2E2 RC3 as well=2E relevant code around /usr/src/sys/dev/xen/netback/netback=2Ec:1715 =2E=2E xnb_txpkt2gnttab(const struct xnb_pkt *pkt, struct mbuf *mbufc, =2E=2E while (size_remaining > 0) { const netif_tx_request_t *txq =3D RING_GET_REQUEST(txb, r_idx); const size_t mbuf_space =3D M_TRAILINGSPACE(mbuf) - m_ofs; /* PANIC ha= ppens here! */ =20 =2E=2E By analyzing the trace i've come to conclusion that mbuf is NULL, thus mac= ro: #define M_TRAILINGSPACE(m) ((m)->m_maxlen - (m)->m_len) introduces panic=2E The only way mbuf can become NULL is within this same loop at line:1751 mb= uf =3D mbuf->m_next; It can not be NULL at the function call, because xnb_recv ensures that it = is not NULL, before call=2E The problem definiteley is because while condition is on size_remaining, b= ut contents are accessed based on mbuf->m_next; So my questions are: 1) would it be possible to add some function before the PANIC line (or mbu= f->m_next) that dumps offending packet in error logs or something similar? = The goal for this would be to find a way to reliably repeat this case and u= nderstand what is the cause? If there is no such a function, which variable= s would be relevant and hellpful in this case? 2) How could this code be modified so that it does not panic in this case,= but just drops offending packet instead? A code snippet in xnb_recv has caught my eye: if (*mbufc =3D=3D NULL) { /* * Couldn't allocate mbufs=2E Respond and drop the packet=2E Do * not consume the requests */ xnb_txpkt2rsp(&pkt, txb, 1); DPRINTF("xnb_intr: Couldn't allocate mbufs, num_consumed=3D%d\n", num_consumed); if_inc_counter(ifnet, IFCOUNTER_IQDROPS, 1); return ENOMEM; } Could it be used in function xnb_txpkt2gnttab to avoid panic in this parti= cular case as well? Thank you! Janis Abens =C2=A0 From nobody Tue Mar 21 10:37:20 2023 X-Original-To: freebsd-xen@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4Pgp2t1Nd1z3ytWp for ; Tue, 21 Mar 2023 10:37:42 +0000 (UTC) (envelope-from prvs=437062dd9=roger.pau@citrix.com) Received: from esa6.hc3370-68.iphmx.com (esa6.hc3370-68.iphmx.com [216.71.155.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mx1.hc3370-68.iphmx.com", Issuer "HydrantID Server CA O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Pgp2q62LZz46d5 for ; Tue, 21 Mar 2023 10:37:39 +0000 (UTC) (envelope-from prvs=437062dd9=roger.pau@citrix.com) Authentication-Results: mx1.freebsd.org; dkim=pass header.d=citrix.com header.s=securemail header.b=ZAtoWfpn; dkim=pass header.d=citrix.onmicrosoft.com header.s=selector2-citrix-onmicrosoft-com header.b=Tyo56aI5; spf=pass (mx1.freebsd.org: domain of "prvs=437062dd9=roger.pau@citrix.com" designates 216.71.155.175 as permitted sender) smtp.mailfrom="prvs=437062dd9=roger.pau@citrix.com"; dmarc=pass (policy=reject) header.from=citrix.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1679395060; h=date:from:to:cc:subject:message-id:references: content-transfer-encoding:in-reply-to:mime-version; bh=mzjY5QN3eklpIWDECd02NZX2UcsCiYuTblXwZhJ0rsw=; b=ZAtoWfpnKRnKXt8va79YoE1jOUBZV9iHIXlvABLovj4FDxMFIesvmuSL c35njcis6vUAdN9S327tnSFDj4pDFjXLPSTlcTfmUZZVGzT460s23HxQf JdgASFJekvU9+rNgZ9p7/958GXkM93r4CNnb2ykqPMplqX6kUdxOYDW1b M=; X-IronPort-RemoteIP: 104.47.51.46 X-IronPort-MID: 101048027 X-IronPort-Reputation: None X-IronPort-Listener: OutboundMail X-IronPort-SenderGroup: RELAY_O365 X-IronPort-MailFlowPolicy: $RELAYED IronPort-Data: A9a23://oXta9jHii7d6B6Da6TDrUDln+TJUtcMsCJ2f8bNWPcYEJGY0x3m mIdXmiCPvjYNmb1etolb9vn9xlXucDWzIBgTgY6/io8E34SpcT7XtnIdU2Y0wF+jCHgZBk+s 5hBMImowOQcFCK0SsKFa+C5xZVE/fjUAOG6UKicYXoZqTZMEE8JkQhkl/MynrlmiN24BxLlk d7pqojUNUTNNwRcawr40Ire7kI/1BjOkGlA5AdmPqoS5Aa2e0Q9V/rzG4ngdxMUfaEMdgKKb 76r5K20+Grf4yAsBruN+losWhRXKlJ6FVHmZkt+A8BOsDAbzsAB+v9T2M4nQVVWk120c+VZk 72hg3ASpTABZcUgkMxFO/VR/roX0aduoNcrKlDn2SCfItGvn9IBDJyCAWlvVbD09NqbDklM1 PUcdDkxZSmcpMOo5IOER9lXot8KeZyD0IM34hmMzBn/JNN+G9XpZfyP4tVVmjAtmspJAPDSI dIDbiZiZwjBZBsJPUoLDJU5n6GjgXyXnz9w8QrJ4/ZopTWKilAvuFTuGIO9ltiiX8Jak1zev mvb12/4HgsbJJqUzj/tHneE37eWxX+rANhNfFG+3sNqo3ev3VI5NAFMUUmQs8vkiRGGYc0Kf iT4/QJr98De7neDR9X0QhK4rWSFog80R9NVDqs35Bzl4qTO7guTHWRBXjNHQNI8ucI8XjBs0 UWG9+4FHhRqubyRDHibr7GdqGvoPTBPdTNcIygZUQEC/t/v5pkpiQ7CRcpiF6jzicDpHTb3w HaBqy1Wa6gvsPPnHp6TpTjv6w9AbLCTFmbZOi2/srqZ0z5E IronPort-HdrOrdr: A9a23:VGravq2/nIG1ZM/1L8USrwqjBdJxeYIsimQD101hICG9Lfb0qy n+pp4mPEHP4wr5OEtOpTlPAtjkfZr5z+8M3WB3B8bYYOCGghrQEGgG1+ffKlLbexEWmtQttp uINpIOcuEYbmIK8voSgjPIdOrIqePvmM7IuQ6d9QYKcegDUdAd0+4TMHf+LqQZfnglOXJvf6 Dsm/av6gDQD0g/X4CePD0oTuLDr9rEmNbPZgMHPQcu7E2jnC6l87nzFjmfx1M7XylUybkv3G DZm0ihj5/T+c2T+1v57Sv+/p5WkNzuxp9qA9GNsNEcLnHBmxulf4NoXpyFpXQQrPu04Fgnvd HQq1MLPth16VnWYmapyCGdkDXI4XIL0TvP2FWYiXzsrYjQQy87MdNIgcZ8fgHC40Qtkdlg2O YTtljp/6Z/PFflpmDQ9tLIXxZlmg6dpmcjq/caizh6XZEFYLFcgIQD9Ad+EYsGHgj99Ic7ed MeRf301bJzSxe3fnrZtm5gzJiFWWkyJA6PRgw4tsmcw1Ft7QVE5npd4PZasmYL9Zo7RZUBzf /DKL5UmLZHSdJTRb5hBc8aKPHHRFDlcFbpCia/MF7nHKYINzbmsJjs+og44+msZdgh0IYyop LcS1lV3FRCNH4GMff+nKGjzyq9A1lUBV/Wu4NjDtlCy/HBrYPQQGy+oAtEqbrknx0daverKc pbdqgmR8MLFlGeabqh7zeOJaW6FkNuIfH9muxLL25m8fi7XbHCh6j8TMv5AobLPHINZl7fa0 FzLwQbYv8wo3yWZg== X-IronPort-AV: E=Sophos;i="5.98,278,1673931600"; d="scan'208";a="101048027" Received: from mail-bn1nam02lp2046.outbound.protection.outlook.com (HELO NAM02-BN1-obe.outbound.protection.outlook.com) ([104.47.51.46]) by ob1.hc3370-68.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 21 Mar 2023 06:37:29 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=mxnarJEmMWp1nUAJd89oN7cGS/evX37R42XBEvMn3U0itGtG8Yd+eAtCSeATbkkNdadgO2zkreJiQymt1rjRT6WYmN+4TE7GRr41d1vVcPtXXBPhAbspbqWZ9S7o4QOif/agsD77RN5olP67KofCYjml43rXuFtW2Vehf5bDFFh1V4Udd1T6ePrD/K7nrDaD41lwfAOuFUsVyql734+lfrzbD5oOfYuyOYDrWT94CWSsNjl/wPTzmd0jlJfvb2g/ftD1zvIJrvnoNSO5NVCWipAdNQKCIIgqaw4ocHuX+DPp50a5xv/NwGg7VmEH4cH2YVWfoGONoNevK8qYEn5WmA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=fJiWnNMCe53eEsoVFMT0g34SbXJ0vYjjefqmv+xk10s=; b=maaDpjZIQJtRIBNld2NSQfGY4zkAZgg8ihLo1z8/1cui2Oq5FphJi6V7frrZ28bt8YMsPJU5dXSwexq8BVgCC+VHttd1izQcPzL90Gbc3EIDB4og5jCL3shG6eXliTpy2X8AqYp9eB7r+wyfFlvvW5z0V/pMNXxG6J4WPIx8yeCgOyOKNgeR6FCYWj1//IsLDL3d6JF81e+GaJc5mwQvsdmjXE2ufVh6hkhfXZwFE616LCNyRKdZa0rSLr4dgP2kosaLGlcTrw68QcgpN/czn55hU0KVswhp5fP9U4NQgBq3b7jqOZdGnYLv7rwLFscwuUaaBgjSzVfDqP6vLcLJxA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.onmicrosoft.com; s=selector2-citrix-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=fJiWnNMCe53eEsoVFMT0g34SbXJ0vYjjefqmv+xk10s=; b=Tyo56aI5v7pttKQHUokv8wR5VLf5w0mhgo74f5kQLR9kl114c4i9ENYrEJ9Z4p6jsR7n+VCqZs4vQIczUq4qmiyRxOXxncfORi0vJl84IzKvPkmM3MXtuMTd+0kLQ1HGRRB7bsiFWZfiDREIE3tHAoVMdpwsC1K1EI1MMZlEHps= Received: from SJ0PR03MB6360.namprd03.prod.outlook.com (2603:10b6:a03:395::11) by DS7PR03MB5526.namprd03.prod.outlook.com (2603:10b6:5:2cb::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6178.37; Tue, 21 Mar 2023 10:37:26 +0000 Received: from SJ0PR03MB6360.namprd03.prod.outlook.com ([fe80::48a7:d1ab:897:acda]) by SJ0PR03MB6360.namprd03.prod.outlook.com ([fe80::48a7:d1ab:897:acda%6]) with mapi id 15.20.6178.037; Tue, 21 Mar 2023 10:37:26 +0000 Date: Tue, 21 Mar 2023 11:37:20 +0100 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: "Daugherity, Andrew W" Cc: "freebsd-xen@FreeBSD.org" Subject: Re: xbd attach as ada Message-ID: References: <7A9C7452-DFEB-417E-B1D1-B18ABA171703@tamu.edu> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <7A9C7452-DFEB-417E-B1D1-B18ABA171703@tamu.edu> X-ClientProxiedBy: LO3P123CA0004.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:ba::9) To SJ0PR03MB6360.namprd03.prod.outlook.com (2603:10b6:a03:395::11) List-Id: Discussion List-Archive: https://lists.freebsd.org/archives/freebsd-xen List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-xen@freebsd.org X-BeenThere: freebsd-xen@freebsd.org MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ0PR03MB6360:EE_|DS7PR03MB5526:EE_ X-MS-Office365-Filtering-Correlation-Id: 4b27caaa-badd-4034-0bc9-08db29f8432d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SJ0PR03MB6360.namprd03.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230025)(4636009)(136003)(376002)(346002)(39860400002)(396003)(366004)(451199018)(66556008)(86362001)(83380400001)(316002)(9686003)(8936002)(186003)(41300700001)(2906002)(26005)(6506007)(6512007)(53546011)(85182001)(3480700007)(6916009)(4326008)(8676002)(66946007)(66476007)(6666004)(38100700002)(6486002)(82960400001)(5660300002)(478600001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?YXFkZWxUd2d1VlBERkFNOEdnbCtXdDl1RE5RQjQ1N3o2c2dKVTQ0T3F3eWV3?= =?utf-8?B?dEZ0WGE2WkloaG1oSWZFZTcwM2VNVjlVU084U0txbUxPNEl6Q1diaDFXQWl3?= =?utf-8?B?OGMwaFdocEZZM04rdTdpMS9BR055aEkxQnhhV0hPNlYvYmY2Nkw1RWlEMHZX?= =?utf-8?B?TitTRjh5ei9BRnA1MGNLaWY2eFg5ZHRJcXZHR2VhQ0dRZmhCMUd5eW1ZL3FJ?= =?utf-8?B?Ri9QRnpEcHBvckxYM0dFU3pwQi9aajREeXgxWlZSNzdIaU4xakNyTlhCcEdQ?= =?utf-8?B?eFdQR2hkbFpobHJIQXVhQzRmb051QUx1eTA1Z1pYUjdSY2VmNXorYVZQR1Y1?= =?utf-8?B?VUI4UVo1bUxsL1lHMDl2T1psVjcyeWNBTWtDMHY0UmMzVGpUQzFHUFk4VlMv?= =?utf-8?B?OTl1d3ZVRzUxQmVNT2Q0eWVWWi9GS0ttbmFYdkUzcDEzVlhZUDVOUXhPZ1pN?= =?utf-8?B?YkZ1YmdqeXAzbitZRzRIamw4OVdORm1WVit0ZDBWV3JSMVFFT0ZUaThPN1Bo?= =?utf-8?B?Q1lPanRqRFYxaGJ3dVo0K3VQVktPOW1UT2ltK25XQzlXL1VBbEpCdkhMVmlB?= =?utf-8?B?RDY2cGpRa1hKbU5aQzdvSWlhdFN6TDFxbUQvR1lCdVJmSjM0bDhhQWtPeEwv?= =?utf-8?B?YVl3VEx3TGd3VW9ENHZoR2xuT0VTTERuVEFIT0Z5UlNwU2xEMDYxMGdSSFhS?= =?utf-8?B?aU9BVnI2QlF3NkRYaTBkUjRJUHV4YjlTMTlCY3ZxZHBCZzJ5N2diUzVxK1po?= =?utf-8?B?VEdSTVB6Nm1FYU52Y0UwQS9xc3A5U0lGOExyMkp6Yk1aZS8rUjNwdW5zdXZX?= =?utf-8?B?VERTZFJTQmpKb0Voc0VaU0J1TU5KQ1hiTUpxSTBtMUF0QTY0Q0FiV0J0R1Nq?= =?utf-8?B?Z1ZhbDJGTFd4ZWR6SnNTRVNaWjM5aG1iTFUrUVliT3lTVWEwN3RQYU4vVmp4?= =?utf-8?B?TGtPSkdCd2FadUgxV3FXeFZ4WEFNRS9WZHVLempSVWxYS1Z3djgwbHVIQ1V5?= =?utf-8?B?bVMwRHVWZlh1QXRZYml6WmJLZE9zT3piekVlcTlGek1YMzlkZ3NnMXNLQU1K?= =?utf-8?B?WnZLc1lPZGZHVHNQNlRoQS9nSHFKeS9Dbk5XdDNNODJDVnVMWlkwNzlFT0ls?= =?utf-8?B?M0JmdTQ3ZlhVYTlYeFA3MWx1OHM1SkJsMjY0Uzk1bjdWRk5iN2t2dkk1cjRZ?= =?utf-8?B?ZEc1cTVIODJaL0xUYUZaSDM5K0YwV1duMUQyalZpU2NFT2NtNXdoLzNrSVcy?= =?utf-8?B?dkd2YUVvS0VjUmRmMys2TVE5U2hDeEd0TEwxb0xpem5IelpvcGV1UEhPdnVT?= =?utf-8?B?dUU4c3pzMnB4WmV1bFpZSmIySkpjbzQvekltQk00bm0wcVhjbzd4Q01PUXox?= =?utf-8?B?WWk1enQ0ZUVkaWt1ZDY1MElOVmREWnBSS3NETWpnc2VtTWVtd2FFM3pEVFNV?= =?utf-8?B?OEVuTlZpWURXWC82THZKLzhMV3o2SE9tRVJLMjVpUnlWVXpzaXJuWmtBcElQ?= =?utf-8?B?bFpjMXpjTmgzM214aXhkQlU4WC9pOWFCZnNiVUVuMWxkeTdzQzRWVnp0WUJY?= =?utf-8?B?TVE1WHN4b3EvVzVOcmtjVFptQysyNjJZVDh2MHUwRXdPRkpUd1VpOXlUbkln?= =?utf-8?B?UDRwQ0toWHlyWGhUREgyT3RyOWZvZE1HdFAvZlBMSzM5b3FRVG5VZmZnRm54?= =?utf-8?B?WC9WSTgrMnNQZTdOZk9xdng1OERyS0I1Mlo5NmhJYkYweStqdHpzWmpTWlpY?= =?utf-8?B?TjhoL25lVlJlYTNnZElHc01iS2RZWVc2eFJVLysyVkZBcjBXVURJbCtzMmxT?= =?utf-8?B?QlRmcHdSbnRHYTExS1prWEZZUnFvQzVBWlBxdVFBT3AyQUYrZjR4NVRXL1FB?= =?utf-8?B?MGNsSGxwaE9HR1VmWG51SUI0YzNDbjRvZ2tqVkhHemp5NjJ2aU4yTXo4L3lL?= =?utf-8?B?ZCs2QW8vN0pUdFFEeEk2bEFGWWlPZlFhZVdwYmZyakM5VFNDSXYvMkxOUFRh?= =?utf-8?B?L0YwZ05JdWxYOEhNRzZZNzZQTDJYckNIUVBVc05nN0NBMlZNa1cwWkpoU3Rp?= =?utf-8?B?ejVtZmRLZVY2Q3RhRlFrTU9BcEN4SStlbFpZMU8renFtUUwrQXRNdmdGMHAw?= =?utf-8?B?MUF1YlByaUN0d1M5K0UvbGhEVkJ6WkQveE5zTVJXNHVSd2VlcEFHdy9MVXlD?= =?utf-8?B?TkE9PQ==?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: citrix.com X-MS-Exchange-CrossTenant-Network-Message-Id: 4b27caaa-badd-4034-0bc9-08db29f8432d X-MS-Exchange-CrossTenant-AuthSource: SJ0PR03MB6360.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Mar 2023 10:37:26.1835 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 335836de-42ef-43a2-b145-348c2ee9ca5b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: LBHSnmRsdbejr8xNTL3xhENfWLhx3UBntWY32g3M0Dpy2VjCMPXQi6OYeTRboj2E15NCL9Va4hhw+CAUXQkRQw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR03MB5526 X-Spamd-Result: default: False [-6.06 / 15.00]; ARC_ALLOW(-1.00)[microsoft.com:s=arcselector9901:i=1]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; DWL_DNSWL_LOW(-1.00)[citrix.com:dkim]; NEURAL_HAM_SHORT(-0.99)[-0.987]; R_MIXED_CHARSET(0.63)[subject]; DMARC_POLICY_ALLOW(-0.50)[citrix.com,reject]; RCVD_DKIM_ARC_DNSWL_MED(-0.50)[]; R_DKIM_ALLOW(-0.20)[citrix.com:s=securemail,citrix.onmicrosoft.com:s=selector2-citrix-onmicrosoft-com]; RCVD_IN_DNSWL_MED(-0.20)[216.71.155.175:from]; R_SPF_ALLOW(-0.20)[+exists:216.71.155.175.spf.hc3370-68.iphmx.com]; MIME_GOOD(-0.10)[text/plain]; FROM_HAS_DN(0.00)[]; FORGED_SENDER_VERP_SRS(0.00)[]; TO_DN_EQ_ADDR_SOME(0.00)[]; ASN(0.00)[asn:16417, ipnet:216.71.154.0/23, country:US]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_COUNT_THREE(0.00)[4]; TO_DN_SOME(0.00)[]; FROM_NEQ_ENVFROM(0.00)[roger.pau@citrix.com,prvs=437062dd9=roger.pau@citrix.com]; RCPT_COUNT_TWO(0.00)[2]; RCVD_TLS_LAST(0.00)[]; DKIM_TRACE(0.00)[citrix.com:+,citrix.onmicrosoft.com:+]; MIME_TRACE(0.00)[0:+]; MLMMJ_DEST(0.00)[freebsd-xen@freebsd.org] X-Rspamd-Queue-Id: 4Pgp2q62LZz46d5 X-Spamd-Bar: ------ X-ThisMailContainsUnwantedMimeParts: N On Fri, Jan 20, 2023 at 12:21:36AM +0000, Daugherity, Andrew W wrote: > On Jan 19, 2023, at 1:48 AM, Echo Nar wrote: > > Hello, > > > > I've been trying to understand a bit more about how FreeBSD handles xvd (xbd) > > disks due to Bug 269023. I was wondering why does xbd blocks attach as ada > > devices rather than just act as xbd devices directly. > > > > > > dmesg snipit: > > xbd0: 16384MB at device/vbd/768 on xenbusb_front0 > > xbd0: attaching as ada0 > > xbd0: features: write_barrier > > xbd0: synchronize cache commands enabled. > > > I can’t speak to that — it’s probably related to how emulated ATA devices get “taken over” by the blkfront (xbd) driver — but one detail I can provide is that depending on how you configure the VM, it is possible for the device to show up as _only_ an xbd device and not adaN. > > For example, from one of my VMs (Linux Dom0, FreeBSD 12.3 VM), using the xl.cfg(5)/xl-disk-configuration(5) syntax: > # hda/ada0: LV in xen_san VG > # xvdb/xbd1: permanent device ID (rather than sdc) for LUN 2 from SAN > disk=[ 'phy:/dev/xen_san/backup,hda,w', 'phy:/dev/disk/by-id/wwn-0x60004d9...,xvdb,w', ] > > Inside the VM, they show up like this: > xbd0: 12288MB at device/vbd/768 on xenbusb_front0 > xbd0: attaching as ada0 > xbd0: features: flush, write_barrier > xbd0: synchronize cache commands enabled. > xbd1: 1933233MB at device/vbd/51728 on xenbusb_front0 > xbd1: features: flush, write_barrier > xbd1: synchronize cache commands enabled. > > Note that xbd1 does not attach as an ada device. > > When I upgraded the OS on the Dom0 (which included upgrading Xen from 4.4 to 4.12; there was no change inside the VM at this time), one change was that I could no longer attach different virtual disks as 'hda' and 'xvda' (aka ada0 and xbd0) or I’d get a similar issue to what you’re experiencing. I had to change the VM config to use xvdb instead. The reason for attaching as 'adaX' when using the 'hdX' notation in the guest config files is for compatibility with the emulated disk drives provided by QEMU. There was a time when Xen support was not compiled in the GENERIC kernel, so you would first install a plain FreeBSD guest using the emulated disks provided by QEMU, and after install you would build a XEN kernel to replace the GENERIC one. It was important that the disk names stayed the same when switching between the emulated devices and the para-virtualized ones, or else you would need to change fstab and any references to the emulated disks. Roger. From nobody Tue Mar 21 12:07:34 2023 X-Original-To: freebsd-xen@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4Pgr2s2wTPz400GP for ; Tue, 21 Mar 2023 12:07:49 +0000 (UTC) (envelope-from prvs=437062dd9=roger.pau@citrix.com) Received: from esa3.hc3370-68.iphmx.com (esa3.hc3370-68.iphmx.com [216.71.145.155]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mx1.hc3370-68.iphmx.com", Issuer "HydrantID Server CA O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Pgr2r6lxvz4FJg for ; Tue, 21 Mar 2023 12:07:48 +0000 (UTC) (envelope-from prvs=437062dd9=roger.pau@citrix.com) Authentication-Results: mx1.freebsd.org; none DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1679400468; h=date:from:to:cc:subject:message-id:references: content-transfer-encoding:in-reply-to:mime-version; bh=jAYHqVjt5RHaGZHMV3KWkXXiWDZ5GLiQ8zsv9UgZP+A=; b=cJ1JZTne5kGB7yREgQarvvBgN6uXGzqANVF98T3lKnPir5PVK86EC7M5 +sgWPX7hcpArJXGLqWuFFNmYe3qTMQI/NuS/1Da8KYPelGZA2jpIIAN5o ma2yyv4TYgxT+qxBAXlJC0T8LC2eBV6b1rd37xsDv8pZGcS9jFE9nLSAf U=; X-IronPort-RemoteIP: 104.47.55.170 X-IronPort-MID: 101696288 X-IronPort-Reputation: None X-IronPort-Listener: OutboundMail X-IronPort-SenderGroup: RELAY_O365 X-IronPort-MailFlowPolicy: $RELAYED IronPort-Data: A9a23:PtV8ZK00PNxwHP1AEvbD5dhwkn2cJEfYwER7XKvMYLTBsI5bpzdUm zEbCDiAa/2PZ2X2fIsibYi180JS7cDRxtZiGQo9pC1hF35El5HIVI+TRqvS04F+DeWYFR46s J9OAjXkBJppJpMJjk71atANlVEliefTAOK6ULWeUsxIbVcMYD87jh5+kPIOjIdtgNyoayuAo tq3qMDEULOf82cc3lk8tuTS+HuDgNyo4GlD5gdkPKgS1LPjvyJ94Kw3dPnZw0TQGuG4LsbiL 87fwbew+H/u/htFIrtJRZ6iLyXm6paLVeS/oiI+t5qK23CulQRrukoPD9IOaF8/ttm8t4sZJ OOhF3CHYVxB0qXkwIzxWvTDes10FfUuFLTveRBTvSEPpqFvnrSFL/hGVSkL0YMkFulfMHlp0 OYmLy0xcU7aqcya+K2ZY9BVmZF2RCXrFNt3VnBI6xj8VKxja7aTBqLA6JlfwSs6gd1IEbDGf c0FZDFzbRPGJRpSJlMQD5F4l+Ct7pX9W2QA9BTJ+uxqvi6Kk1QZPLvFabI5fvSQQspYhACAr 3/u9GXlGBAKcteYzFJp91r13raRzH2hCNJ6+LuQseNpgVuuyE8pUyY4TniwovmA1lK1VIcKQ 6AT0m90xUQoz2SiRNu7UxCmiHGBrlgXXN84O+Mg5QyH0aaR8wufLmYeQzNLc9Bgs9U5LQHGz XeMltLtQDZp4LucTCvH8q/O9Gzqfy8IMWUFeCkICxMf5MXuq50yiRSJSct/FKmyjZv+HjSYL y22kRXSTo471aYjv5hXN3ic695wjvAlljII2zg= IronPort-HdrOrdr: A9a23:D6y+R61N5SwEHFY/AwKXEAqjBKUkLtp133Aq2lEZdPUzSKylfq GV/cjzsCWe4gr5N0tQ++xoR5PwJE80maQZ3WBzB9mftWvdyQiVxehZhOPfKlbbdBEWmNQw6U 5oSdkbNOHN X-IronPort-AV: E=Sophos;i="5.98,278,1673931600"; d="scan'208";a="101696288" Received: from mail-bn8nam12lp2170.outbound.protection.outlook.com (HELO NAM12-BN8-obe.outbound.protection.outlook.com) ([104.47.55.170]) by ob1.hc3370-68.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 21 Mar 2023 08:07:44 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=dLx5vyzYOxOWHqr6HX6LlMe4hMl2H2WsPZl1Q0mAnXEdGuywKSKCFRbXuIn3yDBSaac1V5SXbtqm0JcZ9mAMJYLRIPgKdBvgwCNzqnboGieEy2TP2lxVlMAtdtnuEGRBfpFiQvC4/q1iBbhxBMlnG6wAP1LvTBw3QejcpKSb9lVMDhudz2243DxkpD94p6XmUCUVBrlaRD7HM7KeSFvU6w5OB2cbqu3EQghRVxtmnI70/2Um+0saJbevcSrbAb1UBT1hfJ9FCFNYXmHsi5Mj3O2G31V6UHCQwpvdpdYB/KIaOdhieAL3S8UD+vAh4YLyE04s+xXNg+Lk159y+4xSEg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=jimKpa0JdjVkf2foihzPLFUEXsGKGpOBEH0OQ7V9s0I=; b=ZyOEcaWyQrCXNgU+qr/Ww9Aiylq2dHgzR9w5y/8EcuxzRr/lol9OMMFQmE7iUerzRiZXvNRk2iGJYAvyHPfOpc9ETbs2CBOE18nQjs0f8BTpwbhEyV+FbAKAHalQt/mJYPFD3uWqkUUJlkHgIql4HJ7rSvUPhCWs6wjOXsHHVNBK6QWXZFPENUHTw67fU2KG4f2ef4oZhmLilYg5PMXkWCBYC0yLTjbXQCvXS+dHBZ9ihheY+tHTgeLPUbWjMWjcOg5uOotXG4RSYa02wjq14Ae0ZclxjEFvSYagTHIHvVckORadQOcHOWLkohIk75gjwfq07B7yVoZOhfjaWgBSjg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.onmicrosoft.com; s=selector2-citrix-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=jimKpa0JdjVkf2foihzPLFUEXsGKGpOBEH0OQ7V9s0I=; b=rRLLABwuMxZ0yNTYs6E3UsLIQxfLMyZ9UrmK8kiwI4nOKVw6w43yltDldRZZNsYgNjTq2iEKkJtp1p8SVa8F5bQ5us0367oonc/wfsTxP8Pt8ve/ONXAc2Vql5U075wrlXjRSdN+QNA0J7OGR5piEgA/s0bCAMIniAg5gvCezfA= Received: from SJ0PR03MB6360.namprd03.prod.outlook.com (2603:10b6:a03:395::11) by MW4PR03MB6473.namprd03.prod.outlook.com (2603:10b6:303:120::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6178.37; Tue, 21 Mar 2023 12:07:41 +0000 Received: from SJ0PR03MB6360.namprd03.prod.outlook.com ([fe80::48a7:d1ab:897:acda]) by SJ0PR03MB6360.namprd03.prod.outlook.com ([fe80::48a7:d1ab:897:acda%6]) with mapi id 15.20.6178.037; Tue, 21 Mar 2023 12:07:40 +0000 Date: Tue, 21 Mar 2023 13:07:34 +0100 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Janis Abens Cc: Xen FreeBSD Subject: Re: Kernel panic due to netback.c Message-ID: References: Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: LO4P265CA0079.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:2bd::12) To SJ0PR03MB6360.namprd03.prod.outlook.com (2603:10b6:a03:395::11) List-Id: Discussion List-Archive: https://lists.freebsd.org/archives/freebsd-xen List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-xen@freebsd.org X-BeenThere: freebsd-xen@freebsd.org MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ0PR03MB6360:EE_|MW4PR03MB6473:EE_ X-MS-Office365-Filtering-Correlation-Id: 07c74f1b-a93c-4bb7-05c6-08db2a04de50 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SJ0PR03MB6360.namprd03.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230025)(4636009)(136003)(396003)(39860400002)(346002)(366004)(376002)(451199018)(86362001)(478600001)(82960400001)(316002)(66476007)(41300700001)(38100700002)(5660300002)(6486002)(8936002)(85182001)(2906002)(6506007)(6666004)(6512007)(66556008)(6916009)(9686003)(66946007)(4326008)(8676002)(186003)(83380400001)(26005);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Uy8rcFVkRG9yY2FQOVp6V0toNE5EbW9PdHN1OTJqUmc0N0YyUkFtbzZwbXVk?= =?utf-8?B?UU55NHJGbmF6S042dU5zSVVlUFlkV3FJenZXZTRJc0ZkUjZmRmtjZjJ0YjF1?= =?utf-8?B?eWNoL1FJWmNaRmd4SDcvdnRGdTdzTGR2a3pyU1NQVWJZM2RoRHdVOUxWb2M1?= =?utf-8?B?UDRpQlFRYlIwbTdaaUxtT3JMOXVmT3lrT1RJUTFvb2VIL3NBQWtDbm1yd3V2?= =?utf-8?B?ckZlMmlvcGhhTUtFRm5NL2I2MUFvdXd3NmhIQnJBZDlwQ0JabWVVZDZWbWZh?= =?utf-8?B?bUluWmFmZDFKaDFUQUIyTGFtZ2l0ZkgySmZ3ZUI3RHZCblB1aVd5WWI1dnQr?= =?utf-8?B?M29tZkJBbDc1ZTcvU240c0RSZFA2SVcwTlhDd1FWcU5DTng0YVNQMVFpTVVi?= =?utf-8?B?L3hNUnhERTB1bGNYY0tvNEtkUEIyU2t0UGo3Q0dZQVkxWk1JYzZ2OUhBTTU3?= =?utf-8?B?U2dDZWlzSlMwMnJhREZWUnZiSkRhRGpJRHlQVHB4OVhoMmJPaTBuNTVmWERM?= =?utf-8?B?REh0cVpDV3ZSUS9lemU3TWVHRjVOS0FnSHRENzNjd2hWSXpRaXYrOElCYzl6?= =?utf-8?B?elQ0SmZObWpZRjhXY1ltRVVlcXJVczd3NnNSYldIVUtjMVR5dkVMS1JHNzdU?= =?utf-8?B?aEhXajJ1cFF4aCtlRWRhMTJpR2lxNG11ZUlRUENFaXd3eXpvclVSK2pyZGRu?= =?utf-8?B?RlhUZVhSUEc2NnN3VlhJaHpHdmVzcGRLWGR5bjhQRS9kMTdXTG90OEoxY0sy?= =?utf-8?B?RSt5Ty90eUU4VS9GVjg3YWFKMTZPeTlORm0rb0p6V3BSYTFuMjhhNzN1UFN1?= =?utf-8?B?c04vMGRmVWVKaFlyMEMwdGlsTkxkQW84R1NhL2N1VElvZ0RMakU2Y29raGRh?= =?utf-8?B?VEM1MjhvbUl6b2lvRmRYM3ROUUNiM3J4RmVhMGRoMWNHZElFelpZUWo4OHZU?= =?utf-8?B?TURuTm54NmJCaERTemxBMzQ5TmhmS25PZ1g5L0c2OEFrSVFNOEZQcFJidXRK?= =?utf-8?B?Q1BvUm93cjhSakZsbDZxUjhlOXV0UnplT3JlcGZGOUQ0VjhZVGRUYnpqQURG?= =?utf-8?B?NWxOSWMvRGNYN1RXVk1ZYVBLNm5RSmpIaGk4Z2xnRlowTk1tU1RCMDFWbU9N?= =?utf-8?B?eWVPMGRmT3I4c3ZwNXd4Z2hNdFVIbENvTUM5Q0hXSUxHTXRwSHhKK3FYcVFW?= =?utf-8?B?Tk45MTljTUZMQ0RxMUowcWZnaEhtelpaVEk2ckFFNlcrMDVwT3IyVmdzdUR6?= =?utf-8?B?d05taFhlais3dGlPa2JveGwyb0dHdDNEV1hkcXFZQ1RSdUt3emhBQ0NaNllK?= =?utf-8?B?UjNRUFIwdW1lTnJtcHNhUlFEa0hjT28rRDFsZVl4RkRBV2lnSDNMMzZ1WHVH?= =?utf-8?B?ekN2TzNDSnl0KzMzUGY4SjFHdUZpQnNhT1RtM1VoZmpRQzEyeGxjbzYxbzgw?= =?utf-8?B?Qmd0SVd4QjlDeDh5cFRpNlZOTHFSYktiQ0pOUTIxeW1FLzJCcjNJYWhxMkg0?= =?utf-8?B?K0NKamJid0ZNdHQzbTkrQTNXUDJQV3RYS2pXTEJOQTZOdlVTQklLTGY5aWE3?= =?utf-8?B?cGtEZnBBVDhDeHI1WUJYTzZKUUljakRTOHk3eVNrTCtUa1ZSMUZaWStld1pU?= =?utf-8?B?MUgzSHIwNlFnY2E0YzRYZW9yQit4a3NIVFVhQ3A2TWVZbTB2Um5GYWVOSkhE?= =?utf-8?B?bDF3VjkvejNyeFJuWHNEV1VOZFJBWWdNYVlSNktJUzlJcDFwaFl1ajVXS2JJ?= =?utf-8?B?Nm5OVHlMVkdRc1RCNHBnY2R5Y3RFTjhuenI2NlZRcnpwaTIvKzJqWEExZTVa?= =?utf-8?B?K3F0Qys2Q1ZyaHdxaVlpQlh1Zyt1NUhaWHI3dWVzZUFwdm4wc2lMMG1HZmNy?= =?utf-8?B?aUw0MGhHV3pTTU1UbURSSmpaZmRET2MwNFZEWTNtMmpVZTUweXEyQzVzWFMx?= =?utf-8?B?SU9nWW1jM0swamY2Z0JidVpLaXRmOG9OUVFnQ3V2YkY5Vk93elNScWJVcFN5?= =?utf-8?B?bHRiNGlORjdXZlYrMER0cFliRWpzUXlrODlXNXUvaXdTdFlMZmJLU2s4aWJX?= =?utf-8?B?c29TVHFwSXBNWld2TFkzenMxUHRjcXFabURJdU1mZktRR0pHUXNIMmVpWDc5?= =?utf-8?B?WGZKVlZGeWh6eko1RHRZSTdabVJIbndJQnMvTDZUY2FrWXRrZUU4TTh0cE9q?= =?utf-8?B?Rmc9PQ==?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: citrix.com X-MS-Exchange-CrossTenant-Network-Message-Id: 07c74f1b-a93c-4bb7-05c6-08db2a04de50 X-MS-Exchange-CrossTenant-AuthSource: SJ0PR03MB6360.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Mar 2023 12:07:40.5013 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 335836de-42ef-43a2-b145-348c2ee9ca5b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: EZkK6N6UO2YaqVgraPXPr7UnO39ljTFr/aFRkfaetrFNYlgUxdyd5w4rNZekWRGtt8vb7X7d0VkTswMDGh/ikQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR03MB6473 X-Rspamd-Queue-Id: 4Pgr2r6lxvz4FJg X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:16417, ipnet:216.71.145.0/24, country:US] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-ThisMailContainsUnwantedMimeParts: N On Mon, Mar 20, 2023 at 09:25:17PM +0100, Janis Abens wrote: > I'm sorry, it's unreadable. I sen't it from the new webmail, that has a default setting to HTML. Fixing my error and resending previous message as text. >   > Hello, > > From time to time a kernel panic occurs. Xen-kernel-4.15, dom0, FreeBSD 13.0-RELEASE. > > "Fatal trap 12: page fault while in kernel mode" > > I can not repeat it reliably, but eventually it happens. I have captured a stack trace (always the same on crash), relevant part is: > .. > #9 xnb_txpkt2gnttab (pkt=, pkt@entry=0xfffffe00c49fdac8, mbufc=, mbufc@entry=0xfffff8002f958500, gnttab=gnttab@entry=0xfffffe019ae94a70, > txb=txb@entry=0xfffffe019ae95480, otherend_id=6) at /usr/src/sys/dev/xen/netback/netback.c:1715 > #10 0xffffffff80a8d72a in xnb_recv (txb=0xfffffe019ae95480, otherend=6, mbufc=, ifnet=0xfffff80170f81000, gnttab=0xfffffe019ae94a70) > at /usr/src/sys/dev/xen/netback/netback.c:1851 > #11 xnb_intr (arg=0xfffffe019ae94000) at /usr/src/sys/dev/xen/netback/netback.c:1446 > .. > > It seems netback.c has not changed in ages, same lines are valid in 13.2 RC3 as well. > > relevant code around /usr/src/sys/dev/xen/netback/netback.c:1715 > .. > xnb_txpkt2gnttab(const struct xnb_pkt *pkt, struct mbuf *mbufc, > .. > while (size_remaining > 0) { > const netif_tx_request_t *txq = RING_GET_REQUEST(txb, r_idx); > const size_t mbuf_space = M_TRAILINGSPACE(mbuf) - m_ofs; /* PANIC happens here! */ > > .. > > By analyzing the trace i've come to conclusion that mbuf is NULL, thus macro: > #define M_TRAILINGSPACE(m) ((m)->m_maxlen - (m)->m_len) > introduces panic. > > The only way mbuf can become NULL is within this same loop at line:1751 mbuf = mbuf->m_next; > It can not be NULL at the function call, because xnb_recv ensures that it is not NULL, before call. > > The problem definiteley is because while condition is on size_remaining, but contents are accessed based on mbuf->m_next; > > So my questions are: > 1) would it be possible to add some function before the PANIC line (or mbuf->m_next) that dumps offending packet in error logs or something similar? The goal for this would be to find a way to reliably repeat this case and understand what is the cause? If there is no such a function, which variables would be relevant and hellpful in this case? > 2) How could this code be modified so that it does not panic in this case, but just drops offending packet instead? Likely, that would be a more graceful failure rather than a pointer dereference. I believe this is not supposed to happen in the first place, and thus the deref is a result of a bug elsewhere. I'm attaching a patch below that will print the relevant values from the previous loop when m_next is NULL and there's still data from the ring packet to copy. I've also added a break in that case, but I'm unsure that the rest of the logic can cope with this situation, it's quite possible that you will get a deref or a panic elsewhere in netback. Let me know what output you get with this patch. > A code snippet in xnb_recv has caught my eye: > if (*mbufc == NULL) { > /* > * Couldn't allocate mbufs. Respond and drop the packet. Do > * not consume the requests > */ > xnb_txpkt2rsp(&pkt, txb, 1); > DPRINTF("xnb_intr: Couldn't allocate mbufs, num_consumed=%d\n", > num_consumed); > if_inc_counter(ifnet, IFCOUNTER_IQDROPS, 1); > return ENOMEM; > } > > Could it be used in function xnb_txpkt2gnttab to avoid panic in this particular case as well? Hm, not really, at least not without understanding what causes this mismatch. Regards, Roger. --- diff --git a/sys/dev/xen/netback/netback.c b/sys/dev/xen/netback/netback.c index ddd5218a8936..89b9de2a3c98 100644 --- a/sys/dev/xen/netback/netback.c +++ b/sys/dev/xen/netback/netback.c @@ -1749,6 +1749,11 @@ xnb_txpkt2gnttab(const struct xnb_pkt *pkt, struct mbuf *mbufc, /* Must move to the next mbuf */ m_ofs = 0; mbuf = mbuf->m_next; + if (mbuf == NULL && size_remaining > 0) { + printf("next mbuf == NULL size_remaining: %d r_ofs %d m_ofs %d mbuf_space %zu req_size %zu pkt_space %zu space %zu", + size_remaining, r_ofs, m_ofs, mbuf_space, req_size, pkt_space, space); + break; + } } }