Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752696AbbKKMsP (ORCPT ); Wed, 11 Nov 2015 07:48:15 -0500 Received: from mail-ig0-f170.google.com ([209.85.213.170]:36649 "EHLO mail-ig0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752435AbbKKMsN (ORCPT ); Wed, 11 Nov 2015 07:48:13 -0500 Subject: Re: [PATCH 0/3] Infinite loops in microcode while running guests To: Paolo Bonzini , linux-kernel@vger.kernel.org, kvm@vger.kernel.org References: <1447158174-10484-1-git-send-email-pbonzini@redhat.com> Cc: digitaleric@google.com From: Austin S Hemmelgarn Message-ID: <564338F6.3070207@gmail.com> Date: Wed, 11 Nov 2015 07:47:50 -0500 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <1447158174-10484-1-git-send-email-pbonzini@redhat.com> Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-512; boundary="------------ms030204030000070106000202" X-Antivirus: avast! (VPS 151110-1, 2015-11-10), Outbound message X-Antivirus-Status: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6101 Lines: 109 This is a cryptographically signed message in MIME format. --------------ms030204030000070106000202 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable On 2015-11-10 07:22, Paolo Bonzini wrote: > Yes, these can happen. The issue is that benign exceptions are > delivered serially, but two of them (#DB and #AC) can also happen > during exception delivery itself. The subsequent infinite stream > of exceptions causes the processor to never exit guest mode. > > Paolo > > Eric Northup (1): > KVM: x86: work around infinite loop in microcode when #AC is deliver= ed > > Paolo Bonzini (2): > KVM: svm: unconditionally intercept #DB > KVM: x86: rename update_db_bp_intercept to update_bp_intercept > > arch/x86/include/asm/kvm_host.h | 2 +- > arch/x86/include/uapi/asm/svm.h | 1 + > arch/x86/kvm/svm.c | 22 +++++++++++----------- > arch/x86/kvm/vmx.c | 7 +++++-- > arch/x86/kvm/x86.c | 2 +- > 5 files changed, 19 insertions(+), 15 deletions(-) > I just finished running a couple of tests in a KVM instance running=20 nested on a Xen HVM instance, and found no issues, so for the set as a=20 whole: Tested-by: Austin S. Hemmelgarn Now to hope the equivalent fix for Xen gets into the Gentoo repositories = soon, as the issue propagates down through nested virtualization and=20 ties up the CPU regardless (and in turn triggers the watchdog). --------------ms030204030000070106000202 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgMFADCABgkqhkiG9w0BBwEAAKCC Brgwgga0MIIEnKADAgECAgMRLfgwDQYJKoZIhvcNAQENBQAweTEQMA4GA1UEChMHUm9vdCBD QTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNp Z25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcwHhcN MTUwOTIxMTEzNTEzWhcNMTYwMzE5MTEzNTEzWjBjMRgwFgYDVQQDEw9DQWNlcnQgV29UIFVz ZXIxIzAhBgkqhkiG9w0BCQEWFGFoZmVycm9pbjdAZ21haWwuY29tMSIwIAYJKoZIhvcNAQkB FhNhaGVtbWVsZ0BvaGlvZ3QuY29tMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEA nQ/81tq0QBQi5w316VsVNfjg6kVVIMx760TuwA1MUaNQgQ3NyUl+UyFtjhpkNwwChjgAqfGd LIMTHAdObcwGfzO5uI2o1a8MHVQna8FRsU3QGouysIOGQlX8jFYXMKPEdnlt0GoQcd+BtESr pivbGWUEkPs1CwM6WOrs+09bAJP3qzKIr0VxervFrzrC5Dg9Rf18r9WXHElBuWHg4GYHNJ2V Ab8iKc10h44FnqxZK8RDN8ts/xX93i9bIBmHnFfyNRfiOUtNVeynJbf6kVtdHP+CRBkXCNRZ qyQT7gbTGD24P92PS2UTmDfplSBcWcTn65o3xWfesbf02jF6PL3BCrVnDRI4RgYxG3zFBJuG qvMoEODLhHKSXPAyQhwZINigZNdw5G1NqjXqUw+lIqdQvoPijK9J3eijiakh9u2bjWOMaleI SMRR6XsdM2O5qun1dqOrCgRkM0XSNtBQ2JjY7CycIx+qifJWsRaYWZz0aQU4ZrtAI7gVhO9h pyNaAGjvm7PdjEBiXq57e4QcgpwzvNlv8pG1c/hnt0msfDWNJtl3b6elhQ2Pz4w/QnWifZ8E BrFEmjeeJa2dqjE3giPVWrsH+lOvQQONsYJOuVb8b0zao4vrWeGmW2q2e3pdv0Axzm/60cJQ haZUv8+JdX9ZzqxOm5w5eUQSclt84u+D+hsCAwEAAaOCAVkwggFVMAwGA1UdEwEB/wQCMAAw VgYJYIZIAYb4QgENBEkWR1RvIGdldCB5b3VyIG93biBjZXJ0aWZpY2F0ZSBmb3IgRlJFRSBo ZWFkIG92ZXIgdG8gaHR0cDovL3d3dy5DQWNlcnQub3JnMA4GA1UdDwEB/wQEAwIDqDBABgNV HSUEOTA3BggrBgEFBQcDBAYIKwYBBQUHAwIGCisGAQQBgjcKAwQGCisGAQQBgjcKAwMGCWCG SAGG+EIEATAyBggrBgEFBQcBAQQmMCQwIgYIKwYBBQUHMAGGFmh0dHA6Ly9vY3NwLmNhY2Vy dC5vcmcwMQYDVR0fBCowKDAmoCSgIoYgaHR0cDovL2NybC5jYWNlcnQub3JnL3Jldm9rZS5j cmwwNAYDVR0RBC0wK4EUYWhmZXJyb2luN0BnbWFpbC5jb22BE2FoZW1tZWxnQG9oaW9ndC5j b20wDQYJKoZIhvcNAQENBQADggIBADMnxtSLiIunh/TQcjnRdf63yf2D8jMtYUm4yDoCF++J jCXbPQBGrpCEHztlNSGIkF3PH7ohKZvlqF4XePWxpY9dkr/pNyCF1PRkwxUURqvuHXbu8Lwn 8D3U2HeOEU3KmrfEo65DcbanJCMTTW7+mU9lZICPP7ZA9/zB+L0Gm1UNFZ6AU50N/86vjQfY WgkCd6dZD4rQ5y8L+d/lRbJW7ZGEQw1bSFVTRpkxxDTOwXH4/GpQfnfqTAtQuJ1CsKT12e+H NSD/RUWGTr289dA3P4nunBlz7qfvKamxPymHeBEUcuICKkL9/OZrnuYnGROFwcdvfjGE5iLB kjp/ttrY4aaVW5EsLASNgiRmA6mbgEAMlw3RwVx0sVelbiIAJg9Twzk4Ct6U9uBKiJ8S0sS2 8RCSyTmCRhJs0vvva5W9QUFGmp5kyFQEoSfBRJlbZfGX2ehI2Hi3U2/PMUm2ONuQG1E+a0AP u7I0NJc/Xil7rqR0gdbfkbWp0a+8dAvaM6J00aIcNo+HkcQkUgtfrw+C2Oyl3q8IjivGXZqT 5UdGUb2KujLjqjG91Dun3/RJ/qgQlotH7WkVBs7YJVTCxfkdN36rToPcnMYOI30FWa0Q06gn F6gUv9/mo6riv3A5bem/BdbgaJoPnWQD9D8wSyci9G4LKC+HQAMdLmGoeZfpJzKHMYIE0TCC BM0CAQEwgYAweTEQMA4GA1UEChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNl cnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcN AQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DANBglghkgBZQMEAgMFAKCCAiEwGAYJKoZI hvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTUxMTExMTI0NzUwWjBPBgkq hkiG9w0BCQQxQgRA3F5FoMzw+QHEW/KyRUsNJo84416q8pJNGpcM6fe2fMB0XA7BlGNeExi1 Fi1Kzvp27awHYy2MVKsADwwS1Hf8UDBsBgkqhkiG9w0BCQ8xXzBdMAsGCWCGSAFlAwQBKjAL BglghkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFA MAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGRBgkrBgEEAYI3EAQxgYMwgYAweTEQMA4GA1UE ChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlD QSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2Vy dC5vcmcCAxEt+DCBkwYLKoZIhvcNAQkQAgsxgYOggYAweTEQMA4GA1UEChMHUm9vdCBDQTEe MBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25p bmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DAN BgkqhkiG9w0BAQEFAASCAgAv9vKS1rFFcKTsg7Dbdfvkz8rGZ7GVgKQlQhqLuhLhvshahgba i1Ns6LlEdCsfXQ4r6lITcpcCgzfstrQVbQ41YTtwS1U3J9RpLZJ9JL5R2WaOzP810i4CETyp oHDb4Wejf2oy9eHOlU7PxnTXdoCsZhtDUnAe3S+adwTXsduhGN89gzYzVXqLbTPkfHsdWh/O C1MGFbstVIWhDF7FEI6VWjm7BJB1+dJ488hYvnbDCutZjdXyEQJ8Dn8DW2vv1HrJD0uiBXz9 iA3xTCW+JljDzitATSlDODG7ZV8JzFrvbfCY8OF6xjF229M1vuc5EUhCWROB8cc+8U2TAeXE Lyeej+mOn8m/O+jK4Qn3B8V1GsDDxs9wyrzBLyAqrEpU+Ir3K8VnZZafSTj2vBEWrXeSn5Xt PT4xLazr1Z/SR8uvRnaeeCzOE5/jCNqiCCbtR7m1MDJsOnvNa+ICEkqZFnjeiWsJFeVMTHaj nl4h2SuesroGiMlFgWaQE1uGglqlQM9zu5NARtsffEiHg6GMHKZY71b4s/giyrw4tWkFT+0y uprgbLPmh1gbIYgWiRKbSAiNat41bpCTx0QrX2nQu7cVJ/LJLMwKD7F7hD+h2WS1ttKuNBKq jSVCIYBEwENEJNEfoiPnh4sWwLe790yktsqbvFRF+9J3wwoH3etHRKs+rgAAAAAAAA== --------------ms030204030000070106000202-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/