From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C0A3ECAAD3 for ; Mon, 5 Sep 2022 22:00:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232031AbiIEWAa (ORCPT ); Mon, 5 Sep 2022 18:00:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231997AbiIEWAX (ORCPT ); Mon, 5 Sep 2022 18:00:23 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F180426ACD for ; Mon, 5 Sep 2022 15:00:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1662415214; 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; bh=NycFywALOql0/ca0A4x2CHoaBZkltjZTIH9JQYcZImU=; b=F4P1HODa8WNlGJHSo7hkR90GC8d1j+m66h408OGWwnos+gsHP7AW65pnYG3Xh7GJ0ak9lD nLtGUn7DIbFNK52ozcla7nLb27w9G36ZdNOSx9ikYjLOUGvayyDyvA/ynUZuzZt0//vUMF j4+6HZRvda/oZlbXCRtZvak45Hh4b78= Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-668-q25sJZ1WMlWELE2oI2HfSA-1; Mon, 05 Sep 2022 18:00:12 -0400 X-MC-Unique: q25sJZ1WMlWELE2oI2HfSA-1 Received: by mail-ed1-f70.google.com with SMTP id w17-20020a056402269100b0043da2189b71so6286490edd.6 for ; Mon, 05 Sep 2022 15:00:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date; bh=NycFywALOql0/ca0A4x2CHoaBZkltjZTIH9JQYcZImU=; b=l2CqDelp6iDwIahYiTcKN0aviX9us720XfVZZgN6XgfyYbry2KhXFGhtWdsRXfmyEh ZwGq5OqYCDymAqlUJ0psE7bUYwQmbgETWsbYJWD9rQfKH7zABkNxXARxopJbM+7RdfxC IRxA2M5bVy/3BibZEnlcPLWmmTsREi4CCuuXZlzWNrEty9TTPuvfJUztio+72rEYhtaj qgTNGyZoQHTBpl69B+MeaesMDdvjZQVsb86//0teQSq78am0AkCk9TQ2iyp405x5AvvW ogBsNYu+9CqLYqiMwBdu9zAMUqBjuMXwU2s3lMJK3BrdBpTJlbMNF4DiCxhR0uM10RDi 7eug== X-Gm-Message-State: ACgBeo01uu2UpBmM/HWQkN5MiDOvK7mAIvsO4rQ1VKqGs4xxqoijBfdc K9xLq09/r3C+13IqJqIbMqSwyzf83KpbafiWCejZFQBVtj5zZKvw2+nDklifuUMI+kjwtsBRmG5 YHN//BORXkBbZ X-Received: by 2002:a17:907:7208:b0:73d:7097:ac6f with SMTP id dr8-20020a170907720800b0073d7097ac6fmr38643636ejc.388.1662415211692; Mon, 05 Sep 2022 15:00:11 -0700 (PDT) X-Google-Smtp-Source: AA6agR7hM8eM+Xiuv8kXwmqBlg+wcV9zQxoLA+piVkr8Rq4/+ovIa7+JXsHqtDA1/MKLFHEQun/FjQ== X-Received: by 2002:a17:907:7208:b0:73d:7097:ac6f with SMTP id dr8-20020a170907720800b0073d7097ac6fmr38643619ejc.388.1662415211492; Mon, 05 Sep 2022 15:00:11 -0700 (PDT) Received: from ?IPV6:2001:b07:6468:f312:e3ec:5559:7c5c:1928? ([2001:b07:6468:f312:e3ec:5559:7c5c:1928]) by smtp.googlemail.com with ESMTPSA id q3-20020a17090676c300b007030c97ae62sm5550526ejn.191.2022.09.05.15.00.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 05 Sep 2022 15:00:11 -0700 (PDT) Message-ID: Date: Mon, 5 Sep 2022 23:59:52 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.1 Subject: Re: [PATCH v2 03/23] KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid target Content-Language: en-US To: Sean Christopherson Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Suravee Suthikulpanit , Maxim Levitsky , Li RongQing References: <20220903002254.2411750-1-seanjc@google.com> <20220903002254.2411750-4-seanjc@google.com> From: Paolo Bonzini In-Reply-To: <20220903002254.2411750-4-seanjc@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 9/3/22 02:22, Sean Christopherson wrote: > Emulate ICR writes on AVIC IPI failures due to invalid targets using the > same logic as failures due to invalid types. AVIC acceleration fails if > _any_ of the targets are invalid, and crucially VM-Exits before sending > IPIs to targets that _are_ valid. In logical mode, the destination is a > bitmap, i.e. a single IPI can target multiple logical IDs. Doing nothing > causes KVM to drop IPIs if at least one target is valid and at least one > target is invalid. > > Fixes: 18f40c53e10f ("svm: Add VMEXIT handlers for AVIC") > Cc: stable@vger.kernel.org > Signed-off-by: Sean Christopherson > Reviewed-by: Maxim Levitsky > --- > arch/x86/kvm/svm/avic.c | 16 +++++++++------- > 1 file changed, 9 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c > index 4fbef2af1efc..6a3d225eb02c 100644 > --- a/arch/x86/kvm/svm/avic.c > +++ b/arch/x86/kvm/svm/avic.c > @@ -502,14 +502,18 @@ int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu) > trace_kvm_avic_incomplete_ipi(vcpu->vcpu_id, icrh, icrl, id, index); > > switch (id) { > + case AVIC_IPI_FAILURE_INVALID_TARGET: > case AVIC_IPI_FAILURE_INVALID_INT_TYPE: > /* > * Emulate IPIs that are not handled by AVIC hardware, which > - * only virtualizes Fixed, Edge-Triggered INTRs. The exit is > - * a trap, e.g. ICR holds the correct value and RIP has been > - * advanced, KVM is responsible only for emulating the IPI. > - * Sadly, hardware may sometimes leave the BUSY flag set, in > - * which case KVM needs to emulate the ICR write as well in > + * only virtualizes Fixed, Edge-Triggered INTRs, and falls over > + * if _any_ targets are invalid, e.g. if the logical mode mask > + * is a superset of running vCPUs. > + * > + * The exit is a trap, e.g. ICR holds the correct value and RIP > + * has been advanced, KVM is responsible only for emulating the > + * IPI. Sadly, hardware may sometimes leave the BUSY flag set, > + * in which case KVM needs to emulate the ICR write as well in > * order to clear the BUSY flag. > */ > if (icrl & APIC_ICR_BUSY) > @@ -525,8 +529,6 @@ int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu) > */ > avic_kick_target_vcpus(vcpu->kvm, apic, icrl, icrh, index); > break; > - case AVIC_IPI_FAILURE_INVALID_TARGET: > - break; > case AVIC_IPI_FAILURE_INVALID_BACKING_PAGE: > WARN_ONCE(1, "Invalid backing page\n"); > break; Reviewed-by: Paolo Bonzini