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spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:47558 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lo90Z-0003wg-BW for qemu-devel@archiver.kernel.org; Tue, 01 Jun 2021 14:20:55 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45546) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lo8yW-0006fe-F2 for qemu-devel@nongnu.org; Tue, 01 Jun 2021 14:18:48 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:29155) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lo8yU-0002Br-CJ for qemu-devel@nongnu.org; Tue, 01 Jun 2021 14:18:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622571524; 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: in-reply-to:in-reply-to:references:references; bh=KO98er9cpBwUDbVV1jtCg6P5cAaaWxhxnRS1ZDw4IOI=; b=Z/te24mWElCTOHwnUPm5tyyj9ggfQVQ+tjsU6cdE7uWiPuN+3nkhEPziGewwPuEruAsHH8 U6IZUbPp5GNK6emTBo8llXOAskUBYsDXHyuSgTQ/fI0verFYGIqvvb0bj2f1s1KL9wd1AL WE18+Lm/4ETBuRu/zwy4jvMm34VZB9I= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-219-hl-IBaQLNm60_Ystdit0RA-1; Tue, 01 Jun 2021 14:18:41 -0400 X-MC-Unique: hl-IBaQLNm60_Ystdit0RA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 39192107ACE6; Tue, 1 Jun 2021 18:18:38 +0000 (UTC) Received: from localhost (ovpn-112-239.rdu2.redhat.com [10.10.112.239]) by smtp.corp.redhat.com (Postfix) with ESMTP id 092405D6CF; Tue, 1 Jun 2021 18:18:37 +0000 (UTC) Date: Tue, 1 Jun 2021 14:18:37 -0400 From: Eduardo Habkost To: Chenyi Qiang Subject: Re: [PATCH v4] i386: Add ratelimit for bus locks acquired in guest Message-ID: <20210601181837.dl5tcyqywtoidu57@habkost.net> References: <20210521043820.29678-1-chenyi.qiang@intel.com> <20210527211904.sjmkely4t4ragxva@habkost.net> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=ehabkost@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=ehabkost@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.371, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Marcelo Tosatti , Richard Henderson , qemu-devel@nongnu.org, Xiaoyao Li Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, May 31, 2021 at 01:14:54PM +0800, Chenyi Qiang wrote: > > > On 5/28/2021 5:19 AM, Eduardo Habkost wrote: > > On Fri, May 21, 2021 at 12:38:20PM +0800, Chenyi Qiang wrote: > > [...] > > > @@ -4222,6 +4247,15 @@ void kvm_arch_pre_run(CPUState *cpu, struct kvm_run *run) > > > } > > > } > > > +static void kvm_rate_limit_on_bus_lock(void) > > > +{ > > > + uint64_t delay_ns = ratelimit_calculate_delay(&bus_lock_ratelimit_ctrl, 1); > > > + > > > + if (delay_ns) { > > > + g_usleep(delay_ns / SCALE_US); > > > + } > > > +} > > > + > > > MemTxAttrs kvm_arch_post_run(CPUState *cpu, struct kvm_run *run) > > > { > > > X86CPU *x86_cpu = X86_CPU(cpu); > > > @@ -4237,6 +4271,9 @@ MemTxAttrs kvm_arch_post_run(CPUState *cpu, struct kvm_run *run) > > > } else { > > > env->eflags &= ~IF_MASK; > > > } > > > + if (run->flags & KVM_RUN_X86_BUS_LOCK) { > > > > Does the KVM API guarantee that KVM_RUN_X86_BUS_LOCK will never > > be set if KVM_BUS_LOCK_DETECTION_EXIT isn't enabled? (Otherwise > > we risk crashing in ratelimit_calculate_delay() above if rate > > limiting is disabled). > > > > Yes. KVM_RUN_X86_BUS_LOCK flag is set when bus lock VM exit happens. Bus > lock VM exit is disabled by default and can only be enabled through the > KVM_BUS_LOCK_DETECTION_EXIT capability. I'm queueing on x86-next, thanks! -- Eduardo