From patchwork Wed Jul 14 21:38:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 478346 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 041D0C12002 for ; Wed, 14 Jul 2021 21:38:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6827613AB for ; Wed, 14 Jul 2021 21:38:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233918AbhGNVln (ORCPT ); Wed, 14 Jul 2021 17:41:43 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:33856 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231177AbhGNVlm (ORCPT ); Wed, 14 Jul 2021 17:41:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626298730; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=AS2PhfoWmQKR8Ft5CX0e3UMsUDYv8nJr/WqBjmF1Fek=; b=IDlFRxObJsHVuTeKtwnpZp9BwSL31ZlHRXa7Pghpg0GA9/b92MaTE+vDkmWdRoxJsGf2jq FqbYoLRhvFUwTjPJZs+u1BCIjfsvXsPnIvw4FhaZ/cOMgGntAZ7oz+bzww+NzRZcDYETcb 9mBCuvBNTWTbyVdNLbgReRpcWfMFwh0= 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-518-l4tbBZzgNjqr1nduikmTsw-1; Wed, 14 Jul 2021 17:38:48 -0400 X-MC-Unique: l4tbBZzgNjqr1nduikmTsw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 46B7710C1ADC; Wed, 14 Jul 2021 21:38:47 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id DA2435D9DD; Wed, 14 Jul 2021 21:38:46 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: stable@vger.kernel.org, Stas Sergeev Subject: [PATCH] KVM: x86: accept userspace interrupt only if no event is injected Date: Wed, 14 Jul 2021 17:38:46 -0400 Message-Id: <20210714213846.854837-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Once an exception has been injected, any side effects related to the exception (such as setting CR2 or DR6) have been taked place. Therefore, once KVM sets the VM-entry interruption information field or the AMD EVENTINJ field, the next VM-entry must deliver that exception. Pending interrupts are processed after injected exceptions, so in theory it would not be a problem to use KVM_INTERRUPT when an injected exception is present. However, DOSBox is using run->ready_for_interrupt_injection to detect interrupt windows and then using KVM_SET_SREGS/KVM_SET_REGS to inject the interrupt manually. For this to work, the interrupt window must be delayed after the completion of the previous event injection. Cc: stable@vger.kernel.org Reported-by: Stas Sergeev Tested-by: Stas Sergeev Fixes: 71cc849b7093 ("KVM: x86: Fix split-irqchip vs interrupt injection window request") Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fe3aaf195292..7fbab29b3569 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4342,6 +4342,9 @@ static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu, static int kvm_cpu_accept_dm_intr(struct kvm_vcpu *vcpu) { + if (kvm_event_needs_reinjection(vcpu)) + return false; + /* * We can accept userspace's request for interrupt injection * as long as we have a place to store the interrupt number.