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 310A0C76195 for ; Mon, 20 Mar 2023 15:31:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233080AbjCTPbi (ORCPT ); Mon, 20 Mar 2023 11:31:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233014AbjCTPbU (ORCPT ); Mon, 20 Mar 2023 11:31:20 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83C8C1BF7 for ; Mon, 20 Mar 2023 08:23:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0AAA4615AC for ; Mon, 20 Mar 2023 15:23:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B5E4C433EF; Mon, 20 Mar 2023 15:23:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1679325819; bh=itjs6iFZRt2JynM6LYNqrcpc5v86ZBjvB4BLoUlCYyM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ilTakTe+orBp9UwDyPs1WZtQIXZfe7ITE8rO9B5Ve04ahdKT41CjmPqJGje7HyCzv vnDsCDg3pshT4Y7raIZ18p3kWBwVAd5/GVNxAVuoP+iu7Be1foAS+hq6QAhYMyO2y3 q6dlzNnMIkc5OhvtOU+Ypq7XKipLid9gY07e7d1U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alejandro Jimenez , Suravee Suthikulpanit , Sean Christopherson , Paolo Bonzini Subject: [PATCH 6.1 148/198] KVM: SVM: Modify AVIC GATag to support max number of 512 vCPUs Date: Mon, 20 Mar 2023 15:54:46 +0100 Message-Id: <20230320145513.755489646@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230320145507.420176832@linuxfoundation.org> References: <20230320145507.420176832@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Suravee Suthikulpanit commit 5999715922c5a3ede5d8fe2a6b17aba58a157d41 upstream. Define AVIC_VCPU_ID_MASK based on AVIC_PHYSICAL_MAX_INDEX, i.e. the mask that effectively controls the largest guest physical APIC ID supported by x2AVIC, instead of hardcoding the number of bits to 8 (and the number of VM bits to 24). The AVIC GATag is programmed into the AMD IOMMU IRTE to provide a reference back to KVM in case the IOMMU cannot inject an interrupt into a non-running vCPU. In such a case, the IOMMU notifies software by creating a GALog entry with the corresponded GATag, and KVM then uses the GATag to find the correct VM+vCPU to kick. Dropping bit 8 from the GATag results in kicking the wrong vCPU when targeting vCPUs with x2APIC ID > 255. Fixes: 4d1d7942e36a ("KVM: SVM: Introduce logic to (de)activate x2AVIC mode") Cc: stable@vger.kernel.org Reported-by: Alejandro Jimenez Signed-off-by: Suravee Suthikulpanit Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson Reviewed-by: Suravee Suthikulpanit Tested-by: Suravee Suthikulpanit Message-Id: <20230207002156.521736-3-seanjc@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm/avic.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index ca684979e90d..326341a22153 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -27,19 +27,29 @@ #include "irq.h" #include "svm.h" -/* AVIC GATAG is encoded using VM and VCPU IDs */ -#define AVIC_VCPU_ID_BITS 8 -#define AVIC_VCPU_ID_MASK ((1 << AVIC_VCPU_ID_BITS) - 1) +/* + * Encode the arbitrary VM ID and the vCPU's default APIC ID, i.e the vCPU ID, + * into the GATag so that KVM can retrieve the correct vCPU from a GALog entry + * if an interrupt can't be delivered, e.g. because the vCPU isn't running. + * + * For the vCPU ID, use however many bits are currently allowed for the max + * guest physical APIC ID (limited by the size of the physical ID table), and + * use whatever bits remain to assign arbitrary AVIC IDs to VMs. Note, the + * size of the GATag is defined by hardware (32 bits), but is an opaque value + * as far as hardware is concerned. + */ +#define AVIC_VCPU_ID_MASK AVIC_PHYSICAL_MAX_INDEX_MASK -#define AVIC_VM_ID_BITS 24 -#define AVIC_VM_ID_NR (1 << AVIC_VM_ID_BITS) -#define AVIC_VM_ID_MASK ((1 << AVIC_VM_ID_BITS) - 1) +#define AVIC_VM_ID_SHIFT HWEIGHT32(AVIC_PHYSICAL_MAX_INDEX_MASK) +#define AVIC_VM_ID_MASK (GENMASK(31, AVIC_VM_ID_SHIFT) >> AVIC_VM_ID_SHIFT) -#define AVIC_GATAG(x, y) (((x & AVIC_VM_ID_MASK) << AVIC_VCPU_ID_BITS) | \ +#define AVIC_GATAG(x, y) (((x & AVIC_VM_ID_MASK) << AVIC_VM_ID_SHIFT) | \ (y & AVIC_VCPU_ID_MASK)) -#define AVIC_GATAG_TO_VMID(x) ((x >> AVIC_VCPU_ID_BITS) & AVIC_VM_ID_MASK) +#define AVIC_GATAG_TO_VMID(x) ((x >> AVIC_VM_ID_SHIFT) & AVIC_VM_ID_MASK) #define AVIC_GATAG_TO_VCPUID(x) (x & AVIC_VCPU_ID_MASK) +static_assert(AVIC_GATAG(AVIC_VM_ID_MASK, AVIC_VCPU_ID_MASK) == -1u); + static bool force_avic; module_param_unsafe(force_avic, bool, 0444); -- 2.40.0