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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 0A460C32753 for ; Wed, 14 Aug 2019 16:21:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C767B2064A for ; Wed, 14 Aug 2019 16:21:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565799696; bh=9zX3DiOU8a9RmwwNkpHbmDXZPwMXGImwgEYFs6N0CeY=; h=Subject:To:Cc:From:Date:List-ID:From; b=0slbG+Xl6vbiIUbHrBxH75daKheDuuFrV3Tg8eYWg1fCr+zxKF0oXV3e7lDy0lO2q lQhL2PSmHVCIP2x9tjH0o96PmrvuPmQ+d5qYJTyPcODjE/9Ts/t1JpuWZUokiWzBkj 1hRDu+aX/BLrXp57VUUeE0PHBy9ztFJwvtYRmWK0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726704AbfHNQVg (ORCPT ); Wed, 14 Aug 2019 12:21:36 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:53093 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727110AbfHNQVg (ORCPT ); Wed, 14 Aug 2019 12:21:36 -0400 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id 0FF7821EAD; Wed, 14 Aug 2019 12:21:35 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute6.internal (MEProxy); Wed, 14 Aug 2019 12:21:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=/3EXVb a+TFbDa7lzL8Wlh/rheWrrmU+nn/miMuIt78g=; b=FuWb9YlPlCL/6t02ZRZ4ov mlMR6hftuNREdyDZdAi0VW12hY3yEpNTY5HpPxJWjAcHKFB+iGHmzkhTYa0P8aO/ iA0KvSyKpW+gL5B6q9HeqHtUus3bgXHLLXA1rTTbsxfsllhmBb5XrIRrB4Zw4wIQ xOlvCMzjNhkYruBGayV6eckZWfJCriSnaIfsndmXwlSmmsq86QDLGmE+kiQFauis QUvyQH3vHpfPa4PLGVSY3E2XJVEIpqleXADEZ/TrU+WMHoZBy3tCWSc1M3/8XMs4 y/Y2tqUg8I6H5toFW+j/TrSlfUmGJhs2NHlzD9rIDutHJCt0YB2SijmKmhkTjjrA == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduvddruddvledgfeekucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefuvffhfffkgggtgfesthekredttd dtlfenucfhrhhomhepoehgrhgvghhkhheslhhinhhugihfohhunhgurghtihhonhdrohhr gheqnecuffhomhgrihhnpehvghhitgdrihhnnecukfhppeekfedrkeeirdekledruddtje enucfrrghrrghmpehmrghilhhfrhhomhepghhrvghgsehkrhhorghhrdgtohhmnecuvehl uhhsthgvrhfuihiivgeptd X-ME-Proxy: Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) by mail.messagingengine.com (Postfix) with ESMTPA id 1602C380085; Wed, 14 Aug 2019 12:21:33 -0400 (EDT) Subject: FAILED: patch "[PATCH] KVM: arm/arm64: Sync ICH_VMCR_EL2 back when about to block" failed to apply to 4.14-stable tree To: maz@kernel.org Cc: From: Date: Wed, 14 Aug 2019 18:21:32 +0200 Message-ID: <1565799692123125@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 5eeaf10eec394b28fad2c58f1f5c3a5da0e87d1c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 2 Aug 2019 10:28:32 +0100 Subject: [PATCH] KVM: arm/arm64: Sync ICH_VMCR_EL2 back when about to block Since commit commit 328e56647944 ("KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/put"), we leave ICH_VMCR_EL2 (or its GICv2 equivalent) loaded as long as we can, only syncing it back when we're scheduled out. There is a small snag with that though: kvm_vgic_vcpu_pending_irq(), which is indirectly called from kvm_vcpu_check_block(), needs to evaluate the guest's view of ICC_PMR_EL1. At the point were we call kvm_vcpu_check_block(), the vcpu is still loaded, and whatever changes to PMR is not visible in memory until we do a vcpu_put(). Things go really south if the guest does the following: mov x0, #0 // or any small value masking interrupts msr ICC_PMR_EL1, x0 [vcpu preempted, then rescheduled, VMCR sampled] mov x0, #ff // allow all interrupts msr ICC_PMR_EL1, x0 wfi // traps to EL2, so samping of VMCR [interrupt arrives just after WFI] Here, the hypervisor's view of PMR is zero, while the guest has enabled its interrupts. kvm_vgic_vcpu_pending_irq() will then say that no interrupts are pending (despite an interrupt being received) and we'll block for no reason. If the guest doesn't have a periodic interrupt firing once it has blocked, it will stay there forever. To avoid this unfortuante situation, let's resync VMCR from kvm_arch_vcpu_blocking(), ensuring that a following kvm_vcpu_check_block() will observe the latest value of PMR. This has been found by booting an arm64 Linux guest with the pseudo NMI feature, and thus using interrupt priorities to mask interrupts instead of the usual PSTATE masking. Cc: stable@vger.kernel.org # 4.12 Fixes: 328e56647944 ("KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/put") Signed-off-by: Marc Zyngier diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 46bbc949c20a..7a30524a80ee 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -350,6 +350,7 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu); void kvm_vgic_load(struct kvm_vcpu *vcpu); void kvm_vgic_put(struct kvm_vcpu *vcpu); +void kvm_vgic_vmcr_sync(struct kvm_vcpu *vcpu); #define irqchip_in_kernel(k) (!!((k)->arch.vgic.in_kernel)) #define vgic_initialized(k) ((k)->arch.vgic.initialized) diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index c704fa696184..482b20256fa8 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -323,6 +323,17 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) { + /* + * If we're about to block (most likely because we've just hit a + * WFI), we need to sync back the state of the GIC CPU interface + * so that we have the lastest PMR and group enables. This ensures + * that kvm_arch_vcpu_runnable has up-to-date data to decide + * whether we have pending interrupts. + */ + preempt_disable(); + kvm_vgic_vmcr_sync(vcpu); + preempt_enable(); + kvm_vgic_v4_enable_doorbell(vcpu); } diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c index 6dd5ad706c92..96aab77d0471 100644 --- a/virt/kvm/arm/vgic/vgic-v2.c +++ b/virt/kvm/arm/vgic/vgic-v2.c @@ -484,10 +484,17 @@ void vgic_v2_load(struct kvm_vcpu *vcpu) kvm_vgic_global_state.vctrl_base + GICH_APR); } -void vgic_v2_put(struct kvm_vcpu *vcpu) +void vgic_v2_vmcr_sync(struct kvm_vcpu *vcpu) { struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2; cpu_if->vgic_vmcr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VMCR); +} + +void vgic_v2_put(struct kvm_vcpu *vcpu) +{ + struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2; + + vgic_v2_vmcr_sync(vcpu); cpu_if->vgic_apr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_APR); } diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c index c2c9ce009f63..0c653a1e5215 100644 --- a/virt/kvm/arm/vgic/vgic-v3.c +++ b/virt/kvm/arm/vgic/vgic-v3.c @@ -662,12 +662,17 @@ void vgic_v3_load(struct kvm_vcpu *vcpu) __vgic_v3_activate_traps(vcpu); } -void vgic_v3_put(struct kvm_vcpu *vcpu) +void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu) { struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3; if (likely(cpu_if->vgic_sre)) cpu_if->vgic_vmcr = kvm_call_hyp_ret(__vgic_v3_read_vmcr); +} + +void vgic_v3_put(struct kvm_vcpu *vcpu) +{ + vgic_v3_vmcr_sync(vcpu); kvm_call_hyp(__vgic_v3_save_aprs, vcpu); diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c index 04786c8ec77e..13d4b38a94ec 100644 --- a/virt/kvm/arm/vgic/vgic.c +++ b/virt/kvm/arm/vgic/vgic.c @@ -919,6 +919,17 @@ void kvm_vgic_put(struct kvm_vcpu *vcpu) vgic_v3_put(vcpu); } +void kvm_vgic_vmcr_sync(struct kvm_vcpu *vcpu) +{ + if (unlikely(!irqchip_in_kernel(vcpu->kvm))) + return; + + if (kvm_vgic_global_state.type == VGIC_V2) + vgic_v2_vmcr_sync(vcpu); + else + vgic_v3_vmcr_sync(vcpu); +} + int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu) { struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index 57205beaa981..11adbdac1d56 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h @@ -193,6 +193,7 @@ int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address, void vgic_v2_init_lrs(void); void vgic_v2_load(struct kvm_vcpu *vcpu); void vgic_v2_put(struct kvm_vcpu *vcpu); +void vgic_v2_vmcr_sync(struct kvm_vcpu *vcpu); void vgic_v2_save_state(struct kvm_vcpu *vcpu); void vgic_v2_restore_state(struct kvm_vcpu *vcpu); @@ -223,6 +224,7 @@ bool vgic_v3_check_base(struct kvm *kvm); void vgic_v3_load(struct kvm_vcpu *vcpu); void vgic_v3_put(struct kvm_vcpu *vcpu); +void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu); bool vgic_has_its(struct kvm *kvm); int kvm_vgic_register_its_device(void);