From patchwork Fri May 15 16:53:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tamas K Lengyel X-Patchwork-Id: 11552611 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 64F12739 for ; Fri, 15 May 2020 16:54:07 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4CA34206C0 for ; Fri, 15 May 2020 16:54:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4CA34206C0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=tklengyel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jZdaD-0001pM-Ie; Fri, 15 May 2020 16:53:13 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jZdaB-0001p2-N7 for xen-devel@lists.xenproject.org; Fri, 15 May 2020 16:53:11 +0000 X-Inumbo-ID: 8f3ce28e-96cc-11ea-ae69-bc764e2007e4 Received: from mail-il1-f182.google.com (unknown [209.85.166.182]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 8f3ce28e-96cc-11ea-ae69-bc764e2007e4; Fri, 15 May 2020 16:53:11 +0000 (UTC) Received: by mail-il1-f182.google.com with SMTP id b15so3189423ilq.12 for ; Fri, 15 May 2020 09:53:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=EVHM5utimK/juoVOGf87kC9v393UUF6EscVsahd5AAI=; b=jsgolpbrSYsh05kCr67iZz3aPrdbzMu/v4Ye8VS0AVrz76Ch9LxgVGOlBx829V1RlX 3FwJ+L7/eabS2G4spR4yoKhwQSfir+6PF/V3G+NGOJGlCDUfHuHsV4CQ2DIfT/FxuW4c nwxbagYYlFV0iDsQjln8Az2jc+su9/RHjVRZcqtmz8duWp9FyvLHGN+I1Xy3CLWlyAI8 y+cxmFUs6pkuehkagmhsMxgBEu244vzDX5/c9sptje3PZSIGQHwQshiGEH5g4AuOUU6J oCtU1QWFhGtITjbkYNPnv1MHYjQjWZcEXzmEVLwMuNz53ob/EyyHAqYuoaVo1G7uqE/T ru7g== X-Gm-Message-State: AOAM531XfG7vftDlrcAIXRKFA+1sBN0ipKjA5FjxwIU0i5zq1rKolCvv ByFZA04REBwwHB5DPoE2UhxvSu5J X-Google-Smtp-Source: ABdhPJxnYPY7tDAaD9tQ8BK9qzAgu5onEgM2zJjYOSVSILd7u8NqWQxDge/1JaA1cp+uIFoZ4XZ5qg== X-Received: by 2002:a92:3954:: with SMTP id g81mr4477788ila.105.1589561590277; Fri, 15 May 2020 09:53:10 -0700 (PDT) Received: from t0.lan (c-71-205-12-124.hsd1.co.comcast.net. [71.205.12.124]) by smtp.googlemail.com with ESMTPSA id f17sm932136iol.26.2020.05.15.09.53.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 May 2020 09:53:09 -0700 (PDT) From: Tamas K Lengyel To: xen-devel@lists.xenproject.org Subject: [PATCH 3/3] xen/vm_event: Add safe to disable vm_event Date: Fri, 15 May 2020 10:53:02 -0600 Message-Id: <1168bacc61f655f559c236cdf63a6b2beccd4d6b.1589561218.git.tamas@tklengyel.com> X-Mailer: git-send-email 2.26.1 In-Reply-To: References: MIME-Version: 1.0 X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Petre Pircalabu , Tamas K Lengyel , Julien Grall , Wei Liu , Andrew Cooper , Ian Jackson , George Dunlap , Stefano Stabellini , Jan Beulich , Alexandru Isaila , =?utf-8?q?Roger_Pau_Monn=C3=A9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Instead of having to repeatedly try to disable vm_events, request a specific vm_event to be sent when the domain is safe to continue with shutting down the vm_event interface. Signed-off-by: Tamas K Lengyel --- xen/arch/x86/hvm/hvm.c | 38 ++++++++++++++++++++++++++----- xen/arch/x86/hvm/monitor.c | 14 ++++++++++++ xen/arch/x86/monitor.c | 13 +++++++++++ xen/include/asm-x86/domain.h | 1 + xen/include/asm-x86/hvm/monitor.h | 1 + xen/include/public/domctl.h | 2 ++ xen/include/public/vm_event.h | 8 +++++++ 7 files changed, 71 insertions(+), 6 deletions(-) diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 063f8ddc18..50c67e7b8e 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -563,15 +563,41 @@ void hvm_do_resume(struct vcpu *v) v->arch.hvm.inject_event.vector = HVM_EVENT_VECTOR_UNSET; } - if ( unlikely(v->arch.vm_event) && v->arch.monitor.next_interrupt_enabled ) + if ( unlikely(v->arch.vm_event) ) { - struct x86_event info; + struct domain *d = v->domain; + + if ( v->arch.monitor.next_interrupt_enabled ) + { + struct x86_event info; + + if ( hvm_get_pending_event(v, &info) ) + { + hvm_monitor_interrupt(info.vector, info.type, info.error_code, + info.cr2); + v->arch.monitor.next_interrupt_enabled = false; + } + } - if ( hvm_get_pending_event(v, &info) ) + if ( d->arch.monitor.safe_to_disable ) { - hvm_monitor_interrupt(info.vector, info.type, info.error_code, - info.cr2); - v->arch.monitor.next_interrupt_enabled = false; + struct vcpu *check_vcpu; + bool pending_op = false; + + for_each_vcpu ( d, check_vcpu ) + { + if ( vm_event_check_pending_op(check_vcpu) ) + { + pending_op = true; + break; + } + } + + if ( !pending_op ) + { + hvm_monitor_safe_to_disable(); + d->arch.monitor.safe_to_disable = false; + } } } } diff --git a/xen/arch/x86/hvm/monitor.c b/xen/arch/x86/hvm/monitor.c index f5d89e71d1..8e67dd1a0b 100644 --- a/xen/arch/x86/hvm/monitor.c +++ b/xen/arch/x86/hvm/monitor.c @@ -300,6 +300,20 @@ bool hvm_monitor_check_p2m(unsigned long gla, gfn_t gfn, uint32_t pfec, return monitor_traps(curr, true, &req) >= 0; } +bool hvm_monitor_safe_to_disable(void) +{ + struct vcpu *curr = current; + struct arch_domain *ad = &curr->domain->arch; + vm_event_request_t req = {}; + + if ( !ad->monitor.safe_to_disable ) + return 0; + + req.reason = VM_EVENT_REASON_SAFE_TO_DISABLE; + + return monitor_traps(curr, 0, &req); +} + /* * Local variables: * mode: C diff --git a/xen/arch/x86/monitor.c b/xen/arch/x86/monitor.c index 1517a97f50..86e0ba2fbc 100644 --- a/xen/arch/x86/monitor.c +++ b/xen/arch/x86/monitor.c @@ -339,6 +339,19 @@ int arch_monitor_domctl_event(struct domain *d, break; } + case XEN_DOMCTL_MONITOR_EVENT_SAFE_TO_DISABLE: + { + bool old_status = ad->monitor.safe_to_disable; + + if ( unlikely(old_status == requested_status) ) + return -EEXIST; + + domain_pause(d); + ad->monitor.safe_to_disable = requested_status; + domain_unpause(d); + break; + } + default: /* * Should not be reached unless arch_monitor_get_capabilities() is diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h index d890ab7a22..948b750c71 100644 --- a/xen/include/asm-x86/domain.h +++ b/xen/include/asm-x86/domain.h @@ -417,6 +417,7 @@ struct arch_domain */ unsigned int inguest_pagefault_disabled : 1; unsigned int control_register_values : 1; + unsigned int safe_to_disable : 1; struct monitor_msr_bitmap *msr_bitmap; uint64_t write_ctrlreg_mask[4]; } monitor; diff --git a/xen/include/asm-x86/hvm/monitor.h b/xen/include/asm-x86/hvm/monitor.h index 66de24cb75..194e2f857e 100644 --- a/xen/include/asm-x86/hvm/monitor.h +++ b/xen/include/asm-x86/hvm/monitor.h @@ -52,6 +52,7 @@ bool hvm_monitor_emul_unimplemented(void); bool hvm_monitor_check_p2m(unsigned long gla, gfn_t gfn, uint32_t pfec, uint16_t kind); +bool hvm_monitor_safe_to_disable(void); #endif /* __ASM_X86_HVM_MONITOR_H__ */ diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h index cbcd25f12c..247e809a6c 100644 --- a/xen/include/public/domctl.h +++ b/xen/include/public/domctl.h @@ -1040,6 +1040,8 @@ struct xen_domctl_psr_cmt_op { #define XEN_DOMCTL_MONITOR_EVENT_EMUL_UNIMPLEMENTED 10 /* Enabled by default */ #define XEN_DOMCTL_MONITOR_EVENT_INGUEST_PAGEFAULT 11 +/* Always async, disables automaticaly on first event */ +#define XEN_DOMCTL_MONITOR_EVENT_SAFE_TO_DISABLE 12 struct xen_domctl_monitor_op { uint32_t op; /* XEN_DOMCTL_MONITOR_OP_* */ diff --git a/xen/include/public/vm_event.h b/xen/include/public/vm_event.h index fdd3ad8a30..b66d2a8634 100644 --- a/xen/include/public/vm_event.h +++ b/xen/include/public/vm_event.h @@ -159,6 +159,14 @@ #define VM_EVENT_REASON_DESCRIPTOR_ACCESS 13 /* Current instruction is not implemented by the emulator */ #define VM_EVENT_REASON_EMUL_UNIMPLEMENTED 14 +/* + * When shutting down vm_event it may not be immediately safe to complete the + * process as some vCPUs may be pending synchronization. This async event + * type can be used to receive a notification when its safe to finish disabling + * the vm_event interface. All other event types need to be disabled before + * registering to this one. + */ +#define VM_EVENT_REASON_SAFE_TO_DISABLE 15 /* Supported values for the vm_event_write_ctrlreg index. */ #define VM_EVENT_X86_CR0 0