From patchwork Thu Feb 10 00:27:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 12741118 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 4473FC433EF for ; Thu, 10 Feb 2022 01:31:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232676AbiBJBbo (ORCPT ); Wed, 9 Feb 2022 20:31:44 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:38510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232869AbiBJBbi (ORCPT ); Wed, 9 Feb 2022 20:31:38 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45CF8BE7 for ; Wed, 9 Feb 2022 17:31:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=3rLfMCSe7vev48x81sQgwmtolCxeLUwn1CMNLy33ODg=; b=YslOGmLYBV4n8Gb5vWB4q7fnCN GBu2+mm4XLE4QGhVCRPDLiHFmXybadByvoOPPEGf36H2/jgPSVOfwXbvV2ZNGIEnKAKzZv2+wln4+ qPY2K0kzcpL0sPRni3buR2j1nWjdV+TRSF9Enj2LnAcMEGS1v1mYptnPCYMbQ59w5vQ9pvNAzuJCc iFUsGqnVFO3EQZ6zs39S4irs1sADO45pdp2Btg6LTQ9kYv9v+IlF7qdy6Hot9/KjDk3eBXwpXjufh 7qcHBv/e2vmgwINbFuefvjrHkx9pLjKn1lsrOZJuqFtjX0IvTPRONxQT6LPZrloNex2+FBMMis7Sr cYCAD1ow==; Received: from i7.infradead.org ([2001:8b0:10b:1:21e:67ff:fecb:7a92]) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHxIy-008xlC-Pl; Thu, 10 Feb 2022 00:27:24 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHxIy-0019Dh-8A; Thu, 10 Feb 2022 00:27:24 +0000 From: David Woodhouse To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Joao Martins , Boris Ostrovsky , Metin Kaya , Paul Durrant Subject: [PATCH v0 13/15] KVM: x86/xen: Support per-vCPU event channel upcall via local APIC Date: Thu, 10 Feb 2022 00:27:19 +0000 Message-Id: <20220210002721.273608-14-dwmw2@infradead.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20220210002721.273608-1-dwmw2@infradead.org> References: <20220210002721.273608-1-dwmw2@infradead.org> MIME-Version: 1.0 Sender: David Woodhouse X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: David Woodhouse Windows uses a per-vCPU vector, and it's delivered via the local APIC basically like an MSI (with associated EOI) unlike the traditional guest-wide vector which is just magically asserted by Xen (and in the KVM case by kvm_xen_has_interrupt() / kvm_cpu_get_extint()). Now that the kernel is able to raise event channel events for itself, being able to do so for Windows guests is also going to be useful. Signed-off-by: David Woodhouse --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/xen.c | 40 +++++++++++++++++++++++++++++++++ include/uapi/linux/kvm.h | 2 ++ 3 files changed, 43 insertions(+) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 1c064c2ec937..50cbea89739b 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -601,6 +601,7 @@ struct kvm_vcpu_hv { struct kvm_vcpu_xen { u64 hypercall_rip; u32 current_runstate; + u8 upcall_vector; struct gfn_to_pfn_cache vcpu_info_cache; struct gfn_to_pfn_cache vcpu_time_info_cache; struct gfn_to_pfn_cache runstate_cache; diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index 735fccd44488..60459e52a2fd 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -326,6 +326,22 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state) mark_page_dirty_in_slot(v->kvm, gpc->memslot, gpc->gpa >> PAGE_SHIFT); } +static void kvm_xen_inject_vcpu_vector(struct kvm_vcpu *v) +{ + struct kvm_lapic_irq irq = { }; + int r; + + irq.dest_id = v->vcpu_id; + irq.vector = v->arch.xen.upcall_vector; + irq.dest_mode = APIC_DEST_PHYSICAL; + irq.shorthand = APIC_DEST_NOSHORT; + irq.delivery_mode = APIC_DM_FIXED; + irq.level = 1; + + /* The fast version will always work for physical unicast */ + WARN_ON_ONCE(!kvm_irq_delivery_to_apic_fast(v->kvm, NULL, &irq, &r, NULL)); +} + /* * On event channel delivery, the vcpu_info may not have been accessible. * In that case, there are bits in vcpu->arch.xen.evtchn_pending_sel which @@ -387,6 +403,10 @@ void kvm_xen_inject_pending_events(struct kvm_vcpu *v) } read_unlock_irqrestore(&gpc->lock, flags); + /* For the per-vCPU lapic vector, deliver it as MSI. */ + if (v->arch.xen.upcall_vector) + kvm_xen_inject_vcpu_vector(v); + mark_page_dirty_in_slot(v->kvm, gpc->memslot, gpc->gpa >> PAGE_SHIFT); } @@ -716,6 +736,15 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) r = 0; break; + case KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR: + if (data->u.vector && data->u.vector < 0x10) + r = -EINVAL; + else { + vcpu->arch.xen.upcall_vector = data->u.vector; + r = 0; + } + break; + default: break; } @@ -803,6 +832,11 @@ int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) r = 0; break; + case KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR: + data->u.vector = vcpu->arch.xen.upcall_vector; + r = 0; + break; + default: break; } @@ -1212,6 +1246,12 @@ int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe, struct kvm *kvm) kick_vcpu = true; } } + + /* For the per-vCPU lapic vector, deliver it as MSI. */ + if (kick_vcpu && vcpu->arch.xen.upcall_vector) { + kvm_xen_inject_vcpu_vector(vcpu); + kick_vcpu = false; + } } out_rcu: diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 243917851e0d..3506186ad16f 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1746,6 +1746,7 @@ struct kvm_xen_vcpu_attr { __u32 priority; __u64 expires_ns; } timer; + __u8 vector; } u; }; @@ -1759,6 +1760,7 @@ struct kvm_xen_vcpu_attr { /* Available with KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_EVTCHN_SEND */ #define KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID 0x6 #define KVM_XEN_VCPU_ATTR_TYPE_TIMER 0x7 +#define KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR 0x8 /* Secure Encrypted Virtualization command */ enum sev_cmd_id {