From patchwork Mon Feb 28 20:05:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 12763766 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 15695C433FE for ; Mon, 28 Feb 2022 20:06:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230004AbiB1UHF (ORCPT ); Mon, 28 Feb 2022 15:07:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33150 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229961AbiB1UGx (ORCPT ); Mon, 28 Feb 2022 15:06:53 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43DB437AA1 for ; Mon, 28 Feb 2022 12:06:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=X9TYdlGb1LByw7tcFn8Ijmt8GeM6mHevHAZ0b8vbW7k=; b=XXZhZC7ADTKBvdl0mNCYTW4yoC KOfL+dJCUaDFJyr7703tftx/Gonn1DRocIh/bhrGYSHnlAzP8Ry16+ilRlcbjs/p0GtwvoF1bpd92 8TPjgbq5dD4mAx8Zk8S2BoCFuN2jkJoSzwknFnpw5EdBdwm/ZBw4T/CB/Oiapcn7dGdKaiytw8kIh vXQgDAfpfu1hGuCMW8k5HF60BFUUMMqxRg9uEd8L2S8h3OOm2xNIkIFvw430WK/LpOYO5wLU6T/1h kWi/lM4m22BeukwpncCBz93CUnL5oz4rWTVWTbzqyMVT/C7hjI+gt2bvSRfjqYLSK6gfi8Tdgwwol 5Av4L5tA==; Received: from [2001:8b0:10b:1:85c4:81a:fb42:714d] (helo=i7.infradead.org) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nOmHK-00DzoG-Tq; Mon, 28 Feb 2022 20:05:55 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nOmHK-000d9z-6l; Mon, 28 Feb 2022 20:05:54 +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 v2 14/17] KVM: x86/xen: Support per-vCPU event channel upcall via local APIC Date: Mon, 28 Feb 2022 20:05:49 +0000 Message-Id: <20220228200552.150406-15-dwmw2@infradead.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20220228200552.150406-1-dwmw2@infradead.org> References: <20220228200552.150406-1-dwmw2@infradead.org> MIME-Version: 1.0 Sender: David Woodhouse X-SRS-Rewrite: SMTP reverse-path rewritten from by desiato.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 7a15363199b1..139c8213fcc0 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -600,6 +600,7 @@ 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 7889609c6627..b562b6aa08de 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -332,6 +332,22 @@ 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 @@ -392,6 +408,10 @@ 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); } @@ -725,6 +745,15 @@ 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; } @@ -812,6 +841,11 @@ 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; } @@ -1245,6 +1279,12 @@ 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 2b28237dad1a..709b48dd256f 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1752,6 +1752,7 @@ struct kvm_xen_vcpu_attr { __u32 priority; __u64 expires_ns; } timer; + __u8 vector; } u; }; @@ -1765,6 +1766,7 @@ 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 {