From patchwork Mon May 25 14:41:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 11568935 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 8C54513B4 for ; Mon, 25 May 2020 14:42:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7521820888 for ; Mon, 25 May 2020 14:42:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Y09MEEnV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404044AbgEYOmH (ORCPT ); Mon, 25 May 2020 10:42:07 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:30940 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2404035AbgEYOmD (ORCPT ); Mon, 25 May 2020 10:42:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590417722; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=gcWPQcy0dLcM/idycFzBWKrR20stKK5D971BAOD+nRg=; b=Y09MEEnVC7am+z62gP2Ih0JysJ3BzgIjtgOM1anF75uvDvbDDdKtzPimv9iM7Oj+MXNCPz PX80QUL++wQxmXbKFhouLN58wercMYy9gHeCwJUotG5BmO9RJPZHonRnPT6KHQwGB21m+g qInqzZ3rpKPQRCVcCDbqDnzCTbPvmAg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-45-QbeNpbpcO82crC9H4IItqA-1; Mon, 25 May 2020 10:42:00 -0400 X-MC-Unique: QbeNpbpcO82crC9H4IItqA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D186118FE86C; Mon, 25 May 2020 14:41:58 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.40.194.114]) by smtp.corp.redhat.com (Postfix) with ESMTP id B86B95D9C5; Mon, 25 May 2020 14:41:55 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, x86@kernel.org Cc: Paolo Bonzini , Andy Lutomirski , Thomas Gleixner , Borislav Petkov , "H. Peter Anvin" , Wanpeng Li , Sean Christopherson , Jim Mattson , Vivek Goyal , Gavin Shan , Peter Zijlstra , linux-kernel@vger.kernel.org Subject: [PATCH v2 07/10] KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT Date: Mon, 25 May 2020 16:41:22 +0200 Message-Id: <20200525144125.143875-8-vkuznets@redhat.com> In-Reply-To: <20200525144125.143875-1-vkuznets@redhat.com> References: <20200525144125.143875-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Introduce new capability to indicate that KVM supports interrupt based delivery of 'page ready' APF events. This includes support for both MSR_KVM_ASYNC_PF_INT and MSR_KVM_ASYNC_PF_ACK. Signed-off-by: Vitaly Kuznetsov --- Documentation/virt/kvm/cpuid.rst | 6 ++++++ Documentation/virt/kvm/msr.rst | 12 ++++++++---- arch/x86/include/uapi/asm/kvm_para.h | 1 + arch/x86/kvm/cpuid.c | 3 ++- arch/x86/kvm/x86.c | 1 + include/uapi/linux/kvm.h | 1 + 6 files changed, 19 insertions(+), 5 deletions(-) diff --git a/Documentation/virt/kvm/cpuid.rst b/Documentation/virt/kvm/cpuid.rst index 01b081f6e7ea..98cbd257ac33 100644 --- a/Documentation/virt/kvm/cpuid.rst +++ b/Documentation/virt/kvm/cpuid.rst @@ -86,6 +86,12 @@ KVM_FEATURE_PV_SCHED_YIELD 13 guest checks this feature bit before using paravirtualized sched yield. +KVM_FEATURE_ASYNC_PF_INT 14 guest checks this feature bit + before using the second async + pf control msr 0x4b564d06 and + async pf acknowledgment msr + 0x4b564d07. + KVM_FEATURE_CLOCSOURCE_STABLE_BIT 24 host will warn if no guest-side per-cpu warps are expeced in kvmclock diff --git a/Documentation/virt/kvm/msr.rst b/Documentation/virt/kvm/msr.rst index 8ea3fbcc67fd..d409cc26193f 100644 --- a/Documentation/virt/kvm/msr.rst +++ b/Documentation/virt/kvm/msr.rst @@ -213,7 +213,8 @@ data: cpl == 0. Bit 2 is 1 if asynchronous page faults are delivered to L1 as #PF vmexits. Bit 2 can be set only if KVM_FEATURE_ASYNC_PF_VMEXIT is present in CPUID. Bit 3 enables interrupt based delivery of 'page ready' - events. + events. Bit 3 can only be set if KVM_FEATURE_ASYNC_PF_INT is present in + CPUID. 'Page not present' events are currently always delivered as synthetic #PF exception. During delivery of these events APF CR2 register contains @@ -243,7 +244,8 @@ data: Note, MSR_KVM_ASYNC_PF_INT MSR specifying the interrupt vector for 'page ready' APF delivery needs to be written to before enabling APF mechanism - in MSR_KVM_ASYNC_PF_EN or interrupt #0 can get injected. + in MSR_KVM_ASYNC_PF_EN or interrupt #0 can get injected. The MSR is + available if KVM_FEATURE_ASYNC_PF_INT is present in CPUID. Note, previously, 'page ready' events were delivered via the same #PF exception as 'page not present' events but this is now deprecated. If @@ -361,7 +363,8 @@ data: Interrupt vector for asynchnonous 'page ready' notifications delivery. The vector has to be set up before asynchronous page fault mechanism - is enabled in MSR_KVM_ASYNC_PF_EN. + is enabled in MSR_KVM_ASYNC_PF_EN. The MSR is only available if + KVM_FEATURE_ASYNC_PF_INT is present in CPUID. MSR_KVM_ASYNC_PF_ACK: 0x4b564d07 @@ -372,4 +375,5 @@ data: When the guest is done processing 'page ready' APF event and 'token' field in 'struct kvm_vcpu_pv_apf_data' is cleared it is supposed to write '1' to bit 0 of the MSR, this caused the host to re-scan its queue - and check if there are more notifications pending. + and check if there are more notifications pending. The MSR is available + if KVM_FEATURE_ASYNC_PF_INT is present in CPUID. diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h index 7ac20df80ba8..812e9b4c1114 100644 --- a/arch/x86/include/uapi/asm/kvm_para.h +++ b/arch/x86/include/uapi/asm/kvm_para.h @@ -31,6 +31,7 @@ #define KVM_FEATURE_PV_SEND_IPI 11 #define KVM_FEATURE_POLL_CONTROL 12 #define KVM_FEATURE_PV_SCHED_YIELD 13 +#define KVM_FEATURE_ASYNC_PF_INT 14 #define KVM_HINTS_REALTIME 0 diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 901cd1fdecd9..790fe4988001 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -712,7 +712,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) | (1 << KVM_FEATURE_PV_SEND_IPI) | (1 << KVM_FEATURE_POLL_CONTROL) | - (1 << KVM_FEATURE_PV_SCHED_YIELD); + (1 << KVM_FEATURE_PV_SCHED_YIELD) | + (1 << KVM_FEATURE_ASYNC_PF_INT); if (sched_info_on()) entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ffe1497b7beb..cc1bf6cfc5e0 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3404,6 +3404,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_X86_ROBUST_SINGLESTEP: case KVM_CAP_XSAVE: case KVM_CAP_ASYNC_PF: + case KVM_CAP_ASYNC_PF_INT: case KVM_CAP_GET_TSC_KHZ: case KVM_CAP_KVMCLOCK_CTRL: case KVM_CAP_READONLY_MEM: diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 428c7dde6b4b..15012f78a691 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1017,6 +1017,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_S390_VCPU_RESETS 179 #define KVM_CAP_S390_PROTECTED 180 #define KVM_CAP_PPC_SECURE_GUEST 181 +#define KVM_CAP_ASYNC_PF_INT 182 #ifdef KVM_CAP_IRQ_ROUTING