From patchwork Mon Dec 12 18:37:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vipin Sharma X-Patchwork-Id: 13071366 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 4E152C4332F for ; Mon, 12 Dec 2022 18:38:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233695AbiLLSiT (ORCPT ); Mon, 12 Dec 2022 13:38:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233218AbiLLShl (ORCPT ); Mon, 12 Dec 2022 13:37:41 -0500 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1226D5F68 for ; Mon, 12 Dec 2022 10:37:39 -0800 (PST) Received: by mail-pl1-x64a.google.com with SMTP id i4-20020a17090332c400b0018f82951826so3301463plr.20 for ; Mon, 12 Dec 2022 10:37:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=ocUPVz8ANM21EwPfg3tXA9E2skPDsvTTK6JWONirGoA=; b=JxzKtapsPiPTDLxMGnXHtcuPc/3a2vdU1jztHn7/Dbo+KqCwm5TEIWr5lEAvNGjzfP hLjnmKj0t9g7tdCps8hlYta2ObsB7zdCyrhLeJ00xOOG+f3aQR27mNlm1U3HSX0XUGEz 6FSa0S53usUm4cJNpXeWRFAjeUVgdNqOLQWXT1IIYGq+V9XHak9G1cjMerDJebE/modI YJlo3+DiHIHH6/tv3KyYu6NMmZhHgEBL6ALxnbHWYdP2ZEHfQic4FHbScTFZAbSbSVUY /slW6dPoyl9+z5xhvIVM0k1nWXRsewQKV3dcz3Z50nU2K37JWITMTbmN/Fvbg7urK/FZ wIJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ocUPVz8ANM21EwPfg3tXA9E2skPDsvTTK6JWONirGoA=; b=oePsow9lo3qkyFwL+O5ksijC7r7sw5SbtSFBn5Dl2zrW4U+YPuwnJK7RoWwhpQlsol DW3V/kvD+tAUI0l7ss24C96S8Kn2GX70eHU740U44rfw899a0nG46YiQ0D73L6nuoHSN xJ/tF+TY4k/MvmhFDAHuqDVBA+AD3PXmSQ5Qoj7OAKwH58+eGlz4H9EGAYM8kIMxXLLB k2J3z/tMZrKLE/2q9KiFYvKLcvFeT0a4Bce0Q2Iow1hgMACI1kiN0FZM0AArfAzClNlL kSkrWqSYijLgwRZeHKlkhqeKdfdAkKURiSlPy8PonufP8P1cPR1n7GE5SmHeDtL4x9Un 3KFQ== X-Gm-Message-State: ANoB5plTDYgbI+kUOwVm+lI8YP/TkIcM4EwmFT24x/RGZxEPqWaI8ykY DxFd4ZFGxHqGWONdnic+8Rj+UXWrcGxz X-Google-Smtp-Source: AA0mqf79uqNPfzIfWoUMpQcM4MXW7aQVy4foX+HZz7Lc/dkJOGMNXt5KpD404Edg4OCbwPrs1zHrO4U7azoo X-Received: from vipin.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:479f]) (user=vipinsh job=sendgmr) by 2002:a62:b501:0:b0:563:771d:417f with SMTP id y1-20020a62b501000000b00563771d417fmr79842609pfe.45.1670870258540; Mon, 12 Dec 2022 10:37:38 -0800 (PST) Date: Mon, 12 Dec 2022 10:37:16 -0800 In-Reply-To: <20221212183720.4062037-1-vipinsh@google.com> Mime-Version: 1.0 References: <20221212183720.4062037-1-vipinsh@google.com> X-Mailer: git-send-email 2.39.0.rc1.256.g54fd8350bd-goog Message-ID: <20221212183720.4062037-10-vipinsh@google.com> Subject: [Patch v4 09/13] KVM: x86: hyper-v: Add extended hypercall support in Hyper-v From: Vipin Sharma To: seanjc@google.com, pbonzini@redhat.com, vkuznets@redhat.com, dmatlack@google.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Vipin Sharma Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Add support for extended hypercall in Hyper-v. Hyper-v TLFS 6.0b describes hypercalls above call code 0x8000 as extended hypercalls. A Hyper-v hypervisor's guest VM finds availability of extended hypercalls via CPUID.0x40000003.EBX BIT(20). If the bit is set then the guest can call extended hypercalls. All extended hypercalls will exit to userspace by default. This allows for easy support of future hypercalls without being dependent on KVM releases. If there will be need to process the hypercall in KVM instead of userspace then KVM can create a capability which userspace can query to know which hypercalls can be handled by the KVM and enable handling of those hypercalls. Signed-off-by: Vipin Sharma Reviewed-by: Vitaly Kuznetsov --- arch/x86/kvm/hyperv.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 2eb68533d188..e232ea578ba5 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -43,6 +43,24 @@ #define KVM_HV_MAX_SPARSE_VCPU_SET_BITS DIV_ROUND_UP(KVM_MAX_VCPUS, HV_VCPUS_PER_SPARSE_BANK) +/* + * As per Hyper-V TLFS, extended hypercalls start from 0x8001 + * (HvExtCallQueryCapabilities). Response of this hypercalls is a 64 bit value + * where each bit tells which extended hypercall is available besides + * HvExtCallQueryCapabilities. + * + * 0x8001 - First extended hypercall, HvExtCallQueryCapabilities, no bit + * assigned. + * + * 0x8002 - Bit 0 + * 0x8003 - Bit 1 + * .. + * 0x8041 - Bit 63 + * + * Therefore, HV_EXT_CALL_MAX = 0x8001 + 64 + */ +#define HV_EXT_CALL_MAX (HV_EXT_CALL_QUERY_CAPABILITIES + 64) + static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer, bool vcpu_kick); @@ -2429,6 +2447,9 @@ static bool hv_check_hypercall_access(struct kvm_vcpu_hv *hv_vcpu, u16 code) case HVCALL_SEND_IPI: return hv_vcpu->cpuid_cache.enlightenments_eax & HV_X64_CLUSTER_IPI_RECOMMENDED; + case HV_EXT_CALL_QUERY_CAPABILITIES ... HV_EXT_CALL_MAX: + return hv_vcpu->cpuid_cache.features_ebx & + HV_ENABLE_EXTENDED_HYPERCALLS; default: break; } @@ -2582,6 +2603,12 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) } goto hypercall_userspace_exit; } + case HV_EXT_CALL_QUERY_CAPABILITIES ... HV_EXT_CALL_MAX: + if (unlikely(hc.fast)) { + ret = HV_STATUS_INVALID_PARAMETER; + break; + } + goto hypercall_userspace_exit; default: ret = HV_STATUS_INVALID_HYPERCALL_CODE; break; @@ -2741,6 +2768,7 @@ int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, ent->ebx |= HV_POST_MESSAGES; ent->ebx |= HV_SIGNAL_EVENTS; + ent->ebx |= HV_ENABLE_EXTENDED_HYPERCALLS; ent->edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE; ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;