From mboxrd@z Thu Jan 1 00:00:00 1970 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 644FBC433FE for ; Mon, 21 Nov 2022 23:40:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231828AbiKUXkm (ORCPT ); Mon, 21 Nov 2022 18:40:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231757AbiKUXkd (ORCPT ); Mon, 21 Nov 2022 18:40:33 -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 44AD0C67CC for ; Mon, 21 Nov 2022 15:40:33 -0800 (PST) Received: by mail-pl1-x64a.google.com with SMTP id a6-20020a170902ecc600b00186f035ed74so10352548plh.12 for ; Mon, 21 Nov 2022 15:40:33 -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=5FAc41uak7V4S0p5RiUjDgCWZhDYnRWzhKZhqfKXil4=; b=XMdnfb0YgLN7WmgPCdeAVpGm2ClvIvjJ7QxQ4eKpOA9UmZvTDEV7sXbb8WlNxP0Wom lJ6Y5VhzeK7P3uuJVTpdy3ew+u1lcDGR9FuWNQY57OMQv0yg3RSpnIBn4VsGXGSj19Z8 EryEezWhhawqfPZZQV9u3MzQk/vWrnhK/kKSA3+1fIXHlk+YyxxpNybwNd1ORC5H5x83 TY3aGzsDFrcKZIsz8PBJaCY6cGuDre2ztFUqEla8/NpXchcxzBFw4QshSDpS4m2WPwuZ camofsf4qtNCeA0oUQwKErEsPig0ICFhAPTs1tOZemy5jYcHx31tcV72dvNO++xhZ/tH I+WA== 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=5FAc41uak7V4S0p5RiUjDgCWZhDYnRWzhKZhqfKXil4=; b=JSWQwpbnd98ROVNlJqcMgqccB1ulG84zl6lcuk9c+0LKAPsw+oB+aCsB8kYx2ApKxm sUAVf58XwG+cZSt+w1y772wsGnlKdCEbKBO2A2HXWG/my6Vp9B52TeXqIyp76FGFmoKH f+GHkwvsHoI92l3trQiXCkY0YVKHQQg5t55t+mQWAVWG3BspWMBKRohLpyxanPmU0Jl8 a3YcRKh1PtLLWIapGfnpZAcMldr2Jb8fD7hHqfAKHFVx6t1Jw11bc5ZQvPUi9GK6whiK UHF0joP+PoxjyEBD9T55xo/hlEGrU73ntBGsMhlNmGKBPQZYgxKzmCT3WVxu46TvxYe2 1K5g== X-Gm-Message-State: ANoB5plkjgCqVJnljsrO2E0a1VJf/cFXHM4AeFbmEKoL2ofuse9ygZKk opp/GZ3mPAdnwHSqi4UiGiHsn42pPziI X-Google-Smtp-Source: AA0mqf6/0cj3G02GDWiZDiOMf+eg0GQ8KHBBOi7Qvz1ACUOpHEC1N+Le/vUSyAKY5SEpykgbmIa5lX3reMTK X-Received: from vipin.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:479f]) (user=vipinsh job=sendgmr) by 2002:a62:5b43:0:b0:573:6cfc:2210 with SMTP id p64-20020a625b43000000b005736cfc2210mr3423492pfb.55.1669074032803; Mon, 21 Nov 2022 15:40:32 -0800 (PST) Date: Mon, 21 Nov 2022 15:40:22 -0800 In-Reply-To: <20221121234026.3037083-1-vipinsh@google.com> Mime-Version: 1.0 References: <20221121234026.3037083-1-vipinsh@google.com> X-Mailer: git-send-email 2.38.1.584.g0f3c55d4c2-goog Message-ID: <20221121234026.3037083-3-vipinsh@google.com> Subject: [PATCH v2 2/6] 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 --- arch/x86/kvm/hyperv.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 0b6964ed2e66..8551ef495cc9 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -43,6 +43,12 @@ #define KVM_HV_MAX_SPARSE_VCPU_SET_BITS DIV_ROUND_UP(KVM_MAX_VCPUS, HV_VCPUS_PER_SPARSE_BANK) +/* + * The TLFS carves out 64 possible extended hypercalls, numbered sequentially + * after the base capabilities extended hypercall. + */ +#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); @@ -2411,6 +2417,9 @@ 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; } @@ -2564,6 +2573,12 @@ 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; @@ -2722,6 +2737,7 @@ 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; -- 2.38.1.584.g0f3c55d4c2-goog