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 58C97C76188 for ; Wed, 5 Apr 2023 00:59:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236710AbjDEA7Z (ORCPT ); Tue, 4 Apr 2023 20:59:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236617AbjDEA7T (ORCPT ); Tue, 4 Apr 2023 20:59:19 -0400 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1DF841BEA for ; Tue, 4 Apr 2023 17:59:18 -0700 (PDT) Received: by mail-pf1-x44a.google.com with SMTP id y15-20020a62f24f000000b00627dd180a30so15332020pfl.6 for ; Tue, 04 Apr 2023 17:59:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1680656357; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=/LlxEKk640KODqyIXhxgneIbkJJUkcc+ai741c33zE8=; b=UNFKuAHYj2mFuBI2Q/+O3KVQ0ZS5y6NNYC6EoMkQXyoAlpDwwWmh2xswrRJLTcF4UE PRwO0hnL5DSc/bdyWhXa6RL/tPpQt+UB35gEI4DkaXbxVfgJ4mlG8aaJWu4gDWPLCHLz itsfBduIOCypfCPOQH2koafLF+sRhreYKTpUG1hX30XD7PZ6p2lmUTHm20GXbYeHKsx8 tnxKAdPd04iLrkr/7U4ClEfEd7JjpaB1qp2B8Bo8gz6mLr48TebLwBdw/6L0G30SHCGN L0yHlPucDMThI8erO/qRmpf9icQ7gdhJrLnOjhfJ+WZ5f+SXF9QJi3SKFydYeinyshkT dZtw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680656357; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=/LlxEKk640KODqyIXhxgneIbkJJUkcc+ai741c33zE8=; b=S5wbdZrHn8xZXKzN6fskBAB/+hlR/wFf0vHIsWUXb4noe4jGP6N4T/e7V28378ymWm WSkeW2Aal5xMWb7fEu0Xb7Ag6rHbhXN+5v3m+WzOI32UxvPOtsCPjCyLK5WhA/ARu0xF MBPIkc/sox+tpJqeArwP+K4wEnf/IV8p/mtYmXsxf07iZJzklHKN5XQZ9w5CHmAJJ/UO AO+iT2FrsshMTPCdX3MCfc/CHNuDVwIs7+5WVauQ9V1K4X6j1FfO1fRbVRsVcHl45lS3 5rQCMP8wB2hY4zvVPeQ+f9e5fbGG+GHTCEUXSA+8SLvdgzlxm67CzmEVtsFAnONh9JFd lUtg== X-Gm-Message-State: AAQBX9fRanccqoltZ5P0W5QX6qjmhFpkkrq9hT/P77f8jWl1/dkkWloX 0IvENa6MR9PnJw9MToCjvvOvY2tB97w= X-Google-Smtp-Source: AKy350YCSwsgMepLpJrPs+q3saso46a65PtfgrMxb+8i3hWXKcMkCMsmZ0/aYcPqs9Ysfb0RhdiJyCq0/ps= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a65:4c88:0:b0:513:92e7:4555 with SMTP id m8-20020a654c88000000b0051392e74555mr420188pgt.4.1680656357670; Tue, 04 Apr 2023 17:59:17 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 4 Apr 2023 17:59:10 -0700 In-Reply-To: <20230405005911.423699-1-seanjc@google.com> Mime-Version: 1.0 References: <20230405005911.423699-1-seanjc@google.com> X-Mailer: git-send-email 2.40.0.348.gf938b09366-goog Message-ID: <20230405005911.423699-3-seanjc@google.com> Subject: [PATCH 2/3] KVM: x86: Don't adjust guest's CPUID.0x12.1 (allowed SGX enclave XFRM) From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Kai Huang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Drop KVM's manipulation of guest's CPUID.0x12.1 ECX and EDX, i.e. the allowed XFRM of SGX enclaves, now that KVM explicitly checks the guest's allowed XCR0 when emulating ECREATE. Note, this could theoretically break a setup where userspace advertises a "bad" XFRM and relies on KVM to provide a sane CPUID model, but QEMU is the only known user of KVM SGX, and QEMU explicitly sets the SGX CPUID XFRM subleaf based on the guest's XCR0. Cc: Kai Huang Signed-off-by: Sean Christopherson --- arch/x86/kvm/cpuid.c | 16 ---------------- 1 file changed, 16 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 6972e0be60fa..d28c4fb14d43 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -253,7 +253,6 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e int nent) { struct kvm_cpuid_entry2 *best; - u64 guest_supported_xcr0 = cpuid_get_supported_xcr0(entries, nent); best = cpuid_entry2_find(entries, nent, 1, KVM_CPUID_INDEX_NOT_SIGNIFICANT); if (best) { @@ -292,21 +291,6 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e vcpu->arch.ia32_misc_enable_msr & MSR_IA32_MISC_ENABLE_MWAIT); } - - /* - * Bits 127:0 of the allowed SECS.ATTRIBUTES (CPUID.0x12.0x1) enumerate - * the supported XSAVE Feature Request Mask (XFRM), i.e. the enclave's - * requested XCR0 value. The enclave's XFRM must be a subset of XCRO - * at the time of EENTER, thus adjust the allowed XFRM by the guest's - * supported XCR0. Similar to XCR0 handling, FP and SSE are forced to - * '1' even on CPUs that don't support XSAVE. - */ - best = cpuid_entry2_find(entries, nent, 0x12, 0x1); - if (best) { - best->ecx &= guest_supported_xcr0 & 0xffffffff; - best->edx &= guest_supported_xcr0 >> 32; - best->ecx |= XFEATURE_MASK_FPSSE; - } } void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) -- 2.40.0.348.gf938b09366-goog