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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=DATE_IN_PAST_12_24, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5E08C43381 for ; Tue, 26 Feb 2019 06:33:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AFC012147C for ; Tue, 26 Feb 2019 06:33:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726878AbfBZGdE (ORCPT ); Tue, 26 Feb 2019 01:33:04 -0500 Received: from mga17.intel.com ([192.55.52.151]:18116 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726781AbfBZGdC (ORCPT ); Tue, 26 Feb 2019 01:33:02 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Feb 2019 22:33:01 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,414,1544515200"; d="scan'208";a="141666222" Received: from local-michael-cet-test.sh.intel.com ([10.239.159.128]) by orsmga001.jf.intel.com with ESMTP; 25 Feb 2019 22:32:59 -0800 From: Yang Weijiang To: pbonzini@redhat.com, rkrcmar@redhat.com, sean.j.christopherson@intel.com, jmattson@google.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, mst@redhat.com, yu-cheng.yu@intel.com Cc: Yang Weijiang Subject: [PATCH v3 8/8] KVM:X86: Add user-space read/write interface for CET MSRs. Date: Mon, 25 Feb 2019 21:27:16 +0800 Message-Id: <20190225132716.6982-9-weijiang.yang@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190225132716.6982-1-weijiang.yang@intel.com> References: <20190225132716.6982-1-weijiang.yang@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The Guest MSRs are stored in fpu storage area, they are operated by XSAVES/XRSTORS, so use kvm_load_guest_fpu to restore them is a convenient way to let KVM access them. After finish operation, need to restore Host MSR contents by kvm_put_guest_fpu. Signed-off-by: Yang Weijiang --- arch/x86/kvm/x86.c | 46 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 43 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a0f8b71b2132..a4bdbef3a712 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -75,6 +75,8 @@ #define MAX_IO_MSRS 256 #define KVM_MAX_MCE_BANKS 32 +#define MAX_GUEST_CET_MSRS 5 + u64 __read_mostly kvm_mce_cap_supported = MCG_CTL_P | MCG_SER_P; EXPORT_SYMBOL_GPL(kvm_mce_cap_supported); @@ -214,6 +216,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { u64 __read_mostly host_xcr0; static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt); +static void kvm_load_guest_fpu(struct kvm_vcpu *vcpu); +static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu); static inline void kvm_async_pf_hash_reset(struct kvm_vcpu *vcpu) { @@ -2889,21 +2893,57 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) } EXPORT_SYMBOL_GPL(kvm_get_msr_common); +static int do_cet_msrs(struct kvm_vcpu *vcpu, int entry_num, + struct kvm_msr_entry *entries, bool read) +{ + int i = entry_num; + int j = MAX_GUEST_CET_MSRS; + bool has_cet; + + has_cet = guest_cpuid_has(vcpu, X86_FEATURE_SHSTK) | + guest_cpuid_has(vcpu, X86_FEATURE_IBT); + /* + * Guest CET MSRs are saved by XSAVES, so need to restore + * them first, then read out or update the contents and + * restore Host ones. + */ + if (has_cet) { + kvm_load_guest_fpu(vcpu); + + if (read) { + for (j = 0; j < MAX_GUEST_CET_MSRS; j++, i++) + rdmsrl(entries[i].index, entries[i].data); + } else { + for (j = 0; j < MAX_GUEST_CET_MSRS; j++, i++) + wrmsrl(entries[i].index, entries[i].data); + } + + kvm_put_guest_fpu(vcpu); + } + return j; +} /* * Read or write a bunch of msrs. All parameters are kernel addresses. * * @return number of msrs set successfully. */ static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs, - struct kvm_msr_entry *entries, + struct kvm_msr_entry *entries, bool read, int (*do_msr)(struct kvm_vcpu *vcpu, unsigned index, u64 *data)) { int i; - for (i = 0; i < msrs->nmsrs; ++i) + for (i = 0; i < msrs->nmsrs; ++i) { + /* If it comes to CET related MSRs, read them together. */ + if (entries[i].index == MSR_IA32_U_CET) { + i += do_cet_msrs(vcpu, i, entries, read) - 1; + continue; + } + if (do_msr(vcpu, entries[i].index, &entries[i].data)) break; + } return i; } @@ -2938,7 +2978,7 @@ static int msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs __user *user_msrs, goto out; } - r = n = __msr_io(vcpu, &msrs, entries, do_msr); + r = n = __msr_io(vcpu, &msrs, entries, !!writeback, do_msr); if (r < 0) goto out_free; -- 2.17.1