From patchwork Thu Jul 16 03:16:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Yang, Weijiang" X-Patchwork-Id: 11666571 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 A59CB722 for ; Thu, 16 Jul 2020 03:17:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97D5420791 for ; Thu, 16 Jul 2020 03:17:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728252AbgGPDRK (ORCPT ); Wed, 15 Jul 2020 23:17:10 -0400 Received: from mga06.intel.com ([134.134.136.31]:8148 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728238AbgGPDRG (ORCPT ); Wed, 15 Jul 2020 23:17:06 -0400 IronPort-SDR: /W1/v4ee3af8ZAyWtPZhVMDXUfrp/fhA+QO/kOUKNKYcDns8EhuVeBPkrMFrJ+UYiZBNVLDQK3 WPpb/sa95rgw== X-IronPort-AV: E=McAfee;i="6000,8403,9683"; a="210844855" X-IronPort-AV: E=Sophos;i="5.75,357,1589266800"; d="scan'208";a="210844855" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jul 2020 20:17:05 -0700 IronPort-SDR: sBbk95E8CgFg+2aBOH0e5p1KT6FjtbJKGU0/G1lD+eGSi0PsqlpeS7SUykkiauNfRnMhMQubjz 6+wTJfj1M2Tw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,357,1589266800"; d="scan'208";a="360910452" Received: from unknown (HELO local-michael-cet-test.sh.intel.com) ([10.239.159.128]) by orsmga001.jf.intel.com with ESMTP; 15 Jul 2020 20:17:03 -0700 From: Yang Weijiang To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, sean.j.christopherson@intel.com, jmattson@google.com Cc: yu.c.zhang@linux.intel.com, Yang Weijiang Subject: [RESEND v13 05/11] KVM: x86: Refresh CPUID once guest changes XSS bits Date: Thu, 16 Jul 2020 11:16:21 +0800 Message-Id: <20200716031627.11492-6-weijiang.yang@intel.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20200716031627.11492-1-weijiang.yang@intel.com> References: <20200716031627.11492-1-weijiang.yang@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org CPUID(0xd, 1) reports the current required storage size of XCR0 | XSS, when guest updates the XSS, it's necessary to update the CPUID leaf, otherwise guest will fetch old state size, and results to some WARN traces during guest running. supported_xss is initialized to host_xss & KVM_SUPPORTED_XSS to indicate current MSR_IA32_XSS bits supported in KVM, but actual XSS bits seen in guest depends on the setting of CPUID(0xd,1).{ECX, EDX} for guest. Co-developed-by: Zhang Yi Z Signed-off-by: Zhang Yi Z Signed-off-by: Yang Weijiang --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/cpuid.c | 23 +++++++++++++++++++---- arch/x86/kvm/x86.c | 12 ++++++++---- 3 files changed, 28 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index be5363b21540..e8c749596ba2 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -654,6 +654,7 @@ struct kvm_vcpu_arch { u64 xcr0; u64 guest_supported_xcr0; + u64 guest_supported_xss; struct kvm_pio_request pio; void *pio_data; diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 8a294f9747aa..d97b2a6e8a8c 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -88,14 +88,29 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) vcpu->arch.guest_supported_xcr0 = 0; } else { vcpu->arch.guest_supported_xcr0 = - (best->eax | ((u64)best->edx << 32)) & supported_xcr0; + (((u64)best->edx << 32) | best->eax) & supported_xcr0; best->ebx = xstate_required_size(vcpu->arch.xcr0, false); } best = kvm_find_cpuid_entry(vcpu, 0xD, 1); - if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) || - cpuid_entry_has(best, X86_FEATURE_XSAVEC))) - best->ebx = xstate_required_size(vcpu->arch.xcr0, true); + if (best) { + if (cpuid_entry_has(best, X86_FEATURE_XSAVES) || + cpuid_entry_has(best, X86_FEATURE_XSAVEC)) { + u64 xstate = vcpu->arch.xcr0 | vcpu->arch.ia32_xss; + + best->ebx = xstate_required_size(xstate, true); + } + + if (!cpuid_entry_has(best, X86_FEATURE_XSAVES)) { + best->ecx = 0; + best->edx = 0; + } + vcpu->arch.guest_supported_xss = + (((u64)best->edx << 32) | best->ecx) & supported_xss; + + } else { + vcpu->arch.guest_supported_xss = 0; + } /* * The existing code assumes virtual address is 48-bit or 57-bit in the diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 906e07039d59..8aed32ff9c0c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2912,9 +2912,12 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) * IA32_XSS[bit 8]. Guests have to use RDMSR/WRMSR rather than * XSAVES/XRSTORS to save/restore PT MSRs. */ - if (data & ~supported_xss) + if (data & ~vcpu->arch.guest_supported_xss) return 1; - vcpu->arch.ia32_xss = data; + if (vcpu->arch.ia32_xss != data) { + vcpu->arch.ia32_xss = data; + kvm_update_cpuid(vcpu); + } break; case MSR_SMI_COUNT: if (!msr_info->host_initiated) @@ -9779,8 +9782,9 @@ int kvm_arch_hardware_setup(void *opaque) memcpy(&kvm_x86_ops, ops->runtime_ops, sizeof(kvm_x86_ops)); - if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES)) - supported_xss = 0; + supported_xss = 0; + if (kvm_cpu_cap_has(X86_FEATURE_XSAVES)) + supported_xss = host_xss & KVM_SUPPORTED_XSS; #define __kvm_cpu_cap_has(UNUSED_, f) kvm_cpu_cap_has(f) cr4_reserved_bits = __cr4_reserved_bits(__kvm_cpu_cap_has, UNUSED_);