From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x227rnBCGuqu2nl7/PjoVFPn85Cgw8RJ28debJ+4Wlb+Zd1ESYqLF4gw/BKThVm36I70BKnml ARC-Seal: i=1; a=rsa-sha256; t=1517569156; cv=none; d=google.com; s=arc-20160816; b=Qn+9nCIcEFGSspkBY6w6lHwgkVJPDD5aH/OVpYXRPijftbFeUUCn84dH/SD5EkBtbP q+wIRUycK0hvN6C+x8Zl9Px2mMe3RRuGCiNTcekYwKaxbP/FBwJzuDIaHmmtJh82T1v4 UPjPA/URTci4HemIhcwIMYcPLrZ50pZHVCS7LdwGt7M9JOVDypQ/hJ7+kdGTf1GALtBX XZt7r2MHLY0i4yMFs8J/LUnqET4KdSRGB95IL2B0dGSK8GPuScj3uEoJAmiBQZlPwEMp Cg+uWYEZcFmoaZ+te5ZN9rpTEqD9TUKhfeXf034T03YboK2VJ/scNS0mnX21+LD8l62N RGMA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date:dkim-signature :arc-authentication-results; bh=joj3bM1H/58a7sQDLAuwGq9qIicDXHPHAk/DLuUou8o=; b=j8DzpBX20Sy1TAJSFoxQ/ZQFWUFB1lM+FiTkWhs9xSgnSooHR/tZ0DCIaPSoJk0Uvd BjvMV98I3tCxOoNQMtlPVOHUtpRj+cRwR4QJxat9OLCQlm5C8HQh3tJTcU+R7x0EGz8i Jm3P4jJEfuJtsidatMSvTcZZSXksHKeQk9OTgg+PskAx/FmnKnLXYol1MMF/YfFXJUwG 9wmhzNDwSR05WAqelrvym0aj3WbRrLv1BqFd0H8EGYgo37OPRkbZkg0mOyyKuyYSi3+9 qHWiJbUUBeOPnsmuXb00KL3c/seEplHF2+MptBJ9tGAAJw/lvetneRZ9mg5JPQzJYagY Vjow== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2017-10-26 header.b=iQEbPoUw; spf=pass (google.com: domain of darren.kenny@oracle.com designates 141.146.126.79 as permitted sender) smtp.mailfrom=darren.kenny@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2017-10-26 header.b=iQEbPoUw; spf=pass (google.com: domain of darren.kenny@oracle.com designates 141.146.126.79 as permitted sender) smtp.mailfrom=darren.kenny@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Date: Fri, 2 Feb 2018 10:53:26 +0000 From: Darren Kenny To: KarimAllah Ahmed Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, Asit Mallick , Dave Hansen , Arjan Van De Ven , Tim Chen , Linus Torvalds , Andrea Arcangeli , Andi Kleen , Thomas Gleixner , Dan Williams , Jun Nakajima , Andy Lutomirski , Greg KH , Paolo Bonzini , Ashok Raj , David Woodhouse Subject: Re: [PATCH v6 3/5] KVM: VMX: Emulate MSR_IA32_ARCH_CAPABILITIES Message-ID: <20180202105326.v53jv7ry4yd6icm4@starbug-vm.ie.oracle.com> Mail-Followup-To: KarimAllah Ahmed , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, Asit Mallick , Dave Hansen , Arjan Van De Ven , Tim Chen , Linus Torvalds , Andrea Arcangeli , Andi Kleen , Thomas Gleixner , Dan Williams , Jun Nakajima , Andy Lutomirski , Greg KH , Paolo Bonzini , Ashok Raj , David Woodhouse References: <1517522386-18410-1-git-send-email-karahmed@amazon.de> <1517522386-18410-4-git-send-email-karahmed@amazon.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline In-Reply-To: <1517522386-18410-4-git-send-email-karahmed@amazon.de> User-Agent: NeoMutt/20171215 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8792 signatures=668660 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802020135 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1591237582262223506?= X-GMAIL-MSGID: =?utf-8?q?1591286596258634541?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Thu, Feb 01, 2018 at 10:59:44PM +0100, KarimAllah Ahmed wrote: >Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO >(bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the >contents will come directly from the hardware, but user-space can still >override it. > >[dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional] > >Cc: Asit Mallick >Cc: Dave Hansen >Cc: Arjan Van De Ven >Cc: Tim Chen >Cc: Linus Torvalds >Cc: Andrea Arcangeli >Cc: Andi Kleen >Cc: Thomas Gleixner >Cc: Dan Williams >Cc: Jun Nakajima >Cc: Andy Lutomirski >Cc: Greg KH >Cc: Paolo Bonzini >Cc: Ashok Raj >Reviewed-by: Paolo Bonzini >Signed-off-by: KarimAllah Ahmed >Signed-off-by: David Woodhouse Reviewed-by: Darren Kenny >--- > arch/x86/kvm/cpuid.c | 2 +- > arch/x86/kvm/vmx.c | 15 +++++++++++++++ > arch/x86/kvm/x86.c | 1 + > 3 files changed, 17 insertions(+), 1 deletion(-) > >diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c >index 033004d..1909635 100644 >--- a/arch/x86/kvm/cpuid.c >+++ b/arch/x86/kvm/cpuid.c >@@ -394,7 +394,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > > /* cpuid 7.0.edx*/ > const u32 kvm_cpuid_7_0_edx_x86_features = >- F(AVX512_4VNNIW) | F(AVX512_4FMAPS); >+ F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(ARCH_CAPABILITIES); > > /* all calls to cpuid_count() should be made on the same cpu */ > get_cpu(); >diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >index 263eb1f..b13314a 100644 >--- a/arch/x86/kvm/vmx.c >+++ b/arch/x86/kvm/vmx.c >@@ -593,6 +593,8 @@ struct vcpu_vmx { > u64 msr_guest_kernel_gs_base; > #endif > >+ u64 arch_capabilities; >+ > u32 vm_entry_controls_shadow; > u32 vm_exit_controls_shadow; > u32 secondary_exec_control; >@@ -3262,6 +3264,12 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > case MSR_IA32_TSC: > msr_info->data = guest_read_tsc(vcpu); > break; >+ case MSR_IA32_ARCH_CAPABILITIES: >+ if (!msr_info->host_initiated && >+ !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES)) >+ return 1; >+ msr_info->data = to_vmx(vcpu)->arch_capabilities; >+ break; > case MSR_IA32_SYSENTER_CS: > msr_info->data = vmcs_read32(GUEST_SYSENTER_CS); > break; >@@ -3397,6 +3405,11 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap, MSR_IA32_PRED_CMD, > MSR_TYPE_W); > break; >+ case MSR_IA32_ARCH_CAPABILITIES: >+ if (!msr_info->host_initiated) >+ return 1; >+ vmx->arch_capabilities = data; >+ break; > case MSR_IA32_CR_PAT: > if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) { > if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data)) >@@ -5659,6 +5672,8 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx) > ++vmx->nmsrs; > } > >+ if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) >+ rdmsrl(MSR_IA32_ARCH_CAPABILITIES, vmx->arch_capabilities); > > vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl); > >diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >index c53298d..4ec142e 100644 >--- a/arch/x86/kvm/x86.c >+++ b/arch/x86/kvm/x86.c >@@ -1009,6 +1009,7 @@ static u32 msrs_to_save[] = { > #endif > MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA, > MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX, >+ MSR_IA32_ARCH_CAPABILITIES > }; > > static unsigned num_msrs_to_save; >-- >2.7.4 >