From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZroSJn3a0Ihl2CwKOz8/NfDbUbvqsnWUZLdsuJOZyCurpixgErvCWMP66ss4Y9Rd2+MMwuJ ARC-Seal: i=1; a=rsa-sha256; t=1526937916; cv=none; d=google.com; s=arc-20160816; b=SvW/IXansScvFLESC6QEwxCD56FHf+SduhpH8NAsMJWW2A18bjHIIg5OG5PVcmdoDJ wm7l3GWFg0vtKaWzQBv84tZDCRaAHNqkU1nR2ek0EZRVxzplVRqONkb7XF6ILnhyb/Wc 7AKZV+vp/xBqghtr0NkdCjZC2IgXxXgKaD03ItHoChgdBxczCr4By9DnwR6SAomZA4mY yhQLXKfVQPr/1doHPcQTrsdR9A+RTzChoBoZTTDiw4gW5+cBVt9eVO+uBgbxEbK9H9iw NVuUf33UIWiZNZ6YwKEPbL4p+ksgmrJChjCiAXXzANrANcnjhhg8RpNlOqw0BDHELcIT DkAQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:arc-authentication-results; bh=rGacbnJKxVsvY6/D3TNFoXh4hood7vQ2wdKrSpDlMJg=; b=hzrnJRxJUa0NkVq86mSwvEeMLDb7Zi3G3anCiZl/ETh0poo1k4vT9e/LKv1KWnq0DG rwxxbbgI5nnEBJnPoaMnSd0mRL7wb8HE6w4UZYc5Ko+z1wc2J4QNmlOZhIqwafMGYz8v nQLlkI++gG/x+npb4D7wTxMHRk+s+jH1Dcu6W4zSx3FCrLdaJFcOo/CAmh/dh1XsFZHJ +UpcHEG2pQa4i+PuzNdtAVynvK8h16kDb0d5MwZcXK0H6OD+fhZMf8rw5WLDC6PwPUU/ RMc3G4nXQWJdzOx+0pQTJH3CNhuzGrc16FC/VyWR5qTAr8AaTmM0P50OMqWFPHYjBjWP 3tbg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=At1lOX8+; spf=pass (google.com: domain of srs0=nia/=ii=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=nia/=II=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=At1lOX8+; spf=pass (google.com: domain of srs0=nia/=ii=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=nia/=II=linuxfoundation.org=gregkh@kernel.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Konrad Rzeszutek Wilk , Thomas Gleixner , Ingo Molnar Subject: [PATCH 4.16 073/110] x86/KVM/VMX: Expose SPEC_CTRL Bit(2) to the guest Date: Mon, 21 May 2018 23:12:10 +0200 Message-Id: <20180521210512.632685068@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180521210503.823249477@linuxfoundation.org> References: <20180521210503.823249477@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1601109855664030596?= X-GMAIL-MSGID: =?utf-8?q?1601110452440858441?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Konrad Rzeszutek Wilk commit da39556f66f5cfe8f9c989206974f1cb16ca5d7c upstream Expose the CPUID.7.EDX[31] bit to the guest, and also guard against various combinations of SPEC_CTRL MSR values. The handling of the MSR (to take into account the host value of SPEC_CTRL Bit(2)) is taken care of in patch: KVM/SVM/VMX/x86/spectre_v2: Support the combination of guest and host IBRS Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/cpuid.c | 2 +- arch/x86/kvm/vmx.c | 8 +++++--- 2 files changed, 6 insertions(+), 4 deletions(-) --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -402,7 +402,7 @@ static inline int __do_cpuid_ent(struct /* cpuid 7.0.edx*/ const u32 kvm_cpuid_7_0_edx_x86_features = - F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | + F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | F(RDS) | F(ARCH_CAPABILITIES); /* all calls to cpuid_count() should be made on the same cpu */ --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3276,7 +3276,8 @@ static int vmx_get_msr(struct kvm_vcpu * case MSR_IA32_SPEC_CTRL: if (!msr_info->host_initiated && !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) && - !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL)) + !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) && + !guest_cpuid_has(vcpu, X86_FEATURE_RDS)) return 1; msr_info->data = to_vmx(vcpu)->spec_ctrl; @@ -3397,11 +3398,12 @@ static int vmx_set_msr(struct kvm_vcpu * case MSR_IA32_SPEC_CTRL: if (!msr_info->host_initiated && !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) && - !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL)) + !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) && + !guest_cpuid_has(vcpu, X86_FEATURE_RDS)) return 1; /* The STIBP bit doesn't fault even if it's not advertised */ - if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP)) + if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | SPEC_CTRL_RDS)) return 1; vmx->spec_ctrl = data;