From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELvxbRZ8vIWmOw0CvgdtvTt1XHbXOnxxakMfoO7VPx4g2gP536lqV86VbCpDZQxGMfNtmCSH ARC-Seal: i=1; a=rsa-sha256; t=1520451858; cv=none; d=google.com; s=arc-20160816; b=oJjKlaOMav1W6xjrDyle+9Hua1tx0cvvt1/ASm71hqtXmNcT9Z5ODH9bpN/KkXtpfR grH441j2RkheiYAkfHpwdv01gtS2OxMOUfbLPc/o6rXQzTyeqUHvSpklv48G1x2FHzKb gQNywIEo1X+e4Lrg61QltueAco7x7SsDhE4fFtsPlg0p9tfRWIDNmqGmR/GqZeDB8OUB 971w+7z+kwPt/lbzWdZBJG8R2AsebhWCoBJzIdjInAR12GgCqSLREkIyjVEc2m4lItGa hzEvAMfysD6c15jc6Y+h/ILRR5vZO62rv9FeDjWNOsy/LGOdSwvyHZ4VS4tztew8ZKp1 J0GA== 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:arc-authentication-results; bh=8hTWWEdo0YXFiuk4GW/3hqmquccaN2CYzArana47oRo=; b=tXVkXKvvF2iW/w3AvtOborOrGebmp4KCAbtt96hXyWTWBtjsZSZ1PdPFYJaUW9bZL5 Q74jXCpO5xWK3OgTtmNk//kgErieZ7xWpOW1szvmqswrH4qQ9Yo0PHas1wX4G7HkY+Mf JoLUTlIcqjLhHRtsSFYCqX8djAOjDx4lyULwQkj9XydNIadcN/W6Vxtc7r2ftE1Qi9si Om1ngfYX5cVLiUNbTiC0sPT13fcvtqpqQqWWBfWrVPtkV+NNkmw173b4DBdIpjzQLGg8 TmqBloH/EZf8MOaMHqntcQtbZZ7dQZq4KCZ2b0VIt+7OTRCMXDCR+nTvODZQZeQQdSpS /k4g== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 185.236.200.248 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 185.236.200.248 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paolo Bonzini , Jim Mattson , David Woodhouse , KarimAllah Ahmed , Linus Torvalds , Peter Zijlstra , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Thomas Gleixner , kvm@vger.kernel.org, Ingo Molnar Subject: [PATCH 4.15 113/122] KVM/x86: Remove indirect MSR op calls from SPEC_CTRL Date: Wed, 7 Mar 2018 11:38:45 -0800 Message-Id: <20180307191746.018327420@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180307191729.190879024@linuxfoundation.org> References: <20180307191729.190879024@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?1594309327572733329?= X-GMAIL-MSGID: =?utf-8?q?1594309327572733329?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Bonzini commit ecb586bd29c99fb4de599dec388658e74388daad upstream. Having a paravirt indirect call in the IBRS restore path is not a good idea, since we are trying to protect from speculative execution of bogus indirect branch targets. It is also slower, so use native_wrmsrl() on the vmentry path too. Signed-off-by: Paolo Bonzini Reviewed-by: Jim Mattson Cc: David Woodhouse Cc: KarimAllah Ahmed Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Radim Krčmář Cc: Thomas Gleixner Cc: kvm@vger.kernel.org Cc: stable@vger.kernel.org Fixes: d28b387fb74da95d69d2615732f50cceb38e9a4d Link: http://lkml.kernel.org/r/20180222154318.20361-2-pbonzini@redhat.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm.c | 7 ++++--- arch/x86/kvm/vmx.c | 7 ++++--- 2 files changed, 8 insertions(+), 6 deletions(-) --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -45,6 +45,7 @@ #include #include #include +#include #include #include @@ -5029,7 +5030,7 @@ static void svm_vcpu_run(struct kvm_vcpu * being speculatively taken. */ if (svm->spec_ctrl) - wrmsrl(MSR_IA32_SPEC_CTRL, svm->spec_ctrl); + native_wrmsrl(MSR_IA32_SPEC_CTRL, svm->spec_ctrl); asm volatile ( "push %%" _ASM_BP "; \n\t" @@ -5139,10 +5140,10 @@ static void svm_vcpu_run(struct kvm_vcpu * save it. */ if (!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL)) - rdmsrl(MSR_IA32_SPEC_CTRL, svm->spec_ctrl); + svm->spec_ctrl = native_read_msr(MSR_IA32_SPEC_CTRL); if (svm->spec_ctrl) - wrmsrl(MSR_IA32_SPEC_CTRL, 0); + native_wrmsrl(MSR_IA32_SPEC_CTRL, 0); /* Eliminate branch target predictions from guest mode */ vmexit_fill_RSB(); --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -51,6 +51,7 @@ #include #include #include +#include #include #include "trace.h" @@ -9443,7 +9444,7 @@ static void __noclone vmx_vcpu_run(struc * being speculatively taken. */ if (vmx->spec_ctrl) - wrmsrl(MSR_IA32_SPEC_CTRL, vmx->spec_ctrl); + native_wrmsrl(MSR_IA32_SPEC_CTRL, vmx->spec_ctrl); vmx->__launched = vmx->loaded_vmcs->launched; asm( @@ -9579,10 +9580,10 @@ static void __noclone vmx_vcpu_run(struc * save it. */ if (!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL)) - rdmsrl(MSR_IA32_SPEC_CTRL, vmx->spec_ctrl); + vmx->spec_ctrl = native_read_msr(MSR_IA32_SPEC_CTRL); if (vmx->spec_ctrl) - wrmsrl(MSR_IA32_SPEC_CTRL, 0); + native_wrmsrl(MSR_IA32_SPEC_CTRL, 0); /* Eliminate branch target predictions from guest mode */ vmexit_fill_RSB();