From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-180.mta1.migadu.com (out-180.mta1.migadu.com [95.215.58.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B48D93164C5 for ; Wed, 3 Dec 2025 18:42:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764787375; cv=none; b=SqkFKB1MPCw2bPHdCTyxT3OJ2RpL7vQCHJGSUT+sAQk7QEVXToyDPoQspbsrGI2qDk2DyfINSsneu00Rj5tmS2Jl2WD62+4TttPUmy2YkZgg6YVMbXP/rEHRxFU7SS6foKoa+jYRs7ZedRms/t79my014rGmyUI4YVYheg4j2W0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764787375; c=relaxed/simple; bh=n0tJua9+02fHhH5qeSOeuS2+p3nHuh5vtuietnNo9fI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gGNPKlYZyJz2zNBeT6Vfuue8dEazPqRYuBOgNafeqG7ZSfprq2QKGjJD3eNqdBz3DVP2PUl1KizetwuvYSCbnun+LIjX45Ck4NupZxx0YNlT4aHuaBsYCPdTENMhjMPkAYTvO87JtSd5sxjyNGJSBo+TQRF1tvqHBfIViIEtc+w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=PQIBuQGY; arc=none smtp.client-ip=95.215.58.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="PQIBuQGY" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1764787369; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HQUv+WGjmXGw1sOpM5UH7nCy5ZT8LQ0vahCvp0Opnpk=; b=PQIBuQGY3OcTQq1CUIWEU0VlOCJbFp8MqLeQyx8FQZJhlAxwEABN09NWy+XmM1cVmaAJDd GBbdrCQKVF/lkyCJ0CQ+TwOql+baa0trCOK5EGEfl5JdjiPseJKTGR7wbukTbc7gqrkoYM F/tyaj49LG9d0GHaYCWYt3q4tFZOWUc= From: Yosry Ahmed To: stable@vger.kernel.org Cc: Paolo Bonzini , Sean Christopherson , Yosry Ahmed Subject: [PATCH 6.6.y 1/4] KVM: SVM: Introduce svm_recalc_lbr_msr_intercepts() Date: Wed, 3 Dec 2025 18:42:17 +0000 Message-ID: <20251203184220.2693264-1-yosry.ahmed@linux.dev> In-Reply-To: <2025112059-labrador-contently-dd98@gregkh> References: <2025112059-labrador-contently-dd98@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Introduce a helper updating the intercepts for LBR MSRs, similar to the one introduced upstream by commit 160f143cc131 ("KVM: SVM: Manually recalc all MSR intercepts on userspace MSR filter change"). The main difference is that this version uses set_msr_interception(), which has inverted polarity compared to svm_set_intercept_for_msr(). This is intended to simplify incoming backports. No functional changes intended. Signed-off-by: Yosry Ahmed --- arch/x86/kvm/svm/svm.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 99180d0af3ea..d0bfcf737512 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1009,18 +1009,31 @@ void svm_copy_lbrs(struct vmcb *to_vmcb, struct vmcb *from_vmcb) vmcb_mark_dirty(to_vmcb, VMCB_LBR); } -void svm_enable_lbrv(struct kvm_vcpu *vcpu) +static void svm_recalc_lbr_msr_intercepts(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); + bool intercept = !(svm->vmcb->control.virt_ext & LBR_CTL_ENABLE_MASK); - svm->vmcb->control.virt_ext |= LBR_CTL_ENABLE_MASK; - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHFROMIP, 1, 1); - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHTOIP, 1, 1); - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTFROMIP, 1, 1); - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTTOIP, 1, 1); + set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHFROMIP, + !intercept, !intercept); + set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHTOIP, + !intercept, !intercept); + set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTFROMIP, + !intercept, !intercept); + set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTTOIP, + !intercept, !intercept); if (sev_es_guest(vcpu->kvm)) - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_DEBUGCTLMSR, 1, 1); + set_msr_interception(vcpu, svm->msrpm, MSR_IA32_DEBUGCTLMSR, + !intercept, !intercept); +} + +void svm_enable_lbrv(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm = to_svm(vcpu); + + svm->vmcb->control.virt_ext |= LBR_CTL_ENABLE_MASK; + svm_recalc_lbr_msr_intercepts(vcpu); /* Move the LBR msrs to the vmcb02 so that the guest can see them. */ if (is_guest_mode(vcpu)) @@ -1034,10 +1047,7 @@ static void svm_disable_lbrv(struct kvm_vcpu *vcpu) KVM_BUG_ON(sev_es_guest(vcpu->kvm), vcpu->kvm); svm->vmcb->control.virt_ext &= ~LBR_CTL_ENABLE_MASK; - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHFROMIP, 0, 0); - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHTOIP, 0, 0); - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTFROMIP, 0, 0); - set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTTOIP, 0, 0); + svm_recalc_lbr_msr_intercepts(vcpu); /* * Move the LBR msrs back to the vmcb01 to avoid copying them -- 2.52.0.158.g65b55ccf14-goog