From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9ED793AE6E2; Tue, 24 Feb 2026 22:34:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771972472; cv=none; b=s3dJm5j/tb8hqdbhIYr39Dxv+TuQkEzKN5/zSXdyg8iUQOt+vx3GeteDpWiI3tq2GzEQqWuuHQVy3acx0/b5Kc5S/0azhPNZco3oWuLOAbS4sUMBF+67dTZ0Yf+BnObMlRklt+rQkjN4qXkcSNHnMfFZDjjctd8ZuLlS0ksSxus= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771972472; c=relaxed/simple; bh=iE/e2/DcJolfWaFpaNXrD2k53hM94zPMsuIvNRn7BlY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LvQyvfTKzyPQnqzCPYzPjhuAAHVqUyuODvrqcjZDxsiPlrGn87gI+dvSsU+9kW/f+hJN1jfuR/mI/53zIu0eIjdRZkPdR3ywspLwplLFfMTdUEHmIujIDVQu/E8+YiN1NL/51izmGbTYGsqhjKmr3yWk786GYbHzEaIiMmzQOH0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HgsKovIz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HgsKovIz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D0B5C19423; Tue, 24 Feb 2026 22:34:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771972472; bh=iE/e2/DcJolfWaFpaNXrD2k53hM94zPMsuIvNRn7BlY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HgsKovIzcan0SWOAK88n1VBFRnDb2G98wYW+sTFWGcPvBJzchk3i8u95BRpUw7+k3 QJv1Io6Sa0Kob0ucd2D7Wpf0tTvkUXmui7lNBT58y8ylf8v2EgRkAN+bwnOgHVTQBc HEX2mj2dQAV0QbZujAXOk91SHhcb7xwRJLTfL79aQlHB/aOKh3YUKzzdvGaR44ZxH2 yBMDxtpi+SSCkwg26xZZ1LWuSg2b50WMwTqGuJSHJITqjmr+VAIlU/YMtWui3M6ceh 96PV5bk8XZIJo1lMYc6qvsnRkTezhkOVCW51d3KhlC/R9KKK7w69YTfHdsFNQSw3Ke 4efM30TsITnDg== From: Yosry Ahmed To: Sean Christopherson Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yosry Ahmed Subject: [PATCH v6 28/31] KVM: nSVM: Sanitize TLB_CONTROL field when copying from vmcb12 Date: Tue, 24 Feb 2026 22:34:02 +0000 Message-ID: <20260224223405.3270433-29-yosry@kernel.org> X-Mailer: git-send-email 2.53.0.414.gf7e9f6c205-goog In-Reply-To: <20260224223405.3270433-1-yosry@kernel.org> References: <20260224223405.3270433-1-yosry@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The APM defines possible values for TLB_CONTROL as 0, 1, 3, and 7 -- all of which are always allowed for KVM guests as KVM always supports X86_FEATURE_FLUSHBYASID. Only copy bits 0 to 2 from vmcb12's TLB_CONTROL, such that no unhandled or reserved bits end up in vmcb02. Note that TLB_CONTROL in vmcb12 is currently ignored by KVM, as it nukes the TLB on nested transitions anyway (see nested_svm_transition_tlb_flush()). However, such sanitization will be needed once the TODOs there are addressed, and it's minimal churn to add it now. Signed-off-by: Yosry Ahmed --- arch/x86/include/asm/svm.h | 2 ++ arch/x86/kvm/svm/nested.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index c169256c415fb..16cf4f435aebd 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -182,6 +182,8 @@ struct __attribute__ ((__packed__)) vmcb_control_area { #define TLB_CONTROL_FLUSH_ASID 3 #define TLB_CONTROL_FLUSH_ASID_LOCAL 7 +#define TLB_CONTROL_MASK GENMASK(2, 0) + #define ERAP_CONTROL_ALLOW_LARGER_RAP BIT(0) #define ERAP_CONTROL_CLEAR_RAP BIT(1) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 28a8bfc632ef5..d7c353ac42d88 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -502,7 +502,7 @@ void __nested_copy_vmcb_control_to_cache(struct kvm_vcpu *vcpu, to->iopm_base_pa = from->iopm_base_pa & PAGE_MASK; to->msrpm_base_pa = from->msrpm_base_pa & PAGE_MASK; to->tsc_offset = from->tsc_offset; - to->tlb_ctl = from->tlb_ctl; + to->tlb_ctl = from->tlb_ctl & TLB_CONTROL_MASK; to->erap_ctl = from->erap_ctl; to->int_ctl = from->int_ctl; to->int_vector = from->int_vector; -- 2.53.0.414.gf7e9f6c205-goog