From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B0873C43458 for ; Mon, 6 Jul 2026 18:13:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=BORF2qb/YzOTRyzZ0zTQ3HANIUsxjeDLfDvy6Tmd+Js=; b=MYqry0g267yiGVYcvJBjtAzTsi wybwoZpTsEAfztiMlWCYT5GXLiUQV/OKRLVZlR0skx4lc3hheWUiaqKywfkPjS1I3hIQUbvsDM/sV A06MwmgYL0AwI/nlmcCnEjeIEYmMpWm1ihzLLKYoTTaTx6YQAK+pZvdwDbHEjzTbGf+wxRiSfiVOA niIzdIF9SUFRyNxzPrP3yLNZN20uZbtFTcoUxxFlyDOmuaQSvXndaf6DZ7uqT8hS2xY3rj8My/pF2 b15uqtmdCzk5FFYEqU6EehjMmkFENkWPUzxXJpuinlDoB+4qQJBdSc1hKhMP07wS5ujmB0qV60gmY e+akO7jg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wgnX2-0000000DG9e-02UH; Mon, 06 Jul 2026 17:55:00 +0000 Received: from mail-wm1-x34a.google.com ([2a00:1450:4864:20::34a]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wgnWl-0000000DFiX-1SCC for linux-arm-kernel@lists.infradead.org; Mon, 06 Jul 2026 17:54:44 +0000 Received: by mail-wm1-x34a.google.com with SMTP id 5b1f17b1804b1-493c526df6bso26469345e9.3 for ; Mon, 06 Jul 2026 10:54:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1783360481; x=1783965281; darn=lists.infradead.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=BORF2qb/YzOTRyzZ0zTQ3HANIUsxjeDLfDvy6Tmd+Js=; b=YlAb3inlnDQzAQRa1YsOOIwx0laBiMb5fA6jfaJ4pT7qDMBkS9sUK9LmTL7VNLJ9gL HZW9p8IZTd65prHl6WNbY2jRvUr1T/2EEBQYovZ0fnd8rTmk15T1mHAGsJercLQLGzG+ gcKlZ08oAg0+PBgzoROaLCmWXuGNt1PEpj0Lvo4cHTu9ZC6Cfm+vZWfNxtuoV9WjlsOv zqVQSj3DuMOpW04pJVsXC12bG+yzRNDo4j84S0otK6a/nSlPwWnOnM/HXjR3tsHL/Ryr x6MmuMXbRJhX7gpebM/+L9j3GZnNOtigciq55t2mnvTm5TizhOEinmK7w++TwK800Kuy Vm6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783360481; x=1783965281; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=BORF2qb/YzOTRyzZ0zTQ3HANIUsxjeDLfDvy6Tmd+Js=; b=CZ0Q5I1+yhbv5hYrlUHoWryybLbaodRPidsSvFQ0Li44cSnfZJnn+HqaASfZLGVErH 3Rs3Pb0t0B92KERgV9aTIPG52J+FLXybH+ScJde4YBlPBMzF9D8cTtHf0zj3Nv9oDcqx KHoVuPUrTfZB+Xn2wn/grOyyq8lsfmKeRIC5j82cHF8VTAwZrXWA3lYT81Aoqgo4Kym6 tQmhOB5aO8aTu7b7egfWPst72A2Btkk0+xFitgxgdTwnYrju5MwMpPkccUTOUYqO7y4R ihktDvcsltqily4X02iVCbi3ByZwq78BK2ttf2vJD7pPca9HmsUQFH4R/V2OXrMBiuPX DC/A== X-Gm-Message-State: AOJu0YyRfAoQCJ/WcZlNDeikEvJIxWqgfTdk9MBJ4gxyhTBDjNChPnxT Z+HcaVMpGNo0eUnPJODOuO/VXIJTsgFtTrPDMsq1kVqSxNlExYYJ3VSi7zSM5KtbRT4t15sEdq4 rSlCB4Qpxnofh3SaAElLCwA== X-Received: from wmbb19.prod.google.com ([2002:a05:600c:5893:b0:493:b636:4ee9]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:6d4d:b0:493:b720:ce11 with SMTP id 5b1f17b1804b1-493df088fddmr14317875e9.31.1783360480767; Mon, 06 Jul 2026 10:54:40 -0700 (PDT) Date: Mon, 6 Jul 2026 18:54:14 +0100 In-Reply-To: <20260706175415.2604046-1-vdonnefort@google.com> Mime-Version: 1.0 References: <20260706175415.2604046-1-vdonnefort@google.com> X-Mailer: git-send-email 2.55.0.rc2.803.g1fd1e6609c-goog Message-ID: <20260706175415.2604046-18-vdonnefort@google.com> Subject: [PATCH v2 17/18] KVM: arm64: Reject hyp trace descriptors with fewer CPUs than hyp_nr_cpus From: Vincent Donnefort To: maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kernel-team@android.com, qperret@google.com, tabba@google.com, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260706_105443_468174_9C0D4B94 X-CRM114-Status: UNSURE ( 8.16 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org While a trace descriptor with fewer CPUs than hyp_nr_cpus currently causes no functional issue, such a configuration is invalid and would cause the hypervisor to skip ring buffer initialization when allocating backing pages in EL2. Enforce nr_cpus == hyp_nr_cpus during trace descriptor validation to guarantee that every possible CPU has a valid ring buffer descriptor. Signed-off-by: Vincent Donnefort diff --git a/arch/arm64/kvm/hyp/nvhe/trace.c b/arch/arm64/kvm/hyp/nvhe/trace.c index e7e150ab265f..6e716295247a 100644 --- a/arch/arm64/kvm/hyp/nvhe/trace.c +++ b/arch/arm64/kvm/hyp/nvhe/trace.c @@ -181,6 +181,9 @@ static bool hyp_trace_desc_is_valid(struct hyp_trace_desc *desc, size_t desc_siz desc_end = (void *)desc + desc_size; nr_bpages = desc->bpages_backing_size / sizeof(struct simple_buffer_page); + if (desc->trace_buffer_desc.nr_cpus != hyp_nr_cpus) + return false; + for_each_ring_buffer_desc(rb_desc, cpu, &desc->trace_buffer_desc) { /* Can we read nr_page_va? */ if ((void *)rb_desc + struct_size(rb_desc, page_va, 0) > desc_end) -- 2.55.0.rc2.803.g1fd1e6609c-goog