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 0191ECD5BAC for ; Thu, 21 May 2026 12:46:38 +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=Ya0EIolpgZkRZly38TaGSqahWi+4I2R7BKxWyyv4pQc=; b=Ot2aiQUW7ke2UyMhFaWaSDZrBA sJdCn++ZcjHokMvwXWaMFvZlS6+/hSGHmtE6/sdzMKaqwJwPA7rEB37bMcM6auCgO/fbJAUJ+QKiJ c5k0DyGrjP3pmaoDINkHrr20y5YFFFNaNbdv/5YBcd/XmmbKnxKRjNNgIOr534TTBLpPzmZnPHULO pvAwuGRHn9sIZBNlPfUoddr3nbJ4OUvcpF1PIAxXi4i67ns3WLC3uNZ6QfDZRovSNqrBmpsPgYZQ/ hMriZ4qEdgGpoRUYIYCWaI7oga/ioVqXeDBo8+fz1PZOoRKVVNnOAnL3+XuX0pVhFonR3BEMNkO4w k9Q7itOg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wQ2nI-00000007lGr-3kBy; Thu, 21 May 2026 12:46:32 +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 1wQ2nE-00000007lEI-2rwG for linux-arm-kernel@lists.infradead.org; Thu, 21 May 2026 12:46:29 +0000 Received: by mail-wm1-x34a.google.com with SMTP id 5b1f17b1804b1-48fe6894f3fso36018195e9.2 for ; Thu, 21 May 2026 05:46:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779367586; x=1779972386; darn=lists.infradead.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Ya0EIolpgZkRZly38TaGSqahWi+4I2R7BKxWyyv4pQc=; b=s5lQbJmVux3R6pH/diOv1Agk8EIM2de8gblXyR2kqWRuc0gium1EULHkKSgKtxfGrc Mm5+/nmvgPgJwopzdp88GwTKUMlnRowUNh9QiN4643PW9ZGSdMVn3rwpwZHFq1iOuMZA 3AOv9kYcpY88ODcAlmIyWV91jTRVe5oZxizxydYexdpf8HC7wIrogzho2JRYKn9ORpgB xTWi2so4Ii7RYNcXrcJ/9J748RSsI7xyM+b87eGiMZsG9ZalxweoNdVomL1CiBGRrBeG 1ONx1NypLuqcK4w7Gs/d34n6xgS7JN7V16bTOYlQycUQjLg/SIpWbZrrC2ryTLe8KjxB yzmw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779367586; x=1779972386; h=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; bh=Ya0EIolpgZkRZly38TaGSqahWi+4I2R7BKxWyyv4pQc=; b=nHoXv+T0+7/1Cut8XoD1MHScvzC5D5r1zI+1Okfr2GWVHb2Ve/9iVuo0X39sPJmCM6 DXqC/De9BtVdJLK4GI7zYVFd6ZcSxvYWNKcmrALSPPDGTSk/a6nJlJzJUYII9Dbru9IM jR413oP38KiHjzJYNzdDPzlzkCv7y3PcmfwUymqR08yNtjfdo13oBAO6e2wC0QDhgqRw hpl+tLyvru0NjBJdU48jWRyuahkyRRu5M9PitrbVJtwaU1+B6b3rBl72lafHFp6+m1v5 D0dds7SF6WIJN4dkLDzp76dM8fciMSxBSrKoQ7kjt8D9yDBD7qwyy7EwOpVTn2WqcVQn 7LHw== X-Gm-Message-State: AOJu0YzICOJhKZAUbrCE15aGZc6kCy8bUfz6jj+NBQrrIgoIhSPYOJdO FpdxNOlLNG5dmCXDLbgVyFXjQngjYWYncFhhYq5G8MDIV165SCYQn1AufI/NYCFq6o3hAcjwdRI izwL6ojAioakO2c2YbRewBQ== X-Received: from wmom17.prod.google.com ([2002:a05:600c:4611:b0:48a:8f50:6c57]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:3545:b0:48a:54a6:b29f with SMTP id 5b1f17b1804b1-490360a87admr35403265e9.17.1779367585711; Thu, 21 May 2026 05:46:25 -0700 (PDT) Date: Thu, 21 May 2026 13:46:12 +0100 In-Reply-To: <20260521124613.911067-1-vdonnefort@google.com> Mime-Version: 1.0 References: <20260521124613.911067-1-vdonnefort@google.com> X-Mailer: git-send-email 2.54.0.746.g67dd491aae-goog Message-ID: <20260521124613.911067-3-vdonnefort@google.com> Subject: [PATCH v2 2/3] KVM: arm64: Fix rollback in hyp_trace_buffer_share_hyp() 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, Vincent Donnefort , Sashiko Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260521_054628_728144_DBD1A1B5 X-CRM114-Status: UNSURE ( 9.00 ) 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 When sharing the trace buffer with the hypervisor, if sharing a page fails, the rollback path in hyp_trace_buffer_share_hyp() misses unsharing the metadata page (meta_va) which was successfully shared before entering the page sharing loop. Additionally, if a failure occurs, the cleanup calls hyp_trace_buffer_unshare_hyp() with an incorrect CPU index. Since that CPU's pages were already rolled back locally in the loop, this leads to duplicate unsharing attempts. Fix both issues affecting the rollback. Fixes: 3aed038aac8d ("KVM: arm64: Add trace remote for the nVHE/pKVM hyp") Reported-by: Sashiko Signed-off-by: Vincent Donnefort diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c index 06805b426101..8595f9bdb3dc 100644 --- a/arch/arm64/kvm/hyp_trace.c +++ b/arch/arm64/kvm/hyp_trace.c @@ -212,14 +212,15 @@ static int hyp_trace_buffer_share_hyp(struct hyp_trace_buffer *trace_buffer) } if (ret) { - for (p--; p >= 0; p--) + while (--p >= 0) __unshare_page(rb_desc->page_va[p]); + __unshare_page(rb_desc->meta_va); break; } } if (ret) - hyp_trace_buffer_unshare_hyp(trace_buffer, cpu--); + hyp_trace_buffer_unshare_hyp(trace_buffer, --cpu); return ret; } -- 2.54.0.746.g67dd491aae-goog