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[192.237.175.120]) by mx.google.com with ESMTPS id 68si6163085ios.118.2017.05.04.10.56.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 May 2017 10:56:29 -0700 (PDT) Received-SPF: neutral (google.com: 192.237.175.120 is neither permitted nor denied by best guess record for domain of xen-devel-bounces@lists.xen.org) client-ip=192.237.175.120; Authentication-Results: mx.google.com; spf=neutral (google.com: 192.237.175.120 is neither permitted nor denied by best guess record for domain of xen-devel-bounces@lists.xen.org) smtp.mailfrom=xen-devel-bounces@lists.xen.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d6Kxg-0002Mo-Ca; Thu, 04 May 2017 17:54:44 +0000 Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d6Kxf-0002Ls-Fw for xen-devel@lists.xen.org; Thu, 04 May 2017 17:54:43 +0000 Received: from [85.158.139.211] by server-3.bemta-5.messagelabs.com id 77/AA-02022-2EA6B095; Thu, 04 May 2017 17:54:42 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrALMWRWlGSWpSXmKPExsVysyfVTfd+Fne kwZIFQhZLPi5mcWD0OLr7N1MAYxRrZl5SfkUCa8bhN2YFr3grun/PYmxgXMTdxcjJISSwmVHi 4AO3LkYuIPs0o0TPzg+MIAk2AU2JO58/MYHYIgLSEtc+XwaLMwukSSxb8RrMFhawl3h5ZAKYz SKgKvH7wSqwel4BS4k7J4+xgNgSAvISu9ousoLYnAJWEnO3tjJ3MXIALbOU+NqiMYGRewEjwy pGjeLUorLUIl1DI72kosz0jJLcxMwcXUMDU73c1OLixPTUnMSkYr3k/NxNjEDfMgDBDsa+Wc6 HGCU5mJREedVfsUcK8SXlp1RmJBZnxBeV5qQWH2KU4eBQkuAVBIaKkGBRanpqRVpmDjDIYNIS HDxKIrzHM4HSvMUFibnFmekQqVOMuhzvln54zyTEkpeflyolzvsPpEgApCijNA9uBCzgLzHKS gnzMgIdJcRTkFqUm1mCKv+KUZyDUUmYNxdkCk9mXgncpldARzABHdEsywFyREkiQkqqgdFwwi vt6gKrH9YzazwLDrkrfTCpKwsxnmx957y1yq36SY2FDuuPBrU27Ha79phP9nTl+y/rWqfelQ0 1by9Q0fVlWDFfyXLfe4Wcj1a8jZ/v+iXyftlR0PHxsJHeR3mp01r3G0tPZvb+Z1UMZ4vc9o7l lqdZVpBe8FnxTlO2AKmIdQ+nSlW9VGIpzkg01GIuKk4EAPS5lKBzAgAA X-Env-Sender: julien.grall@arm.com X-Msg-Ref: server-15.tower-206.messagelabs.com!1493920478!82429905!1 X-Originating-IP: [217.140.101.70] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 9.4.12; banners=-,-,- X-VirusChecked: Checked Received: (qmail 3960 invoked from network); 4 May 2017 17:54:39 -0000 Received: from foss.arm.com (HELO foss.arm.com) (217.140.101.70) by server-15.tower-206.messagelabs.com with SMTP; 4 May 2017 17:54:39 -0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7BDB515BE; Thu, 4 May 2017 10:54:38 -0700 (PDT) Received: from e108454-lin.cambridge.arm.com (e108454-lin.cambridge.arm.com [10.1.206.53]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B94943F4FF; Thu, 4 May 2017 10:54:37 -0700 (PDT) From: Julien Grall To: xen-devel@lists.xen.org Date: Thu, 4 May 2017 18:54:25 +0100 Message-Id: <20170504175425.22759-4-julien.grall@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170504175425.22759-1-julien.grall@arm.com> References: <20170504175425.22759-1-julien.grall@arm.com> Cc: Mark Rutland , Julien Grall , sstabellini@kernel.org Subject: [Xen-devel] [PATCH 3/3] xen/arm: Survive unknown traps from guests X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" Currently we crash Xen if we see an ESR_EL2.EC value we don't recognise. As configurable disables/enables are added to the architecture (controlled by RES1/RESO bits respectively), with associated synchronous exceptions, it may be possible for a guest to trigger exceptions with classes that we don't recognise. While we can't service these exceptions in a manner useful to the guest, we can avoid bringing down the host. Per ARM DDI 0487A.k_iss10775, page D7-1937, EC values within the range 0x00 - 0x2c are reserved for future use with synchronous exceptions, and EC within the range 0x2d - 0x3f may be used for either synchronous or asynchronous exceptions. The patch makes Xen handle any unknown EC by injecting an UNDEFINED exception into the guest, with a corresponding (ratelimited) warning in the log. This patch is based on Linux commit f050fe7a9164 "arm: KVM: Survive unknown traps from the guest". Signed-off-by: Julien Grall Acked-by: Mark Rutland Reviewed-by: Stefano Stabellini --- xen/arch/arm/traps.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c index c8ce62ff96..c0203da097 100644 --- a/xen/arch/arm/traps.c +++ b/xen/arch/arm/traps.c @@ -2926,9 +2926,10 @@ asmlinkage void do_trap_guest_sync(struct cpu_user_regs *regs) break; default: - printk("Guest Trap. HSR=0x%x EC=0x%x IL=%x Syndrome=0x%"PRIx32"\n", - hsr.bits, hsr.ec, hsr.len, hsr.iss); - do_unexpected_trap("Guest", regs); + gprintk(XENLOG_WARNING, + "Guest Trap. HSR=0x%x EC=0x%x IL=%x Syndrome=0x%"PRIx32"\n", + hsr.bits, hsr.ec, hsr.len, hsr.iss); + inject_undef_exception(regs, hsr); } }