From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39761) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d2x7s-0005Vy-Rm for qemu-devel@nongnu.org; Tue, 25 Apr 2017 05:51:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d2x7o-0004WX-6E for qemu-devel@nongnu.org; Tue, 25 Apr 2017 05:51:16 -0400 Received: from mail-wr0-x243.google.com ([2a00:1450:400c:c0c::243]:34682) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1d2x7n-0004W2-Vu for qemu-devel@nongnu.org; Tue, 25 Apr 2017 05:51:12 -0400 Received: by mail-wr0-x243.google.com with SMTP id 6so10217718wrb.1 for ; Tue, 25 Apr 2017 02:51:11 -0700 (PDT) Sender: Richard Henderson References: <20170423223216.17856-1-aurelien@aurel32.net> <23a3da7d-d330-7cad-5bef-8e80c8d9f50c@suse.de> From: Richard Henderson Message-ID: <70dad7b4-f893-1af7-d0c9-7dbb10506b04@twiddle.net> Date: Tue, 25 Apr 2017 11:51:08 +0200 MIME-Version: 1.0 In-Reply-To: <23a3da7d-d330-7cad-5bef-8e80c8d9f50c@suse.de> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] target-s390x: Mask the SIGP order_code to 8bit. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf , Aurelien Jarno , qemu-devel@nongnu.org Cc: Philipp Kern On 04/24/2017 10:25 AM, Alexander Graf wrote: > > > On 24.04.17 00:32, Aurelien Jarno wrote: >> From: Philipp Kern >> >> According to "CPU Signaling and Response", "Signal-Processor Orders", >> the order field is bit position 56-63. Without this, the Linux >> guest kernel is sometimes unable to stop emulation and enters >> an infinite loop of "XXX unknown sigp: 0xffffffff00000005". >> >> Signed-off-by: Philipp Kern >> Signed-off-by: Aurelien Jarno >> --- >> target/s390x/misc_helper.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> This patch has been sent by Philipp Kern a lot of time ago, and it seems >> has been lost. I am resending it, as it is still useful. >> >> diff --git a/target/s390x/misc_helper.c b/target/s390x/misc_helper.c >> index 3bf09ea222..4946b56ab3 100644 >> --- a/target/s390x/misc_helper.c >> +++ b/target/s390x/misc_helper.c >> @@ -534,7 +534,7 @@ uint32_t HELPER(sigp)(CPUS390XState *env, uint64_t >> order_code, uint32_t r1, >> /* Remember: Use "R1 or R1 + 1, whichever is the odd-numbered register" >> as parameter (input). Status (output) is always R1. */ >> >> - switch (order_code) { >> + switch (order_code & 0xff) { > > This definitely needs a comment above the mask. Ideally I'd love to just change > the function prototype to pass order_code as uint8_t, but I don't think that's > possible with the TCG glue. Correct. We'll need to leave the mask here. r~