From 27dc0700c3be7c681cea03c5230b93d02f623492 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Mon, 10 Feb 2020 11:27:37 -0500 Subject: [PATCH] s390/uv: Fix handling of length extensions The query parameter block might contain additional information and can be extended in the future. If the size of the block does not suffice we get an error code of rc=0x100. The buffer will contain all information up to the specified size and the hypervisor/guest simply do not need the additional information as they do not know about the new data. That means that we can (and must) accept rc=0x100 as success. Cc: stable@vger.kernel.org Reviewed-by: Cornelia Huck Fixes: 5abb9351dfd9 ("s390/uv: introduce guest side ultravisor code") Signed-off-by: Christian Borntraeger Signed-off-by: Vasily Gorbik --- arch/s390/boot/uv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/s390/boot/uv.c b/arch/s390/boot/uv.c index ed007f4a6444..3f501159ee9f 100644 --- a/arch/s390/boot/uv.c +++ b/arch/s390/boot/uv.c @@ -15,7 +15,8 @@ void uv_query_info(void) if (!test_facility(158)) return; - if (uv_call(0, (uint64_t)&uvcb)) + /* rc==0x100 means that there is additional data we do not process */ + if (uv_call(0, (uint64_t)&uvcb) && uvcb.header.rc != 0x100) return; if (test_bit_inv(BIT_UVC_CMD_SET_SHARED_ACCESS, (unsigned long *)uvcb.inst_calls_list) &&