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From:   Steffen Eiden <seiden@linux.ibm.com>
To:     kvm@vger.kernel.org, linux-s390@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Janosch Frank <frankja@linux.ibm.com>,
        Claudio Imbrenda <imbrenda@linux.ibm.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>
Subject: [PATCH v5 1/7] s390/uv: Always export uv_info
Date:   Thu, 15 Jun 2023 12:05:27 +0200
Message-Id: <20230615100533.3996107-2-seiden@linux.ibm.com>
In-Reply-To: <20230615100533.3996107-1-seiden@linux.ibm.com>
References: <20230615100533.3996107-1-seiden@linux.ibm.com>
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KVM needs the struct's values to be able to provide PV support.

The uvdevice is currently guest only and will need the struct's values
for call support checking and potential future expansions.

As uv.c is only compiled with CONFIG_PGSTE or
CONFIG_PROTECTED_VIRTUALIZATION_GUEST we don't need a second check in
the code. Users of uv_info will need to fence for these two config
options for the time being.

Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
 arch/s390/kernel/uv.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 4ada621a2c46..5da3879001bb 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -23,12 +23,20 @@
 int __bootdata_preserved(prot_virt_guest);
 #endif
 
+/*
+ * uv_info contains both host and guest information but it's currently only
+ * expected to be used within modules if it's the KVM module or for
+ * any PV guest module.
+ *
+ * The kernel itself will write these values once in uv_query_info()
+ * and then make some of them readable via a sysfs interface.
+ */
 struct uv_info __bootdata_preserved(uv_info);
+EXPORT_SYMBOL(uv_info);
 
 #if IS_ENABLED(CONFIG_KVM)
 int __bootdata_preserved(prot_virt_host);
 EXPORT_SYMBOL(prot_virt_host);
-EXPORT_SYMBOL(uv_info);
 
 static int __init uv_init(phys_addr_t stor_base, unsigned long stor_len)
 {
-- 
2.40.1