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From:   Janosch Frank <frankja@linux.ibm.com>
To:     linux-kernel@vger.kernel.org
Cc:     kvm@vger.kernel.org, thuth@redhat.com, david@redhat.com,
        borntraeger@de.ibm.com, imbrenda@linux.ibm.com, cohuck@redhat.com,
        linux-s390@vger.kernel.org, gor@linux.ibm.com, hca@linux.ibm.com,
        mihajlov@linux.ibm.com
Subject: [PATCH v2 1/2] s390: uv: Fix sysfs max number of VCPUs reporting
Date:   Thu, 21 Jan 2021 10:14:34 -0500
Message-Id: <20210121151436.417240-2-frankja@linux.ibm.com>
In-Reply-To: <20210121151436.417240-1-frankja@linux.ibm.com>
References: <20210121151436.417240-1-frankja@linux.ibm.com>
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The number reported by the query is N-1 and I think people reading the
sysfs file would expect N instead. For users creating VMs there's no
actual difference because KVM's limit is currently below the UV's
limit.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Fixes: a0f60f8431999 ("s390/protvirt: Add sysfs firmware interface for Ultravisor information")
Cc: stable@vger.kernel.org
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
---
 arch/s390/boot/uv.c        | 2 +-
 arch/s390/include/asm/uv.h | 4 ++--
 arch/s390/kernel/uv.c      | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/s390/boot/uv.c b/arch/s390/boot/uv.c
index a15c033f53ca..87641dd65ccf 100644
--- a/arch/s390/boot/uv.c
+++ b/arch/s390/boot/uv.c
@@ -35,7 +35,7 @@ void uv_query_info(void)
 		uv_info.guest_cpu_stor_len = uvcb.cpu_stor_len;
 		uv_info.max_sec_stor_addr = ALIGN(uvcb.max_guest_stor_addr, PAGE_SIZE);
 		uv_info.max_num_sec_conf = uvcb.max_num_sec_conf;
-		uv_info.max_guest_cpus = uvcb.max_guest_cpus;
+		uv_info.max_guest_cpu_id = uvcb.max_guest_cpu_id;
 	}
 
 #ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index 0325fc0469b7..7b98d4caee77 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -96,7 +96,7 @@ struct uv_cb_qui {
 	u32 max_num_sec_conf;
 	u64 max_guest_stor_addr;
 	u8  reserved88[158 - 136];
-	u16 max_guest_cpus;
+	u16 max_guest_cpu_id;
 	u8  reserveda0[200 - 160];
 } __packed __aligned(8);
 
@@ -273,7 +273,7 @@ struct uv_info {
 	unsigned long guest_cpu_stor_len;
 	unsigned long max_sec_stor_addr;
 	unsigned int max_num_sec_conf;
-	unsigned short max_guest_cpus;
+	unsigned short max_guest_cpu_id;
 };
 
 extern struct uv_info uv_info;
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 883bfed9f5c2..b2d2ad153067 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -368,7 +368,7 @@ static ssize_t uv_query_max_guest_cpus(struct kobject *kobj,
 				       struct kobj_attribute *attr, char *page)
 {
 	return scnprintf(page, PAGE_SIZE, "%d\n",
-			uv_info.max_guest_cpus);
+			uv_info.max_guest_cpu_id + 1);
 }
 
 static struct kobj_attribute uv_query_max_guest_cpus_attr =
-- 
2.25.1