s390: uv: Fix sysfs max number of VCPUs reporting

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>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/arch/s390/boot/uv.c b/arch/s390/boot/uv.c
index a15c033..87641dd 100644 (file)
--- 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 0325fc0..7b98d4c 100644 (file)
--- 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 883bfed..b2d2ad1 100644 (file)
--- 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 =