s390/sthyi: Fix machine name validity indication

[ Upstream commit b5130dc2224d1881f24224c0590c6d97f2168d6a ]

When running as a level 3 guest with no host provided sthyi support
sclp_ocf_cpc_name_copy() will only return zeroes. Zeroes are not a
valid group name, so let's not indicate that the group name field is
valid.

Also the group name is not dependent on stsi, let's not return based
on stsi before setting it.

Fixes: 95ca2cb57985 ("KVM: s390: Add sthyi emulation")
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/s390/kvm/sthyi.c b/arch/s390/kvm/sthyi.c
index 2f04ad1ea01c1a082fcfe6b4c12c14e50f2b4fad..029fd5e707b445cf05466748006b30d3db948174 100644 (file)
--- a/arch/s390/kvm/sthyi.c
+++ b/arch/s390/kvm/sthyi.c
@@ -174,17 +174,19 @@ static void fill_hdr(struct sthyi_sctns *sctns)
 static void fill_stsi_mac(struct sthyi_sctns *sctns,
                          struct sysinfo_1_1_1 *sysinfo)
 {
+       sclp_ocf_cpc_name_copy(sctns->mac.infmname);
+       if (*(u64 *)sctns->mac.infmname != 0)
+               sctns->mac.infmval1 |= MAC_NAME_VLD;
+
        if (stsi(sysinfo, 1, 1, 1))
                return;
 
-       sclp_ocf_cpc_name_copy(sctns->mac.infmname);
-
        memcpy(sctns->mac.infmtype, sysinfo->type, sizeof(sctns->mac.infmtype));
        memcpy(sctns->mac.infmmanu, sysinfo->manufacturer, sizeof(sctns->mac.infmmanu));
        memcpy(sctns->mac.infmpman, sysinfo->plant, sizeof(sctns->mac.infmpman));
        memcpy(sctns->mac.infmseq, sysinfo->sequence, sizeof(sctns->mac.infmseq));
 
-       sctns->mac.infmval1 |= MAC_ID_VLD | MAC_NAME_VLD;
+       sctns->mac.infmval1 |= MAC_ID_VLD;
 }
 
 static void fill_stsi_par(struct sthyi_sctns *sctns,