KVM: s390: Perform early event mask processing during boot

For processing under KVM it is required to detect
the actual SCLP console type in order to set it as
preferred console.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

4 files changed, 50 insertions, 11 deletions

diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index 30f29a0020a1..3fcc000efc53 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -654,16 +654,6 @@ sclp_remove_processed(struct sccb_header *sccb)
 
 EXPORT_SYMBOL(sclp_remove_processed);
 
-struct init_sccb {
-	struct sccb_header header;
-	u16 _reserved;
-	u16 mask_length;
-	sccb_mask_t receive_mask;
-	sccb_mask_t send_mask;
-	sccb_mask_t sclp_receive_mask;
-	sccb_mask_t sclp_send_mask;
-} __attribute__((packed));
-
 /* Prepare init mask request. Called while sclp_lock is locked. */
 static inline void
 __sclp_make_init_req(u32 receive_mask, u32 send_mask)
diff --git a/drivers/s390/char/sclp.h b/drivers/s390/char/sclp.h
index 49a1bb52bc87..d7e97ae9ef6d 100644
--- a/drivers/s390/char/sclp.h
+++ b/drivers/s390/char/sclp.h
@@ -88,6 +88,16 @@ struct sccb_header {
 	u16	response_code;
 } __attribute__((packed));
 
+struct init_sccb {
+	struct sccb_header header;
+	u16 _reserved;
+	u16 mask_length;
+	sccb_mask_t receive_mask;
+	sccb_mask_t send_mask;
+	sccb_mask_t sclp_receive_mask;
+	sccb_mask_t sclp_send_mask;
+} __attribute__((packed));
+
 extern u64 sclp_facilities;
 #define SCLP_HAS_CHP_INFO	(sclp_facilities & 0x8000000000000000ULL)
 #define SCLP_HAS_CHP_RECONFIG	(sclp_facilities & 0x2000000000000000ULL)
diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index 766cb7b19b40..71ea923c322d 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -48,6 +48,7 @@ struct read_info_sccb {
 	u8	_reserved5[4096 - 112];	/* 112-4095 */
 } __attribute__((packed, aligned(PAGE_SIZE)));
 
+static struct init_sccb __initdata early_event_mask_sccb __aligned(PAGE_SIZE);
 static struct read_info_sccb __initdata early_read_info_sccb;
 static int __initdata early_read_info_sccb_valid;
 
@@ -104,6 +105,19 @@ static void __init sclp_read_info_early(void)
 	}
 }
 
+static void __init sclp_event_mask_early(void)
+{
+	struct init_sccb *sccb = &early_event_mask_sccb;
+	int rc;
+
+	do {
+		memset(sccb, 0, sizeof(*sccb));
+		sccb->header.length = sizeof(*sccb);
+		sccb->mask_length = sizeof(sccb_mask_t);
+		rc = sclp_cmd_sync_early(SCLP_CMDW_WRITE_EVENT_MASK, sccb);
+	} while (rc == -EBUSY);
+}
+
 void __init sclp_facilities_detect(void)
 {
 	struct read_info_sccb *sccb;
@@ -119,6 +133,30 @@ void __init sclp_facilities_detect(void)
 	rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
 	rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
 	rzm <<= 20;
+
+	sclp_event_mask_early();
+}
+
+bool __init sclp_has_linemode(void)
+{
+	struct init_sccb *sccb = &early_event_mask_sccb;
+
+	if (sccb->header.response_code != 0x20)
+		return 0;
+	if (sccb->sclp_send_mask & (EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK))
+		return 1;
+	return 0;
+}
+
+bool __init sclp_has_vt220(void)
+{
+	struct init_sccb *sccb = &early_event_mask_sccb;
+
+	if (sccb->header.response_code != 0x20)
+		return 0;
+	if (sccb->sclp_send_mask & EVTYP_VT220MSG_MASK)
+		return 1;
+	return 0;
 }
 
 unsigned long long sclp_get_rnmax(void)
diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c
index d74e9ae6dfb3..d3bdae49512f 100644
--- a/drivers/s390/kvm/kvm_virtio.c
+++ b/drivers/s390/kvm/kvm_virtio.c
@@ -25,6 +25,7 @@
 #include <asm/io.h>
 #include <asm/kvm_para.h>
 #include <asm/kvm_virtio.h>
+#include <asm/sclp.h>
 #include <asm/setup.h>
 #include <asm/irq.h>
 
@@ -468,7 +469,7 @@ static __init int early_put_chars(u32 vtermno, const char *buf, int count)
 
 static int __init s390_virtio_console_init(void)
 {
-	if (!MACHINE_IS_KVM)
+	if (sclp_has_vt220() || sclp_has_linemode())
 		return -ENODEV;
 	return virtio_cons_early_init(early_put_chars);
 }