[PATCH RFC v2 04/12] s390x/css: realize css_sch_build_schib

Dong Jia Shi
2017-01-12T07:25:05Z

From: Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>

The S390 virtual css support already has a mechanism to build virtual
Sub-Channel Information Block and provide virtual subchannels to the
guest. However, to pass-through subchannels to a guest, we need to
introduce a new mechanism to build its schib according to the real
device information. Thus we realize a new css_sch_build_schib function
to extract the path_masks, chpids, chpid type from sysfs. To reuse
the existing code, we refactor css_add_virtual_chpid to css_add_chpid.

Signed-off-by: Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
---
hw/s390x/css.c | 152 ++++++++++++++++++++++++++++++++++++++++++++++++-
include/hw/s390x/css.h | 36 ++++++------
2 files changed, 168 insertions(+), 20 deletions(-)

diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 0f2580d..8703bc3 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -13,6 +13,7 @@
#include "qapi/error.h"
#include "qapi/visitor.h"
#include "hw/qdev.h"
+#include "qemu/error-report.h"
#include "qemu/bitops.h"
#include "exec/address-spaces.h"
#include "cpu.h"
@@ -1278,7 +1279,8 @@ bool css_schid_final(int m, uint8_t cssid, uint8_t ssid, uint16_t schid)
(MAX_SCHID + 1) / sizeof(unsigned long));
}

-static int css_add_virtual_chpid(uint8_t cssid, uint8_t chpid, uint8_t type)
+static int css_add_chpid(uint8_t cssid, uint8_t chpid, uint8_t type,
+ bool is_virt)
{
CssImage *css;

@@ -1292,7 +1294,7 @@ static int css_add_virtual_chpid(uint8_t cssid, uint8_t chpid, uint8_t type)
}
css->chpids[chpid].in_use = 1;
css->chpids[chpid].type = type;
- css->chpids[chpid].is_virtual = 1;
+ css->chpids[chpid].is_virtual = is_virt;

css_generate_chp_crws(cssid, chpid);

@@ -1316,7 +1318,7 @@ void css_sch_build_virtual_schib(SubchDev *sch, uint8_t chpid, uint8_t type)
p->pam = 0x80;
p->chpid[0] = chpid;
if (!css->chpids[chpid].in_use) {
- css_add_virtual_chpid(sch->cssid, chpid, type);
+ css_add_chpid(sch->cssid, chpid, type, true);
}

memset(s, 0, sizeof(SCSW));
@@ -1908,3 +1910,147 @@ SubchDev *css_create_virtual_sch(CssDevId bus_id, Error **errp)
css_subch_assign(sch->cssid, sch->ssid, schid, sch->devno, sch);
return sch;
}
+
+static int css_sch_get_chpids(SubchDev *sch, CssDevId *dev_id)
+{
+ char *fid_path;
+ FILE *fd;
+ uint32_t chpid[8];
+ int i;
+ PMCW *p = &sch->curr_status.pmcw;
+
+ fid_path = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/chpids",
+ dev_id->cssid, dev_id->ssid, dev_id->devid);
+ fd = fopen(fid_path, "r");
+ if (fd == NULL) {
+ error_report("%s: open %s failed", __func__, fid_path);
+ g_free(fid_path);
+ return -EINVAL;
+ }
+
+ if (fscanf(fd, "%x %x %x %x %x %x %x %x",
+ &chpid[0], &chpid[1], &chpid[2], &chpid[3],
+ &chpid[4], &chpid[5], &chpid[6], &chpid[7]) != 8) {
+ fclose(fd);
+ g_free(fid_path);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(p->chpid); i++) {
+ p->chpid[i] = chpid[i];
+ }
+
+ fclose(fd);
+ g_free(fid_path);
+
+ return 0;
+}
+
+static int css_sch_get_path_masks(SubchDev *sch, CssDevId *dev_id)
+{
+ char *fid_path;
+ FILE *fd;
+ uint32_t pim, pam, pom;
+ PMCW *p = &sch->curr_status.pmcw;
+
+ fid_path = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/pimpampom",
+ dev_id->cssid, dev_id->ssid, dev_id->devid);
+ fd = fopen(fid_path, "r");
+ if (fd == NULL) {
+ error_report("%s: open %s failed", __func__, fid_path);
+ g_free(fid_path);
+ return -EINVAL;
+ }
+
+ if (fscanf(fd, "%x %x %x", &pim, &pam, &pom) != 3) {
+ fclose(fd);
+ g_free(fid_path);
+ return -EINVAL;
+ }
+
+ p->pim = pim;
+ p->pam = pam;
+ p->pom = pom;
+ fclose(fd);
+ g_free(fid_path);
+
+ return 0;
+}
+
+static int css_sch_get_chpid_type(uint8_t chpid, uint32_t *type, CssDevId *dev_id)
+{
+ char *fid_path;
+ FILE *fd;
+
+ fid_path = g_strdup_printf("/sys/devices/css%x/chp0.%02x/type",
+ dev_id->cssid, chpid);
+ fd = fopen(fid_path, "r");
+ if (fd == NULL) {
+ error_report("%s: open %s failed", __func__, fid_path);
+ g_free(fid_path);
+ return -EINVAL;
+ }
+
+ if (fscanf(fd, "%x", type) != 1) {
+ fclose(fd);
+ g_free(fid_path);
+ return -EINVAL;
+ }
+
+ fclose(fd);
+ g_free(fid_path);
+
+ return 0;
+}
+
+/*
+ * We currently retrieve the real device information from sysfs to build the
+ * guest subchannel information block without considering the migration feature.
+ * If migrate, it won't be sure to use the real device information directly,
+ * this point will be handled in the future.
+ */
+int css_sch_build_schib(SubchDev *sch, CssDevId *dev_id)
+{
+ CssImage *css = channel_subsys.css[sch->cssid];
+ PMCW *p = &sch->curr_status.pmcw;
+ SCSW *s = &sch->curr_status.scsw;
+ uint32_t type;
+ int i, ret;
+
+ /* We are dealing with I/O subchannels only. */
+ assert(css != NULL);
+ memset(p, 0, sizeof(PMCW));
+ p->flags |= PMCW_FLAGS_MASK_DNV;
+ p->devno = sch->devno;
+
+ /* Grab path mask from sysfs. */
+ ret = css_sch_get_path_masks(sch, dev_id);
+ if (ret) {
+ return ret;
+ }
+
+ /* Grab chpids from sysfs. */
+ ret = css_sch_get_chpids(sch, dev_id);
+ if (ret) {
+ return ret;
+ }
+
+ /* Build chpid type. */
+ for (i = 0; i < ARRAY_SIZE(p->chpid); i++) {
+ if (p->chpid[i] && !css->chpids[p->chpid[i]].in_use) {
+ ret = css_sch_get_chpid_type(p->chpid[i], &type, dev_id);
+ if (ret) {
+ return ret;
+ }
+ css_add_chpid(sch->cssid, p->chpid[i], type, false);
+ }
+ }
+
+ memset(s, 0, sizeof(SCSW));
+ sch->curr_status.mba = 0;
+ for (i = 0; i < ARRAY_SIZE(sch->curr_status.mda); i++) {
+ sch->curr_status.mda[i] = 0;
+ }
+
+ return 0;
+}
diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h
index c96c862..648ea2f 100644
--- a/include/hw/s390x/css.h
+++ b/include/hw/s390x/css.h
@@ -92,6 +92,24 @@ struct SubchDev {
void *driver_data;
};

+/*
+ * Identify a device within the channel subsystem.
+ * Note that this can be used to identify either the subchannel or
+ * the attached I/O device, as there's always one I/O device per
+ * subchannel.
+ */
+typedef struct CssDevId {
+ uint8_t cssid;
+ uint8_t ssid;
+ uint16_t devid;
+ bool valid;
+} CssDevId;
+
+extern PropertyInfo css_devid_propinfo;
+
+#define DEFINE_PROP_CSS_DEV_ID(_n, _s, _f) \
+ DEFINE_PROP(_n, _s, _f, css_devid_propinfo, CssDevId)
+
typedef struct IndAddr {
hwaddr addr;
uint64_t map;
@@ -113,6 +131,7 @@ bool css_devno_used(uint8_t cssid, uint8_t ssid, uint16_t devno);
void css_subch_assign(uint8_t cssid, uint8_t ssid, uint16_t schid,
uint16_t devno, SubchDev *sch);
void css_sch_build_virtual_schib(SubchDev *sch, uint8_t chpid, uint8_t type);
+int css_sch_build_schib(SubchDev *sch, CssDevId *dev_id);
uint16_t css_build_subchannel_id(SubchDev *sch);
void css_reset(void);
void css_reset_sch(SubchDev *sch);
@@ -154,23 +173,6 @@ int css_do_rsch(SubchDev *sch);
int css_do_rchp(uint8_t cssid, uint8_t chpid);
bool css_present(uint8_t cssid);
#endif
-/*
- * Identify a device within the channel subsystem.
- * Note that this can be used to identify either the subchannel or
- * the attached I/O device, as there's always one I/O device per
- * subchannel.
- */
-typedef struct CssDevId {
- uint8_t cssid;
- uint8_t ssid;
- uint16_t devid;
- bool valid;
-} CssDevId;
-
-extern PropertyInfo css_devid_propinfo;
-
-#define DEFINE_PROP_CSS_DEV_ID(_n, _s, _f) \
- DEFINE_PROP(_n, _s, _f, css_devid_propinfo, CssDevId)

/**
* Create a subchannel for the given bus id.
--
2.8.4