[PATCH v7 03/13] s390x/css: add s390-squash-mcss machine option

Dong Jia Shi
2017-05-05T02:03:42Z

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

We want to support real (i.e. not virtual) channel devices
even for guests that do not support MCSS-E (where guests may
see devices from any channel subsystem image at once). As all
virtio-ccw devices are in css 0xfe (and show up in the default
css 0 for guests not activating MCSS-E), we need an option to
squash both the virtio subchannels and e.g. passed-through
subchannels from their real css (0-3, or 0 for hosts not
activating MCSS-E) into the default css. This will be
exploited in a later patch.

Signed-off-by: Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
---
hw/s390x/s390-virtio-ccw.c | 21 +++++++++++++++++++++
include/hw/s390x/s390-virtio-ccw.h | 1 +
qemu-options.hx | 6 +++++-
target/s390x/cpu.h | 10 ++++++++++
4 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index fdd4384..cd007ca 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -303,6 +303,20 @@ static void machine_set_loadparm(Object *obj, const char *val, Error **errp)
ms->loadparm[i] = ' '; /* pad right with spaces */
}
}
+static inline bool machine_get_squash_mcss(Object *obj, Error **errp)
+{
+ S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
+
+ return ms->s390_squash_mcss;
+}
+
+static inline void machine_set_squash_mcss(Object *obj, bool value,
+ Error **errp)
+{
+ S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
+
+ ms->s390_squash_mcss = value;
+}

static inline void s390_machine_initfn(Object *obj)
{
@@ -328,6 +342,13 @@ static inline void s390_machine_initfn(Object *obj)
" to upper case) to pass to machine loader, boot manager,"
" and guest kernel",
NULL);
+ object_property_add_bool(obj, "s390-squash-mcss",
+ machine_get_squash_mcss,
+ machine_set_squash_mcss, NULL);
+ object_property_set_description(obj, "s390-squash-mcss",
+ "enable/disable squashing subchannels into the default css",
+ NULL);
+ object_property_set_bool(obj, false, "s390-squash-mcss", NULL);
}

static const TypeInfo ccw_machine_info = {
diff --git a/include/hw/s390x/s390-virtio-ccw.h b/include/hw/s390x/s390-virtio-ccw.h
index 7b8a3e4..3027555 100644
--- a/include/hw/s390x/s390-virtio-ccw.h
+++ b/include/hw/s390x/s390-virtio-ccw.h
@@ -29,6 +29,7 @@ typedef struct S390CcwMachineState {
bool aes_key_wrap;
bool dea_key_wrap;
uint8_t loadparm[8];
+ bool s390_squash_mcss;
} S390CcwMachineState;

typedef struct S390CcwMachineClass {
diff --git a/qemu-options.hx b/qemu-options.hx
index 9171bd5..2ba4379 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -42,7 +42,8 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
" dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
" suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
" nvdimm=on|off controls NVDIMM support (default=off)\n"
- " enforce-config-section=on|off enforce configuration section migration (default=off)\n",
+ " enforce-config-section=on|off enforce configuration section migration (default=off)\n"
+ " s390-squash-mcss=on|off controls support for squashing into default css (default=off)\n",
QEMU_ARCH_ALL)
STEXI
@item -machine [type=]@var{name}[,prop=@var{value}[,...]]
@@ -81,6 +82,9 @@ controls whether DEA wrapping keys will be created to allow
execution of DEA cryptographic functions. The default is on.
@item nvdimm=on|off
Enables or disables NVDIMM support. The default is off.
+@item s390-squash-mcss=on|off
+Enables or disables squashing subchannels into the default css.
+The default is off.
@end table
ETEXI

diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 058ddad..c367891 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -1250,6 +1250,16 @@ static inline void s390_crypto_reset(void)
}
}

+static inline bool s390_get_squash_mcss(void)
+{
+ if (object_property_get_bool(OBJECT(qdev_get_machine()), "s390-squash-mcss",
+ NULL)) {
+ return true;
+ }
+
+ return false;
+}
+
/* machine check interruption code */

/* subclasses */
--
2.10.2