[Qemu-devel] [RFC PATCH 0/3] pseries: Fix and extend PAPR RTC implementation

[Qemu-devel] [RFC PATCH 0/3] pseries: Fix and extend PAPR RTC implementation

[David Gibson]

At the moment, the PAPR RTC implementation (actually a paravirt
firmware interface, rather than a normal device) works directly off
host time, and so doesn't respect the options such as clock=vm which
can be specified in the -rtc command line option.

This series is a first cut at addressing this.  Caveats:

  * I haven't yet investigated how clock=vm will interact with
    migration.  I suspect badly.

  * We also use a time stamp when delivering RTAS events in
    spapr_events.c.  For now I haven't changed the code here which
    uses host time (via qemu_get_timedate()).  It's not entirely clear
    which clock these timestamps should be linked to.

[Qemu-devel] [RFC PATCH 1/3] pseries: Move sPAPR RTC code into its own file

[David Gibson]

At the moment the RTAS (firmware/hypervisor) time of day functions are
implemented in spapr_rtas.c along with a bunch of other things.  Since
we're going to be expanding these a bit, move the RTAS RTC related code
out into new file spapr_rtc.c.  Also add its own initialization function,
spapr_rtc_init() called from the main machine init routine.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/ppc/Makefile.objs   |  2 +-
 hw/ppc/spapr.c         |  3 ++
 hw/ppc/spapr_rtas.c    | 49 -----------------------------
 hw/ppc/spapr_rtc.c     | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/spapr.h |  1 +
 5 files changed, 88 insertions(+), 50 deletions(-)
 create mode 100644 hw/ppc/spapr_rtc.c

diff --git a/hw/ppc/Makefile.objs b/hw/ppc/Makefile.objs
index 19d9920..437955d 100644
--- a/hw/ppc/Makefile.objs
+++ b/hw/ppc/Makefile.objs
@@ -3,7 +3,7 @@ obj-y += ppc.o ppc_booke.o
 # IBM pSeries (sPAPR)
 obj-$(CONFIG_PSERIES) += spapr.o spapr_vio.o spapr_events.o
 obj-$(CONFIG_PSERIES) += spapr_hcall.o spapr_iommu.o spapr_rtas.o
-obj-$(CONFIG_PSERIES) += spapr_pci.o
+obj-$(CONFIG_PSERIES) += spapr_pci.o spapr_rtc.o
 ifeq ($(CONFIG_PCI)$(CONFIG_PSERIES)$(CONFIG_LINUX), yyy)
 obj-y += spapr_pci_vfio.o
 endif
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 30de25d..16377a3 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1446,6 +1446,9 @@ static void ppc_spapr_init(MachineState *machine)
     /* Set up EPOW events infrastructure */
     spapr_events_init(spapr);
 
+    /* Set up the RTC RTAS interfaces */
+    spapr_rtc_init();
+
     /* Set up VIO bus */
     spapr->vio_bus = spapr_vio_bus_init();
 
diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index 2ec2a8e..0f1ae55 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -52,51 +52,6 @@ static void rtas_display_character(PowerPCCPU *cpu, sPAPREnvironment *spapr,
     }
 }
 
-static void rtas_get_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
-                                 uint32_t token, uint32_t nargs,
-                                 target_ulong args,
-                                 uint32_t nret, target_ulong rets)
-{
-    struct tm tm;
-
-    if (nret != 8) {
-        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
-        return;
-    }
-
-    qemu_get_timedate(&tm, spapr->rtc_offset);
-
-    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
-    rtas_st(rets, 1, tm.tm_year + 1900);
-    rtas_st(rets, 2, tm.tm_mon + 1);
-    rtas_st(rets, 3, tm.tm_mday);
-    rtas_st(rets, 4, tm.tm_hour);
-    rtas_st(rets, 5, tm.tm_min);
-    rtas_st(rets, 6, tm.tm_sec);
-    rtas_st(rets, 7, 0); /* we don't do nanoseconds */
-}
-
-static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
-                                 uint32_t token, uint32_t nargs,
-                                 target_ulong args,
-                                 uint32_t nret, target_ulong rets)
-{
-    struct tm tm;
-
-    tm.tm_year = rtas_ld(args, 0) - 1900;
-    tm.tm_mon = rtas_ld(args, 1) - 1;
-    tm.tm_mday = rtas_ld(args, 2);
-    tm.tm_hour = rtas_ld(args, 3);
-    tm.tm_min = rtas_ld(args, 4);
-    tm.tm_sec = rtas_ld(args, 5);
-
-    /* Just generate a monitor event for the change */
-    qapi_event_send_rtc_change(qemu_timedate_diff(&tm), &error_abort);
-    spapr->rtc_offset = qemu_timedate_diff(&tm);
-
-    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
-}
-
 static void rtas_power_off(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                            uint32_t token, uint32_t nargs, target_ulong args,
                            uint32_t nret, target_ulong rets)
@@ -400,10 +355,6 @@ static void core_rtas_register_types(void)
 {
     spapr_rtas_register(RTAS_DISPLAY_CHARACTER, "display-character",
                         rtas_display_character);
-    spapr_rtas_register(RTAS_GET_TIME_OF_DAY, "get-time-of-day",
-                        rtas_get_time_of_day);
-    spapr_rtas_register(RTAS_SET_TIME_OF_DAY, "set-time-of-day",
-                        rtas_set_time_of_day);
     spapr_rtas_register(RTAS_POWER_OFF, "power-off", rtas_power_off);
     spapr_rtas_register(RTAS_SYSTEM_REBOOT, "system-reboot",
                         rtas_system_reboot);
diff --git a/hw/ppc/spapr_rtc.c b/hw/ppc/spapr_rtc.c
new file mode 100644
index 0000000..e290ac0
--- /dev/null
+++ b/hw/ppc/spapr_rtc.c
@@ -0,0 +1,83 @@
+/*
+ * QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator
+ *
+ * RTAS Real Time Clock
+ *
+ * Copyright (c) 2010-2011 David Gibson, IBM Corporation.
+ * Copyright 2014 David Gibson, Red Hat.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+#include "cpu.h"
+#include "hw/ppc/spapr.h"
+#include "qapi-event.h"
+
+static void rtas_get_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
+                                 uint32_t token, uint32_t nargs,
+                                 target_ulong args,
+                                 uint32_t nret, target_ulong rets)
+{
+    struct tm tm;
+
+    if (nret != 8) {
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+
+    qemu_get_timedate(&tm, spapr->rtc_offset);
+
+    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
+    rtas_st(rets, 1, tm.tm_year + 1900);
+    rtas_st(rets, 2, tm.tm_mon + 1);
+    rtas_st(rets, 3, tm.tm_mday);
+    rtas_st(rets, 4, tm.tm_hour);
+    rtas_st(rets, 5, tm.tm_min);
+    rtas_st(rets, 6, tm.tm_sec);
+    rtas_st(rets, 7, 0); /* we don't do nanoseconds */
+}
+
+static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
+                                 uint32_t token, uint32_t nargs,
+                                 target_ulong args,
+                                 uint32_t nret, target_ulong rets)
+{
+    struct tm tm;
+
+    tm.tm_year = rtas_ld(args, 0) - 1900;
+    tm.tm_mon = rtas_ld(args, 1) - 1;
+    tm.tm_mday = rtas_ld(args, 2);
+    tm.tm_hour = rtas_ld(args, 3);
+    tm.tm_min = rtas_ld(args, 4);
+    tm.tm_sec = rtas_ld(args, 5);
+
+    /* Just generate a monitor event for the change */
+    qapi_event_send_rtc_change(qemu_timedate_diff(&tm), &error_abort);
+    spapr->rtc_offset = qemu_timedate_diff(&tm);
+
+    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
+}
+
+void spapr_rtc_init(void)
+{
+    spapr_rtas_register(RTAS_GET_TIME_OF_DAY, "get-time-of-day",
+                        rtas_get_time_of_day);
+    spapr_rtas_register(RTAS_SET_TIME_OF_DAY, "set-time-of-day",
+                        rtas_set_time_of_day);
+}
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 749daf4..9a468bc 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -479,5 +479,6 @@ int spapr_dma_dt(void *fdt, int node_off, const char *propname,
                  uint32_t liobn, uint64_t window, uint32_t size);
 int spapr_tcet_dma_dt(void *fdt, int node_off, const char *propname,
                       sPAPRTCETable *tcet);
+void spapr_rtc_init(void);
 
 #endif /* !defined (__HW_SPAPR_H__) */
-- 
2.1.0

[Qemu-devel] [RFC PATCH 2/3] pseries: Add more parameter validation in RTAS time of day functions

[David Gibson]

Currently, the RTAS time of day functions only partially validate the
number of parameters they receive and return.  Because of how the
parameters are used, this is unlikely to lead to a crash, but it's messy.

This patch adds the missing checks.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/ppc/spapr_rtc.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/spapr_rtc.c b/hw/ppc/spapr_rtc.c
index e290ac0..13eeab8 100644
--- a/hw/ppc/spapr_rtc.c
+++ b/hw/ppc/spapr_rtc.c
@@ -36,7 +36,7 @@ static void rtas_get_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
 {
     struct tm tm;
 
-    if (nret != 8) {
+    if ((nargs != 0) || (nret != 8)) {
         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
         return;
     }
@@ -60,6 +60,11 @@ static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
 {
     struct tm tm;
 
+    if ((nargs != 7) || (nret != 1)) {
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+
     tm.tm_year = rtas_ld(args, 0) - 1900;
     tm.tm_mon = rtas_ld(args, 1) - 1;
     tm.tm_mday = rtas_ld(args, 2);
-- 
2.1.0

[Qemu-devel] [RFC PATCH 3/3] pseries: Make RTAS time of day functions respect -rtc options

[David Gibson]

In the 'pseries' machine the real time clock is provided by a
paravirtualized firmware interface rather than a device per se; the RTAS
get-time-of-day and set-time-of-day calls.

Out current implementations of those work directly off host time (with
an offset), not respecting options such as clock=vm which can be
specified in the -rtc command line option.

This patch reworks the RTAS RTC code to respect those options, primarily
by basing them on the qemu_clock_get_ns(rtc_clock) function instead of
directly on qemu_get_timedate() (which essentially handles host time, not
virtual rtc time).

As a bonus, this means our get-time-of-day function now also returns
nanoseconds.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/ppc/spapr_rtc.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/hw/ppc/spapr_rtc.c b/hw/ppc/spapr_rtc.c
index 13eeab8..58715d2 100644
--- a/hw/ppc/spapr_rtc.c
+++ b/hw/ppc/spapr_rtc.c
@@ -26,6 +26,7 @@
  *
  */
 #include "cpu.h"
+#include "sysemu/sysemu.h"
 #include "hw/ppc/spapr.h"
 #include "qapi-event.h"
 
@@ -35,13 +36,18 @@ static void rtas_get_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                  uint32_t nret, target_ulong rets)
 {
     struct tm tm;
+    int64_t host_ns;
+    time_t guest_s;
 
     if ((nargs != 0) || (nret != 8)) {
         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
         return;
     }
 
-    qemu_get_timedate(&tm, spapr->rtc_offset);
+    host_ns = qemu_clock_get_ns(rtc_clock);
+
+    guest_s = host_ns / 1000000000LL + spapr->rtc_offset;
+    gmtime_r(&guest_s, &tm);
 
     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
     rtas_st(rets, 1, tm.tm_year + 1900);
@@ -50,7 +56,7 @@ static void rtas_get_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
     rtas_st(rets, 4, tm.tm_hour);
     rtas_st(rets, 5, tm.tm_min);
     rtas_st(rets, 6, tm.tm_sec);
-    rtas_st(rets, 7, 0); /* we don't do nanoseconds */
+    rtas_st(rets, 7, host_ns % 1000000000LL);
 }
 
 static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
@@ -59,6 +65,8 @@ static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                                  uint32_t nret, target_ulong rets)
 {
     struct tm tm;
+    time_t new_s;
+    int64_t host_ns;
 
     if ((nargs != 7) || (nret != 1)) {
         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
@@ -72,15 +80,35 @@ static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
     tm.tm_min = rtas_ld(args, 4);
     tm.tm_sec = rtas_ld(args, 5);
 
-    /* Just generate a monitor event for the change */
+    new_s = mktimegm(&tm);
+    if (new_s == -1) {
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+
+    /* Generate a monitor event for the change */
     qapi_event_send_rtc_change(qemu_timedate_diff(&tm), &error_abort);
-    spapr->rtc_offset = qemu_timedate_diff(&tm);
+
+    host_ns = qemu_clock_get_ns(rtc_clock);
+
+    spapr->rtc_offset = new_s - host_ns / 1000000000L;
 
     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
 }
 
 void spapr_rtc_init(void)
 {
+    struct tm tm;
+    time_t host_s;
+    int64_t rtc_ns;
+
+    /* Initialize the RTAS RTC from host time */
+
+    qemu_get_timedate(&tm, 0);
+    host_s = mktimegm(&tm);
+    rtc_ns = qemu_clock_get_ns(rtc_clock);
+    spapr->rtc_offset = host_s - rtc_ns / 1000000000LL;
+
     spapr_rtas_register(RTAS_GET_TIME_OF_DAY, "get-time-of-day",
                         rtas_get_time_of_day);
     spapr_rtas_register(RTAS_SET_TIME_OF_DAY, "set-time-of-day",
-- 
2.1.0