[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-ppc] [PULL 07/22] spapr: Handle Decimal Floating Point (DFP) as an
From: |
David Gibson |
Subject: |
[Qemu-ppc] [PULL 07/22] spapr: Handle Decimal Floating Point (DFP) as an optional capability |
Date: |
Wed, 17 Jan 2018 13:25:10 +1100 |
Decimal Floating Point has been available on POWER7 and later (server)
cpus. However, it can be disabled on the hypervisor, meaning that it's
not available to guests.
We currently handle this by conditionally advertising DFP support in the
device tree depending on whether the guest CPU model supports it - which
can also depend on what's allowed in the host for -cpu host. That can lead
to confusion on migration, since host properties are silently affecting
guest visible properties.
This patch handles it by treating it as an optional capability for the
pseries machine type.
Signed-off-by: David Gibson <address@hidden>
Reviewed-by: Greg Kurz <address@hidden>
---
hw/ppc/spapr.c | 7 ++++---
hw/ppc/spapr_caps.c | 18 ++++++++++++++++++
include/hw/ppc/spapr.h | 3 +++
3 files changed, 25 insertions(+), 3 deletions(-)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index eca9f11c91..d1acfe8858 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -572,7 +572,7 @@ static void spapr_populate_cpu_dt(CPUState *cs, void *fdt,
int offset,
/* Advertise DFP (Decimal Floating Point) if available
* 0 / no property == no DFP
* 1 == DFP available */
- if (env->insns_flags2 & PPC2_DFP) {
+ if (spapr_has_cap(spapr, SPAPR_CAP_DFP)) {
_FDT((fdt_setprop_cell(fdt, offset, "ibm,dfp", 1)));
}
@@ -3834,7 +3834,7 @@ static void spapr_machine_class_init(ObjectClass *oc,
void *data)
*/
mc->numa_mem_align_shift = 28;
- smc->default_caps = spapr_caps(SPAPR_CAP_VSX);
+ smc->default_caps = spapr_caps(SPAPR_CAP_VSX | SPAPR_CAP_DFP);
spapr_caps_add_properties(smc, &error_abort);
}
@@ -3916,7 +3916,8 @@ static void spapr_machine_2_11_class_options(MachineClass
*mc)
sPAPRMachineClass *smc = SPAPR_MACHINE_CLASS(mc);
spapr_machine_2_12_class_options(mc);
- smc->default_caps = spapr_caps(SPAPR_CAP_HTM | SPAPR_CAP_VSX);
+ smc->default_caps = spapr_caps(SPAPR_CAP_HTM | SPAPR_CAP_VSX
+ | SPAPR_CAP_DFP);
SET_MACHINE_COMPAT(mc, SPAPR_COMPAT_2_11);
}
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index 7c855c67ad..9d070a306c 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -70,6 +70,16 @@ static void cap_vsx_allow(sPAPRMachineState *spapr, Error
**errp)
}
}
+static void cap_dfp_allow(sPAPRMachineState *spapr, Error **errp)
+{
+ PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
+ CPUPPCState *env = &cpu->env;
+
+ if (!(env->insns_flags2 & PPC2_DFP)) {
+ error_setg(errp, "DFP support not available, try cap-dfp=off");
+ }
+}
+
static sPAPRCapabilityInfo capability_table[] = {
{
.name = "htm",
@@ -85,6 +95,13 @@ static sPAPRCapabilityInfo capability_table[] = {
.allow = cap_vsx_allow,
/* TODO: add cap_vsx_disallow */
},
+ {
+ .name = "dfp",
+ .description = "Allow Decimal Floating Point (DFP)",
+ .flag = SPAPR_CAP_DFP,
+ .allow = cap_dfp_allow,
+ /* TODO: add cap_dfp_disallow */
+ },
};
static sPAPRCapabilities default_caps_with_cpu(sPAPRMachineState *spapr,
@@ -104,6 +121,7 @@ static sPAPRCapabilities
default_caps_with_cpu(sPAPRMachineState *spapr,
if (!ppc_check_compat(cpu, CPU_POWERPC_LOGICAL_2_06,
0, spapr->max_compat_pvr)) {
caps.mask &= ~SPAPR_CAP_VSX;
+ caps.mask &= ~SPAPR_CAP_DFP;
}
return caps;
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 148a03d189..26ac17e641 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -62,6 +62,9 @@ typedef enum {
/* Vector Scalar Extensions */
#define SPAPR_CAP_VSX 0x0000000000000002ULL
+/* Decimal Floating Point */
+#define SPAPR_CAP_DFP 0x0000000000000004ULL
+
typedef struct sPAPRCapabilities sPAPRCapabilities;
struct sPAPRCapabilities {
uint64_t mask;
--
2.14.3
- [Qemu-ppc] [PULL 00/22] ppc-for-2.12 queue 20180117, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 04/22] spapr: Validate capabilities on migration, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 21/22] target/ppc: add support for POWER9 HILE, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 09/22] spapr: Remove unnecessary 'options' field from sPAPRCapabilityInfo, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 07/22] spapr: Handle Decimal Floating Point (DFP) as an optional capability,
David Gibson <=
- [Qemu-ppc] [PULL 06/22] spapr: Handle VMX/VSX presence as an spapr capability flag, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 03/22] spapr: Treat Hardware Transactional Memory (HTM) as an optional capability, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 18/22] ppc/pnv: introduce pnv*_is_power9() helpers, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 17/22] ppc/pnv: change core mask for POWER9, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 13/22] spapr: Adjust default VSMT value for better migration compatibility, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 12/22] spapr: Allow some cases where we can't set VSMT mode in the kernel, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 02/22] spapr: Capabilities infrastructure, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 22/22] target-ppc: Fix booke206 tlbwe TLB instruction, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 19/22] ppc/pnv: fix XSCOM core addressing on POWER9, David Gibson, 2018/01/16
- [Qemu-ppc] [PULL 01/22] target/ppc: Yet another fix for KVM-HV HPTE accessors, David Gibson, 2018/01/16