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[Qemu-stable] [PATCH 43/54] spapr: Handle Decimal Floating Point (DFP) a
From: |
Michael Roth |
Subject: |
[Qemu-stable] [PATCH 43/54] spapr: Handle Decimal Floating Point (DFP) as an optional capability |
Date: |
Tue, 6 Feb 2018 13:15:04 -0600 |
From: David Gibson <address@hidden>
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>
(cherry picked from commit 2d1fb9bc8e6e78931d8e1bfeb0ed7a4d223b0480)
Signed-off-by: Michael Roth <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 f006662c5c..c55ed9edfd 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)));
}
@@ -3680,7 +3680,7 @@ 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);
}
@@ -3762,7 +3762,8 @@ 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 7765f3439d..65cab2a65b 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;
--
2.11.0
- [Qemu-stable] [PATCH 32/54] osdep: Retry SETLK upon EINTR, (continued)
- [Qemu-stable] [PATCH 32/54] osdep: Retry SETLK upon EINTR, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 25/54] i386: Add EPYC-IBPB CPU model, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 24/54] i386: Add new -IBRS versions of Intel CPU models, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 30/54] s390x/kvm: Handle bpb feature, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 41/54] target/ppc: Clean up probing of VMX, VSX and DFP availability on KVM, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 42/54] spapr: Handle VMX/VSX presence as an spapr capability flag, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 03/54] target/sh4: fix TCG leak during gusa sequence, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 02/54] block/iscsi: dont leave allocmap in an invalid state on UNMAP failure, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 44/54] hw/ppc/spapr_caps: Rework spapr_caps to use uint8 internal representation, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 45/54] ppc: Change Power9 compat table to support at most 8 threads/core, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 43/54] spapr: Handle Decimal Floating Point (DFP) as an optional capability,
Michael Roth <=
- [Qemu-stable] [PATCH 49/54] target/ppc/kvm: Add cap_ppc_safe_[cache/bounds_check/indirect_branch], Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 47/54] target/ppc: introduce the PPC_BIT() macro, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 48/54] target/ppc/spapr_caps: Add macro to generate spapr_caps migration vmstate, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 46/54] spapr: fix device tree properties when using compatibility mode, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 04/54] qemu-options: Remove stray colons from output of --help, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 54/54] target/ppc/spapr: Add H-Call H_GET_CPU_CHARACTERISTICS, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 53/54] target/ppc/spapr_caps: Add new tristate cap safe_indirect_branch, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 36/54] spapr: don't initialize PATB entry if max-cpu-compat < power9, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 52/54] target/ppc/spapr_caps: Add new tristate cap safe_bounds_check, Michael Roth, 2018/02/06
- [Qemu-stable] [PATCH 39/54] spapr: Treat Hardware Transactional Memory (HTM) as an optional capability, Michael Roth, 2018/02/06