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Re: [Qemu-devel] [RFC 07/17] ppc: Rewrite ppc_set_compat()
From: |
David Gibson |
Subject: |
Re: [Qemu-devel] [RFC 07/17] ppc: Rewrite ppc_set_compat() |
Date: |
Tue, 8 Nov 2016 14:49:30 +1100 |
User-agent: |
Mutt/1.7.1 (2016-10-04) |
On Fri, Nov 04, 2016 at 01:57:45PM +1100, Alexey Kardashevskiy wrote:
> On 30/10/16 22:11, David Gibson wrote:
> > This rewrites the ppc_set_compat() function so that instead of open coding
> > the various compatibility modes, it reads the relevant data from a table.
> > This is a first step in consolidating the information on compatibility
> > modes scattered across the code into a single place.
> >
> > It also makes one change to the logic. The old code masked the bits to be
> > set in the PCR (Processor Compatibility Register) by which bits are valid
> > on the host CPU. This made no sense, since it was done regardless of
> > whether our guest CPU was the same as the host CPU or not. Futhermore,
>
> s/Futhermore/Furthermore/
>
>
> > the actual PCR bits are only relevant for TCG[1] - KVM instead uses the
> > compatibility mode we tell it in kvmppc_set_compat(). When using TCG
> > host cpu information usually isn't even present.
> >
> > While we're at it, we put the new implementation in a new file to make the
> > enormouse translate_init.c a little smaller.
>
> s/enormouse/enormous/
Thanks, spelling corrections applied.
>
>
> >
> > [1] Actually it doesn't even do anything in TCG, but it will if / when we
> > get to implementing compatibility mode logic at that level.
> >
> > Signed-off-by: David Gibson <address@hidden>
>
> Reviewed-by: Alexey Kardashevskiy <address@hidden>
>
> > ---
> > target-ppc/Makefile.objs | 1 +
> > target-ppc/compat.c | 91
> > +++++++++++++++++++++++++++++++++++++++++++++
> > target-ppc/cpu.h | 6 ++-
> > target-ppc/translate_init.c | 41 --------------------
> > 4 files changed, 97 insertions(+), 42 deletions(-)
> > create mode 100644 target-ppc/compat.c
> >
> > diff --git a/target-ppc/Makefile.objs b/target-ppc/Makefile.objs
> > index e667e69..feb5c30 100644
> > --- a/target-ppc/Makefile.objs
> > +++ b/target-ppc/Makefile.objs
> > @@ -15,3 +15,4 @@ obj-y += misc_helper.o
> > obj-y += mem_helper.o
> > obj-$(CONFIG_USER_ONLY) += user_only_helper.o
> > obj-y += gdbstub.o
> > +obj-$(TARGET_PPC64) += compat.o
> > diff --git a/target-ppc/compat.c b/target-ppc/compat.c
> > new file mode 100644
> > index 0000000..f3fd9c6
> > --- /dev/null
> > +++ b/target-ppc/compat.c
> > @@ -0,0 +1,91 @@
> > +/*
> > + * PowerPC CPU initialization for qemu.
> > + *
> > + * Copyright 2016, David Gibson, Red Hat Inc. <address@hidden>
> > + *
> > + * This library is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU Lesser General Public
> > + * License as published by the Free Software Foundation; either
> > + * version 2 of the License, or (at your option) any later version.
> > + *
> > + * This library is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > + * Lesser General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU Lesser General Public
> > + * License along with this library; if not, see
> > <http://www.gnu.org/licenses/>.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include "sysemu/kvm.h"
> > +#include "kvm_ppc.h"
> > +#include "sysemu/cpus.h"
> > +#include "qemu/error-report.h"
> > +#include "qapi/error.h"
> > +#include "cpu-models.h"
> > +
> > +typedef struct {
> > + uint32_t pvr;
> > + uint64_t pcr;
> > +} CompatInfo;
> > +
> > +static const CompatInfo compat_table[] = {
> > + { /* POWER6, ISA2.05 */
> > + .pvr = CPU_POWERPC_LOGICAL_2_05,
> > + .pcr = PCR_COMPAT_2_07 | PCR_COMPAT_2_06 | PCR_COMPAT_2_05
> > + | PCR_TM_DIS | PCR_VSX_DIS,
> > + },
> > + { /* POWER7, ISA2.06 */
> > + .pvr = CPU_POWERPC_LOGICAL_2_06,
> > + .pcr = PCR_COMPAT_2_07 | PCR_COMPAT_2_06 | PCR_TM_DIS,
> > + },
> > + {
> > + .pvr = CPU_POWERPC_LOGICAL_2_06_PLUS,
> > + .pcr = PCR_COMPAT_2_07 | PCR_COMPAT_2_06 | PCR_TM_DIS,
> > + },
> > + { /* POWER8, ISA2.07 */
> > + .pvr = CPU_POWERPC_LOGICAL_2_07,
> > + .pcr = PCR_COMPAT_2_07,
> > + },
> > +};
> > +
> > +static const CompatInfo *compat_by_pvr(uint32_t pvr)
> > +{
> > + int i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
> > + if (compat_table[i].pvr == pvr) {
> > + return &compat_table[i];
> > + }
> > + }
> > + return NULL;
> > +}
> > +
> > +void ppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr, Error **errp)
> > +{
> > + const CompatInfo *compat = compat_by_pvr(compat_pvr);
> > + CPUPPCState *env = &cpu->env;
> > + PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
> > + uint64_t pcr;
> > +
> > + if (!compat_pvr) {
> > + pcr = 0;
> > + } else if (!compat) {
> > + error_setg(errp, "Unknown compatibility PVR 0x%08"PRIx32,
> > compat_pvr);
> > + return;
> > + } else {
> > + pcr = compat->pcr;
> > + }
> > +
> > + cpu->compat_pvr = compat_pvr;
> > + env->spr[SPR_PCR] = pcr & pcc->pcr_mask;
> > +
> > + if (kvm_enabled()) {
> > + int ret = kvmppc_set_compat(cpu, cpu->compat_pvr);
> > + if (ret < 0) {
> > + error_setg_errno(errp, -ret,
> > + "Unable to set CPU compatibility mode in
> > KVM");
> > + }
> > + }
> > +}
> > diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
> > index f7656cb..15d5e4b 100644
> > --- a/target-ppc/cpu.h
> > +++ b/target-ppc/cpu.h
> > @@ -1243,7 +1243,6 @@ void ppc_store_msr (CPUPPCState *env, target_ulong
> > value);
> > void ppc_cpu_list (FILE *f, fprintf_function cpu_fprintf);
> > int ppc_get_compat_smt_threads(PowerPCCPU *cpu);
> > #if defined(TARGET_PPC64)
> > -void ppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr, Error **errp);
> > #endif
> >
> > /* Time-base and decrementer management */
> > @@ -1314,6 +1313,11 @@ static inline int cpu_mmu_index (CPUPPCState *env,
> > bool ifetch)
> > return ifetch ? env->immu_idx : env->dmmu_idx;
> > }
> >
> > +/* Compatibility modes */
> > +#if defined(TARGET_PPC64)
> > +void ppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr, Error **errp);
> > +#endif /* defined(TARGET_PPC64) */
> > +
> > #include "exec/cpu-all.h"
> >
> >
> > /*****************************************************************************/
> > diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
> > index c35065d..a70eafb 100644
> > --- a/target-ppc/translate_init.c
> > +++ b/target-ppc/translate_init.c
> > @@ -9972,47 +9972,6 @@ int ppc_get_compat_smt_threads(PowerPCCPU *cpu)
> > return ret;
> > }
> >
> > -#ifdef TARGET_PPC64
> > -void ppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr, Error **errp)
> > -{
> > - int ret = 0;
> > - CPUPPCState *env = &cpu->env;
> > - PowerPCCPUClass *host_pcc;
> > -
> > - cpu->compat_pvr = compat_pvr;
> > -
> > - switch (compat_pvr) {
> > - case CPU_POWERPC_LOGICAL_2_05:
> > - env->spr[SPR_PCR] = PCR_TM_DIS | PCR_VSX_DIS | PCR_COMPAT_2_07 |
> > - PCR_COMPAT_2_06 | PCR_COMPAT_2_05;
> > - break;
> > - case CPU_POWERPC_LOGICAL_2_06:
> > - case CPU_POWERPC_LOGICAL_2_06_PLUS:
> > - env->spr[SPR_PCR] = PCR_TM_DIS | PCR_COMPAT_2_07 | PCR_COMPAT_2_06;
> > - break;
> > - case CPU_POWERPC_LOGICAL_2_07:
> > - env->spr[SPR_PCR] = PCR_COMPAT_2_07;
> > - break;
> > - default:
> > - env->spr[SPR_PCR] = 0;
> > - break;
> > - }
> > -
> > - host_pcc = kvm_ppc_get_host_cpu_class();
> > - if (host_pcc) {
> > - env->spr[SPR_PCR] &= host_pcc->pcr_mask;
> > - }
> > -
> > - if (kvm_enabled()) {
> > - ret = kvmppc_set_compat(cpu, cpu->compat_pvr);
> > - if (ret < 0) {
> > - error_setg_errno(errp, -ret,
> > - "Unable to set CPU compatibility mode in
> > KVM");
> > - }
> > - }
> > -}
> > -#endif
> > -
> > static gint ppc_cpu_compare_class_pvr(gconstpointer a, gconstpointer b)
> > {
> > ObjectClass *oc = (ObjectClass *)a;
> >
>
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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