Re: [Qemu-devel] [PATCH 4/6] target/arm: Add "-cpu max" support
On Fri, 2 Feb 2018 17:54:43 + Peter Maydell wrote: > On 26 January 2018 at 15:44, Philippe Mathieu-Daudé wrote: > > On 01/26/2018 11:33 AM, Peter Maydell wrote: > >> On 26 January 2018 at 14:29, Philippe Mathieu-Daudé > >> wrote: > >>> Why not use arm_any_initfn() here? > >> > >> That function (and the 'any' cpu) are deliberately only > >> included in the linux-user binaries, not the system-emulation binaries. > > > > why not use the V8 features? > > What v8 features? > > >> (Also arm_any_initfn() only initializes userspace-visible stuff, it > >> doesn't provide ID register values etc for kernel-visible things.) > > > > I'd still use an unique arm_max_initfn() such > > > > // initializes userspace-visible stuff > > #ifndef CONFIG_USER_ONLY > > // initializes kernel-visible things > > #endif > > >>> Actually what seems cleaner is to move "any" features here, and kill the > >>> "any" cpu, using "max" for this purpose. > >> > >> We can't kill 'any', that would break back-compatibility > >> of command lines. > > > > and use an alias for 'any' -> 'max' or just I'd suggest to place easy any -> max compat hack into arm_cpu_class_by_name() > > > > { .name = "any", .initfn = arm_max_initfn }, /* backward compat */ > > Yes, we could probably do something similar to this. > > thanks > -- PMM >
Re: [Qemu-devel] [PATCH 4/6] target/arm: Add "-cpu max" support
On 26 January 2018 at 15:44, Philippe Mathieu-Daudé wrote: > On 01/26/2018 11:33 AM, Peter Maydell wrote: >> On 26 January 2018 at 14:29, Philippe Mathieu-Daudé wrote: >>> Why not use arm_any_initfn() here? >> >> That function (and the 'any' cpu) are deliberately only >> included in the linux-user binaries, not the system-emulation binaries. > > why not use the V8 features? What v8 features? >> (Also arm_any_initfn() only initializes userspace-visible stuff, it >> doesn't provide ID register values etc for kernel-visible things.) > > I'd still use an unique arm_max_initfn() such > > // initializes userspace-visible stuff > #ifndef CONFIG_USER_ONLY > // initializes kernel-visible things > #endif >>> Actually what seems cleaner is to move "any" features here, and kill the >>> "any" cpu, using "max" for this purpose. >> >> We can't kill 'any', that would break back-compatibility >> of command lines. > > and use an alias for 'any' -> 'max' or just > > { .name = "any", .initfn = arm_max_initfn }, /* backward compat */ Yes, we could probably do something similar to this. thanks -- PMM
Re: [Qemu-devel] [PATCH 4/6] target/arm: Add "-cpu max" support
On 26 January 2018 at 14:29, Philippe Mathieu-Daudé wrote: > Hi Peter, > > On 12/07/2017 03:14 PM, Peter Maydell wrote: >> Add support for "-cpu max" for ARM guests. This CPU type behaves >> like "-cpu host" when KVM is enabled, and like a system CPU with >> the maximum possible feature set otherwise. (Note that this means >> it won't be migratable across versions, as we will likely add >> features to it in future.) >> >> Signed-off-by: Peter Maydell >> --- >> +#ifndef TARGET_AARCH64 >> +/* -cpu max: if KVM is enabled, like -cpu host (best possible with this >> host); >> + * otherwise, a CPU with as many features enabled as our emulation supports. >> + * The version of '-cpu max' for qemu-system-aarch64 is defined in cpu64.c; >> + * this only needs to handle 32 bits. >> + */ >> +static void arm_max_initfn(Object *obj) >> +{ >> +ARMCPU *cpu = ARM_CPU(obj); >> + >> +if (kvm_enabled()) { >> +kvm_arm_set_cpu_features_from_host(cpu); >> +} else { >> +cortex_a15_initfn(obj);> +/* In future we might add feature >> bits here even if the >> + * real-world A15 doesn't implement them. >> + */ > > Why not use arm_any_initfn() here? That function (and the 'any' cpu) are deliberately only included in the linux-user binaries, not the system-emulation binaries. (Also arm_any_initfn() only initializes userspace-visible stuff, it doesn't provide ID register values etc for kernel-visible things.) > Actually what seems cleaner is to move "any" features here, and kill the > "any" cpu, using "max" for this purpose. We can't kill 'any', that would break back-compatibility of command lines. thanks -- PMM
Re: [Qemu-devel] [PATCH 4/6] target/arm: Add "-cpu max" support
Hi Peter, On 12/07/2017 03:14 PM, Peter Maydell wrote: > Add support for "-cpu max" for ARM guests. This CPU type behaves > like "-cpu host" when KVM is enabled, and like a system CPU with > the maximum possible feature set otherwise. (Note that this means > it won't be migratable across versions, as we will likely add > features to it in future.) > > Signed-off-by: Peter Maydell > --- > target/arm/cpu-qom.h | 2 ++ > target/arm/cpu.c | 24 > target/arm/cpu64.c | 21 + > 3 files changed, 47 insertions(+) > > diff --git a/target/arm/cpu-qom.h b/target/arm/cpu-qom.h > index a42495b..d135ff8 100644 > --- a/target/arm/cpu-qom.h > +++ b/target/arm/cpu-qom.h > @@ -33,6 +33,8 @@ struct arm_boot_info; > #define ARM_CPU_GET_CLASS(obj) \ > OBJECT_GET_CLASS(ARMCPUClass, (obj), TYPE_ARM_CPU) > > +#define TYPE_ARM_MAX_CPU "max-" TYPE_ARM_CPU > + > /** > * ARMCPUClass: > * @parent_realize: The parent class' realize handler. > diff --git a/target/arm/cpu.c b/target/arm/cpu.c > index 9304277..190da97 100644 > --- a/target/arm/cpu.c > +++ b/target/arm/cpu.c > @@ -1628,6 +1628,27 @@ static void pxa270c5_initfn(Object *obj) > cpu->reset_sctlr = 0x0078; > } > > +#ifndef TARGET_AARCH64 > +/* -cpu max: if KVM is enabled, like -cpu host (best possible with this > host); > + * otherwise, a CPU with as many features enabled as our emulation supports. > + * The version of '-cpu max' for qemu-system-aarch64 is defined in cpu64.c; > + * this only needs to handle 32 bits. > + */ > +static void arm_max_initfn(Object *obj) > +{ > +ARMCPU *cpu = ARM_CPU(obj); > + > +if (kvm_enabled()) { > +kvm_arm_set_cpu_features_from_host(cpu); > +} else { > +cortex_a15_initfn(obj);> +/* In future we might add feature > bits here even if the > + * real-world A15 doesn't implement them. > + */ Why not use arm_any_initfn() here? Actually what seems cleaner is to move "any" features here, and kill the "any" cpu, using "max" for this purpose. > +} > +} > +#endif > + > #ifdef CONFIG_USER_ONLY > static void arm_any_initfn(Object *obj) > { > @@ -1691,6 +1712,9 @@ static const ARMCPUInfo arm_cpus[] = { > { .name = "pxa270-b1", .initfn = pxa270b1_initfn }, > { .name = "pxa270-c0", .initfn = pxa270c0_initfn }, > { .name = "pxa270-c5", .initfn = pxa270c5_initfn }, > +#ifndef TARGET_AARCH64 > +{ .name = "max", .initfn = arm_max_initfn }, > +#endif > #ifdef CONFIG_USER_ONLY > { .name = "any", .initfn = arm_any_initfn }, > #endif and we can remove the last 3 lines. > diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c > index 670c07a..38dcf32 100644 > --- a/target/arm/cpu64.c > +++ b/target/arm/cpu64.c > @@ -28,6 +28,7 @@ > #include "hw/arm/arm.h" > #include "sysemu/sysemu.h" > #include "sysemu/kvm.h" > +#include "kvm_arm.h" > > static inline void set_feature(CPUARMState *env, int feature) > { > @@ -212,6 +213,25 @@ static void aarch64_a53_initfn(Object *obj) > define_arm_cp_regs(cpu, cortex_a57_a53_cp_reginfo); > } > > +/* -cpu max: if KVM is enabled, like -cpu host (best possible with this > host); > + * otherwise, a CPU with as many features enabled as our emulation supports. > + * The version of '-cpu max' for qemu-system-arm is defined in cpu.c; > + * this only needs to handle 64 bits. > + */ > +static void aarch64_max_initfn(Object *obj) > +{ > +ARMCPU *cpu = ARM_CPU(obj); > + > +if (kvm_enabled()) { > +kvm_arm_set_cpu_features_from_host(cpu); > +} else { > +aarch64_a57_initfn(obj); > +/* In future we might add feature bits here even if the > + * real-world A57 doesn't implement them. > + */ > +} > +} > + > #ifdef CONFIG_USER_ONLY > static void aarch64_any_initfn(Object *obj) > { > @@ -240,6 +260,7 @@ typedef struct ARMCPUInfo { > static const ARMCPUInfo aarch64_cpus[] = { > { .name = "cortex-a57", .initfn = aarch64_a57_initfn }, > { .name = "cortex-a53", .initfn = aarch64_a53_initfn }, > +{ .name = "max",.initfn = aarch64_max_initfn }, > #ifdef CONFIG_USER_ONLY > { .name = "any", .initfn = aarch64_any_initfn }, > #endif >
Re: [Qemu-devel] [PATCH 4/6] target/arm: Add "-cpu max" support
On 01/26/2018 11:33 AM, Peter Maydell wrote: > On 26 January 2018 at 14:29, Philippe Mathieu-Daudé wrote: >> Hi Peter, >> >> On 12/07/2017 03:14 PM, Peter Maydell wrote: >>> Add support for "-cpu max" for ARM guests. This CPU type behaves >>> like "-cpu host" when KVM is enabled, and like a system CPU with >>> the maximum possible feature set otherwise. (Note that this means >>> it won't be migratable across versions, as we will likely add >>> features to it in future.) >>> >>> Signed-off-by: Peter Maydell >>> --- > >>> +#ifndef TARGET_AARCH64 >>> +/* -cpu max: if KVM is enabled, like -cpu host (best possible with this >>> host); >>> + * otherwise, a CPU with as many features enabled as our emulation >>> supports. >>> + * The version of '-cpu max' for qemu-system-aarch64 is defined in cpu64.c; >>> + * this only needs to handle 32 bits. >>> + */ >>> +static void arm_max_initfn(Object *obj) >>> +{ >>> +ARMCPU *cpu = ARM_CPU(obj); >>> + >>> +if (kvm_enabled()) { >>> +kvm_arm_set_cpu_features_from_host(cpu); >>> +} else { >>> +cortex_a15_initfn(obj);> +/* In future we might add >>> feature bits here even if the >>> + * real-world A15 doesn't implement them. >>> + */ >> >> Why not use arm_any_initfn() here? > > That function (and the 'any' cpu) are deliberately only > included in the linux-user binaries, not the system-emulation binaries. why not use the V8 features? > (Also arm_any_initfn() only initializes userspace-visible stuff, it > doesn't provide ID register values etc for kernel-visible things.) I'd still use an unique arm_max_initfn() such // initializes userspace-visible stuff #ifndef CONFIG_USER_ONLY // initializes kernel-visible things #endif > >> Actually what seems cleaner is to move "any" features here, and kill the >> "any" cpu, using "max" for this purpose. > > We can't kill 'any', that would break back-compatibility > of command lines. and use an alias for 'any' -> 'max' or just { .name = "any", .initfn = arm_max_initfn }, /* backward compat */ Anyway: Reviewed-by: Philippe Mathieu-Daudé > > thanks > -- PMM >