| Message ID | 1446737696-9749-4-git-send-email-stefano.stabellini@eu.citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 5 Nov 2015, Stefano Stabellini wrote: > Introduce CONFIG_PARAVIRT and PARAVIRT_TIME_ACCOUNTING on ARM64. > Necessary duplication of paravirt.h and paravirt.c with ARM. > > The only paravirt interface supported is pv_time_ops.steal_clock, so no > runtime pvops patching needed. > > This allows us to make use of steal_account_process_tick for stolen > ticks accounting. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > Acked-by: Marc Zyngier <marc.zyngier@arm.com> Ping? Catalin, Will, are you happy with this change? > CC: will.deacon@arm.com > CC: nico@linaro.org > CC: marc.zyngier@arm.com > CC: cov@codeaurora.org > CC: arnd@arndb.de > CC: olof@lixom.net > CC: Catalin.Marinas@arm.com > > --- > > Changes in v10: > - replace "---help---" with "help" > > Changes in v7: > - ifdef CONFIG_PARAVIRT the content of paravirt.h. > --- > arch/arm64/Kconfig | 20 ++++++++++++++++++++ > arch/arm64/include/asm/paravirt.h | 20 ++++++++++++++++++++ > arch/arm64/kernel/Makefile | 1 + > arch/arm64/kernel/paravirt.c | 25 +++++++++++++++++++++++++ > 4 files changed, 66 insertions(+) > create mode 100644 arch/arm64/include/asm/paravirt.h > create mode 100644 arch/arm64/kernel/paravirt.c > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 7b10647..659e286 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -533,6 +533,25 @@ config SECCOMP > and the task is only allowed to execute a few safe syscalls > defined by each seccomp mode. > > +config PARAVIRT > + bool "Enable paravirtualization code" > + help > + This changes the kernel so it can modify itself when it is run > + under a hypervisor, potentially improving performance significantly > + over full virtualization. > + > +config PARAVIRT_TIME_ACCOUNTING > + bool "Paravirtual steal time accounting" > + select PARAVIRT > + default n > + help > + Select this option to enable fine granularity task steal time > + accounting. Time spent executing other tasks in parallel with > + the current vCPU is discounted from the vCPU power. To account for > + that, there can be a small performance impact. > + > + If in doubt, say N here. > + > config XEN_DOM0 > def_bool y > depends on XEN > @@ -541,6 +560,7 @@ config XEN > bool "Xen guest support on ARM64" > depends on ARM64 && OF > select SWIOTLB_XEN > + select PARAVIRT > help > Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. > > diff --git a/arch/arm64/include/asm/paravirt.h b/arch/arm64/include/asm/paravirt.h > new file mode 100644 > index 0000000..fd5f428 > --- /dev/null > +++ b/arch/arm64/include/asm/paravirt.h > @@ -0,0 +1,20 @@ > +#ifndef _ASM_ARM64_PARAVIRT_H > +#define _ASM_ARM64_PARAVIRT_H > + > +#ifdef CONFIG_PARAVIRT > +struct static_key; > +extern struct static_key paravirt_steal_enabled; > +extern struct static_key paravirt_steal_rq_enabled; > + > +struct pv_time_ops { > + unsigned long long (*steal_clock)(int cpu); > +}; > +extern struct pv_time_ops pv_time_ops; > + > +static inline u64 paravirt_steal_clock(int cpu) > +{ > + return pv_time_ops.steal_clock(cpu); > +} > +#endif > + > +#endif > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile > index 474691f..ca9fbe1 100644 > --- a/arch/arm64/kernel/Makefile > +++ b/arch/arm64/kernel/Makefile > @@ -41,6 +41,7 @@ arm64-obj-$(CONFIG_EFI) += efi.o efi-entry.stub.o > arm64-obj-$(CONFIG_PCI) += pci.o > arm64-obj-$(CONFIG_ARMV8_DEPRECATED) += armv8_deprecated.o > arm64-obj-$(CONFIG_ACPI) += acpi.o > +arm64-obj-$(CONFIG_PARAVIRT) += paravirt.o > > obj-y += $(arm64-obj-y) vdso/ > obj-m += $(arm64-obj-m) > diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c > new file mode 100644 > index 0000000..53f371e > --- /dev/null > +++ b/arch/arm64/kernel/paravirt.c > @@ -0,0 +1,25 @@ > +/* > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program 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 General Public License for more details. > + * > + * Copyright (C) 2013 Citrix Systems > + * > + * Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > + */ > + > +#include <linux/export.h> > +#include <linux/jump_label.h> > +#include <linux/types.h> > +#include <asm/paravirt.h> > + > +struct static_key paravirt_steal_enabled; > +struct static_key paravirt_steal_rq_enabled; > + > +struct pv_time_ops pv_time_ops; > +EXPORT_SYMBOL_GPL(pv_time_ops); > -- > 1.7.10.4 >
On Tue, Nov 10, 2015 at 02:11:38PM +0000, Stefano Stabellini wrote: > On Thu, 5 Nov 2015, Stefano Stabellini wrote: > > Introduce CONFIG_PARAVIRT and PARAVIRT_TIME_ACCOUNTING on ARM64. > > Necessary duplication of paravirt.h and paravirt.c with ARM. > > > > The only paravirt interface supported is pv_time_ops.steal_clock, so no > > runtime pvops patching needed. > > > > This allows us to make use of steal_account_process_tick for stolen > > ticks accounting. > > > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > > Acked-by: Marc Zyngier <marc.zyngier@arm.com> > > Ping? > > Catalin, Will, > are you happy with this change? I'm happy if Marc's happy. Marc? Will
On 17/11/15 17:29, Will Deacon wrote: > On Tue, Nov 10, 2015 at 02:11:38PM +0000, Stefano Stabellini wrote: >> On Thu, 5 Nov 2015, Stefano Stabellini wrote: >>> Introduce CONFIG_PARAVIRT and PARAVIRT_TIME_ACCOUNTING on ARM64. >>> Necessary duplication of paravirt.h and paravirt.c with ARM. >>> >>> The only paravirt interface supported is pv_time_ops.steal_clock, so no >>> runtime pvops patching needed. >>> >>> This allows us to make use of steal_account_process_tick for stolen >>> ticks accounting. >>> >>> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> >>> Acked-by: Marc Zyngier <marc.zyngier@arm.com> >> >> Ping? >> >> Catalin, Will, >> are you happy with this change? > > I'm happy if Marc's happy. Marc? My Ack is already on the tin! ;-) M.
On Tue, Nov 17, 2015 at 05:34:36PM +0000, Marc Zyngier wrote: > On 17/11/15 17:29, Will Deacon wrote: > > On Tue, Nov 10, 2015 at 02:11:38PM +0000, Stefano Stabellini wrote: > >> On Thu, 5 Nov 2015, Stefano Stabellini wrote: > >>> Introduce CONFIG_PARAVIRT and PARAVIRT_TIME_ACCOUNTING on ARM64. > >>> Necessary duplication of paravirt.h and paravirt.c with ARM. > >>> > >>> The only paravirt interface supported is pv_time_ops.steal_clock, so no > >>> runtime pvops patching needed. > >>> > >>> This allows us to make use of steal_account_process_tick for stolen > >>> ticks accounting. > >>> > >>> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > >>> Acked-by: Marc Zyngier <marc.zyngier@arm.com> > >> > >> Ping? > >> > >> Catalin, Will, > >> are you happy with this change? > > > > I'm happy if Marc's happy. Marc? > > My Ack is already on the tin! ;-) Ah yes, I only saw the cc line. In which case, I assume Stefano will take this via the xen tree. Will
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 7b10647..659e286 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -533,6 +533,25 @@ config SECCOMP and the task is only allowed to execute a few safe syscalls defined by each seccomp mode. +config PARAVIRT + bool "Enable paravirtualization code" + help + This changes the kernel so it can modify itself when it is run + under a hypervisor, potentially improving performance significantly + over full virtualization. + +config PARAVIRT_TIME_ACCOUNTING + bool "Paravirtual steal time accounting" + select PARAVIRT + default n + help + Select this option to enable fine granularity task steal time + accounting. Time spent executing other tasks in parallel with + the current vCPU is discounted from the vCPU power. To account for + that, there can be a small performance impact. + + If in doubt, say N here. + config XEN_DOM0 def_bool y depends on XEN @@ -541,6 +560,7 @@ config XEN bool "Xen guest support on ARM64" depends on ARM64 && OF select SWIOTLB_XEN + select PARAVIRT help Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. diff --git a/arch/arm64/include/asm/paravirt.h b/arch/arm64/include/asm/paravirt.h new file mode 100644 index 0000000..fd5f428 --- /dev/null +++ b/arch/arm64/include/asm/paravirt.h @@ -0,0 +1,20 @@ +#ifndef _ASM_ARM64_PARAVIRT_H +#define _ASM_ARM64_PARAVIRT_H + +#ifdef CONFIG_PARAVIRT +struct static_key; +extern struct static_key paravirt_steal_enabled; +extern struct static_key paravirt_steal_rq_enabled; + +struct pv_time_ops { + unsigned long long (*steal_clock)(int cpu); +}; +extern struct pv_time_ops pv_time_ops; + +static inline u64 paravirt_steal_clock(int cpu) +{ + return pv_time_ops.steal_clock(cpu); +} +#endif + +#endif diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 474691f..ca9fbe1 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -41,6 +41,7 @@ arm64-obj-$(CONFIG_EFI) += efi.o efi-entry.stub.o arm64-obj-$(CONFIG_PCI) += pci.o arm64-obj-$(CONFIG_ARMV8_DEPRECATED) += armv8_deprecated.o arm64-obj-$(CONFIG_ACPI) += acpi.o +arm64-obj-$(CONFIG_PARAVIRT) += paravirt.o obj-y += $(arm64-obj-y) vdso/ obj-m += $(arm64-obj-m) diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c new file mode 100644 index 0000000..53f371e --- /dev/null +++ b/arch/arm64/kernel/paravirt.c @@ -0,0 +1,25 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program 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 General Public License for more details. + * + * Copyright (C) 2013 Citrix Systems + * + * Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com> + */ + +#include <linux/export.h> +#include <linux/jump_label.h> +#include <linux/types.h> +#include <asm/paravirt.h> + +struct static_key paravirt_steal_enabled; +struct static_key paravirt_steal_rq_enabled; + +struct pv_time_ops pv_time_ops; +EXPORT_SYMBOL_GPL(pv_time_ops);