Re: [PATCH v3 3/3] xen: Expose the PMU to the guests
On Fri, 8 Oct 2021, Michal Orzel wrote:
> Add parameter vpmu to xl domain configuration syntax
> to enable the access to PMU registers by disabling
> the PMU traps(currently only for ARM).
>
> The current status is that the PMU registers are not
> virtualized and the physical registers are directly
> accessible when this parameter is enabled. There is no
> interrupt support and Xen will not save/restore the
> register values on context switches.
>
> Please note that this feature is experimental.
>
> Signed-off-by: Michal Orzel
> Signed-off-by: Julien Grall
The patch needs rebasing
> ---
> Changes since v2:
> -remove redundant check from x86 code
> -do not define bit position and mask separately
> Changes since v1:
> -modify vpmu parameter to be common rather than arch specific
> ---
> docs/man/xl.cfg.5.pod.in | 17 +
> tools/golang/xenlight/helpers.gen.go | 6 ++
> tools/golang/xenlight/types.gen.go | 1 +
> tools/include/libxl.h| 6 ++
> tools/libs/light/libxl_create.c | 4
> tools/libs/light/libxl_types.idl | 2 ++
> tools/ocaml/libs/xc/xenctrl.ml | 1 +
> tools/ocaml/libs/xc/xenctrl.mli | 1 +
> tools/xl/xl_parse.c | 2 ++
> xen/arch/arm/domain.c| 10 --
> xen/arch/arm/setup.c | 1 +
> xen/common/domain.c | 9 -
> xen/include/asm-arm/domain.h | 1 +
> xen/include/public/domctl.h | 4 +++-
> 14 files changed, 61 insertions(+), 4 deletions(-)
>
> diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
> index 4b1e3028d2..55c4881205 100644
> --- a/docs/man/xl.cfg.5.pod.in
> +++ b/docs/man/xl.cfg.5.pod.in
> @@ -690,6 +690,23 @@ default.
> B: Acceptable values are platform specific. For Intel Processor
> Trace, this value must be a power of 2 between 4k and 16M.
>
> +=item B
> +
> +Currently ARM only.
> +
> +Specifies whether to enable the access to PMU registers by disabling
> +the PMU traps.
> +
> +The PMU registers are not virtualized and the physical registers are directly
> +accessible when this parameter is enabled. There is no interrupt support and
> +Xen will not save/restore the register values on context switches.
> +
> +vPMU, by design and purpose, exposes system level performance
> +information to the guest. Only to be used by sufficiently privileged
> +domains. This feature is currently in experimental state.
> +
> +If this option is not specified then it will default to B.
> +
> =back
>
> =head2 Devices
> diff --git a/tools/golang/xenlight/helpers.gen.go
> b/tools/golang/xenlight/helpers.gen.go
> index c8669837d8..2449580bad 100644
> --- a/tools/golang/xenlight/helpers.gen.go
> +++ b/tools/golang/xenlight/helpers.gen.go
> @@ -1119,6 +1119,9 @@ return fmt.Errorf("converting field ArchX86.MsrRelaxed:
> %v", err)
> }
> x.Altp2M = Altp2MMode(xc.altp2m)
> x.VmtraceBufKb = int(xc.vmtrace_buf_kb)
> +if err := x.Vpmu.fromC();err != nil {
> +return fmt.Errorf("converting field Vpmu: %v", err)
> +}
>
> return nil}
>
> @@ -1600,6 +1603,9 @@ return fmt.Errorf("converting field ArchX86.MsrRelaxed:
> %v", err)
> }
> xc.altp2m = C.libxl_altp2m_mode(x.Altp2M)
> xc.vmtrace_buf_kb = C.int(x.VmtraceBufKb)
> +if err := x.Vpmu.toC(); err != nil {
> +return fmt.Errorf("converting field Vpmu: %v", err)
> +}
>
> return nil
> }
> diff --git a/tools/golang/xenlight/types.gen.go
> b/tools/golang/xenlight/types.gen.go
> index 45f2cba3d2..b2e8bd1a85 100644
> --- a/tools/golang/xenlight/types.gen.go
> +++ b/tools/golang/xenlight/types.gen.go
> @@ -521,6 +521,7 @@ MsrRelaxed Defbool
> }
> Altp2M Altp2MMode
> VmtraceBufKb int
> +Vpmu Defbool
> }
>
> type DomainBuildInfoTypeUnion interface {
> diff --git a/tools/include/libxl.h b/tools/include/libxl.h
> index ec5e3badae..ee73eb06f1 100644
> --- a/tools/include/libxl.h
> +++ b/tools/include/libxl.h
> @@ -508,6 +508,12 @@
> */
> #define LIBXL_HAVE_PHYSINFO_CAP_VPMU 1
>
> +/*
> + * LIBXL_HAVE_VPMU indicates that libxl_domain_build_info has a vpmu
> parameter,
> + * which allows to enable the access to PMU registers.
> + */
> +#define LIBXL_HAVE_VPMU 1
> +
> /*
> * libxl ABI compatibility
> *
> diff --git a/tools/libs/light/libxl_create.c b/tools/libs/light/libxl_create.c
> index e356b2106d..d123c2f703 100644
> --- a/tools/libs/light/libxl_create.c
> +++ b/tools/libs/light/libxl_create.c
> @@ -91,6 +91,7 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
> }
>
> libxl_defbool_setdefault(_info->device_model_stubdomain, false);
> +libxl_defbool_setdefault(_info->vpmu, false);
>
> if (libxl_defbool_val(b_info->device_model_stubdomain) &&
> !b_info->device_model_ssidref)
> @@ -622,6 +623,9 @@ int libxl__domain_make(libxl__gc *gc, libxl_domain_config
> *d_config,
> create.flags |= XEN_DOMCTL_CDF_nested_virt;
> }
>
> +if ( libxl_defbool_val(b_info->vpmu) )
>
Re: [PATCH v3 3/3] xen: Expose the PMU to the guests
On Fri, Oct 08, 2021 at 10:19:33AM +0200, Michal Orzel wrote:
> Add parameter vpmu to xl domain configuration syntax
> to enable the access to PMU registers by disabling
> the PMU traps(currently only for ARM).
>
> The current status is that the PMU registers are not
> virtualized and the physical registers are directly
> accessible when this parameter is enabled. There is no
> interrupt support and Xen will not save/restore the
> register values on context switches.
>
> Please note that this feature is experimental.
>
> Signed-off-by: Michal Orzel
> Signed-off-by: Julien Grall
> ---
> Changes since v2:
> -remove redundant check from x86 code
> -do not define bit position and mask separately
> Changes since v1:
> -modify vpmu parameter to be common rather than arch specific
> ---
> docs/man/xl.cfg.5.pod.in | 17 +
> tools/golang/xenlight/helpers.gen.go | 6 ++
> tools/golang/xenlight/types.gen.go | 1 +
> tools/include/libxl.h| 6 ++
> tools/libs/light/libxl_create.c | 4
> tools/libs/light/libxl_types.idl | 2 ++
> tools/ocaml/libs/xc/xenctrl.ml | 1 +
> tools/ocaml/libs/xc/xenctrl.mli | 1 +
> tools/xl/xl_parse.c | 2 ++
> xen/arch/arm/domain.c| 10 --
> xen/arch/arm/setup.c | 1 +
> xen/common/domain.c | 9 -
> xen/include/asm-arm/domain.h | 1 +
> xen/include/public/domctl.h | 4 +++-
> 14 files changed, 61 insertions(+), 4 deletions(-)
>
> diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
> index 4b1e3028d2..55c4881205 100644
> --- a/docs/man/xl.cfg.5.pod.in
> +++ b/docs/man/xl.cfg.5.pod.in
> @@ -690,6 +690,23 @@ default.
> B: Acceptable values are platform specific. For Intel Processor
> Trace, this value must be a power of 2 between 4k and 16M.
>
> +=item B
> +
> +Currently ARM only.
> +
> +Specifies whether to enable the access to PMU registers by disabling
> +the PMU traps.
> +
> +The PMU registers are not virtualized and the physical registers are directly
> +accessible when this parameter is enabled. There is no interrupt support and
> +Xen will not save/restore the register values on context switches.
> +
> +vPMU, by design and purpose, exposes system level performance
> +information to the guest. Only to be used by sufficiently privileged
> +domains. This feature is currently in experimental state.
> +
> +If this option is not specified then it will default to B.
> +
> =back
>
> =head2 Devices
> diff --git a/tools/golang/xenlight/helpers.gen.go
> b/tools/golang/xenlight/helpers.gen.go
> index c8669837d8..2449580bad 100644
> --- a/tools/golang/xenlight/helpers.gen.go
> +++ b/tools/golang/xenlight/helpers.gen.go
> @@ -1119,6 +1119,9 @@ return fmt.Errorf("converting field ArchX86.MsrRelaxed:
> %v", err)
> }
> x.Altp2M = Altp2MMode(xc.altp2m)
> x.VmtraceBufKb = int(xc.vmtrace_buf_kb)
> +if err := x.Vpmu.fromC();err != nil {
> +return fmt.Errorf("converting field Vpmu: %v", err)
> +}
>
> return nil}
>
> @@ -1600,6 +1603,9 @@ return fmt.Errorf("converting field ArchX86.MsrRelaxed:
> %v", err)
> }
> xc.altp2m = C.libxl_altp2m_mode(x.Altp2M)
> xc.vmtrace_buf_kb = C.int(x.VmtraceBufKb)
> +if err := x.Vpmu.toC(); err != nil {
> +return fmt.Errorf("converting field Vpmu: %v", err)
> +}
>
> return nil
> }
> diff --git a/tools/golang/xenlight/types.gen.go
> b/tools/golang/xenlight/types.gen.go
> index 45f2cba3d2..b2e8bd1a85 100644
> --- a/tools/golang/xenlight/types.gen.go
> +++ b/tools/golang/xenlight/types.gen.go
> @@ -521,6 +521,7 @@ MsrRelaxed Defbool
> }
> Altp2M Altp2MMode
> VmtraceBufKb int
> +Vpmu Defbool
> }
>
> type DomainBuildInfoTypeUnion interface {
For the golang re-gen,
Acked-by: Nick Rosbrook
Thanks,
NR
Re: [PATCH v3 3/3] xen: Expose the PMU to the guests
Hi Michal,
> On 8 Oct 2021, at 09:19, Michal Orzel wrote:
>
> Add parameter vpmu to xl domain configuration syntax
> to enable the access to PMU registers by disabling
> the PMU traps(currently only for ARM).
>
> The current status is that the PMU registers are not
> virtualized and the physical registers are directly
> accessible when this parameter is enabled. There is no
> interrupt support and Xen will not save/restore the
> register values on context switches.
>
> Please note that this feature is experimental.
>
> Signed-off-by: Michal Orzel
> Signed-off-by: Julien Grall
Reviewed-by: Bertrand Marquis
Cheers
Bertrand
> ---
> Changes since v2:
> -remove redundant check from x86 code
> -do not define bit position and mask separately
> Changes since v1:
> -modify vpmu parameter to be common rather than arch specific
> ---
> docs/man/xl.cfg.5.pod.in | 17 +
> tools/golang/xenlight/helpers.gen.go | 6 ++
> tools/golang/xenlight/types.gen.go | 1 +
> tools/include/libxl.h| 6 ++
> tools/libs/light/libxl_create.c | 4
> tools/libs/light/libxl_types.idl | 2 ++
> tools/ocaml/libs/xc/xenctrl.ml | 1 +
> tools/ocaml/libs/xc/xenctrl.mli | 1 +
> tools/xl/xl_parse.c | 2 ++
> xen/arch/arm/domain.c| 10 --
> xen/arch/arm/setup.c | 1 +
> xen/common/domain.c | 9 -
> xen/include/asm-arm/domain.h | 1 +
> xen/include/public/domctl.h | 4 +++-
> 14 files changed, 61 insertions(+), 4 deletions(-)
>
> diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
> index 4b1e3028d2..55c4881205 100644
> --- a/docs/man/xl.cfg.5.pod.in
> +++ b/docs/man/xl.cfg.5.pod.in
> @@ -690,6 +690,23 @@ default.
> B: Acceptable values are platform specific. For Intel Processor
> Trace, this value must be a power of 2 between 4k and 16M.
>
> +=item B
> +
> +Currently ARM only.
> +
> +Specifies whether to enable the access to PMU registers by disabling
> +the PMU traps.
> +
> +The PMU registers are not virtualized and the physical registers are directly
> +accessible when this parameter is enabled. There is no interrupt support and
> +Xen will not save/restore the register values on context switches.
> +
> +vPMU, by design and purpose, exposes system level performance
> +information to the guest. Only to be used by sufficiently privileged
> +domains. This feature is currently in experimental state.
> +
> +If this option is not specified then it will default to B.
> +
> =back
>
> =head2 Devices
> diff --git a/tools/golang/xenlight/helpers.gen.go
> b/tools/golang/xenlight/helpers.gen.go
> index c8669837d8..2449580bad 100644
> --- a/tools/golang/xenlight/helpers.gen.go
> +++ b/tools/golang/xenlight/helpers.gen.go
> @@ -1119,6 +1119,9 @@ return fmt.Errorf("converting field ArchX86.MsrRelaxed:
> %v", err)
> }
> x.Altp2M = Altp2MMode(xc.altp2m)
> x.VmtraceBufKb = int(xc.vmtrace_buf_kb)
> +if err := x.Vpmu.fromC();err != nil {
> +return fmt.Errorf("converting field Vpmu: %v", err)
> +}
>
> return nil}
>
> @@ -1600,6 +1603,9 @@ return fmt.Errorf("converting field ArchX86.MsrRelaxed:
> %v", err)
> }
> xc.altp2m = C.libxl_altp2m_mode(x.Altp2M)
> xc.vmtrace_buf_kb = C.int(x.VmtraceBufKb)
> +if err := x.Vpmu.toC(); err != nil {
> +return fmt.Errorf("converting field Vpmu: %v", err)
> +}
>
> return nil
> }
> diff --git a/tools/golang/xenlight/types.gen.go
> b/tools/golang/xenlight/types.gen.go
> index 45f2cba3d2..b2e8bd1a85 100644
> --- a/tools/golang/xenlight/types.gen.go
> +++ b/tools/golang/xenlight/types.gen.go
> @@ -521,6 +521,7 @@ MsrRelaxed Defbool
> }
> Altp2M Altp2MMode
> VmtraceBufKb int
> +Vpmu Defbool
> }
>
> type DomainBuildInfoTypeUnion interface {
> diff --git a/tools/include/libxl.h b/tools/include/libxl.h
> index ec5e3badae..ee73eb06f1 100644
> --- a/tools/include/libxl.h
> +++ b/tools/include/libxl.h
> @@ -508,6 +508,12 @@
> */
> #define LIBXL_HAVE_PHYSINFO_CAP_VPMU 1
>
> +/*
> + * LIBXL_HAVE_VPMU indicates that libxl_domain_build_info has a vpmu
> parameter,
> + * which allows to enable the access to PMU registers.
> + */
> +#define LIBXL_HAVE_VPMU 1
> +
> /*
> * libxl ABI compatibility
> *
> diff --git a/tools/libs/light/libxl_create.c b/tools/libs/light/libxl_create.c
> index e356b2106d..d123c2f703 100644
> --- a/tools/libs/light/libxl_create.c
> +++ b/tools/libs/light/libxl_create.c
> @@ -91,6 +91,7 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
> }
>
> libxl_defbool_setdefault(_info->device_model_stubdomain, false);
> +libxl_defbool_setdefault(_info->vpmu, false);
>
> if (libxl_defbool_val(b_info->device_model_stubdomain) &&
> !b_info->device_model_ssidref)
> @@ -622,6 +623,9 @@ int libxl__domain_make(libxl__gc *gc, libxl_domain_config
> *d_config,
> create.flags |= XEN_DOMCTL_CDF_nested_virt;
> }
>
> +if ( libxl_defbool_val(b_info->vpmu) )
> +
