On 11/21/22 11:21, Roger Pau Monne wrote:
> When running as a Xen dom0 the number of CPUs available to Linux can
> be different from the number of CPUs present on the system, but in
> order to properly fetch processor performance related data _PDC must
> be executed on all the physical CPUs online on the system.
>
> The current checks in processor_physically_present() result in some
> processor objects not getting their _PDC methods evaluated when Linux
> is running as Xen dom0. Fix this by introducing a custom function to
> use when running as Xen dom0 in order to check whether a processor
> object matches a CPU that's online.
>
> Fixes: 5d554a7bb064 ('ACPI: processor: add internal processor_physically_present()')
> Signed-off-by: Roger Pau Monné <[email protected]>
> ---
> arch/x86/include/asm/xen/hypervisor.h | 10 ++++++++++
> arch/x86/xen/enlighten.c | 27 +++++++++++++++++++++++++++
> drivers/acpi/processor_pdc.c | 11 +++++++++++
> 3 files changed, 48 insertions(+)
>
> diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h
> index 16f548a661cf..b9f512138043 100644
> --- a/arch/x86/include/asm/xen/hypervisor.h
> +++ b/arch/x86/include/asm/xen/hypervisor.h
> @@ -61,4 +61,14 @@ void __init xen_pvh_init(struct boot_params *boot_params);
> void __init mem_map_via_hcall(struct boot_params *boot_params_p);
> #endif
>
> +#ifdef CONFIG_XEN_DOM0
> +bool __init xen_processor_present(uint32_t acpi_id);
> +#else
> +static inline bool xen_processor_present(uint32_t acpi_id)
> +{
> + BUG();
> + return false;
> +}
> +#endif
> +
> #endif /* _ASM_X86_XEN_HYPERVISOR_H */
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index b8db2148c07d..d4c44361a26c 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -346,3 +346,30 @@ void xen_arch_unregister_cpu(int num)
> }
> EXPORT_SYMBOL(xen_arch_unregister_cpu);
> #endif
> +
> +#ifdef CONFIG_XEN_DOM0
> +bool __init xen_processor_present(uint32_t acpi_id)
> +{
> + unsigned int i, maxid;
> + struct xen_platform_op op = {
> + .cmd = XENPF_get_cpuinfo,
> + .interface_version = XENPF_INTERFACE_VERSION,
> + };
> + int ret = HYPERVISOR_platform_op(&op);
> +
> + if (ret)
> + return false;
> +
> + maxid = op.u.pcpu_info.max_present;
> + for (i = 0; i <= maxid; i++) {
> + op.u.pcpu_info.xen_cpuid = i;
> + ret = HYPERVISOR_platform_op(&op);
> + if (ret)
> + continue;
> + if (op.u.pcpu_info.acpi_id == acpi_id)
> + return op.u.pcpu_info.flags & XEN_PCPU_FLAGS_ONLINE;
> + }
> +
> + return false;
> +}
My compiler (Default GCC on Fedora 32, compiling for Qubes) complain
loudly that the below was missing.
+}
+EXPORT_SYMBOL(xen_processor_present);
`ERROR: MODPOST xen_processor_present
[drivers/xen/xen-acpi-processor.ko] undefined!`
Same thing with xen_sanitize_pdc in the next patch.
+}
+EXPORT_SYMBOL(xen_sanitize_pdc);
Everything compiled fine after those changes.
> +#endif
> diff --git a/drivers/acpi/processor_pdc.c b/drivers/acpi/processor_pdc.c
> index 8c3f82c9fff3..18fb04523f93 100644
> --- a/drivers/acpi/processor_pdc.c
> +++ b/drivers/acpi/processor_pdc.c
> @@ -14,6 +14,8 @@
> #include <linux/acpi.h>
> #include <acpi/processor.h>
>
> +#include <xen/xen.h>
> +
> #include "internal.h"
>
> static bool __init processor_physically_present(acpi_handle handle)
> @@ -47,6 +49,15 @@ static bool __init processor_physically_present(acpi_handle handle)
> return false;
> }
>
> + if (xen_initial_domain())
> + /*
> + * When running as a Xen dom0 the number of processors Linux
> + * sees can be different from the real number of processors on
> + * the system, and we still need to execute _PDC for all of
> + * them.
> + */
> + return xen_processor_present(acpi_id);
> +
> type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
> cpuid = acpi_get_cpuid(handle, type, acpi_id);
>
On 30.01.2023 10:21, Josef Johansson wrote:
> On 11/21/22 11:21, Roger Pau Monne wrote:
>> --- a/arch/x86/xen/enlighten.c
>> +++ b/arch/x86/xen/enlighten.c
>> @@ -346,3 +346,30 @@ void xen_arch_unregister_cpu(int num)
>> }
>> EXPORT_SYMBOL(xen_arch_unregister_cpu);
>> #endif
>> +
>> +#ifdef CONFIG_XEN_DOM0
>> +bool __init xen_processor_present(uint32_t acpi_id)
>> +{
>> + unsigned int i, maxid;
>> + struct xen_platform_op op = {
>> + .cmd = XENPF_get_cpuinfo,
>> + .interface_version = XENPF_INTERFACE_VERSION,
>> + };
>> + int ret = HYPERVISOR_platform_op(&op);
>> +
>> + if (ret)
>> + return false;
>> +
>> + maxid = op.u.pcpu_info.max_present;
>> + for (i = 0; i <= maxid; i++) {
>> + op.u.pcpu_info.xen_cpuid = i;
>> + ret = HYPERVISOR_platform_op(&op);
>> + if (ret)
>> + continue;
>> + if (op.u.pcpu_info.acpi_id == acpi_id)
>> + return op.u.pcpu_info.flags & XEN_PCPU_FLAGS_ONLINE;
>> + }
>> +
>> + return false;
>> +}
> My compiler (Default GCC on Fedora 32, compiling for Qubes) complain
> loudly that the below was missing.
>
> +}
> +EXPORT_SYMBOL(xen_processor_present);
>
> `ERROR: MODPOST xen_processor_present
> [drivers/xen/xen-acpi-processor.ko] undefined!`
>
> Same thing with xen_sanitize_pdc in the next patch.
>
> +}
> +EXPORT_SYMBOL(xen_sanitize_pdc);
>
> Everything compiled fine after those changes.
Except that you may not export __init symbols. The section mismatch checker
should actually complain about that.
Jan
On 2/3/23 08:05, Jan Beulich wrote:
> On 30.01.2023 10:21, Josef Johansson wrote:
>> On 11/21/22 11:21, Roger Pau Monne wrote:
>>> --- a/arch/x86/xen/enlighten.c
>>> +++ b/arch/x86/xen/enlighten.c
>>> @@ -346,3 +346,30 @@ void xen_arch_unregister_cpu(int num)
>>> }
>>> EXPORT_SYMBOL(xen_arch_unregister_cpu);
>>> #endif
>>> +
>>> +#ifdef CONFIG_XEN_DOM0
>>> +bool __init xen_processor_present(uint32_t acpi_id)
>>> +{
>>> + unsigned int i, maxid;
>>> + struct xen_platform_op op = {
>>> + .cmd = XENPF_get_cpuinfo,
>>> + .interface_version = XENPF_INTERFACE_VERSION,
>>> + };
>>> + int ret = HYPERVISOR_platform_op(&op);
>>> +
>>> + if (ret)
>>> + return false;
>>> +
>>> + maxid = op.u.pcpu_info.max_present;
>>> + for (i = 0; i <= maxid; i++) {
>>> + op.u.pcpu_info.xen_cpuid = i;
>>> + ret = HYPERVISOR_platform_op(&op);
>>> + if (ret)
>>> + continue;
>>> + if (op.u.pcpu_info.acpi_id == acpi_id)
>>> + return op.u.pcpu_info.flags & XEN_PCPU_FLAGS_ONLINE;
>>> + }
>>> +
>>> + return false;
>>> +}
>> My compiler (Default GCC on Fedora 32, compiling for Qubes) complain
>> loudly that the below was missing.
>>
>> +}
>> +EXPORT_SYMBOL(xen_processor_present);
>>
>> `ERROR: MODPOST xen_processor_present
>> [drivers/xen/xen-acpi-processor.ko] undefined!`
>>
>> Same thing with xen_sanitize_pdc in the next patch.
>>
>> +}
>> +EXPORT_SYMBOL(xen_sanitize_pdc);
>>
>> Everything compiled fine after those changes.
> Except that you may not export __init symbols. The section mismatch checker
> should actually complain about that.
>
> Jan
That makes sense. Patch 3 does change it from an __init though.
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 394dd6675113..a7b41103d3e5 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -348,7 +348,7 @@ EXPORT_SYMBOL(xen_arch_unregister_cpu);
#endif
#ifdef CONFIG_XEN_DOM0
-bool __init xen_processor_present(uint32_t acpi_id)
+bool xen_processor_present(uint32_t acpi_id)
{
So the change should be in Patch 3 I guess.
Regards
- Josef