6.6-stable review patch. If anyone has any objections, please let me know.
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From: Roger Pau Monne roger.pau@citrix.com
commit bfa993b355d33a438a746523e7129391c8664e8a upstream.
The Processor capability bits notify ACPI of the OS capabilities, and so ACPI can adjust the return of other Processor methods taking the OS capabilities into account.
When Linux is running as a Xen dom0, the hypervisor is the entity in charge of processor power management, and hence Xen needs to make sure the capabilities reported by _OSC/_PDC match the capabilities of the driver in Xen.
Introduce a small helper to sanitize the buffer when running as Xen dom0.
When Xen supports HWP, this serves as the equivalent of commit a21211672c9a ("ACPI / processor: Request native thermal interrupt handling via _OSC") to avoid SMM crashes. Xen will set bit ACPI_PROC_CAP_COLLAB_PROC_PERF (bit 12) in the capability bits and the _OSC/_PDC call will apply it.
[ jandryuk: Mention Xen HWP's need. Support _OSC & _PDC ] Signed-off-by: Roger Pau Monné roger.pau@citrix.com Cc: stable@vger.kernel.org Signed-off-by: Jason Andryuk jandryuk@gmail.com Reviewed-by: Michal Wilczynski michal.wilczynski@intel.com Reviewed-by: Juergen Gross jgross@suse.com Link: https://lore.kernel.org/r/20231108212517.72279-1-jandryuk@gmail.com Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/include/asm/acpi.h | 14 ++++++++++++++ arch/x86/include/asm/xen/hypervisor.h | 9 +++++++++ drivers/xen/pcpu.c | 22 ++++++++++++++++++++++ 3 files changed, 45 insertions(+)
--- a/arch/x86/include/asm/acpi.h +++ b/arch/x86/include/asm/acpi.h @@ -16,6 +16,9 @@ #include <asm/x86_init.h> #include <asm/cpufeature.h> #include <asm/irq_vectors.h> +#include <asm/xen/hypervisor.h> + +#include <xen/xen.h>
#ifdef CONFIG_ACPI_APEI # include <asm/pgtable_types.h> @@ -127,6 +130,17 @@ static inline void arch_acpi_set_proc_ca if (!cpu_has(c, X86_FEATURE_MWAIT) || boot_option_idle_override == IDLE_NOMWAIT) *cap &= ~(ACPI_PROC_CAP_C_C1_FFH | ACPI_PROC_CAP_C_C2C3_FFH); + + if (xen_initial_domain()) { + /* + * When Linux is running as Xen dom0, the hypervisor is the + * entity in charge of the processor power management, and so + * Xen needs to check the OS capabilities reported in the + * processor capabilities buffer matches what the hypervisor + * driver supports. + */ + xen_sanitize_proc_cap_bits(cap); + } }
static inline bool acpi_has_cpu_in_madt(void) --- a/arch/x86/include/asm/xen/hypervisor.h +++ b/arch/x86/include/asm/xen/hypervisor.h @@ -100,4 +100,13 @@ static inline void leave_lazy(enum xen_l
enum xen_lazy_mode xen_get_lazy_mode(void);
+#if defined(CONFIG_XEN_DOM0) && defined(CONFIG_ACPI) +void xen_sanitize_proc_cap_bits(uint32_t *buf); +#else +static inline void xen_sanitize_proc_cap_bits(uint32_t *buf) +{ + BUG(); +} +#endif + #endif /* _ASM_X86_XEN_HYPERVISOR_H */ --- a/drivers/xen/pcpu.c +++ b/drivers/xen/pcpu.c @@ -47,6 +47,9 @@ #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h>
+#ifdef CONFIG_ACPI +#include <acpi/processor.h> +#endif
/* * @cpu_id: Xen physical cpu logic number @@ -400,4 +403,23 @@ bool __init xen_processor_present(uint32
return online; } + +void xen_sanitize_proc_cap_bits(uint32_t *cap) +{ + struct xen_platform_op op = { + .cmd = XENPF_set_processor_pminfo, + .u.set_pminfo.id = -1, + .u.set_pminfo.type = XEN_PM_PDC, + }; + u32 buf[3] = { ACPI_PDC_REVISION_ID, 1, *cap }; + int ret; + + set_xen_guest_handle(op.u.set_pminfo.pdc, buf); + ret = HYPERVISOR_platform_op(&op); + if (ret) + pr_err("sanitize of _PDC buffer bits from Xen failed: %d\n", + ret); + else + *cap = buf[2]; +} #endif