From 32ca78deedce610f28a85174a86429d66e1e0e02 Mon Sep 17 00:00:00 2001 From: Roger Pau Monne Date: Wed, 8 Nov 2023 16:25:15 -0500 Subject: [PATCH] acpi/processor: sanitize _OSC/_PDC capabilities for Xen dom0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Cc: stable@vger.kernel.org Signed-off-by: Jason Andryuk Reviewed-by: Michal Wilczynski Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20231108212517.72279-1-jandryuk@gmail.com Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- 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(+) diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h index c8a7fc2..f896eed 100644 --- a/arch/x86/include/asm/acpi.h +++ b/arch/x86/include/asm/acpi.h @@ -16,6 +16,9 @@ #include #include #include +#include + +#include #ifdef CONFIG_ACPI_APEI # include @@ -127,6 +130,17 @@ static inline void arch_acpi_set_proc_cap_bits(u32 *cap) 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) diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h index 7048dfa..a908825 100644 --- 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_lazy_mode mode) 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 */ diff --git a/drivers/xen/pcpu.c b/drivers/xen/pcpu.c index b3e3d1b..5086552 100644 --- a/drivers/xen/pcpu.c +++ b/drivers/xen/pcpu.c @@ -47,6 +47,9 @@ #include #include +#ifdef CONFIG_ACPI +#include +#endif /* * @cpu_id: Xen physical cpu logic number @@ -400,4 +403,23 @@ bool __init xen_processor_present(uint32_t acpi_id) 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 -- 2.7.4