From 166deb0f0bcdda70cfa650982777f94da273f0e4 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 25 Jun 2018 04:17:35 -0600 Subject: [PATCH] xen/ACPI: don't upload Px/Cx data for disabled processors This is unnecessary and triggers a warning in the hypervisor. Often systems have more processor entries in their ACPI tables than are actually installed/active. The ACPI_STA_DEVICE_PRESENT bit cannot be reliably used, but the ACPI_MADT_ENABLED bit can. In order to not introduce new functions in the main ACPI processor driver code, simply use acpi_get_phys_id(), which does more than we need, but which checks the MADT enabled bit in the process. Any CPU for which we can't determine the APIC ID is unlikely to work properly anyway, so the extra checks done by acpi_get_phys_id() should do no harm. Signed-off-by: Jan Beulich Reviewed-by: Juergen Gross Acked-by: Rafael J. Wysocki Signed-off-by: Boris Ostrovsky --- drivers/acpi/processor_core.c | 1 + drivers/xen/xen-acpi-processor.c | 6 ++++++ 2 files changed, 7 insertions(+) diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c index b933061..8c0a54d 100644 --- a/drivers/acpi/processor_core.c +++ b/drivers/acpi/processor_core.c @@ -205,6 +205,7 @@ phys_cpuid_t acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id) return phys_id; } +EXPORT_SYMBOL_GPL(acpi_get_phys_id); int acpi_map_cpuid(phys_cpuid_t phys_id, u32 acpi_id) { diff --git a/drivers/xen/xen-acpi-processor.c b/drivers/xen/xen-acpi-processor.c index b29f4e4..fbb9137 100644 --- a/drivers/xen/xen-acpi-processor.c +++ b/drivers/xen/xen-acpi-processor.c @@ -362,6 +362,12 @@ read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv) default: return AE_OK; } + if (invalid_phys_cpuid(acpi_get_phys_id(handle, + acpi_type == ACPI_TYPE_DEVICE, + acpi_id))) { + pr_debug("CPU with ACPI ID %u is unavailable\n", acpi_id); + return AE_OK; + } /* There are more ACPI Processor objects than in x2APIC or MADT. * This can happen with incorrect ACPI SSDT declerations. */ if (acpi_id >= nr_acpi_bits) { -- 2.7.4