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 <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index b933061b6b607c467e20317412c63c78728396fc..8c0a54d50d0e9b90eb7b7bf4d7e0ed2e9f97ee9b 100644 (file)
--- 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 b29f4e40851f0cab2894450e61352285fd28b9f4..fbb9137c7d0287b652cf9c429db0ca593713032b 100644 (file)
--- 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) {