From 558daa289a402dbcce0c065c6ff3cc2e00ffeac8 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 2 May 2012 15:04:51 -0400 Subject: [PATCH] xen/apic: Return the APIC ID (and version) for CPU 0. On x86_64 on AMD machines where the first APIC_ID is not zero, we get: ACPI: LAPIC (acpi_id[0x01] lapic_id[0x10] enabled) BIOS bug: APIC version is 0 for CPU 1/0x10, fixing up to 0x10 BIOS bug: APIC version mismatch, boot CPU: 0, CPU 1: version 10 which means that when the ACPI processor driver loads and tries to parse the _Pxx states it fails to do as, as it ends up calling acpi_get_cpuid which does this: for_each_possible_cpu(i) { if (cpu_physical_id(i) == apic_id) return i; } And the bootup CPU, has not been found so it fails and returns -1 for the first CPU - which then subsequently in the loop that "acpi_processor_get_info" does results in returning an error, which means that "acpi_processor_add" failing and per_cpu(processor) is never set (and is NULL). That means that when xen-acpi-processor tries to load (much much later on) and parse the P-states it gets -ENODEV from acpi_processor_register_performance() (which tries to read the per_cpu(processor)) and fails to parse the data. Reported-by-and-Tested-by: Stefan Bader Suggested-by: Boris Ostrovsky [v2: Bit-shift APIC ID by 24 bits] Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/enlighten.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index a8f8844b8d32..4f437dedbdf5 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -809,9 +809,40 @@ static void xen_io_delay(void) } #ifdef CONFIG_X86_LOCAL_APIC +static unsigned long xen_set_apic_id(unsigned int x) +{ + WARN_ON(1); + return x; +} +static unsigned int xen_get_apic_id(unsigned long x) +{ + return ((x)>>24) & 0xFFu; +} static u32 xen_apic_read(u32 reg) { - return 0; + struct xen_platform_op op = { + .cmd = XENPF_get_cpuinfo, + .interface_version = XENPF_INTERFACE_VERSION, + .u.pcpu_info.xen_cpuid = 0, + }; + int ret = 0; + + /* Shouldn't need this as APIC is turned off for PV, and we only + * get called on the bootup processor. But just in case. */ + if (!xen_initial_domain() || smp_processor_id()) + return 0; + + if (reg == APIC_LVR) + return 0x10; + + if (reg != APIC_ID) + return 0; + + ret = HYPERVISOR_dom0_op(&op); + if (ret) + return 0; + + return op.u.pcpu_info.apic_id << 24; } static void xen_apic_write(u32 reg, u32 val) @@ -849,6 +880,8 @@ static void set_xen_basic_apic_ops(void) apic->icr_write = xen_apic_icr_write; apic->wait_icr_idle = xen_apic_wait_icr_idle; apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle; + apic->set_apic_id = xen_set_apic_id; + apic->get_apic_id = xen_get_apic_id; } #endif -- 2.30.2