This patch fixes the following warning message seen when booting the
kernel as Dom0 with Xen on Intel machines.
[0.003000] [Firmware Bug]: CPU1: APIC id mismatch. Firmware: 0 APIC: 1]
The code generating the warning in validate_apic_and_package_id() matches
cpu_data(cpu).apicid (initialized in init_intel()->
detect_extended_topology() using cpuid) against the apicid returned from
xen_apic_read(). Now, xen_apic_read() makes a hypercall to retrieve apicid
for the boot cpu but returns 0 otherwise. Hence the warning gets thrown
for all but the boot cpu.
The idea behind xen_apic_read() returning 0 for apicid is that the
guests (even Dom0) should not need to know what physical processor their
vcpus are running on. This is because we currently do not have topology
information in Xen and also because xen allows more vcpus than physical
processors. However, boot cpu's apicid is required for loading
xen-acpi-processor driver on AMD machines. Look at following patch for
details:
commit 558daa289a ("xen/apic: Return the APIC ID (and version) for CPU
0.")
So to get rid of the warning, this patch modifies
xen_cpu_present_to_apicid() to return cpu_data(cpu).apicid instead of
calling xen_apic_read().
The warning is not seen on AMD machines because init_amd() populates
cpu_data(cpu).apicid by calling hard_smp_processor_id()->xen_apic_read()
as opposed to using apicid from cpuid as is done on Intel machines.
Signed-off-by: Mohit Gambhir <mohit.gambhir@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Currently Xen uses default_cpu_present_to_apicid() which will always
report BAD_APICID for PV guests since x86_bios_cpu_apic_id is initialised
to that value and is never updated.
With commit 1f12e32f4c ("x86/topology: Create logical package id"), this
op is now called by smp_init_package_map() when deciding whether to call
topology_update_package_map() which sets cpu_data(cpu).logical_proc_id.
The latter (as topology_logical_package_id(cpu)) may be used, for example,
by cpu_to_rapl_pmu() as an array index. Since uninitialized
logical_package_id is set to -1, the index will become 64K which is
obviously problematic.
While RAPL code (and any other users of logical_package_id) should be
careful in their assumptions about id's validity, Xen's
cpu_present_to_apicid op should still provide value consistent with its
own xen_apic_read(APIC_ID).
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The dom0_op hypercall has been renamed to platform_op since Xen 3.2,
which is ancient, and modern upstream Linux kernels cannot run as dom0
and it anymore anyway.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Provide interfaces for recognizing accesses to PMU-related MSRs and
LVTPC APIC and process these accesses in Xen PMU code.
(The interrupt handler performs XENPMU_flush right away in the beginning
since no PMU emulation is available. It will be added with a later patch).
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Map shared data structure that will hold CPU registers, VPMU context,
V/PCPU IDs of the CPU interrupted by PMU interrupt. Hypervisor fills
this information in its handler and passes it to the guest for further
processing.
Set up PMU VIRQ.
Now that perf infrastructure will assume that PMU is available on a PV
guest we need to be careful and make sure that accesses via RDPMC
instruction don't cause fatal traps by the hypervisor. Provide a nop
RDPMC handler.
For the same reason avoid issuing a warning on a write to APIC's LVTPC.
Both of these will be made functional in later patches.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
We should not be writting to the APIC registers under
Xen PV. But if we do instead of just giving an blanket
warning - include some details to help troubleshoot.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Instead of mangling the default APIC driver, provide a Xen PV guest
specific one that explicitly provides appropriate methods.
This allows use to report that all APIC IDs are valid, allowing dom0
to boot with more than 255 VCPUs.
Since the probe order of APIC drivers is link dependent, we add in an
late probe function to change to the Xen PV if it hadn't been done
during bootup.
Suggested-by: David Vrabel <david.vrabel@citrix.com>
Reported-by: Cathy Avery <cathy.avery@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
There is no need for those functions/variables to be visible. Make them
static and also fix the compile warnings of this sort:
drivers/xen/<some file>.c: warning: symbol '<blah>' was not declared. Should it be static?
Some of them just require including the header file that
declares the functions.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This file depends on <xen/xen.h>, but the dependency was hidden due
to: <asm/acpi.h> -> <asm/trampoline.h> -> <asm/io.h> -> <xen/xen.h>
With the removal of <asm/trampoline.h>, this exposed the missing
Cc: Len Brown <lenb@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-7ccybvue6mw6wje3uxzzcglj@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Implements xen_io_apic_read with hypercall, so it returns proper
IO-APIC information instead of fabricated one.
Fallback to return an emulated IO_APIC values if hypercall fails.
[v2: fallback to return an emulated IO_APIC values if hypercall fails]
Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Or rather just implement one different function as opposed
to the native one : the read function.
We synthesize the values.
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
[v1: Rebased on top of tip/x86/urgent]
[v2: Return 0xfd instead of 0xff in the default case]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Mohit Gambhir