linux/arch/x86/xen/apic.c
Boris Ostrovsky ed6069be72 xen/apic: Provide Xen-specific version of cpu_present_to_apicid APIC op
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>
2016-03-25 11:42:53 -04:00

229 lines
5.2 KiB
C

#include <linux/init.h>
#include <asm/x86_init.h>
#include <asm/apic.h>
#include <asm/xen/hypercall.h>
#include <xen/xen.h>
#include <xen/interface/physdev.h>
#include "xen-ops.h"
#include "pmu.h"
#include "smp.h"
static unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
{
struct physdev_apic apic_op;
int ret;
apic_op.apic_physbase = mpc_ioapic_addr(apic);
apic_op.reg = reg;
ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
if (!ret)
return apic_op.value;
/* fallback to return an emulated IO_APIC values */
if (reg == 0x1)
return 0x00170020;
else if (reg == 0x0)
return apic << 24;
return 0xfd;
}
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)
{
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;
#ifdef CONFIG_X86_32
if (reg == APIC_LDR)
return SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
#endif
if (reg != APIC_ID)
return 0;
ret = HYPERVISOR_platform_op(&op);
if (ret)
op.u.pcpu_info.apic_id = BAD_APICID;
return op.u.pcpu_info.apic_id << 24;
}
static void xen_apic_write(u32 reg, u32 val)
{
if (reg == APIC_LVTPC) {
(void)pmu_apic_update(reg);
return;
}
/* Warn to see if there's any stray references */
WARN(1,"register: %x, value: %x\n", reg, val);
}
static u64 xen_apic_icr_read(void)
{
return 0;
}
static void xen_apic_icr_write(u32 low, u32 id)
{
/* Warn to see if there's any stray references */
WARN_ON(1);
}
static u32 xen_safe_apic_wait_icr_idle(void)
{
return 0;
}
static int xen_apic_probe_pv(void)
{
if (xen_pv_domain())
return 1;
return 0;
}
static int xen_madt_oem_check(char *oem_id, char *oem_table_id)
{
return xen_pv_domain();
}
static int xen_id_always_valid(int apicid)
{
return 1;
}
static int xen_id_always_registered(void)
{
return 1;
}
static int xen_phys_pkg_id(int initial_apic_id, int index_msb)
{
return initial_apic_id >> index_msb;
}
#ifdef CONFIG_X86_32
static int xen_x86_32_early_logical_apicid(int cpu)
{
/* Match with APIC_LDR read. Otherwise setup_local_APIC complains. */
return 1 << cpu;
}
#endif
static void xen_noop(void)
{
}
static void xen_silent_inquire(int apicid)
{
}
static int xen_cpu_present_to_apicid(int cpu)
{
if (cpu_present(cpu))
return xen_get_apic_id(xen_apic_read(APIC_ID));
else
return BAD_APICID;
}
static struct apic xen_pv_apic = {
.name = "Xen PV",
.probe = xen_apic_probe_pv,
.acpi_madt_oem_check = xen_madt_oem_check,
.apic_id_valid = xen_id_always_valid,
.apic_id_registered = xen_id_always_registered,
/* .irq_delivery_mode - used in native_compose_msi_msg only */
/* .irq_dest_mode - used in native_compose_msi_msg only */
.target_cpus = default_target_cpus,
.disable_esr = 0,
/* .dest_logical - default_send_IPI_ use it but we use our own. */
.check_apicid_used = default_check_apicid_used, /* Used on 32-bit */
.vector_allocation_domain = flat_vector_allocation_domain,
.init_apic_ldr = xen_noop, /* setup_local_APIC calls it */
.ioapic_phys_id_map = default_ioapic_phys_id_map, /* Used on 32-bit */
.setup_apic_routing = NULL,
.cpu_present_to_apicid = xen_cpu_present_to_apicid,
.apicid_to_cpu_present = physid_set_mask_of_physid, /* Used on 32-bit */
.check_phys_apicid_present = default_check_phys_apicid_present, /* smp_sanity_check needs it */
.phys_pkg_id = xen_phys_pkg_id, /* detect_ht */
.get_apic_id = xen_get_apic_id,
.set_apic_id = xen_set_apic_id, /* Can be NULL on 32-bit. */
.apic_id_mask = 0xFF << 24, /* Used by verify_local_APIC. Match with what xen_get_apic_id does. */
.cpu_mask_to_apicid_and = flat_cpu_mask_to_apicid_and,
#ifdef CONFIG_SMP
.send_IPI_mask = xen_send_IPI_mask,
.send_IPI_mask_allbutself = xen_send_IPI_mask_allbutself,
.send_IPI_allbutself = xen_send_IPI_allbutself,
.send_IPI_all = xen_send_IPI_all,
.send_IPI_self = xen_send_IPI_self,
#endif
/* .wait_for_init_deassert- used by AP bootup - smp_callin which we don't use */
.inquire_remote_apic = xen_silent_inquire,
.read = xen_apic_read,
.write = xen_apic_write,
.eoi_write = xen_apic_write,
.icr_read = xen_apic_icr_read,
.icr_write = xen_apic_icr_write,
.wait_icr_idle = xen_noop,
.safe_wait_icr_idle = xen_safe_apic_wait_icr_idle,
#ifdef CONFIG_X86_32
/* generic_processor_info and setup_local_APIC. */
.x86_32_early_logical_apicid = xen_x86_32_early_logical_apicid,
#endif
};
static void __init xen_apic_check(void)
{
if (apic == &xen_pv_apic)
return;
pr_info("Switched APIC routing from %s to %s.\n", apic->name,
xen_pv_apic.name);
apic = &xen_pv_apic;
}
void __init xen_init_apic(void)
{
x86_io_apic_ops.read = xen_io_apic_read;
/* On PV guests the APIC CPUID bit is disabled so none of the
* routines end up executing. */
if (!xen_initial_domain())
apic = &xen_pv_apic;
x86_platform.apic_post_init = xen_apic_check;
}
apic_driver(xen_pv_apic);