v4.19.13 snapshot.
diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
new file mode 100644
index 0000000..5e53bfb
--- /dev/null
+++ b/arch/x86/xen/apic.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0
+#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 u32 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 0x14;
+#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(u32 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 cpu_data(cpu).apicid;
+ 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 */
+
+ .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 */
+
+ .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. */
+
+ .calc_dest_apicid = apic_flat_calc_apicid,
+
+#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_apic_ops.io_apic_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);