1 files changed, 336 insertions, 0 deletions
diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
new file mode 100644
index 000000000..c66807dd0
--- /dev/null
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -0,0 +1,336 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/acpi.h>
+#include <linux/cpu.h>
+#include <linux/kexec.h>
+#include <linux/memblock.h>
+#include <linux/virtio_anchor.h>
+
+#include <xen/features.h>
+#include <xen/events.h>
+#include <xen/hvm.h>
+#include <xen/interface/hvm/hvm_op.h>
+#include <xen/interface/memory.h>
+
+#include <asm/apic.h>
+#include <asm/cpu.h>
+#include <asm/smp.h>
+#include <asm/io_apic.h>
+#include <asm/reboot.h>
+#include <asm/setup.h>
+#include <asm/idtentry.h>
+#include <asm/hypervisor.h>
+#include <asm/e820/api.h>
+#include <asm/early_ioremap.h>
+
+#include <asm/xen/cpuid.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/page.h>
+
+#include "xen-ops.h"
+#include "mmu.h"
+#include "smp.h"
+
+static unsigned long shared_info_pfn;
+
+__ro_after_init bool xen_percpu_upcall;
+EXPORT_SYMBOL_GPL(xen_percpu_upcall);
+
+void xen_hvm_init_shared_info(void)
+{
+	struct xen_add_to_physmap xatp;
+
+	xatp.domid = DOMID_SELF;
+	xatp.idx = 0;
+	xatp.space = XENMAPSPACE_shared_info;
+	xatp.gpfn = shared_info_pfn;
+	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
+		BUG();
+}
+
+static void __init reserve_shared_info(void)
+{
+	u64 pa;
+
+	/*
+	 * Search for a free page starting at 4kB physical address.
+	 * Low memory is preferred to avoid an EPT large page split up
+	 * by the mapping.
+	 * Starting below X86_RESERVE_LOW (usually 64kB) is fine as
+	 * the BIOS used for HVM guests is well behaved and won't
+	 * clobber memory other than the first 4kB.
+	 */
+	for (pa = PAGE_SIZE;
+	     !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) ||
+	     memblock_is_reserved(pa);
+	     pa += PAGE_SIZE)
+		;
+
+	shared_info_pfn = PHYS_PFN(pa);
+
+	memblock_reserve(pa, PAGE_SIZE);
+	HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE);
+}
+
+static void __init xen_hvm_init_mem_mapping(void)
+{
+	early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE);
+	HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn));
+
+	/*
+	 * The virtual address of the shared_info page has changed, so
+	 * the vcpu_info pointer for VCPU 0 is now stale.
+	 *
+	 * The prepare_boot_cpu callback will re-initialize it via
+	 * xen_vcpu_setup, but we can't rely on that to be called for
+	 * old Xen versions (xen_have_vector_callback == 0).
+	 *
+	 * It is, in any case, bad to have a stale vcpu_info pointer
+	 * so reset it now.
+	 */
+	xen_vcpu_info_reset(0);
+}
+
+static void __init init_hvm_pv_info(void)
+{
+	int major, minor;
+	uint32_t eax, ebx, ecx, edx, base;
+
+	base = xen_cpuid_base();
+	eax = cpuid_eax(base + 1);
+
+	major = eax >> 16;
+	minor = eax & 0xffff;
+	printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
+
+	xen_domain_type = XEN_HVM_DOMAIN;
+
+	/* PVH set up hypercall page in xen_prepare_pvh(). */
+	if (xen_pvh_domain())
+		pv_info.name = "Xen PVH";
+	else {
+		u64 pfn;
+		uint32_t msr;
+
+		pv_info.name = "Xen HVM";
+		msr = cpuid_ebx(base + 2);
+		pfn = __pa(hypercall_page);
+		wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
+	}
+
+	xen_setup_features();
+
+	cpuid(base + 4, &eax, &ebx, &ecx, &edx);
+	if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT)
+		this_cpu_write(xen_vcpu_id, ebx);
+	else
+		this_cpu_write(xen_vcpu_id, smp_processor_id());
+}
+
+DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	if (xen_percpu_upcall)
+		ack_APIC_irq();
+
+	inc_irq_stat(irq_hv_callback_count);
+
+	xen_evtchn_do_upcall();
+
+	set_irq_regs(old_regs);
+}
+
+#ifdef CONFIG_KEXEC_CORE
+static void xen_hvm_shutdown(void)
+{
+	native_machine_shutdown();
+	if (kexec_in_progress)
+		xen_reboot(SHUTDOWN_soft_reset);
+}
+
+static void xen_hvm_crash_shutdown(struct pt_regs *regs)
+{
+	native_machine_crash_shutdown(regs);
+	xen_reboot(SHUTDOWN_soft_reset);
+}
+#endif
+
+static int xen_cpu_up_prepare_hvm(unsigned int cpu)
+{
+	int rc = 0;
+
+	/*
+	 * This can happen if CPU was offlined earlier and
+	 * offlining timed out in common_cpu_die().
+	 */
+	if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
+		xen_smp_intr_free(cpu);
+		xen_uninit_lock_cpu(cpu);
+	}
+
+	if (cpu_acpi_id(cpu) != U32_MAX)
+		per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
+	else
+		per_cpu(xen_vcpu_id, cpu) = cpu;
+	xen_vcpu_setup(cpu);
+	if (!xen_have_vector_callback)
+		return 0;
+
+	if (xen_percpu_upcall) {
+		rc = xen_set_upcall_vector(cpu);
+		if (rc) {
+			WARN(1, "HVMOP_set_evtchn_upcall_vector"
+			     " for CPU %d failed: %d\n", cpu, rc);
+			return rc;
+		}
+	}
+
+	if (xen_feature(XENFEAT_hvm_safe_pvclock))
+		xen_setup_timer(cpu);
+
+	rc = xen_smp_intr_init(cpu);
+	if (rc) {
+		WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
+		     cpu, rc);
+	}
+	return rc;
+}
+
+static int xen_cpu_dead_hvm(unsigned int cpu)
+{
+	xen_smp_intr_free(cpu);
+
+	if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
+		xen_teardown_timer(cpu);
+	return 0;
+}
+
+static void __init xen_hvm_guest_init(void)
+{
+	if (xen_pv_domain())
+		return;
+
+	if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT))
+		virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc);
+
+	init_hvm_pv_info();
+
+	reserve_shared_info();
+	xen_hvm_init_shared_info();
+
+	/*
+	 * xen_vcpu is a pointer to the vcpu_info struct in the shared_info
+	 * page, we use it in the event channel upcall and in some pvclock
+	 * related functions.
+	 */
+	xen_vcpu_info_reset(0);
+
+	xen_panic_handler_init();
+
+	xen_hvm_smp_init();
+	WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm));
+	xen_unplug_emulated_devices();
+	x86_init.irqs.intr_init = xen_init_IRQ;
+	xen_hvm_init_time_ops();
+	xen_hvm_init_mmu_ops();
+
+#ifdef CONFIG_KEXEC_CORE
+	machine_ops.shutdown = xen_hvm_shutdown;
+	machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
+#endif
+}
+
+static __init int xen_parse_nopv(char *arg)
+{
+	pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n");
+
+	if (xen_cpuid_base())
+		nopv = true;
+	return 0;
+}
+early_param("xen_nopv", xen_parse_nopv);
+
+static __init int xen_parse_no_vector_callback(char *arg)
+{
+	xen_have_vector_callback = false;
+	return 0;
+}
+early_param("xen_no_vector_callback", xen_parse_no_vector_callback);
+
+static __init bool xen_x2apic_available(void)
+{
+	return x2apic_supported();
+}
+
+static bool __init msi_ext_dest_id(void)
+{
+       return cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_EXT_DEST_ID;
+}
+
+static __init void xen_hvm_guest_late_init(void)
+{
+#ifdef CONFIG_XEN_PVH
+	/* Test for PVH domain (PVH boot path taken overrides ACPI flags). */
+	if (!xen_pvh &&
+	    (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga))
+		return;
+
+	/* PVH detected. */
+	xen_pvh = true;
+
+	if (nopv)
+		panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest.");
+
+	/* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
+	if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC)
+		acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
+
+	machine_ops.emergency_restart = xen_emergency_restart;
+	pv_info.name = "Xen PVH";
+#endif
+}
+
+static uint32_t __init xen_platform_hvm(void)
+{
+	uint32_t xen_domain = xen_cpuid_base();
+	struct x86_hyper_init *h = &x86_hyper_xen_hvm.init;
+
+	if (xen_pv_domain())
+		return 0;
+
+	if (xen_pvh_domain() && nopv) {
+		/* Guest booting via the Xen-PVH boot entry goes here */
+		pr_info("\"nopv\" parameter is ignored in PVH guest\n");
+		nopv = false;
+	} else if (nopv && xen_domain) {
+		/*
+		 * Guest booting via normal boot entry (like via grub2) goes
+		 * here.
+		 *
+		 * Use interface functions for bare hardware if nopv,
+		 * xen_hvm_guest_late_init is an exception as we need to
+		 * detect PVH and panic there.
+		 */
+		h->init_platform = x86_init_noop;
+		h->x2apic_available = bool_x86_init_noop;
+		h->init_mem_mapping = x86_init_noop;
+		h->init_after_bootmem = x86_init_noop;
+		h->guest_late_init = xen_hvm_guest_late_init;
+		x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop;
+	}
+	return xen_domain;
+}
+
+struct hypervisor_x86 x86_hyper_xen_hvm __initdata = {
+	.name                   = "Xen HVM",
+	.detect                 = xen_platform_hvm,
+	.type			= X86_HYPER_XEN_HVM,
+	.init.init_platform     = xen_hvm_guest_init,
+	.init.x2apic_available  = xen_x2apic_available,
+	.init.init_mem_mapping	= xen_hvm_init_mem_mapping,
+	.init.guest_late_init	= xen_hvm_guest_late_init,
+	.init.msi_ext_dest_id   = msi_ext_dest_id,
+	.runtime.pin_vcpu       = xen_pin_vcpu,
+	.ignore_nopv            = true,
+};