Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 483 insertions, 0 deletions

diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
new file mode 100644
index 000000000..8dc69d825
--- /dev/null
+++ b/arch/x86/kernel/paravirt.c
@@ -0,0 +1,483 @@
+/*  Paravirtualization interfaces
+    Copyright (C) 2006 Rusty Russell IBM Corporation
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+    2007 - x86_64 support added by Glauber de Oliveira Costa, Red Hat Inc
+*/
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/efi.h>
+#include <linux/bcd.h>
+#include <linux/highmem.h>
+#include <linux/kprobes.h>
+
+#include <asm/bug.h>
+#include <asm/paravirt.h>
+#include <asm/debugreg.h>
+#include <asm/desc.h>
+#include <asm/setup.h>
+#include <asm/pgtable.h>
+#include <asm/time.h>
+#include <asm/pgalloc.h>
+#include <asm/irq.h>
+#include <asm/delay.h>
+#include <asm/fixmap.h>
+#include <asm/apic.h>
+#include <asm/tlbflush.h>
+#include <asm/timer.h>
+#include <asm/special_insns.h>
+#include <asm/tlb.h>
+
+/*
+ * nop stub, which must not clobber anything *including the stack* to
+ * avoid confusing the entry prologues.
+ */
+extern void _paravirt_nop(void);
+asm (".pushsection .entry.text, \"ax\"\n"
+     ".global _paravirt_nop\n"
+     "_paravirt_nop:\n\t"
+     "ret\n\t"
+     ".size _paravirt_nop, . - _paravirt_nop\n\t"
+     ".type _paravirt_nop, @function\n\t"
+     ".popsection");
+
+/* identity function, which can be inlined */
+u32 notrace _paravirt_ident_32(u32 x)
+{
+	return x;
+}
+
+u64 notrace _paravirt_ident_64(u64 x)
+{
+	return x;
+}
+
+void __init default_banner(void)
+{
+	printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
+	       pv_info.name);
+}
+
+/* Undefined instruction for dealing with missing ops pointers. */
+static const unsigned char ud2a[] = { 0x0f, 0x0b };
+
+struct branch {
+	unsigned char opcode;
+	u32 delta;
+} __attribute__((packed));
+
+unsigned paravirt_patch_call(void *insnbuf,
+			     const void *target, u16 tgt_clobbers,
+			     unsigned long addr, u16 site_clobbers,
+			     unsigned len)
+{
+	struct branch *b = insnbuf;
+	unsigned long delta = (unsigned long)target - (addr+5);
+
+	if (len < 5) {
+#ifdef CONFIG_RETPOLINE
+		WARN_ONCE(1, "Failing to patch indirect CALL in %ps\n", (void *)addr);
+#endif
+		return len;	/* call too long for patch site */
+	}
+
+	b->opcode = 0xe8; /* call */
+	b->delta = delta;
+	BUILD_BUG_ON(sizeof(*b) != 5);
+
+	return 5;
+}
+
+unsigned paravirt_patch_jmp(void *insnbuf, const void *target,
+			    unsigned long addr, unsigned len)
+{
+	struct branch *b = insnbuf;
+	unsigned long delta = (unsigned long)target - (addr+5);
+
+	if (len < 5) {
+#ifdef CONFIG_RETPOLINE
+		WARN_ONCE(1, "Failing to patch indirect JMP in %ps\n", (void *)addr);
+#endif
+		return len;	/* call too long for patch site */
+	}
+
+	b->opcode = 0xe9;	/* jmp */
+	b->delta = delta;
+
+	return 5;
+}
+
+DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key);
+
+void __init native_pv_lock_init(void)
+{
+	if (!static_cpu_has(X86_FEATURE_HYPERVISOR))
+		static_branch_disable(&virt_spin_lock_key);
+}
+
+/*
+ * Neat trick to map patch type back to the call within the
+ * corresponding structure.
+ */
+static void *get_call_destination(u8 type)
+{
+	struct paravirt_patch_template tmpl = {
+		.pv_init_ops = pv_init_ops,
+		.pv_time_ops = pv_time_ops,
+		.pv_cpu_ops = pv_cpu_ops,
+		.pv_irq_ops = pv_irq_ops,
+		.pv_mmu_ops = pv_mmu_ops,
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+		.pv_lock_ops = pv_lock_ops,
+#endif
+	};
+	return *((void **)&tmpl + type);
+}
+
+unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf,
+				unsigned long addr, unsigned len)
+{
+	void *opfunc = get_call_destination(type);
+	unsigned ret;
+
+	if (opfunc == NULL)
+		/* If there's no function, patch it with a ud2a (BUG) */
+		ret = paravirt_patch_insns(insnbuf, len, ud2a, ud2a+sizeof(ud2a));
+	else if (opfunc == _paravirt_nop)
+		ret = 0;
+
+	/* identity functions just return their single argument */
+	else if (opfunc == _paravirt_ident_32)
+		ret = paravirt_patch_ident_32(insnbuf, len);
+	else if (opfunc == _paravirt_ident_64)
+		ret = paravirt_patch_ident_64(insnbuf, len);
+
+	else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) ||
+		 type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64))
+		/* If operation requires a jmp, then jmp */
+		ret = paravirt_patch_jmp(insnbuf, opfunc, addr, len);
+	else
+		/* Otherwise call the function; assume target could
+		   clobber any caller-save reg */
+		ret = paravirt_patch_call(insnbuf, opfunc, CLBR_ANY,
+					  addr, clobbers, len);
+
+	return ret;
+}
+
+unsigned paravirt_patch_insns(void *insnbuf, unsigned len,
+			      const char *start, const char *end)
+{
+	unsigned insn_len = end - start;
+
+	if (insn_len > len || start == NULL)
+		insn_len = len;
+	else
+		memcpy(insnbuf, start, insn_len);
+
+	return insn_len;
+}
+
+static void native_flush_tlb(void)
+{
+	__native_flush_tlb();
+}
+
+/*
+ * Global pages have to be flushed a bit differently. Not a real
+ * performance problem because this does not happen often.
+ */
+static void native_flush_tlb_global(void)
+{
+	__native_flush_tlb_global();
+}
+
+static void native_flush_tlb_one_user(unsigned long addr)
+{
+	__native_flush_tlb_one_user(addr);
+}
+
+struct static_key paravirt_steal_enabled;
+struct static_key paravirt_steal_rq_enabled;
+
+static u64 native_steal_clock(int cpu)
+{
+	return 0;
+}
+
+/* These are in entry.S */
+extern void native_iret(void);
+extern void native_usergs_sysret64(void);
+
+static struct resource reserve_ioports = {
+	.start = 0,
+	.end = IO_SPACE_LIMIT,
+	.name = "paravirt-ioport",
+	.flags = IORESOURCE_IO | IORESOURCE_BUSY,
+};
+
+/*
+ * Reserve the whole legacy IO space to prevent any legacy drivers
+ * from wasting time probing for their hardware.  This is a fairly
+ * brute-force approach to disabling all non-virtual drivers.
+ *
+ * Note that this must be called very early to have any effect.
+ */
+int paravirt_disable_iospace(void)
+{
+	return request_resource(&ioport_resource, &reserve_ioports);
+}
+
+static DEFINE_PER_CPU(enum paravirt_lazy_mode, paravirt_lazy_mode) = PARAVIRT_LAZY_NONE;
+
+static inline void enter_lazy(enum paravirt_lazy_mode mode)
+{
+	BUG_ON(this_cpu_read(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE);
+
+	this_cpu_write(paravirt_lazy_mode, mode);
+}
+
+static void leave_lazy(enum paravirt_lazy_mode mode)
+{
+	BUG_ON(this_cpu_read(paravirt_lazy_mode) != mode);
+
+	this_cpu_write(paravirt_lazy_mode, PARAVIRT_LAZY_NONE);
+}
+
+void paravirt_enter_lazy_mmu(void)
+{
+	enter_lazy(PARAVIRT_LAZY_MMU);
+}
+
+void paravirt_leave_lazy_mmu(void)
+{
+	leave_lazy(PARAVIRT_LAZY_MMU);
+}
+
+void paravirt_flush_lazy_mmu(void)
+{
+	preempt_disable();
+
+	if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
+		arch_leave_lazy_mmu_mode();
+		arch_enter_lazy_mmu_mode();
+	}
+
+	preempt_enable();
+}
+
+void paravirt_start_context_switch(struct task_struct *prev)
+{
+	BUG_ON(preemptible());
+
+	if (this_cpu_read(paravirt_lazy_mode) == PARAVIRT_LAZY_MMU) {
+		arch_leave_lazy_mmu_mode();
+		set_ti_thread_flag(task_thread_info(prev), TIF_LAZY_MMU_UPDATES);
+	}
+	enter_lazy(PARAVIRT_LAZY_CPU);
+}
+
+void paravirt_end_context_switch(struct task_struct *next)
+{
+	BUG_ON(preemptible());
+
+	leave_lazy(PARAVIRT_LAZY_CPU);
+
+	if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES))
+		arch_enter_lazy_mmu_mode();
+}
+
+enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
+{
+	if (in_interrupt())
+		return PARAVIRT_LAZY_NONE;
+
+	return this_cpu_read(paravirt_lazy_mode);
+}
+
+struct pv_info pv_info = {
+	.name = "bare hardware",
+	.kernel_rpl = 0,
+	.shared_kernel_pmd = 1,	/* Only used when CONFIG_X86_PAE is set */
+
+#ifdef CONFIG_X86_64
+	.extra_user_64bit_cs = __USER_CS,
+#endif
+};
+
+struct pv_init_ops pv_init_ops = {
+	.patch = native_patch,
+};
+
+struct pv_time_ops pv_time_ops = {
+	.sched_clock = native_sched_clock,
+	.steal_clock = native_steal_clock,
+};
+
+__visible struct pv_irq_ops pv_irq_ops = {
+	.save_fl = __PV_IS_CALLEE_SAVE(native_save_fl),
+	.restore_fl = __PV_IS_CALLEE_SAVE(native_restore_fl),
+	.irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable),
+	.irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable),
+	.safe_halt = native_safe_halt,
+	.halt = native_halt,
+};
+
+__visible struct pv_cpu_ops pv_cpu_ops = {
+	.cpuid = native_cpuid,
+	.get_debugreg = native_get_debugreg,
+	.set_debugreg = native_set_debugreg,
+	.read_cr0 = native_read_cr0,
+	.write_cr0 = native_write_cr0,
+	.write_cr4 = native_write_cr4,
+#ifdef CONFIG_X86_64
+	.read_cr8 = native_read_cr8,
+	.write_cr8 = native_write_cr8,
+#endif
+	.wbinvd = native_wbinvd,
+	.read_msr = native_read_msr,
+	.write_msr = native_write_msr,
+	.read_msr_safe = native_read_msr_safe,
+	.write_msr_safe = native_write_msr_safe,
+	.read_pmc = native_read_pmc,
+	.load_tr_desc = native_load_tr_desc,
+	.set_ldt = native_set_ldt,
+	.load_gdt = native_load_gdt,
+	.load_idt = native_load_idt,
+	.store_tr = native_store_tr,
+	.load_tls = native_load_tls,
+#ifdef CONFIG_X86_64
+	.load_gs_index = native_load_gs_index,
+#endif
+	.write_ldt_entry = native_write_ldt_entry,
+	.write_gdt_entry = native_write_gdt_entry,
+	.write_idt_entry = native_write_idt_entry,
+
+	.alloc_ldt = paravirt_nop,
+	.free_ldt = paravirt_nop,
+
+	.load_sp0 = native_load_sp0,
+
+#ifdef CONFIG_X86_64
+	.usergs_sysret64 = native_usergs_sysret64,
+#endif
+	.iret = native_iret,
+	.swapgs = native_swapgs,
+
+	.set_iopl_mask = native_set_iopl_mask,
+	.io_delay = native_io_delay,
+
+	.start_context_switch = paravirt_nop,
+	.end_context_switch = paravirt_nop,
+};
+
+/* At this point, native_get/set_debugreg has real function entries */
+NOKPROBE_SYMBOL(native_get_debugreg);
+NOKPROBE_SYMBOL(native_set_debugreg);
+NOKPROBE_SYMBOL(native_load_idt);
+
+#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE)
+/* 32-bit pagetable entries */
+#define PTE_IDENT	__PV_IS_CALLEE_SAVE(_paravirt_ident_32)
+#else
+/* 64-bit pagetable entries */
+#define PTE_IDENT	__PV_IS_CALLEE_SAVE(_paravirt_ident_64)
+#endif
+
+struct pv_mmu_ops pv_mmu_ops __ro_after_init = {
+
+	.read_cr2 = native_read_cr2,
+	.write_cr2 = native_write_cr2,
+	.read_cr3 = __native_read_cr3,
+	.write_cr3 = native_write_cr3,
+
+	.flush_tlb_user = native_flush_tlb,
+	.flush_tlb_kernel = native_flush_tlb_global,
+	.flush_tlb_one_user = native_flush_tlb_one_user,
+	.flush_tlb_others = native_flush_tlb_others,
+	.tlb_remove_table = (void (*)(struct mmu_gather *, void *))tlb_remove_page,
+
+	.pgd_alloc = __paravirt_pgd_alloc,
+	.pgd_free = paravirt_nop,
+
+	.alloc_pte = paravirt_nop,
+	.alloc_pmd = paravirt_nop,
+	.alloc_pud = paravirt_nop,
+	.alloc_p4d = paravirt_nop,
+	.release_pte = paravirt_nop,
+	.release_pmd = paravirt_nop,
+	.release_pud = paravirt_nop,
+	.release_p4d = paravirt_nop,
+
+	.set_pte = native_set_pte,
+	.set_pte_at = native_set_pte_at,
+	.set_pmd = native_set_pmd,
+
+	.ptep_modify_prot_start = __ptep_modify_prot_start,
+	.ptep_modify_prot_commit = __ptep_modify_prot_commit,
+
+#if CONFIG_PGTABLE_LEVELS >= 3
+#ifdef CONFIG_X86_PAE
+	.set_pte_atomic = native_set_pte_atomic,
+	.pte_clear = native_pte_clear,
+	.pmd_clear = native_pmd_clear,
+#endif
+	.set_pud = native_set_pud,
+
+	.pmd_val = PTE_IDENT,
+	.make_pmd = PTE_IDENT,
+
+#if CONFIG_PGTABLE_LEVELS >= 4
+	.pud_val = PTE_IDENT,
+	.make_pud = PTE_IDENT,
+
+	.set_p4d = native_set_p4d,
+
+#if CONFIG_PGTABLE_LEVELS >= 5
+	.p4d_val = PTE_IDENT,
+	.make_p4d = PTE_IDENT,
+
+	.set_pgd = native_set_pgd,
+#endif /* CONFIG_PGTABLE_LEVELS >= 5 */
+#endif /* CONFIG_PGTABLE_LEVELS >= 4 */
+#endif /* CONFIG_PGTABLE_LEVELS >= 3 */
+
+	.pte_val = PTE_IDENT,
+	.pgd_val = PTE_IDENT,
+
+	.make_pte = PTE_IDENT,
+	.make_pgd = PTE_IDENT,
+
+	.dup_mmap = paravirt_nop,
+	.exit_mmap = paravirt_nop,
+	.activate_mm = paravirt_nop,
+
+	.lazy_mode = {
+		.enter = paravirt_nop,
+		.leave = paravirt_nop,
+		.flush = paravirt_nop,
+	},
+
+	.set_fixmap = native_set_fixmap,
+};
+
+EXPORT_SYMBOL_GPL(pv_time_ops);
+EXPORT_SYMBOL    (pv_cpu_ops);
+EXPORT_SYMBOL    (pv_mmu_ops);
+EXPORT_SYMBOL_GPL(pv_info);
+EXPORT_SYMBOL    (pv_irq_ops);