1 files changed, 106 insertions, 0 deletions
diff --git a/arch/x86/kernel/paravirt_patch.c b/arch/x86/kernel/paravirt_patch.c
new file mode 100644
index 000000000000..a47899db9932
--- /dev/null
+++ b/arch/x86/kernel/paravirt_patch.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/stringify.h>
+
+#include <asm/paravirt.h>
+#include <asm/asm-offsets.h>
+
+#ifdef CONFIG_X86_64
+# ifdef CONFIG_PARAVIRT_XXL
+DEF_NATIVE(irq, irq_disable, "cli");
+DEF_NATIVE(irq, irq_enable, "sti");
+DEF_NATIVE(irq, restore_fl, "pushq %rdi; popfq");
+DEF_NATIVE(irq, save_fl, "pushfq; popq %rax");
+DEF_NATIVE(mmu, read_cr2, "movq %cr2, %rax");
+DEF_NATIVE(mmu, read_cr3, "movq %cr3, %rax");
+DEF_NATIVE(mmu, write_cr3, "movq %rdi, %cr3");
+DEF_NATIVE(cpu, wbinvd, "wbinvd");
+DEF_NATIVE(cpu, usergs_sysret64, "swapgs; sysretq");
+DEF_NATIVE(cpu, swapgs, "swapgs");
+DEF_NATIVE(, mov64, "mov %rdi, %rax");
+
+unsigned int paravirt_patch_ident_64(void *insnbuf, unsigned int len)
+{
+	return paravirt_patch_insns(insnbuf, len, start__mov64, end__mov64);
+}
+# endif /* CONFIG_PARAVIRT_XXL */
+
+# ifdef CONFIG_PARAVIRT_SPINLOCKS
+DEF_NATIVE(lock, queued_spin_unlock, "movb $0, (%rdi)");
+DEF_NATIVE(lock, vcpu_is_preempted, "xor %eax, %eax");
+# endif
+
+#else /* CONFIG_X86_64 */
+
+# ifdef CONFIG_PARAVIRT_XXL
+DEF_NATIVE(irq, irq_disable, "cli");
+DEF_NATIVE(irq, irq_enable, "sti");
+DEF_NATIVE(irq, restore_fl, "push %eax; popf");
+DEF_NATIVE(irq, save_fl, "pushf; pop %eax");
+DEF_NATIVE(cpu, iret, "iret");
+DEF_NATIVE(mmu, read_cr2, "mov %cr2, %eax");
+DEF_NATIVE(mmu, write_cr3, "mov %eax, %cr3");
+DEF_NATIVE(mmu, read_cr3, "mov %cr3, %eax");
+
+unsigned int paravirt_patch_ident_64(void *insnbuf, unsigned int len)
+{
+	/* arg in %edx:%eax, return in %edx:%eax */
+	return 0;
+}
+# endif /* CONFIG_PARAVIRT_XXL */
+
+# ifdef CONFIG_PARAVIRT_SPINLOCKS
+DEF_NATIVE(lock, queued_spin_unlock, "movb $0, (%eax)");
+DEF_NATIVE(lock, vcpu_is_preempted, "xor %eax, %eax");
+# endif
+
+#endif /* !CONFIG_X86_64 */
+
+unsigned int native_patch(u8 type, void *ibuf, unsigned long addr,
+			  unsigned int len)
+{
+#define PATCH_SITE(ops, x)					\
+	case PARAVIRT_PATCH(ops.x):				\
+		return paravirt_patch_insns(ibuf, len, start_##ops##_##x, end_##ops##_##x)
+
+	switch (type) {
+#ifdef CONFIG_PARAVIRT_XXL
+		PATCH_SITE(irq, restore_fl);
+		PATCH_SITE(irq, save_fl);
+		PATCH_SITE(irq, irq_enable);
+		PATCH_SITE(irq, irq_disable);
+
+		PATCH_SITE(mmu, read_cr2);
+		PATCH_SITE(mmu, read_cr3);
+		PATCH_SITE(mmu, write_cr3);
+
+# ifdef CONFIG_X86_64
+		PATCH_SITE(cpu, usergs_sysret64);
+		PATCH_SITE(cpu, swapgs);
+		PATCH_SITE(cpu, wbinvd);
+# else
+		PATCH_SITE(cpu, iret);
+# endif
+#endif
+
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+	case PARAVIRT_PATCH(lock.queued_spin_unlock):
+		if (pv_is_native_spin_unlock())
+			return paravirt_patch_insns(ibuf, len,
+						    start_lock_queued_spin_unlock,
+						    end_lock_queued_spin_unlock);
+		break;
+
+	case PARAVIRT_PATCH(lock.vcpu_is_preempted):
+		if (pv_is_native_vcpu_is_preempted())
+			return paravirt_patch_insns(ibuf, len,
+						    start_lock_vcpu_is_preempted,
+						    end_lock_vcpu_is_preempted);
+		break;
+#endif
+
+	default:
+		break;
+	}
+#undef PATCH_SITE
+	return paravirt_patch_default(type, ibuf, addr, len);
+}