2 files changed, 57 insertions, 0 deletions

diff --git a/arch/x86/kernel/Makefile_64 b/arch/x86/kernel/Makefile_64
index 7fcf972aa5d6..b8f9d13eb5e3 100644
--- a/arch/x86/kernel/Makefile_64
+++ b/arch/x86/kernel/Makefile_64
@@ -41,6 +41,7 @@ obj-$(CONFIG_X86_VSMP)		+= vsmp_64.o
 obj-$(CONFIG_K8_NB)             += k8.o
 obj-$(CONFIG_AUDIT)             += audit_64.o
 obj-$(CONFIG_EFI)               += efi.o efi_64.o efi_stub_64.o
+obj-$(CONFIG_PARAVIRT)          += paravirt.o paravirt_patch_64.o
 
 obj-$(CONFIG_MODULES)           += module_64.o
 obj-$(CONFIG_PCI)               += early-quirks.o
diff --git a/arch/x86/kernel/paravirt_patch_64.c b/arch/x86/kernel/paravirt_patch_64.c
new file mode 100644
index 000000000000..cbfc4f3069e3
--- /dev/null
+++ b/arch/x86/kernel/paravirt_patch_64.c
@@ -0,0 +1,56 @@
+#include <asm/paravirt.h>
+#include <asm/asm-offsets.h>
+
+DEF_NATIVE(pv_irq_ops, irq_disable, "cli");
+DEF_NATIVE(pv_irq_ops, irq_enable, "sti");
+DEF_NATIVE(pv_irq_ops, restore_fl, "pushq %rdi; popfq");
+DEF_NATIVE(pv_irq_ops, save_fl, "pushfq; popq %rax");
+DEF_NATIVE(pv_cpu_ops, iret, "iretq");
+DEF_NATIVE(pv_mmu_ops, read_cr2, "movq %cr2, %rax");
+DEF_NATIVE(pv_mmu_ops, read_cr3, "movq %cr3, %rax");
+DEF_NATIVE(pv_mmu_ops, write_cr3, "movq %rdi, %cr3");
+DEF_NATIVE(pv_mmu_ops, flush_tlb_single, "invlpg (%rdi)");
+DEF_NATIVE(pv_cpu_ops, clts, "clts");
+DEF_NATIVE(pv_cpu_ops, wbinvd, "wbinvd");
+
+/* the three commands give us more control to how to return from a syscall */
+DEF_NATIVE(pv_cpu_ops, irq_enable_syscall_ret, "movq %gs:" __stringify(pda_oldrsp) ", %rsp; swapgs; sysretq;");
+DEF_NATIVE(pv_cpu_ops, swapgs, "swapgs");
+
+unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
+                      unsigned long addr, unsigned len)
+{
+        const unsigned char *start, *end;
+        unsigned ret;
+
+#define PATCH_SITE(ops, x)                                      \
+                case PARAVIRT_PATCH(ops.x):                     \
+                        start = start_##ops##_##x;              \
+                        end = end_##ops##_##x;                  \
+                        goto patch_site
+        switch(type) {
+                PATCH_SITE(pv_irq_ops, restore_fl);
+                PATCH_SITE(pv_irq_ops, save_fl);
+                PATCH_SITE(pv_irq_ops, irq_enable);
+                PATCH_SITE(pv_irq_ops, irq_disable);
+                PATCH_SITE(pv_cpu_ops, iret);
+                PATCH_SITE(pv_cpu_ops, irq_enable_syscall_ret);
+                PATCH_SITE(pv_cpu_ops, swapgs);
+                PATCH_SITE(pv_mmu_ops, read_cr2);
+                PATCH_SITE(pv_mmu_ops, read_cr3);
+                PATCH_SITE(pv_mmu_ops, write_cr3);
+                PATCH_SITE(pv_cpu_ops, clts);
+                PATCH_SITE(pv_mmu_ops, flush_tlb_single);
+                PATCH_SITE(pv_cpu_ops, wbinvd);
+
+        patch_site:
+                ret = paravirt_patch_insns(ibuf, len, start, end);
+                break;
+
+        default:
+                ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
+                break;
+        }
+#undef PATCH_SITE
+        return ret;
+}