[PATCH] paravirt: Patch inline replacements for paravirt intercepts

It turns out that the most called ops, by several orders of magnitude,
are the interrupt manipulation ops.  These are obvious candidates for
patching, so mark them up and create infrastructure for it.

The method used is that the ops structure has a patch function, which
is called for each place which needs to be patched: this returns a
number of instructions (the rest are NOP-padded).

Usually we can spare a register (%eax) for the binary patched code to
use, but in a couple of critical places in entry.S we can't: we make
the clobbers explicit at the call site, and manually clobber the
allowed registers in debug mode as an extra check.

And:

Don't abuse CONFIG_DEBUG_KERNEL, add CONFIG_DEBUG_PARAVIRT.

And:

AK:  Fix warnings in x86-64 alternative.c build

And:

AK: Fix compilation with defconfig

And:

^From: Andrew Morton <akpm@osdl.org>

Some binutlises still like to emit references to __stop_parainstructions and
__start_parainstructions.

And:

AK: Fix warnings about unused variables when PARAVIRT is disabled.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>

1 files changed, 99 insertions, 99 deletions

diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h
index 6c2c4457be0a..5f0418d0078c 100644
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -156,59 +156,6 @@ static inline fastcall void native_cpuid(unsigned int *eax, unsigned int *ebx,
                 : "0" (*eax), "2" (*ecx));
 }
 
-/*
- * Generic CPUID function
- * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
- * resulting in stale register contents being returned.
- */
-static inline void cpuid(unsigned int op, unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx)
-{
-        *eax = op;
-        *ecx = 0;
-        __cpuid(eax, ebx, ecx, edx);
-}
-
-/* Some CPUID calls want 'count' to be placed in ecx */
-static inline void cpuid_count(int op, int count, int *eax, int *ebx, int *ecx,
-                               int *edx)
-{
-        *eax = op;
-        *ecx = count;
-        __cpuid(eax, ebx, ecx, edx);
-}
-
-/*
- * CPUID functions returning a single datum
- */
-static inline unsigned int cpuid_eax(unsigned int op)
-{
-        unsigned int eax, ebx, ecx, edx;
-
-        cpuid(op, &eax, &ebx, &ecx, &edx);
-        return eax;
-}
-static inline unsigned int cpuid_ebx(unsigned int op)
-{
-        unsigned int eax, ebx, ecx, edx;
-
-        cpuid(op, &eax, &ebx, &ecx, &edx);
-        return ebx;
-}
-static inline unsigned int cpuid_ecx(unsigned int op)
-{
-        unsigned int eax, ebx, ecx, edx;
-
-        cpuid(op, &eax, &ebx, &ecx, &edx);
-        return ecx;
-}
-static inline unsigned int cpuid_edx(unsigned int op)
-{
-        unsigned int eax, ebx, ecx, edx;
-
-        cpuid(op, &eax, &ebx, &ecx, &edx);
-        return edx;
-}
-
 #define load_cr3(pgdir) write_cr3(__pa(pgdir))
 
 /*
@@ -491,22 +438,6 @@ struct thread_struct {
         .io_bitmap      = { [ 0 ... IO_BITMAP_LONGS] = ~0 },            \
 }
 
-#ifdef CONFIG_PARAVIRT
-#include <asm/paravirt.h>
-#else
-#define paravirt_enabled() 0
-#define __cpuid native_cpuid
-
-static inline void load_esp0(struct tss_struct *tss, struct thread_struct *thread)
-{
-        tss->esp0 = thread->esp0;
-        /* This can only happen when SEP is enabled, no need to test "SEP"arately */
-        if (unlikely(tss->ss1 != thread->sysenter_cs)) {
-                tss->ss1 = thread->sysenter_cs;
-                wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
-        }
-}
-
 #define start_thread(regs, new_eip, new_esp) do {               \
         __asm__("movl %0,%%fs": :"r" (0));                      \
         regs->xgs = 0;                                          \
@@ -519,36 +450,6 @@ static inline void load_esp0(struct tss_struct *tss, struct thread_struct *threa
         regs->esp = new_esp;                                    \
 } while (0)
 
-/*
- * These special macros can be used to get or set a debugging register
- */
-#define get_debugreg(var, register)                             \
-                __asm__("movl %%db" #register ", %0"            \
-                        :"=r" (var))
-#define set_debugreg(value, register)                   \
-                __asm__("movl %0,%%db" #register                \
-                        : /* no output */                       \
-                        :"r" (value))
-
-#define set_iopl_mask native_set_iopl_mask
-#endif /* CONFIG_PARAVIRT */
-
-/*
- * Set IOPL bits in EFLAGS from given mask
- */
-static fastcall inline void native_set_iopl_mask(unsigned mask)
-{
-        unsigned int reg;
-        __asm__ __volatile__ ("pushfl;"
-                              "popl %0;"
-                              "andl %1, %0;"
-                              "orl %2, %0;"
-                              "pushl %0;"
-                              "popfl"
-                                : "=&r" (reg)
-                                : "i" (~X86_EFLAGS_IOPL), "r" (mask));
-}
-
 /* Forward declaration, a strange C thing */
 struct task_struct;
 struct mm_struct;
@@ -640,6 +541,105 @@ static inline void rep_nop(void)
 
 #define cpu_relax()     rep_nop()
 
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
+#define paravirt_enabled() 0
+#define __cpuid native_cpuid
+
+static inline void load_esp0(struct tss_struct *tss, struct thread_struct *thread)
+{
+        tss->esp0 = thread->esp0;
+        /* This can only happen when SEP is enabled, no need to test "SEP"arately */
+        if (unlikely(tss->ss1 != thread->sysenter_cs)) {
+                tss->ss1 = thread->sysenter_cs;
+                wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
+        }
+}
+
+/*
+ * These special macros can be used to get or set a debugging register
+ */
+#define get_debugreg(var, register)                             \
+                __asm__("movl %%db" #register ", %0"            \
+                        :"=r" (var))
+#define set_debugreg(value, register)                   \
+                __asm__("movl %0,%%db" #register                \
+                        : /* no output */                       \
+                        :"r" (value))
+
+#define set_iopl_mask native_set_iopl_mask
+#endif /* CONFIG_PARAVIRT */
+
+/*
+ * Set IOPL bits in EFLAGS from given mask
+ */
+static fastcall inline void native_set_iopl_mask(unsigned mask)
+{
+        unsigned int reg;
+        __asm__ __volatile__ ("pushfl;"
+                              "popl %0;"
+                              "andl %1, %0;"
+                              "orl %2, %0;"
+                              "pushl %0;"
+                              "popfl"
+                                : "=&r" (reg)
+                                : "i" (~X86_EFLAGS_IOPL), "r" (mask));
+}
+
+/*
+ * Generic CPUID function
+ * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
+ * resulting in stale register contents being returned.
+ */
+static inline void cpuid(unsigned int op, unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx)
+{
+        *eax = op;
+        *ecx = 0;
+        __cpuid(eax, ebx, ecx, edx);
+}
+
+/* Some CPUID calls want 'count' to be placed in ecx */
+static inline void cpuid_count(int op, int count, int *eax, int *ebx, int *ecx,
+                               int *edx)
+{
+        *eax = op;
+        *ecx = count;
+        __cpuid(eax, ebx, ecx, edx);
+}
+
+/*
+ * CPUID functions returning a single datum
+ */
+static inline unsigned int cpuid_eax(unsigned int op)
+{
+        unsigned int eax, ebx, ecx, edx;
+
+        cpuid(op, &eax, &ebx, &ecx, &edx);
+        return eax;
+}
+static inline unsigned int cpuid_ebx(unsigned int op)
+{
+        unsigned int eax, ebx, ecx, edx;
+
+        cpuid(op, &eax, &ebx, &ecx, &edx);
+        return ebx;
+}
+static inline unsigned int cpuid_ecx(unsigned int op)
+{
+        unsigned int eax, ebx, ecx, edx;
+
+        cpuid(op, &eax, &ebx, &ecx, &edx);
+        return ecx;
+}
+static inline unsigned int cpuid_edx(unsigned int op)
+{
+        unsigned int eax, ebx, ecx, edx;
+
+        cpuid(op, &eax, &ebx, &ecx, &edx);
+        return edx;
+}
+
 /* generic versions from gas */
 #define GENERIC_NOP1    ".byte 0x90\n"
 #define GENERIC_NOP2            ".byte 0x89,0xf6\n"