[PATCH] paravirt.h

Rusty Russell
2006-08-10T09:35:16Z

This version over last version:
(1) Gets rid of the no_paravirt.h header and leaves native ops in place
(with some reshuffling to keep then under one #ifdef).
(2) Fixes the "X crashes with CONFIG_PARAVIRT=y" bug.
(3) Puts __ex_table entry in paravirt iret.

Another followup patch implements binary patching...
Rusty.
===
Create a paravirt.h header for all the critical operations which need
to be replaced with hypervisor calls, and include that instead of
defining native operations, when CONFIG_PARAVIRT.

This patch does the dumbest possible replacement of paravirtualized
instructions: calls through a "paravirt_ops" structure. Currently
these are function implementations of native hardware: hypervisors
will override the ops structure with their own variants.

All the pv-ops functions are declared "fastcall" so that a specific
register-based ABI is used, to make inlining assember easier.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

===================================================================
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -179,6 +179,17 @@ config X86_ES7000
should say N here.

endchoice
+
+config PARAVIRT
+ bool "Paravirtualization support (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ help
+ Paravirtualization is a way of running multiple instances of
+ Linux on the same machine, under a hypervisor. This option
+ changes the kernel so it can modify itself when it is run
+ under a hypervisor, improving performance significantly.
+ However, when run without a hypervisor the kernel is
+ theoretically slower. If in doubt, say N.

config ACPI_SRAT
bool
===================================================================
--- a/arch/i386/kernel/Makefile
+++ b/arch/i386/kernel/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_HPET_TIMER) += hpet.o
obj-$(CONFIG_HPET_TIMER) += hpet.o
obj-$(CONFIG_K8_NB) += k8.o
obj-$(CONFIG_AUDIT) += audit.o
+obj-$(CONFIG_PARAVIRT) += paravirt.o

EXTRA_AFLAGS := -traditional

===================================================================
--- a/arch/i386/kernel/asm-offsets.c
+++ b/arch/i386/kernel/asm-offsets.c
@@ -74,4 +74,11 @@ void foo(void)
DEFINE(VDSO_PRELINK, VDSO_PRELINK);

OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx);
+#ifdef CONFIG_PARAVIRT
+ OFFSET(PARAVIRT_irq_disable, paravirt_ops, irq_disable);
+ OFFSET(PARAVIRT_irq_enable, paravirt_ops, irq_enable);
+ OFFSET(PARAVIRT_irq_enable_sysexit, paravirt_ops, irq_enable_sysexit);
+ OFFSET(PARAVIRT_iret, paravirt_ops, iret);
+ OFFSET(PARAVIRT_read_cr0, paravirt_ops, read_cr0);
+#endif
}
===================================================================
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -76,13 +76,6 @@ NT_MASK = 0x00004000
NT_MASK = 0x00004000
VM_MASK = 0x00020000

-/* These are replaces for paravirtualization */
-#define DISABLE_INTERRUPTS cli
-#define ENABLE_INTERRUPTS sti
-#define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit
-#define INTERRUPT_RETURN iret
-#define GET_CR0_INTO_EAX movl %cr0, %eax
-
#ifdef CONFIG_PREEMPT
#define preempt_stop DISABLE_INTERRUPTS; TRACE_IRQS_OFF
#else
@@ -809,6 +802,19 @@ 1: INTERRUPT_RETURN
.long 1b,iret_exc
.previous

+#ifdef CONFIG_PARAVIRT
+ENTRY(nopara_iret)
+1: iret
+.section __ex_table,"a"
+ .align 4
+ .long 1b,iret_exc
+.previous
+
+ENTRY(nopara_irq_enable_sysexit)
+ sti
+ sysexit
+#endif
+
KPROBE_ENTRY(int3)
RING0_INT_FRAME
pushl $-1 # mark this as an int
===================================================================
--- a/include/asm-i386/desc.h
+++ b/include/asm-i386/desc.h
@@ -64,6 +64,9 @@ static inline void pack_gate(__u32 *a, _
#define DESCTYPE_DPL3 0x60 /* DPL-3 */
#define DESCTYPE_S 0x10 /* !system */

+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
#define load_TR_desc() __asm__ __volatile__("ltr %w0"::"q" (GDT_ENTRY_TSS*8))
#define load_LDT_desc() __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8))

@@ -98,6 +101,7 @@ static inline void write_dt_entry(void *
#define write_ldt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b)
#define write_gdt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b)
#define write_idt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b)
+#endif /* CONFIG_PARAVIRT */

static inline void _set_gate(int gate, unsigned int type, void *addr, unsigned short seg)
{
===================================================================
--- a/include/asm-i386/irqflags.h
+++ b/include/asm-i386/irqflags.h
@@ -10,6 +10,9 @@
#ifndef _ASM_IRQFLAGS_H
#define _ASM_IRQFLAGS_H

+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
#ifndef __ASSEMBLY__

static inline unsigned long __raw_local_save_flags(void)
@@ -24,9 +27,6 @@ static inline unsigned long __raw_local_

return flags;
}
-
-#define raw_local_save_flags(flags) \
- do { (flags) = __raw_local_save_flags(); } while (0)

static inline void raw_local_irq_restore(unsigned long flags)
{
@@ -66,18 +66,6 @@ static inline void halt(void)
__asm__ __volatile__("hlt": : :"memory");
}

-static inline int raw_irqs_disabled_flags(unsigned long flags)
-{
- return !(flags & (1 << 9));
-}
-
-static inline int raw_irqs_disabled(void)
-{
- unsigned long flags = __raw_local_save_flags();
-
- return raw_irqs_disabled_flags(flags);
-}
-
/*
* For spinlocks, etc:
*/
@@ -90,9 +78,33 @@ static inline unsigned long __raw_local_
return flags;
}

+#else
+#define DISABLE_INTERRUPTS cli
+#define ENABLE_INTERRUPTS sti
+#define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit
+#define INTERRUPT_RETURN iret
+#define GET_CR0_INTO_EAX movl %cr0, %eax
+#endif /* __ASSEMBLY__ */
+#endif /* CONFIG_PARAVIRT */
+
+#ifndef __ASSEMBLY__
+#define raw_local_save_flags(flags) \
+ do { (flags) = __raw_local_save_flags(); } while (0)
+
#define raw_local_irq_save(flags) \
do { (flags) = __raw_local_irq_save(); } while (0)

+static inline int raw_irqs_disabled_flags(unsigned long flags)
+{
+ return !(flags & (1 << 9));
+}
+
+static inline int raw_irqs_disabled(void)
+{
+ unsigned long flags = __raw_local_save_flags();
+
+ return raw_irqs_disabled_flags(flags);
+}
#endif /* __ASSEMBLY__ */

/*
===================================================================
--- a/include/asm-i386/msr.h
+++ b/include/asm-i386/msr.h
@@ -1,5 +1,9 @@
#ifndef __ASM_MSR_H
#define __ASM_MSR_H
+
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else

/*
* Access to machine-specific registers (available on 586 and better only)
@@ -77,6 +81,7 @@ static inline void wrmsrl (unsigned long
__asm__ __volatile__("rdpmc" \
: "=a" (low), "=d" (high) \
: "c" (counter))
+#endif /* !CONFIG_PARAVIRT */

/* symbolic names for some interesting MSRs */
/* Intel defined MSRs. */
===================================================================
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -143,6 +143,9 @@ static inline void detect_ht(struct cpui
#define X86_EFLAGS_VIP 0x00100000 /* Virtual Interrupt Pending */
#define X86_EFLAGS_ID 0x00200000 /* CPUID detection flag */

+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
unsigned int *ecx, unsigned int *edx)
{
@@ -154,6 +157,34 @@ static inline void __cpuid(unsigned int
"=d" (*edx)
: "0" (*eax), "2" (*ecx));
}
+
+/*
+ * 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))
+
+/*
+ * Set IOPL bits in EFLAGS from given mask
+ */
+static inline void 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));
+}
+#endif /* CONFIG_PARAVIRT */

/*
* Generic CPUID function
@@ -508,33 +539,6 @@ static inline void load_esp0(struct tss_
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))
-
-/*
- * Set IOPL bits in EFLAGS from given mask
- */
-static inline void 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;
===================================================================
--- a/include/asm-i386/segment.h
+++ b/include/asm-i386/segment.h
@@ -128,5 +128,7 @@
#define SEGMENT_LDT 0x4
#define SEGMENT_GDT 0x0

+#ifndef CONFIG_PARAVIRT
#define get_kernel_rpl() 0
#endif
+#endif
===================================================================
--- a/include/asm-i386/spinlock.h
+++ b/include/asm-i386/spinlock.h
@@ -17,8 +17,12 @@
* (the type definitions are in asm/spinlock_types.h)
*/

+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
#define CLI_STRING "cli"
#define STI_STRING "sti"
+#endif /* CONFIG_PARAVIRT */

#define __raw_spin_is_locked(x) \
(*(volatile signed char *)(&(x)->slock) <= 0)
===================================================================
--- a/include/asm-i386/system.h
+++ b/include/asm-i386/system.h
@@ -82,6 +82,9 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t"
#define savesegment(seg, value) \
asm volatile("mov %%" #seg ",%0":"=rm" (value))

+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
#define read_cr0() ({ \
unsigned int __dummy; \
__asm__ __volatile__( \
@@ -133,16 +136,17 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t"
#define write_cr4(x) \
__asm__ __volatile__("movl %0,%%cr4": :"r" (x))

-/*
- * Clear and set 'TS' bit respectively
- */
-#define clts() __asm__ __volatile__ ("clts")
-#define stts() write_cr0(8 | read_cr0())
-
-#endif /* __KERNEL__ */
-
#define wbinvd() \
__asm__ __volatile__ ("wbinvd": : :"memory")
+
+/* Clear the 'TS' bit */
+#define clts() __asm__ __volatile__ ("clts")
+#endif/* CONFIG_PARAVIRT */
+
+/* Set the 'TS' bit */
+#define stts() write_cr0(8 | read_cr0())
+
+#endif /* __KERNEL__ */

static inline unsigned long get_limit(unsigned long segment)
{
===================================================================
--- /dev/null
+++ b/arch/i386/kernel/paravirt.c
@@ -0,0 +1,375 @@
+/* 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
+*/
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <asm/bug.h>
+#include <asm/paravirt.h>
+#include <asm/desc.h>
+
+static fastcall void nopara_cpuid(unsigned int *eax, unsigned int *ebx,
+ unsigned int *ecx, unsigned int *edx)
+{
+ /* must be "asm volatile" so that it won't be optimised out in
+ nopara_sync_core */
+ asm volatile ("cpuid"
+ : "=a" (*eax),
+ "=b" (*ebx),
+ "=c" (*ecx),
+ "=d" (*edx)
+ : "0" (*eax), "2" (*ecx));
+}
+
+static fastcall unsigned int nopara_get_debugreg(int regno)
+{
+ unsigned int val = 0; /* Damn you, gcc! */
+
+ switch (regno) {
+ case 0:
+ __asm__("movl %%db0, %0" :"=r" (val)); break;
+ case 1:
+ __asm__("movl %%db1, %0" :"=r" (val)); break;
+ case 2:
+ __asm__("movl %%db2, %0" :"=r" (val)); break;
+ case 3:
+ __asm__("movl %%db3, %0" :"=r" (val)); break;
+ case 6:
+ __asm__("movl %%db6, %0" :"=r" (val)); break;
+ case 7:
+ __asm__("movl %%db7, %0" :"=r" (val)); break;
+ default:
+ BUG();
+ }
+ return val;
+}
+
+static fastcall void nopara_set_debugreg(int regno, unsigned int value)
+{
+ switch (regno) {
+ case 0:
+ __asm__("movl %0,%%db0" : /* no output */ :"r" (value));
+ break;
+ case 1:
+ __asm__("movl %0,%%db1" : /* no output */ :"r" (value));
+ break;
+ case 2:
+ __asm__("movl %0,%%db2" : /* no output */ :"r" (value));
+ break;
+ case 3:
+ __asm__("movl %0,%%db3" : /* no output */ :"r" (value));
+ break;
+ case 6:
+ __asm__("movl %0,%%db6" : /* no output */ :"r" (value));
+ break;
+ case 7:
+ __asm__("movl %0,%%db7" : /* no output */ :"r" (value));
+ break;
+ default:
+ BUG();
+ }
+}
+
+static fastcall void nopara_clts(void)
+{
+ __asm__ __volatile__ ("clts");
+}
+
+static fastcall unsigned int nopara_read_cr0(void)
+{
+ unsigned int val;
+ __asm__ __volatile__("movl %%cr0,%0\n\t" :"=r" (val));
+ return val;
+}
+
+static fastcall void nopara_write_cr0(unsigned int val)
+{
+ __asm__ __volatile__("movl %0,%%cr0": :"r" (val));
+}
+
+static fastcall unsigned int nopara_read_cr2(void)
+{
+ unsigned int val;
+ __asm__ __volatile__("movl %%cr2,%0\n\t" :"=r" (val));
+ return val;
+}
+
+static fastcall void nopara_write_cr2(unsigned int val)
+{
+ __asm__ __volatile__("movl %0,%%cr2": :"r" (val));
+}
+
+static fastcall unsigned int nopara_read_cr3(void)
+{
+ unsigned int val;
+ __asm__ __volatile__("movl %%cr3,%0\n\t" :"=r" (val));
+ return val;
+}
+
+static fastcall void nopara_write_cr3(unsigned int val)
+{
+ __asm__ __volatile__("movl %0,%%cr3": :"r" (val));
+}
+
+static fastcall unsigned int nopara_read_cr4(void)
+{
+ unsigned int val;
+ __asm__ __volatile__("movl %%cr4,%0\n\t" :"=r" (val));
+ return val;
+}
+
+static fastcall unsigned int nopara_read_cr4_safe(void)
+{
+ unsigned int val;
+ /* This could fault if %cr4 does not exist */
+ __asm__("1: movl %%cr4, %0 \n"
+ "2: \n"
+ ".section __ex_table,\"a\" \n"
+ ".long 1b,2b \n"
+ ".previous \n"
+ : "=r" (val): "0" (0));
+ return val;
+}
+
+static fastcall void nopara_write_cr4(unsigned int val)
+{
+ __asm__ __volatile__("movl %0,%%cr4": :"r" (val));
+}
+
+static fastcall unsigned long nopara_save_fl(void)
+{
+ unsigned long f;
+ __asm__ __volatile__("pushfl ; popl %0":"=g" (f): /* no input */);
+ return f;
+}
+
+static fastcall unsigned long nopara_save_fl_irq_disable(void)
+{
+ unsigned long f;
+ __asm__ __volatile__("pushfl ; popl %0; cli":"=g" (f): : "memory");
+ return f;
+}
+
+static fastcall void nopara_restore_fl(unsigned long f)
+{
+ __asm__ __volatile__("pushl %0 ; popfl": /* no output */
+ :"g" (f)
+ :"memory", "cc");
+}
+
+static fastcall void nopara_irq_disable(void)
+{
+ __asm__ __volatile__("cli": : :"memory");
+}
+
+static fastcall void nopara_irq_enable(void)
+{
+ __asm__ __volatile__("sti": : :"memory");
+}
+
+static fastcall void nopara_safe_halt(void)
+{
+ __asm__ __volatile__("sti; hlt": : :"memory");
+}
+
+static fastcall void nopara_halt(void)
+{
+ __asm__ __volatile__("hlt": : :"memory");
+}
+
+static fastcall void nopara_wbinvd(void)
+{
+ __asm__ __volatile__("wbinvd": : :"memory");
+}
+
+static fastcall unsigned long long nopara_read_msr(unsigned int msr, int *err)
+{
+ unsigned long long val;
+
+ asm volatile("2: rdmsr ; xorl %0,%0\n"
+ "1:\n\t"
+ ".section .fixup,\"ax\"\n\t"
+ "3: movl %3,%0 ; jmp 1b\n\t"
+ ".previous\n\t"
+ ".section __ex_table,\"a\"\n"
+ " .align 4\n\t"
+ " .long 2b,3b\n\t"
+ ".previous"
+ : "=r" (*err), "=A" (val)
+ : "c" (msr), "i" (-EFAULT));
+
+ return val;
+}
+
+static fastcall int nopara_write_msr(unsigned int msr, unsigned long long val)
+{
+ int err;
+ asm volatile("2: wrmsr ; xorl %0,%0\n"
+ "1:\n\t"
+ ".section .fixup,\"ax\"\n\t"
+ "3: movl %4,%0 ; jmp 1b\n\t"
+ ".previous\n\t"
+ ".section __ex_table,\"a\"\n"
+ " .align 4\n\t"
+ " .long 2b,3b\n\t"
+ ".previous"
+ : "=a" (err)
+ : "c" (msr), "0" ((u32)val), "d" ((u32)(val>>32)),
+ "i" (-EFAULT));
+ return err;
+}
+
+static fastcall unsigned long long nopara_read_tsc(void)
+{
+ unsigned long long val;
+ __asm__ __volatile__("rdtsc" : "=A" (val));
+ return val;
+}
+
+static fastcall unsigned long long nopara_read_pmc(void)
+{
+ unsigned long long val;
+ __asm__ __volatile__("rdpmc" : "=A" (val));
+ return val;
+}
+
+static fastcall void nopara_load_tr_desc(void)
+{
+ __asm__ __volatile__("ltr %w0"::"q" (GDT_ENTRY_TSS*8));
+}
+
+static fastcall void nopara_load_ldt_desc(void)
+{
+ __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8));
+}
+
+static fastcall void nopara_load_gdt(const struct Xgt_desc_struct *dtr)
+{
+ __asm__ __volatile("lgdt %0"::"m" (*dtr));
+}
+
+static fastcall void nopara_load_idt(const struct Xgt_desc_struct *dtr)
+{
+ __asm__ __volatile("lidt %0"::"m" (*dtr));
+}
+
+static fastcall void nopara_store_gdt(struct Xgt_desc_struct *dtr)
+{
+ __asm__ ("sgdt %0":"=m" (*dtr));
+}
+
+static fastcall void nopara_store_idt(struct Xgt_desc_struct *dtr)
+{
+ __asm__ ("sidt %0":"=m" (*dtr));
+}
+
+static fastcall unsigned long nopara_store_tr(void)
+{
+ unsigned long tr;
+ __asm__ ("str %0":"=r" (tr));
+ return tr;
+}
+
+static fastcall void nopara_load_tls(struct thread_struct *t, unsigned int cpu)
+{
+#define C(i) get_cpu_gdt_table(cpu)[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i]
+ C(0); C(1); C(2);
+#undef C
+}
+
+static inline void nopara_write_dt_entry(void *dt, int entry, __u32 entry_a, __u32 entry_b)
+{
+ __u32 *lp = (__u32 *)((char *)dt + entry*8);
+ *lp = entry_a;
+ *(lp+1) = entry_b;
+}
+
+static fastcall void nopara_write_ldt_entry(void *dt, int entrynum, u64 entry)
+{
+ nopara_write_dt_entry(dt, entrynum, entry >> 32, entry);
+}
+
+static fastcall void nopara_write_gdt_entry(void *dt, int entrynum, u64 entry)
+{
+ nopara_write_dt_entry(dt, entrynum, entry >> 32, entry);
+}
+
+static fastcall void nopara_write_idt_entry(void *dt, int entrynum, u64 entry)
+{
+ nopara_write_dt_entry(dt, entrynum, entry >> 32, entry);
+}
+
+static fastcall void nopara_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));
+}
+
+/* These are in entry.S */
+extern fastcall void nopara_iret(void);
+extern fastcall void nopara_irq_enable_sysexit(void);
+
+struct paravirt_ops paravirt_ops = {
+ .kernel_rpl = 0,
+ .cpuid = nopara_cpuid,
+ .get_debugreg = nopara_get_debugreg,
+ .set_debugreg = nopara_set_debugreg,
+ .clts = nopara_clts,
+ .read_cr0 = nopara_read_cr0,
+ .write_cr0 = nopara_write_cr0,
+ .read_cr2 = nopara_read_cr2,
+ .write_cr2 = nopara_write_cr2,
+ .read_cr3 = nopara_read_cr3,
+ .write_cr3 = nopara_write_cr3,
+ .read_cr4 = nopara_read_cr4,
+ .read_cr4_safe = nopara_read_cr4_safe,
+ .write_cr4 = nopara_write_cr4,
+ .save_fl = nopara_save_fl,
+ .restore_fl = nopara_restore_fl,
+ .save_fl_irq_disable = nopara_save_fl_irq_disable,
+ .irq_disable = nopara_irq_disable,
+ .irq_enable = nopara_irq_enable,
+ .safe_halt = nopara_safe_halt,
+ .halt = nopara_halt,
+ .wbinvd = nopara_wbinvd,
+ .read_msr = nopara_read_msr,
+ .write_msr = nopara_write_msr,
+ .read_tsc = nopara_read_tsc,
+ .read_pmc = nopara_read_pmc,
+ .load_tr_desc = nopara_load_tr_desc,
+ .load_ldt_desc = nopara_load_ldt_desc,
+ .load_gdt = nopara_load_gdt,
+ .load_idt = nopara_load_idt,
+ .store_gdt = nopara_store_gdt,
+ .store_idt = nopara_store_idt,
+ .store_tr = nopara_store_tr,
+ .load_tls = nopara_load_tls,
+ .write_ldt_entry = nopara_write_ldt_entry,
+ .write_gdt_entry = nopara_write_gdt_entry,
+ .write_idt_entry = nopara_write_idt_entry,
+
+ .set_iopl_mask = nopara_set_iopl_mask,
+ .irq_enable_sysexit = nopara_irq_enable_sysexit,
+ .iret = nopara_iret,
+};
+EXPORT_SYMBOL_GPL(paravirt_ops);
===================================================================
--- /dev/null
+++ b/include/asm-i386/paravirt.h
@@ -0,0 +1,219 @@
+#ifndef __ASM_PARAVIRT_H
+#define __ASM_PARAVIRT_H
+/* Various instructions on x86 need to be replaced for
+ * para-virtualization: those hooks are defined here. */
+#include <linux/linkage.h>
+
+#ifndef __ASSEMBLY__
+struct thread_struct;
+struct Xgt_desc_struct;
+struct paravirt_ops
+{
+ unsigned int kernel_rpl;
+
+ /* All the function pointers here are declared as "fastcall"
+ so that we get a specific register-based calling
+ convention. This makes it easier to implement inline
+ assembler replacements. */
+
+ void (fastcall *cpuid)(unsigned int *eax, unsigned int *ebx,
+ unsigned int *ecx, unsigned int *edx);
+
+ unsigned int (fastcall *get_debugreg)(int regno);
+ void (fastcall *set_debugreg)(int regno, unsigned int value);
+
+ void (fastcall *clts)(void);
+
+ unsigned int (fastcall *read_cr0)(void);
+ void (fastcall *write_cr0)(unsigned int);
+
+ unsigned int (fastcall *read_cr2)(void);
+ void (fastcall *write_cr2)(unsigned int);
+
+ unsigned int (fastcall *read_cr3)(void);
+ void (fastcall *write_cr3)(unsigned int);
+
+ unsigned int (fastcall *read_cr4_safe)(void);
+ unsigned int (fastcall *read_cr4)(void);
+ void (fastcall *write_cr4)(unsigned int);
+
+ unsigned long (fastcall *save_fl)(void);
+ void (fastcall *restore_fl)(unsigned long);
+ unsigned long (fastcall *save_fl_irq_disable)(void);
+ void (fastcall *irq_disable)(void);
+ void (fastcall *irq_enable)(void);
+ void (fastcall *safe_halt)(void);
+ void (fastcall *halt)(void);
+ void (fastcall *wbinvd)(void);
+
+ /* err = 0/-EFAULT. wrmsr returns 0/-EFAULT. */
+ u64 (fastcall *read_msr)(unsigned int msr, int *err);
+ int (fastcall *write_msr)(unsigned int msr, u64 val);
+
+ u64 (fastcall *read_tsc)(void);
+ u64 (fastcall *read_pmc)(void);
+
+ void (fastcall *load_tr_desc)(void);
+ void (fastcall *load_ldt_desc)(void);
+ void (fastcall *load_gdt)(const struct Xgt_desc_struct *);
+ void (fastcall *load_idt)(const struct Xgt_desc_struct *);
+ void (fastcall *store_gdt)(struct Xgt_desc_struct *);
+ void (fastcall *store_idt)(struct Xgt_desc_struct *);
+ unsigned long (fastcall *store_tr)(void);
+ void (fastcall *load_tls)(struct thread_struct *t, unsigned int cpu);
+ void (fastcall *write_ldt_entry)(void *dt, int entrynum, u64 entry);
+ void (fastcall *write_gdt_entry)(void *dt, int entrynum, u64 entry);
+ void (fastcall *write_idt_entry)(void *dt, int entrynum, u64 entry);
+
+ void (fastcall *set_iopl_mask)(unsigned mask);
+
+ /* These two are jmp to, not actually called. */
+ void (fastcall *irq_enable_sysexit)(void);
+ void (fastcall *iret)(void);
+};
+
+extern struct paravirt_ops paravirt_ops;
+
+/* The paravirtualized CPUID instruction. */
+static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
+ unsigned int *ecx, unsigned int *edx)
+{
+ paravirt_ops.cpuid(eax, ebx, ecx, edx);
+}
+
+/*
+ * These special macros can be used to get or set a debugging register
+ */
+#define get_debugreg(var, reg) var = paravirt_ops.get_debugreg(reg)
+#define set_debugreg(val, reg) paravirt_ops.set_debugreg(reg, val)
+
+#define clts() paravirt_ops.clts()
+
+#define read_cr0() paravirt_ops.read_cr0()
+#define write_cr0(x) paravirt_ops.write_cr0(x)
+
+#define read_cr2() paravirt_ops.read_cr2()
+#define write_cr2(x) paravirt_ops.write_cr2(x)
+
+#define read_cr3() paravirt_ops.read_cr3()
+#define write_cr3(x) paravirt_ops.write_cr3(x)
+
+#define read_cr4() paravirt_ops.read_cr4()
+#define read_cr4_safe(x) paravirt_ops.read_cr4_safe()
+#define write_cr4(x) paravirt_ops.write_cr4(x)
+
+static inline unsigned long __raw_local_save_flags(void)
+{
+ return paravirt_ops.save_fl();
+}
+
+static inline void raw_local_irq_restore(unsigned long flags)
+{
+ return paravirt_ops.restore_fl(flags);
+}
+
+static inline void raw_local_irq_disable(void)
+{
+ paravirt_ops.irq_disable();
+}
+
+static inline void raw_local_irq_enable(void)
+{
+ paravirt_ops.irq_enable();
+}
+
+static inline unsigned long __raw_local_irq_save(void)
+{
+ return paravirt_ops.save_fl_irq_disable();
+}
+
+static inline void raw_safe_halt(void)
+{
+ paravirt_ops.safe_halt();
+}
+
+static inline void halt(void)
+{
+ paravirt_ops.safe_halt();
+}
+#define wbinvd() paravirt_ops.wbinvd()
+
+#define get_kernel_rpl() (paravirt_ops.kernel_rpl)
+
+#define rdmsr(msr,val1,val2) do { \
+ int _err; \
+ u64 _l = paravirt_ops.read_msr(msr,&_err); \
+ val1 = (u32)_l; \
+ val2 = _l >> 32; \
+} while(0)
+
+#define wrmsr(msr,val1,val2) do { \
+ u64 _l = ((u64)(val2) << 32) | (val1); \
+ paravirt_ops.write_msr((msr), _l); \
+} while(0)
+
+#define rdmsrl(msr,val) do { \
+ int _err; \
+ val = paravirt_ops.read_msr((msr),&_err); \
+} while(0)
+
+#define wrmsrl(msr,val) (paravirt_ops.write_msr((msr),(val)))
+#define wrmsr_safe(msr,a,b) ({ \
+ u64 _l = ((u64)(b) << 32) | (a); \
+ paravirt_ops.write_msr((msr),_l); \
+})
+
+/* rdmsr with exception handling */
+#define rdmsr_safe(msr,a,b) ({ \
+ int _err; \
+ u64 _l = paravirt_ops.read_msr(msr,&_err); \
+ (*a) = (u32)_l; \
+ (*b) = _l >> 32; \
+ _err; })
+
+#define rdtsc(low,high) do { \
+ u64 _l = paravirt_ops.read_tsc(); \
+ low = (u32)_l; \
+ high = _l >> 32; \
+} while(0)
+
+#define rdtscl(low) do { \
+ u64 _l = paravirt_ops.read_tsc(); \
+ low = (int)_l; \
+} while(0)
+
+#define rdtscll(val) (val = paravirt_ops.read_tsc())
+
+#define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
+
+#define rdpmc(counter,low,high) do { \
+ u64 _l = paravirt_ops.read_pmc(); \
+ low = (u32)_l; \
+ high = _l >> 32; \
+} while(0)
+
+#define load_TR_desc() (paravirt_ops.load_tr_desc())
+#define load_LDT_desc() (paravirt_ops.load_ldt_desc())
+#define load_gdt(dtr) (paravirt_ops.load_gdt(dtr))
+#define load_idt(dtr) (paravirt_ops.load_idt(dtr))
+#define store_gdt(dtr) (paravirt_ops.store_gdt(dtr))
+#define store_idt(dtr) (paravirt_ops.store_idt(dtr))
+#define store_tr(tr) ((tr) = paravirt_ops.store_tr())
+#define load_TLS(t,cpu) (paravirt_ops.load_tls((t),(cpu)))
+#define write_ldt_entry(dt, entry, a, b) (paravirt_ops.write_ldt_entry((dt), (entry), ((u64)a) << 32 | b))
+#define write_gdt_entry(dt, entry, a, b) (paravirt_ops.write_gdt_entry((dt), (entry), ((u64)a) << 32 | b))
+#define write_idt_entry(dt, entry, a, b) (paravirt_ops.write_idt_entry((dt), (entry), ((u64)a) << 32 | b))
+#define set_iopl_mask(mask) (paravirt_ops.set_iopl_mask(mask))
+
+#define CLI_STRING "pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_disable; popl %edx; popl %ecx; popl %eax"
+#define STI_STRING "pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_enable; popl %edx; popl %ecx; popl %eax"
+#else /* __ASSEMBLY__ */
+
+#define INTERRUPT_RETURN jmp *%cs:paravirt_ops+PARAVIRT_iret
+#define DISABLE_INTERRUPTS pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_disable; popl %edx; popl %ecx; popl %eax
+#define ENABLE_INTERRUPTS pushl %eax; pushl %ecx; pushl %edx; call *%cs:paravirt_ops+PARAVIRT_irq_enable; popl %edx; popl %ecx; popl %eax
+#define ENABLE_INTERRUPTS_SYSEXIT jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit
+#define GET_CR0_INTO_EAX call *paravirt_ops+PARAVIRT_read_cr0
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_PARAVIRT_H */

--
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