[PATCH] paravirt: header and stubs for paravirtualisation
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.
And:
+From: Andy Whitcroft <apw@shadowen.org>
The paravirt ops introduce a 'weak' attribute onto memory_setup().
Code ordering leads to the following warnings on x86:
arch/i386/kernel/setup.c:651: warning: weak declaration of
`memory_setup' after first use results in unspecified behavior
Move memory_setup() to avoid this.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
diff --git a/include/asm-i386/paravirt.h b/include/asm-i386/paravirt.h
new file mode 100644
index 0000000..a7551a4
--- /dev/null
+++ b/include/asm-i386/paravirt.h
@@ -0,0 +1,281 @@
+#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>
+
+#ifdef CONFIG_PARAVIRT
+#ifndef __ASSEMBLY__
+struct thread_struct;
+struct Xgt_desc_struct;
+struct tss_struct;
+struct paravirt_ops
+{
+ unsigned int kernel_rpl;
+ int paravirt_enabled;
+ const char *name;
+
+ void (*arch_setup)(void);
+ char *(*memory_setup)(void);
+ void (*init_IRQ)(void);
+
+ void (*banner)(void);
+
+ unsigned long (*get_wallclock)(void);
+ int (*set_wallclock)(unsigned long);
+ void (*time_init)(void);
+
+ /* 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 long (fastcall *get_debugreg)(int regno);
+ void (fastcall *set_debugreg)(int regno, unsigned long value);
+
+ void (fastcall *clts)(void);
+
+ unsigned long (fastcall *read_cr0)(void);
+ void (fastcall *write_cr0)(unsigned long);
+
+ unsigned long (fastcall *read_cr2)(void);
+ void (fastcall *write_cr2)(unsigned long);
+
+ unsigned long (fastcall *read_cr3)(void);
+ void (fastcall *write_cr3)(unsigned long);
+
+ unsigned long (fastcall *read_cr4_safe)(void);
+ unsigned long (fastcall *read_cr4)(void);
+ void (fastcall *write_cr4)(unsigned long);
+
+ unsigned long (fastcall *save_fl)(void);
+ void (fastcall *restore_fl)(unsigned long);
+ 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_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 *);
+ void (fastcall *set_ldt)(const void *desc, unsigned entries);
+ 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,
+ u32 low, u32 high);
+ void (fastcall *write_gdt_entry)(void *dt, int entrynum,
+ u32 low, u32 high);
+ void (fastcall *write_idt_entry)(void *dt, int entrynum,
+ u32 low, u32 high);
+ void (fastcall *load_esp0)(struct tss_struct *tss,
+ struct thread_struct *thread);
+
+ void (fastcall *set_iopl_mask)(unsigned mask);
+
+ void (fastcall *io_delay)(void);
+ void (*const_udelay)(unsigned long loops);
+
+ /* These two are jmp to, not actually called. */
+ void (fastcall *irq_enable_sysexit)(void);
+ void (fastcall *iret)(void);
+};
+
+extern struct paravirt_ops paravirt_ops;
+
+#define paravirt_enabled() (paravirt_ops.paravirt_enabled)
+
+static inline void load_esp0(struct tss_struct *tss,
+ struct thread_struct *thread)
+{
+ paravirt_ops.load_esp0(tss, thread);
+}
+
+#define ARCH_SETUP paravirt_ops.arch_setup();
+static inline unsigned long get_wallclock(void)
+{
+ return paravirt_ops.get_wallclock();
+}
+
+static inline int set_wallclock(unsigned long nowtime)
+{
+ return paravirt_ops.set_wallclock(nowtime);
+}
+
+static inline void do_time_init(void)
+{
+ return paravirt_ops.time_init();
+}
+
+/* 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)
+{
+ unsigned long flags = paravirt_ops.save_fl();
+
+ paravirt_ops.irq_disable();
+
+ return flags;
+}
+
+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_gdt(dtr) (paravirt_ops.load_gdt(dtr))
+#define load_idt(dtr) (paravirt_ops.load_idt(dtr))
+#define set_ldt(addr, entries) (paravirt_ops.set_ldt((addr), (entries)))
+#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, low, high) \
+ (paravirt_ops.write_ldt_entry((dt), (entry), (low), (high)))
+#define write_gdt_entry(dt, entry, low, high) \
+ (paravirt_ops.write_gdt_entry((dt), (entry), (low), (high)))
+#define write_idt_entry(dt, entry, low, high) \
+ (paravirt_ops.write_idt_entry((dt), (entry), (low), (high)))
+#define set_iopl_mask(mask) (paravirt_ops.set_iopl_mask(mask))
+
+/* The paravirtualized I/O functions */
+static inline void slow_down_io(void) {
+ paravirt_ops.io_delay();
+#ifdef REALLY_SLOW_IO
+ paravirt_ops.io_delay();
+ paravirt_ops.io_delay();
+ paravirt_ops.io_delay();
+#endif
+}
+
+#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 /* CONFIG_PARAVIRT */
+#endif /* __ASM_PARAVIRT_H */