diff options
| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2008-06-25 00:19:26 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-08 13:13:15 +0200 |
| commit | d75cd22fdd5f7d203fb60014d426942df33dd9a6 (patch) | |
| tree | 0613fca9d594eab9a0679f80510fa11b48b31571 /include | |
| parent | e04e0a630d8b5c621b3a8e70ff20db737d3a5728 (diff) | |
x86/paravirt: split sysret and sysexit
Don't conflate sysret and sysexit; they're different instructions with
different semantics, and may be in use at the same time (at least
within the same kernel, depending on whether its an Intel or AMD
system).
sysexit - just return to userspace, does no register restoration of
any kind; must explicitly atomically enable interrupts.
sysret - reloads flags from r11, so no need to explicitly enable
interrupts on 64-bit, responsible for restoring usermode %gs
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citirx.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-x86/irqflags.h | 4 | ||||
| -rw-r--r-- | include/asm-x86/paravirt.h | 15 |
2 files changed, 12 insertions, 7 deletions
diff --git a/include/asm-x86/irqflags.h b/include/asm-x86/irqflags.h index c242527f970e..99ee5256a7e3 100644 --- a/include/asm-x86/irqflags.h +++ b/include/asm-x86/irqflags.h @@ -112,13 +112,13 @@ static inline unsigned long __raw_local_irq_save(void) #ifdef CONFIG_X86_64 #define INTERRUPT_RETURN iretq -#define ENABLE_INTERRUPTS_SYSCALL_RET \ +#define USERSP_SYSRET \ movq %gs:pda_oldrsp, %rsp; \ swapgs; \ sysretq; #else #define INTERRUPT_RETURN iret -#define ENABLE_INTERRUPTS_SYSCALL_RET sti; sysexit +#define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit #define GET_CR0_INTO_EAX movl %cr0, %eax #endif diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h index 82cdcde4b222..2668903b70f5 100644 --- a/include/asm-x86/paravirt.h +++ b/include/asm-x86/paravirt.h @@ -141,8 +141,9 @@ struct pv_cpu_ops { u64 (*read_pmc)(int counter); unsigned long long (*read_tscp)(unsigned int *aux); - /* These two are jmp to, not actually called. */ - void (*irq_enable_syscall_ret)(void); + /* These three are jmp to, not actually called. */ + void (*irq_enable_sysexit)(void); + void (*usersp_sysret)(void); void (*iret)(void); void (*swapgs)(void); @@ -1480,10 +1481,10 @@ static inline unsigned long __raw_local_irq_save(void) call PARA_INDIRECT(pv_irq_ops+PV_IRQ_irq_enable); \ PV_RESTORE_REGS;) -#define ENABLE_INTERRUPTS_SYSCALL_RET \ - PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_irq_enable_syscall_ret),\ +#define ENABLE_INTERRUPTS_SYSEXIT \ + PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_irq_enable_sysexit), \ CLBR_NONE, \ - jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_irq_enable_syscall_ret)) + jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_irq_enable_sysexit)) #ifdef CONFIG_X86_32 @@ -1504,6 +1505,10 @@ static inline unsigned long __raw_local_irq_save(void) movq %rax, %rcx; \ xorq %rax, %rax; +#define USERSP_SYSRET \ + PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usersp_sysret), \ + CLBR_NONE, \ + jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_usersp_sysret)) #endif #endif /* __ASSEMBLY__ */ |