[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 2/2] x86/xen: allow privcmd hypercalls to be preempted
On 12/10/2014 03:34 PM, Luis R. Rodriguez wrote: > diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S > index 344b63f..40b5c0c 100644 > --- a/arch/x86/kernel/entry_32.S > +++ b/arch/x86/kernel/entry_32.S > @@ -982,7 +982,28 @@ ENTRY(xen_hypervisor_callback) > ENTRY(xen_do_upcall) > 1: mov %esp, %eax > call xen_evtchn_do_upcall > +#ifdef CONFIG_PREEMPT > jmp ret_from_intr > +#else > + GET_THREAD_INFO(%ebp) > +#ifdef CONFIG_VM86 > + movl PT_EFLAGS(%esp), %eax # mix EFLAGS and CS > + movb PT_CS(%esp), %al > + andl $(X86_EFLAGS_VM | SEGMENT_RPL_MASK), %eax > +#else > + movl PT_CS(%esp), %eax > + andl $SEGMENT_RPL_MASK, %eax > +#endif > + cmpl $USER_RPL, %eax > + jae resume_userspace # returning to v8086 or userspace > + DISABLE_INTERRUPTS(CLBR_ANY) > + cmpb $0,PER_CPU_VAR(xen_in_preemptible_hcall) > + jz resume_kernel > + movb $0,PER_CPU_VAR(xen_in_preemptible_hcall) > + call cond_resched_irq > + movb $1,PER_CPU_VAR(xen_in_preemptible_hcall) > + jmp resume_kernel > +#endif /* CONFIG_PREEMPT */ > CFI_ENDPROC > ENDPROC(xen_hypervisor_callback) > > diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S > index c0226ab..0ccdd06 100644 > --- a/arch/x86/kernel/entry_64.S > +++ b/arch/x86/kernel/entry_64.S > @@ -1170,7 +1170,23 @@ ENTRY(xen_do_hypervisor_callback) # > do_hypervisor_callback(struct *pt_regs) > popq %rsp > CFI_DEF_CFA_REGISTER rsp > decl PER_CPU_VAR(irq_count) > +#ifdef CONFIG_PREEMPT > jmp error_exit > +#else > + movl %ebx, %eax > + RESTORE_REST > + DISABLE_INTERRUPTS(CLBR_NONE) > + TRACE_IRQS_OFF > + GET_THREAD_INFO(%rcx) > + testl %eax, %eax > + je error_exit_user > + cmpb $0,PER_CPU_VAR(xen_in_preemptible_hcall) > + jz retint_kernel > + movb $0,PER_CPU_VAR(xen_in_preemptible_hcall) > + call cond_resched_irq > + movb $1,PER_CPU_VAR(xen_in_preemptible_hcall) > + jmp retint_kernel > +#endif /* CONFIG_PREEMPT */ > CFI_ENDPROC > END(xen_do_hypervisor_callback) > > @@ -1398,6 +1414,7 @@ ENTRY(error_exit) > GET_THREAD_INFO(%rcx) > testl %eax,%eax > jne retint_kernel > +error_exit_user: > LOCKDEP_SYS_EXIT_IRQ > movl TI_flags(%rcx),%edx > movl $_TIF_WORK_MASK,%edi You're adding a bunch of code for the *non*-preemptive case here... why? -hpa _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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