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| author | Thomas Gleixner <tglx@linutronix.de> | 2020-05-21 22:05:26 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 15:15:08 +0200 |
| commit | 2f6474e4636bcc68af6c44abb2703f12d7f083da (patch) | |
| tree | 317a6b92fc169077e1eb9c3d7a10e3c62869109d /arch/x86/entry/entry_64.S | |
| parent | 1de16e0c17155d138282f3a9f65914a9a5da757e (diff) | |
| download | linux-2f6474e4636bcc68af6c44abb2703f12d7f083da.tar.bz2 | |
x86/entry: Switch XEN/PV hypercall entry to IDTENTRY
Convert the XEN/PV hypercall to IDTENTRY:
- Emit the ASM stub with DECLARE_IDTENTRY
- Remove the ASM idtentry in 64-bit
- Remove the open coded ASM entry code in 32-bit
- Remove the old prototypes
The handler stubs need to stay in ASM code as they need corner case handling
and adjustment of the stack pointer.
Provide a new C function which invokes the entry/exit handling and calls
into the XEN handler on the interrupt stack if required.
The exit code is slightly different from the regular idtentry_exit() on
non-preemptible kernels. If the hypercall is preemptible and need_resched()
is set then XEN provides a preempt hypercall scheduling function.
Move this functionality into the entry code so it can use the existing
idtentry functionality.
[ mingo: Build fixes. ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com>
Tested-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20200521202118.055270078@linutronix.de
Diffstat (limited to 'arch/x86/entry/entry_64.S')
| -rw-r--r-- | arch/x86/entry/entry_64.S | 20 |
1 files changed, 6 insertions, 14 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 6b518be4da0a..dadb37d07266 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1067,10 +1067,6 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt idtentry X86_TRAP_PF page_fault do_page_fault has_error_code=1 -#ifdef CONFIG_XEN_PV -idtentry 512 /* dummy */ hypervisor_callback xen_do_hypervisor_callback has_error_code=0 -#endif - /* * Reload gs selector with exception handling * edi: new selector @@ -1158,9 +1154,10 @@ SYM_FUNC_END(asm_call_on_stack) * So, on entry to the handler we detect whether we interrupted an * existing activation in its critical region -- if so, we pop the current * activation and restart the handler using the previous one. + * + * C calling convention: exc_xen_hypervisor_callback(struct *pt_regs) */ -/* do_hypervisor_callback(struct *pt_regs) */ -SYM_CODE_START_LOCAL(xen_do_hypervisor_callback) +SYM_CODE_START_LOCAL(exc_xen_hypervisor_callback) /* * Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will @@ -1170,15 +1167,10 @@ SYM_CODE_START_LOCAL(xen_do_hypervisor_callback) movq %rdi, %rsp /* we don't return, adjust the stack frame */ UNWIND_HINT_REGS - ENTER_IRQ_STACK old_rsp=%r10 - call xen_evtchn_do_upcall - LEAVE_IRQ_STACK + call xen_pv_evtchn_do_upcall -#ifndef CONFIG_PREEMPTION - call xen_maybe_preempt_hcall -#endif - jmp error_exit -SYM_CODE_END(xen_do_hypervisor_callback) + jmp error_return +SYM_CODE_END(exc_xen_hypervisor_callback) /* * Hypervisor uses this for application faults while it executes. |