diff options
| 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 /drivers | |
| parent | 1de16e0c17155d138282f3a9f65914a9a5da757e (diff) | |
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 'drivers')
| -rw-r--r-- | drivers/xen/Makefile | 2 | ||||
| -rw-r--r-- | drivers/xen/preempt.c | 42 |
2 files changed, 1 insertions, 43 deletions
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index 0c4efa6fe450..0d322f3d90cd 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o -obj-y += grant-table.o features.o balloon.o manage.o preempt.o time.o +obj-y += grant-table.o features.o balloon.o manage.o time.o obj-y += mem-reservation.o obj-y += events/ obj-y += xenbus/ diff --git a/drivers/xen/preempt.c b/drivers/xen/preempt.c deleted file mode 100644 index 17240c5325a3..000000000000 --- a/drivers/xen/preempt.c +++ /dev/null @@ -1,42 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Preemptible hypercalls - * - * Copyright (C) 2014 Citrix Systems R&D ltd. - */ - -#include <linux/sched.h> -#include <xen/xen-ops.h> - -#ifndef CONFIG_PREEMPTION - -/* - * Some hypercalls issued by the toolstack can take many 10s of - * seconds. Allow tasks running hypercalls via the privcmd driver to - * be voluntarily preempted even if full kernel preemption is - * disabled. - * - * Such preemptible hypercalls are bracketed by - * xen_preemptible_hcall_begin() and xen_preemptible_hcall_end() - * calls. - */ - -DEFINE_PER_CPU(bool, xen_in_preemptible_hcall); -EXPORT_SYMBOL_GPL(xen_in_preemptible_hcall); - -asmlinkage __visible void xen_maybe_preempt_hcall(void) -{ - if (unlikely(__this_cpu_read(xen_in_preemptible_hcall) - && need_resched())) { - /* - * Clear flag as we may be rescheduled on a different - * cpu. - */ - __this_cpu_write(xen_in_preemptible_hcall, false); - local_irq_enable(); - cond_resched(); - local_irq_disable(); - __this_cpu_write(xen_in_preemptible_hcall, true); - } -} -#endif /* CONFIG_PREEMPTION */ |