diff options
| author | Juergen Gross <jgross@suse.com> | 2021-01-20 16:55:46 +0300 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-02-10 14:36:45 +0300 |
| commit | ab234a260b1f625b26cbefa93ca365b0ae66df33 (patch) | |
| tree | 3308ecacbf6f66119fb14707eb506de1ab43e027 /arch/x86/xen/xen-asm.S | |
| parent | afd30525a659ac0ae0904f0cb4a2ca75522c3123 (diff) | |
| download | linux-ab234a260b1f625b26cbefa93ca365b0ae66df33.tar.xz | |
x86/pv: Rework arch_local_irq_restore() to not use popf
POPF is a rather expensive operation, so don't use it for restoring
irq flags. Instead, test whether interrupts are enabled in the flags
parameter and enable interrupts via STI in that case.
This results in the restore_fl paravirt op to be no longer needed.
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210120135555.32594-7-jgross@suse.com
Diffstat (limited to 'arch/x86/xen/xen-asm.S')
| -rw-r--r-- | arch/x86/xen/xen-asm.S | 28 |
1 files changed, 0 insertions, 28 deletions
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S index 1d738c5957f5..02f31341e435 100644 --- a/arch/x86/xen/xen-asm.S +++ b/arch/x86/xen/xen-asm.S @@ -72,34 +72,6 @@ SYM_FUNC_START(xen_save_fl_direct) ret SYM_FUNC_END(xen_save_fl_direct) - -/* - * In principle the caller should be passing us a value return from - * xen_save_fl_direct, but for robustness sake we test only the - * X86_EFLAGS_IF flag rather than the whole byte. After setting the - * interrupt mask state, it checks for unmasked pending events and - * enters the hypervisor to get them delivered if so. - */ -SYM_FUNC_START(xen_restore_fl_direct) - FRAME_BEGIN - testw $X86_EFLAGS_IF, %di - setz PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask - /* - * Preempt here doesn't matter because that will deal with any - * pending interrupts. The pending check may end up being run - * on the wrong CPU, but that doesn't hurt. - */ - - /* check for unmasked and pending */ - cmpw $0x0001, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_pending - jnz 1f - call check_events -1: - FRAME_END - ret -SYM_FUNC_END(xen_restore_fl_direct) - - /* * Force an event check by making a hypercall, but preserve regs * before making the call. |