diff options
| author | Juergen Gross <jgross@suse.com> | 2021-01-20 14:55:46 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-02-10 12:36:45 +0100 |
| commit | ab234a260b1f625b26cbefa93ca365b0ae66df33 (patch) | |
| tree | 3308ecacbf6f66119fb14707eb506de1ab43e027 /arch/x86/xen/irq.c | |
| parent | x86/xen: Drop USERGS_SYSRET64 paravirt call (diff) | |
| download | linux-ab234a260b1f625b26cbefa93ca365b0ae66df33.tar.xz linux-ab234a260b1f625b26cbefa93ca365b0ae66df33.zip | |
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/irq.c')
| -rw-r--r-- | arch/x86/xen/irq.c | 23 |
1 files changed, 0 insertions, 23 deletions
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c index 850c93f346c7..dfa091d79c2e 100644 --- a/arch/x86/xen/irq.c +++ b/arch/x86/xen/irq.c @@ -42,28 +42,6 @@ asmlinkage __visible unsigned long xen_save_fl(void) } PV_CALLEE_SAVE_REGS_THUNK(xen_save_fl); -__visible void xen_restore_fl(unsigned long flags) -{ - struct vcpu_info *vcpu; - - /* convert from IF type flag */ - flags = !(flags & X86_EFLAGS_IF); - - /* See xen_irq_enable() for why preemption must be disabled. */ - preempt_disable(); - vcpu = this_cpu_read(xen_vcpu); - vcpu->evtchn_upcall_mask = flags; - - if (flags == 0) { - barrier(); /* unmask then check (avoid races) */ - if (unlikely(vcpu->evtchn_upcall_pending)) - xen_force_evtchn_callback(); - preempt_enable(); - } else - preempt_enable_no_resched(); -} -PV_CALLEE_SAVE_REGS_THUNK(xen_restore_fl); - asmlinkage __visible void xen_irq_disable(void) { /* There's a one instruction preempt window here. We need to @@ -118,7 +96,6 @@ static void xen_halt(void) static const struct pv_irq_ops xen_irq_ops __initconst = { .save_fl = PV_CALLEE_SAVE(xen_save_fl), - .restore_fl = PV_CALLEE_SAVE(xen_restore_fl), .irq_disable = PV_CALLEE_SAVE(xen_irq_disable), .irq_enable = PV_CALLEE_SAVE(xen_irq_enable), |