[PATCH] i386: PARAVIRT: add flush_tlb_others paravirt_op
This patch adds a pv_op for flush_tlb_others. Linux running on native
hardware uses cross-CPU IPIs to flush the TLB on any CPU which may
have a particular mm's pagetable entries cached in its TLB. This is
inefficient in a paravirtualized environment, since the hypervisor
knows which real CPUs actually contain cached mappings, which may be a
small subset of a guest's VCPUs.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/arch/i386/kernel/paravirt.c b/arch/i386/kernel/paravirt.c
index b0ed163..c7f0cf9 100644
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -300,6 +300,7 @@
.flush_tlb_user = native_flush_tlb,
.flush_tlb_kernel = native_flush_tlb_global,
.flush_tlb_single = native_flush_tlb_single,
+ .flush_tlb_others = native_flush_tlb_others,
.map_pt_hook = paravirt_nop,
diff --git a/arch/i386/kernel/smp.c b/arch/i386/kernel/smp.c
index 9d84f6f..892cd64 100644
--- a/arch/i386/kernel/smp.c
+++ b/arch/i386/kernel/smp.c
@@ -256,7 +256,6 @@
static struct mm_struct * flush_mm;
static unsigned long flush_va;
static DEFINE_SPINLOCK(tlbstate_lock);
-#define FLUSH_ALL 0xffffffff
/*
* We cannot call mmdrop() because we are in interrupt context,
@@ -338,7 +337,7 @@
if (flush_mm == per_cpu(cpu_tlbstate, cpu).active_mm) {
if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_OK) {
- if (flush_va == FLUSH_ALL)
+ if (flush_va == TLB_FLUSH_ALL)
local_flush_tlb();
else
__flush_tlb_one(flush_va);
@@ -353,9 +352,11 @@
put_cpu_no_resched();
}
-static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
- unsigned long va)
+void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm,
+ unsigned long va)
{
+ cpumask_t cpumask = *cpumaskp;
+
/*
* A couple of (to be removed) sanity checks:
*
@@ -417,7 +418,7 @@
local_flush_tlb();
if (!cpus_empty(cpu_mask))
- flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
+ flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL);
preempt_enable();
}
@@ -436,7 +437,7 @@
leave_mm(smp_processor_id());
}
if (!cpus_empty(cpu_mask))
- flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
+ flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL);
preempt_enable();
}