From d4c104771a1c58e3de2a888b73b0ba1b54c0ae76 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Wed, 2 May 2007 19:27:15 +0200 Subject: [PATCH] [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 Signed-off-by: Andi Kleen --- arch/i386/kernel/paravirt.c | 1 + arch/i386/kernel/smp.c | 13 +++++++------ include/asm-i386/paravirt.h | 9 +++++++++ include/asm-i386/tlbflush.h | 19 +++++++++++++++++-- 4 files changed, 34 insertions(+), 8 deletions(-) diff --git a/arch/i386/kernel/paravirt.c b/arch/i386/kernel/paravirt.c index b0ed163e6f70..c7f0cf92925f 100644 --- a/arch/i386/kernel/paravirt.c +++ b/arch/i386/kernel/paravirt.c @@ -300,6 +300,7 @@ struct paravirt_ops paravirt_ops = { .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 9d84f6f001bf..892cd64130bc 100644 --- a/arch/i386/kernel/smp.c +++ b/arch/i386/kernel/smp.c @@ -256,7 +256,6 @@ static cpumask_t flush_cpumask; 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 @@ fastcall void smp_invalidate_interrupt(struct pt_regs *regs) 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 @@ out: 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 @@ void flush_tlb_current_task(void) 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 @@ void flush_tlb_mm (struct mm_struct * mm) 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(); } diff --git a/include/asm-i386/paravirt.h b/include/asm-i386/paravirt.h index 4b3d50858670..f880b06d6d56 100644 --- a/include/asm-i386/paravirt.h +++ b/include/asm-i386/paravirt.h @@ -15,6 +15,7 @@ #ifndef __ASSEMBLY__ #include +#include struct thread_struct; struct Xgt_desc_struct; @@ -165,6 +166,8 @@ struct paravirt_ops void (*flush_tlb_user)(void); void (*flush_tlb_kernel)(void); void (*flush_tlb_single)(unsigned long addr); + void (*flush_tlb_others)(const cpumask_t *cpus, struct mm_struct *mm, + unsigned long va); void (*map_pt_hook)(int type, pte_t *va, u32 pfn); @@ -853,6 +856,12 @@ static inline void __flush_tlb_single(unsigned long addr) PVOP_VCALL1(flush_tlb_single, addr); } +static inline void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm, + unsigned long va) +{ + PVOP_VCALL3(flush_tlb_others, &cpumask, mm, va); +} + static inline void paravirt_map_pt_hook(int type, pte_t *va, u32 pfn) { PVOP_VCALL3(map_pt_hook, type, va, pfn); diff --git a/include/asm-i386/tlbflush.h b/include/asm-i386/tlbflush.h index 4dd82840d53b..db7f77eacfa0 100644 --- a/include/asm-i386/tlbflush.h +++ b/include/asm-i386/tlbflush.h @@ -79,11 +79,15 @@ * - flush_tlb_range(vma, start, end) flushes a range of pages * - flush_tlb_kernel_range(start, end) flushes a range of kernel pages * - flush_tlb_pgtables(mm, start, end) flushes a range of page tables + * - flush_tlb_others(cpumask, mm, va) flushes a TLBs on other cpus * * ..but the i386 has somewhat limited tlb flushing capabilities, * and page-granular flushes are available only on i486 and up. */ +#define TLB_FLUSH_ALL 0xffffffff + + #ifndef CONFIG_SMP #define flush_tlb() __flush_tlb() @@ -110,7 +114,12 @@ static inline void flush_tlb_range(struct vm_area_struct *vma, __flush_tlb(); } -#else +static inline void native_flush_tlb_others(const cpumask_t *cpumask, + struct mm_struct *mm, unsigned long va) +{ +} + +#else /* SMP */ #include @@ -129,6 +138,9 @@ static inline void flush_tlb_range(struct vm_area_struct * vma, unsigned long st flush_tlb_mm(vma->vm_mm); } +void native_flush_tlb_others(const cpumask_t *cpumask, struct mm_struct *mm, + unsigned long va); + #define TLBSTATE_OK 1 #define TLBSTATE_LAZY 2 @@ -139,8 +151,11 @@ struct tlb_state char __cacheline_padding[L1_CACHE_BYTES-8]; }; DECLARE_PER_CPU(struct tlb_state, cpu_tlbstate); +#endif /* SMP */ - +#ifndef CONFIG_PARAVIRT +#define flush_tlb_others(mask, mm, va) \ + native_flush_tlb_others(&mask, mm, va) #endif #define flush_tlb_kernel_range(start, end) flush_tlb_all()