From b407fc57b815b2016186220baabc76cc8264206e Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 17 Feb 2009 23:46:21 -0800 Subject: x86/paravirt: flush pending mmu updates on context switch Impact: allow preemption during lazy mmu updates If we're in lazy mmu mode when context switching, leave lazy mmu mode, but remember the task's state in TIF_LAZY_MMU_UPDATES. When we resume the task, check this flag and re-enter lazy mmu mode if its set. This sets things up for allowing lazy mmu mode while preemptible, though that won't actually be active until the next change. Signed-off-by: Jeremy Fitzhardinge Acked-by: Peter Zijlstra --- arch/x86/lguest/boot.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'arch/x86/lguest') diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index 9fe4ddaa8f6..41a5562e710 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -147,10 +147,16 @@ static void lazy_hcall(unsigned long call, /* When lazy mode is turned off reset the per-cpu lazy mode variable and then * issue the do-nothing hypercall to flush any stored calls. */ -static void lguest_leave_lazy_mode(void) +static void lguest_leave_lazy_mmu_mode(void) { - paravirt_leave_lazy(paravirt_get_lazy_mode()); hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0); + paravirt_leave_lazy_mmu(); +} + +static void lguest_leave_lazy_cpu_mode(void) +{ + hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0); + paravirt_leave_lazy_cpu(); } /*G:033 @@ -1026,7 +1032,7 @@ __init void lguest_init(void) pv_cpu_ops.write_idt_entry = lguest_write_idt_entry; pv_cpu_ops.wbinvd = lguest_wbinvd; pv_cpu_ops.lazy_mode.enter = paravirt_enter_lazy_cpu; - pv_cpu_ops.lazy_mode.leave = lguest_leave_lazy_mode; + pv_cpu_ops.lazy_mode.leave = lguest_leave_lazy_cpu_mode; /* pagetable management */ pv_mmu_ops.write_cr3 = lguest_write_cr3; @@ -1039,7 +1045,7 @@ __init void lguest_init(void) pv_mmu_ops.read_cr2 = lguest_read_cr2; pv_mmu_ops.read_cr3 = lguest_read_cr3; pv_mmu_ops.lazy_mode.enter = paravirt_enter_lazy_mmu; - pv_mmu_ops.lazy_mode.leave = lguest_leave_lazy_mode; + pv_mmu_ops.lazy_mode.leave = lguest_leave_lazy_mmu_mode; #ifdef CONFIG_X86_LOCAL_APIC /* apic read/write intercepts */ -- cgit v1.2.3-70-g09d2 From 224101ed69d3fbb486868e0f6e0f9fa37302efb4 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Wed, 18 Feb 2009 11:18:57 -0800 Subject: x86/paravirt: finish change from lazy cpu to context switch start/end Impact: fix lazy context switch API Pass the previous and next tasks into the context switch start end calls, so that the called functions can properly access the task state (esp in end_context_switch, in which the next task is not yet completely current). Signed-off-by: Jeremy Fitzhardinge Acked-by: Peter Zijlstra --- arch/x86/include/asm/paravirt.h | 17 ++++++++++------- arch/x86/include/asm/pgtable.h | 2 ++ arch/x86/kernel/paravirt.c | 14 ++++++-------- arch/x86/kernel/process_32.c | 2 +- arch/x86/kernel/process_64.c | 2 +- arch/x86/kernel/vmi_32.c | 12 ++++++------ arch/x86/lguest/boot.c | 8 ++++---- arch/x86/xen/enlighten.c | 10 ++++------ include/asm-frv/pgtable.h | 2 +- include/asm-generic/pgtable.h | 2 +- kernel/sched.c | 2 +- 11 files changed, 37 insertions(+), 36 deletions(-) (limited to 'arch/x86/lguest') diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 58d2481b01a..dfdee0ca57d 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -56,6 +56,7 @@ struct desc_ptr; struct tss_struct; struct mm_struct; struct desc_struct; +struct task_struct; /* * Wrapper type for pointers to code which uses the non-standard @@ -203,7 +204,8 @@ struct pv_cpu_ops { void (*swapgs)(void); - struct pv_lazy_ops lazy_mode; + void (*start_context_switch)(struct task_struct *prev); + void (*end_context_switch)(struct task_struct *next); }; struct pv_irq_ops { @@ -1414,20 +1416,21 @@ enum paravirt_lazy_mode { }; enum paravirt_lazy_mode paravirt_get_lazy_mode(void); -void paravirt_enter_lazy_cpu(void); -void paravirt_leave_lazy_cpu(void); +void paravirt_start_context_switch(struct task_struct *prev); +void paravirt_end_context_switch(struct task_struct *next); + void paravirt_enter_lazy_mmu(void); void paravirt_leave_lazy_mmu(void); #define __HAVE_ARCH_START_CONTEXT_SWITCH -static inline void arch_start_context_switch(void) +static inline void arch_start_context_switch(struct task_struct *prev) { - PVOP_VCALL0(pv_cpu_ops.lazy_mode.enter); + PVOP_VCALL1(pv_cpu_ops.start_context_switch, prev); } -static inline void arch_end_context_switch(void) +static inline void arch_end_context_switch(struct task_struct *next) { - PVOP_VCALL0(pv_cpu_ops.lazy_mode.leave); + PVOP_VCALL1(pv_cpu_ops.end_context_switch, next); } #define __HAVE_ARCH_ENTER_LAZY_MMU_MODE diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index d0812e155f1..24e42836e92 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -83,6 +83,8 @@ static inline void __init paravirt_pagetable_setup_done(pgd_t *base) #define pte_val(x) native_pte_val(x) #define __pte(x) native_make_pte(x) +#define arch_end_context_switch(prev) do {} while(0) + #endif /* CONFIG_PARAVIRT */ /* diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 430a0e30577..cf1437503ba 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -270,20 +270,20 @@ void paravirt_leave_lazy_mmu(void) leave_lazy(PARAVIRT_LAZY_MMU); } -void paravirt_enter_lazy_cpu(void) +void paravirt_start_context_switch(struct task_struct *prev) { if (percpu_read(paravirt_lazy_mode) == PARAVIRT_LAZY_MMU) { arch_leave_lazy_mmu_mode(); - set_thread_flag(TIF_LAZY_MMU_UPDATES); + set_ti_thread_flag(task_thread_info(prev), TIF_LAZY_MMU_UPDATES); } enter_lazy(PARAVIRT_LAZY_CPU); } -void paravirt_leave_lazy_cpu(void) +void paravirt_end_context_switch(struct task_struct *next) { leave_lazy(PARAVIRT_LAZY_CPU); - if (test_and_clear_thread_flag(TIF_LAZY_MMU_UPDATES)) + if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES)) arch_enter_lazy_mmu_mode(); } @@ -399,10 +399,8 @@ struct pv_cpu_ops pv_cpu_ops = { .set_iopl_mask = native_set_iopl_mask, .io_delay = native_io_delay, - .lazy_mode = { - .enter = paravirt_nop, - .leave = paravirt_nop, - }, + .start_context_switch = paravirt_nop, + .end_context_switch = paravirt_nop, }; struct pv_apic_ops pv_apic_ops = { diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 57e49a8278a..d766c7616fd 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -407,7 +407,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) * done before math_state_restore, so the TS bit is up * to date. */ - arch_end_context_switch(); + arch_end_context_switch(next_p); /* If the task has used fpu the last 5 timeslices, just do a full * restore of the math state immediately to avoid the trap; the diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 7115e608532..e8a9aaf9df8 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -428,7 +428,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) * done before math_state_restore, so the TS bit is up * to date. */ - arch_end_context_switch(); + arch_end_context_switch(next_p); /* * Switch FS and GS. diff --git a/arch/x86/kernel/vmi_32.c b/arch/x86/kernel/vmi_32.c index 950929c607d..55a5d6938e5 100644 --- a/arch/x86/kernel/vmi_32.c +++ b/arch/x86/kernel/vmi_32.c @@ -467,16 +467,16 @@ vmi_startup_ipi_hook(int phys_apicid, unsigned long start_eip, } #endif -static void vmi_enter_lazy_cpu(void) +static void vmi_start_context_switch(struct task_struct *prev) { - paravirt_enter_lazy_cpu(); + paravirt_start_context_switch(prev); vmi_ops.set_lazy_mode(2); } -static void vmi_leave_lazy_cpu(void) +static void vmi_end_context_switch(struct task_struct *next) { vmi_ops.set_lazy_mode(0); - paravirt_leave_lazy_cpu(); + paravirt_end_context_switch(next); } static void vmi_enter_lazy_mmu(void) @@ -722,9 +722,9 @@ static inline int __init activate_vmi(void) para_fill(pv_cpu_ops.set_iopl_mask, SetIOPLMask); para_fill(pv_cpu_ops.io_delay, IODelay); - para_wrap(pv_cpu_ops.lazy_mode.enter, vmi_enter_lazy_cpu, + para_wrap(pv_cpu_ops.start_context_switch, vmi_start_context_switch, set_lazy_mode, SetLazyMode); - para_wrap(pv_cpu_ops.lazy_mode.leave, vmi_leave_lazy_cpu, + para_wrap(pv_cpu_ops.end_context_switch, vmi_end_context_switch, set_lazy_mode, SetLazyMode); para_wrap(pv_mmu_ops.lazy_mode.enter, vmi_enter_lazy_mmu, diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index 41a5562e710..5287081b356 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -153,10 +153,10 @@ static void lguest_leave_lazy_mmu_mode(void) paravirt_leave_lazy_mmu(); } -static void lguest_leave_lazy_cpu_mode(void) +static void lguest_end_context_switch(struct task_struct *next) { hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0); - paravirt_leave_lazy_cpu(); + paravirt_end_context_switch(next); } /*G:033 @@ -1031,8 +1031,8 @@ __init void lguest_init(void) pv_cpu_ops.write_gdt_entry = lguest_write_gdt_entry; pv_cpu_ops.write_idt_entry = lguest_write_idt_entry; pv_cpu_ops.wbinvd = lguest_wbinvd; - pv_cpu_ops.lazy_mode.enter = paravirt_enter_lazy_cpu; - pv_cpu_ops.lazy_mode.leave = lguest_leave_lazy_cpu_mode; + pv_cpu_ops.start_context_switch = paravirt_start_context_switch; + pv_cpu_ops.end_context_switch = lguest_end_context_switch; /* pagetable management */ pv_mmu_ops.write_cr3 = lguest_write_cr3; diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index f586e63b9a6..70b355d3a86 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -203,10 +203,10 @@ static unsigned long xen_get_debugreg(int reg) return HYPERVISOR_get_debugreg(reg); } -static void xen_leave_lazy_cpu(void) +static void xen_end_context_switch(struct task_struct *next) { xen_mc_flush(); - paravirt_leave_lazy_cpu(); + paravirt_end_context_switch(next); } static unsigned long xen_store_tr(void) @@ -817,10 +817,8 @@ static const struct pv_cpu_ops xen_cpu_ops __initdata = { /* Xen takes care of %gs when switching to usermode for us */ .swapgs = paravirt_nop, - .lazy_mode = { - .enter = paravirt_enter_lazy_cpu, - .leave = xen_leave_lazy_cpu, - }, + .start_context_switch = paravirt_start_context_switch, + .end_context_switch = xen_end_context_switch, }; static const struct pv_apic_ops xen_apic_ops __initdata = { diff --git a/include/asm-frv/pgtable.h b/include/asm-frv/pgtable.h index 235e34a7a34..09887045d03 100644 --- a/include/asm-frv/pgtable.h +++ b/include/asm-frv/pgtable.h @@ -74,7 +74,7 @@ static inline int pte_file(pte_t pte) { return 0; } #define arch_enter_lazy_mmu_mode() do {} while (0) #define arch_leave_lazy_mmu_mode() do {} while (0) -#define arch_start_context_switch() do {} while (0) +#define arch_start_context_switch(prev) do {} while (0) #else /* !CONFIG_MMU */ /*****************************************************************************/ diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 922f03671dd..e410f602cab 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -291,7 +291,7 @@ static inline void ptep_modify_prot_commit(struct mm_struct *mm, * definition. */ #ifndef __HAVE_ARCH_START_CONTEXT_SWITCH -#define arch_start_context_switch() do {} while (0) +#define arch_start_context_switch(prev) do {} while (0) #endif #ifndef __HAVE_PFNMAP_TRACKING diff --git a/kernel/sched.c b/kernel/sched.c index 7530fdd7c98..133762aece5 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2746,7 +2746,7 @@ context_switch(struct rq *rq, struct task_struct *prev, * combine the page table reload and the switch backend into * one hypercall. */ - arch_start_context_switch(); + arch_start_context_switch(prev); if (unlikely(!mm)) { next->active_mm = oldmm; -- cgit v1.2.3-70-g09d2 From 169aafbc8d3f05431b5cfeb60294a12b8ef2bcee Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 7 Apr 2009 13:37:26 -0700 Subject: lguest: update lazy mmu changes to match lguest's use of kvm hypercalls Duplicate hcall -> kvm_hypercall0 convertion from "lguest: use KVM hypercalls". Signed-off-by: Jeremy Fitzhardinge Cc: Matias Zabaljauregui Cc: Rusty Russell --- arch/x86/lguest/boot.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/lguest') diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index 5ab239711cc..cfb2d68dc79 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -168,7 +168,7 @@ static void lazy_hcall3(unsigned long call, * issue the do-nothing hypercall to flush any stored calls. */ static void lguest_leave_lazy_mmu_mode(void) { - hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0); + kvm_hypercall0(LHCALL_FLUSH_ASYNC); paravirt_leave_lazy_mmu(); } -- cgit v1.2.3-70-g09d2