litmus-rt.git - The LITMUS^RT kernel.

diff options

author	Paul E. McKenney <paulmck@linux.vnet.ibm.com>	2009-08-27 17:58:16 -0400
committer	Ingo Molnar <mingo@elte.hu>	2009-08-29 09:34:39 -0400
commit	dd5d19bafd90d33043a4a14b2e2d98612caa293c (patch)
tree	c21d547124d277f00332bdb01c75f2f4f321de8c /lib/debugobjects.c
parent	06e799764eb7c2e4640888d438c3524d756613e1 (diff)

rcu: Create rcutree plugins to handle hotplug CPU for multi-level trees

When offlining CPUs from a multi-level tree, there is the possibility of offlining the last CPU from a given node when there are preempted RCU read-side critical sections that started life on one of the CPUs on that node. In this case, the corresponding tasks will be enqueued via the task_struct's rcu_node_entry list_head onto one of the rcu_node's blocked_tasks[] lists. These tasks need to be moved somewhere else so that they will prevent the current grace period from ending. That somewhere is the root rcu_node. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <20090827215816.GA30472@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>

Diffstat (limited to 'lib/debugobjects.c')

0 files changed, 0 insertions, 0 deletions

/* * Kernel-based Virtual Machine driver for Linux * cpuid support routines * * derived from arch/x86/kvm/x86.c * * Copyright 2011 Red Hat, Inc. and/or its affiliates. * Copyright IBM Corporation, 2008 * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. * */ #include <linux/kvm_host.h> #include <linux/module.h> #include <linux/vmalloc.h> #include <linux/uaccess.h> #include <asm/user.h> #include <asm/xsave.h> #include "cpuid.h" #include "lapic.h" #include "mmu.h" #include "trace.h" void kvm_update_cpuid(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *best; struct kvm_lapic *apic = vcpu->arch.apic; best = kvm_find_cpuid_entry(vcpu, 1, 0); if (!best) return; /* Update OSXSAVE bit */ if (cpu_has_xsave && best->function == 0x1) { best->ecx &= ~(bit(X86_FEATURE_OSXSAVE)); if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) best->ecx |= bit(X86_FEATURE_OSXSAVE); } if (apic) { if (best->ecx & bit(X86_FEATURE_TSC_DEADLINE_TIMER)) apic->lapic_timer.timer_mode_mask = 3 << 17; else apic->lapic_timer.timer_mode_mask = 1 << 17; } kvm_pmu_cpuid_update(vcpu); } static int is_efer_nx(void) { unsigned long long efer = 0; rdmsrl_safe(MSR_EFER, &efer); return efer & EFER_NX; } static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) { int i; struct kvm_cpuid_entry2 *e, *entry; entry = NULL; for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { e = &vcpu->arch.cpuid_entries[i]; if (e->function == 0x80000001) { entry = e; break; } } if (entry && (entry->edx & (1 << 20)) && !is_efer_nx()) { entry->edx &= ~(1 << 20); printk(KERN_INFO "kvm: guest NX capability removed\n"); } } /* when an old userspace process fills a new kernel module */ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid *cpuid, struct kvm_cpuid_entry __user *entries) { int r, i; struct kvm_cpuid_entry *cpuid_entries; r = -E2BIG; if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) goto out; r = -ENOMEM; cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent); if (!cpuid_entries) goto out; r = -EFAULT; if (copy_from_user(cpuid_entries, entries, cpuid->nent * sizeof(struct kvm_cpuid_entry))) goto out_free; for (i = 0; i < cpuid->nent; i++) { vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; vcpu->arch.cpuid_entries[i].index = 0; vcpu->arch.cpuid_entries[i].flags = 0; vcpu->arch.cpuid_entries[i].padding[0] = 0; vcpu->arch.cpuid_entries[i].padding[1] = 0; vcpu->arch.cpuid_entries[i].padding[2] = 0; } vcpu->arch.cpuid_nent = cpuid->nent; cpuid_fix_nx_cap(vcpu); r = 0; kvm_apic_set_version(vcpu); kvm_x86_ops->cpuid_update(vcpu); kvm_update_cpuid(vcpu); out_free: vfree(cpuid_entries); out: return r; } int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, struct kvm_cpuid_entry2 __user *entries) { int r; r = -E2BIG; if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) goto out; r = -EFAULT; if (copy_from_user(&vcpu->arch.cpuid_entries, entries, cpuid->nent * sizeof(struct kvm_cpuid_entry2))) goto out; vcpu->arch.cpuid_nent = cpuid->nent; kvm_apic_set_version(vcpu); kvm_x86_ops->cpuid_update(vcpu); kvm_update_cpuid(vcpu); return 0; out: return r; } int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, struct kvm_cpuid_entry2 __user *entries) { int r; r = -E2BIG; if (cpuid->nent < vcpu->arch.cpuid_nent) goto out; r = -EFAULT; if (copy_to_user(entries, &vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) goto out; return 0; out: cpuid->nent = vcpu->arch.cpuid_nent; return r; } static void cpuid_mask(u32 *word, int wordnum) { *word &= boot_cpu_data.x86_capability[wordnum]; } static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, u32 index) { entry->function = function; entry->index = index; cpuid_count(entry->function, entry->index, &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); entry->flags = 0; } static bool supported_xcr0_bit(unsigned bit) { u64 mask = ((u64)1 << bit); return mask & (XSTATE_FP | XSTATE_SSE | XSTATE_YMM) & host_xcr0; } #define F(x) bit(X86_FEATURE_##x) static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, u32 index, int *nent, int maxnent) { int r; unsigned f_nx = is_efer_nx() ? F(NX) : 0; #ifdef CONFIG_X86_64 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) ? F(GBPAGES) : 0; unsigned f_lm = F(LM); #else unsigned f_gbpages = 0; unsigned f_lm = 0; #endif unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; /* cpuid 1.edx */ const u32 kvm_supported_word0_x86_features = F(FPU) | F(VME) | F(DE) | F(PSE) | F(TSC) | F(MSR) | F(PAE) | F(MCE) | F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLSH) | 0 /* Reserved, DS, ACPI */ | F(MMX) | F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 0 /* HTT, TM, Reserved, PBE */; /* cpuid 0x80000001.edx */ const u32 kvm_supported_word1_x86_features = F(FPU) | F(VME) | F(DE) | F(PSE) | F(TSC) | F(MSR) | F(PAE) | F(MCE) | F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | F(PAT) | F(PSE36) | 0 /* Reserved */ | f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); /* cpuid 1.ecx */ const u32 kvm_supported_word4_x86_features = F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 0 /* DS-CPL, VMX, SMX, EST */ | 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | F(F16C) | F(RDRAND); /* cpuid 0x80000001.ecx */ const u32 kvm_supported_word6_x86_features = F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM); /* cpuid 0xC0000001.edx */ const u32 kvm_supported_word5_x86_features = F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | F(PMM) | F(PMM_EN); /* cpuid 7.0.ebx */ const u32 kvm_supported_word9_x86_features = F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | F(BMI2) | F(ERMS) | f_invpcid | F(RTM); /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); r = -E2BIG; if (*nent >= maxnent) goto out; do_cpuid_1_ent(entry, function, index); ++*nent; switch (function) { case 0: entry->eax = min(entry->eax, (u32)0xd); break; case 1: entry->edx &= kvm_supported_word0_x86_features; cpuid_mask(&entry->edx, 0); entry->ecx &= kvm_supported_word4_x86_features; cpuid_mask(&entry->ecx, 4); /* we support x2apic emulation even if host does not support * it since we emulate x2apic in software */ entry->ecx |= F(X2APIC); break; /* function 2 entries are STATEFUL. That is, repeated cpuid commands * may return different values. This forces us to get_cpu() before * issuing the first command, and also to emulate this annoying behavior


context:
space:
mode: