From 013f6a5d3dd9e4ebf4b49ca427b9c1f2e2a1b767 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Thu, 3 Jan 2013 11:41:39 -0200 Subject: [PATCH] KVM: x86: use dynamic percpu allocations for shared msrs area Use dynamic percpu allocations for the shared msrs structure, to avoid using the limited reserved percpu space. Reviewed-by: Gleb Natapov Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/x86.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 76f5446..c243b81 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -120,7 +120,7 @@ struct kvm_shared_msrs { }; static struct kvm_shared_msrs_global __read_mostly shared_msrs_global; -static DEFINE_PER_CPU(struct kvm_shared_msrs, shared_msrs); +static struct kvm_shared_msrs __percpu *shared_msrs; struct kvm_stats_debugfs_item debugfs_entries[] = { { "pf_fixed", VCPU_STAT(pf_fixed) }, @@ -191,10 +191,10 @@ static void kvm_on_user_return(struct user_return_notifier *urn) static void shared_msr_update(unsigned slot, u32 msr) { - struct kvm_shared_msrs *smsr; u64 value; + unsigned int cpu = smp_processor_id(); + struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu); - smsr = &__get_cpu_var(shared_msrs); /* only read, and nobody should modify it at this time, * so don't need lock */ if (slot >= shared_msrs_global.nr) { @@ -226,7 +226,8 @@ static void kvm_shared_msr_cpu_online(void) void kvm_set_shared_msr(unsigned slot, u64 value, u64 mask) { - struct kvm_shared_msrs *smsr = &__get_cpu_var(shared_msrs); + unsigned int cpu = smp_processor_id(); + struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu); if (((value ^ smsr->values[slot].curr) & mask) == 0) return; @@ -242,7 +243,8 @@ EXPORT_SYMBOL_GPL(kvm_set_shared_msr); static void drop_user_return_notifiers(void *ignore) { - struct kvm_shared_msrs *smsr = &__get_cpu_var(shared_msrs); + unsigned int cpu = smp_processor_id(); + struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu); if (smsr->registered) kvm_on_user_return(&smsr->urn); @@ -5233,9 +5235,16 @@ int kvm_arch_init(void *opaque) goto out; } + r = -ENOMEM; + shared_msrs = alloc_percpu(struct kvm_shared_msrs); + if (!shared_msrs) { + printk(KERN_ERR "kvm: failed to allocate percpu kvm_shared_msrs\n"); + goto out; + } + r = kvm_mmu_module_init(); if (r) - goto out; + goto out_free_percpu; kvm_set_mmio_spte_mask(); kvm_init_msr_list(); @@ -5258,6 +5267,8 @@ int kvm_arch_init(void *opaque) return 0; +out_free_percpu: + free_percpu(shared_msrs); out: return r; } @@ -5275,6 +5286,7 @@ void kvm_arch_exit(void) #endif kvm_x86_ops = NULL; kvm_mmu_module_exit(); + free_percpu(shared_msrs); } int kvm_emulate_halt(struct kvm_vcpu *vcpu) -- 2.7.4