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| author | Tang Chen <tangchen@cn.fujitsu.com> | 2014-09-24 15:57:58 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-09-24 14:08:01 +0200 |
| commit | c24ae0dcd3e8695efa43e71704d1fc4bc7e29e9b (patch) | |
| tree | 9cd5baf0a56807097bebe6ccea30664e581c61ef /arch/x86 | |
| parent | 38b9917350cb2946e368ba684cfc33d1672f104e (diff) | |
| download | linux-c24ae0dcd3e8695efa43e71704d1fc4bc7e29e9b.tar.gz | |
kvm: x86: Unpin and remove kvm_arch->apic_access_page
In order to make the APIC access page migratable, stop pinning it in memory. And because the APIC access page is not pinned in memory, we can remove kvm_arch->apic_access_page. When we need to write its physical address into vmcs, we use gfn_to_page() to get its page struct, which is needed to call page_to_phys(); the page is then immediately unpinned. Suggested-by: Gleb Natapov <gleb@kernel.org> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx.c | 9 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 22 |
3 files changed, 24 insertions, 9 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 60f9d73c6282..7d603a71ab3a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -574,7 +574,7 @@ struct kvm_arch { struct kvm_apic_map *apic_map; unsigned int tss_addr; - struct page *apic_access_page; + bool apic_access_page_done; gpa_t wall_clock; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 881d266eb3ae..04fa1b8298c8 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4033,7 +4033,7 @@ static int alloc_apic_access_page(struct kvm *kvm) int r = 0; mutex_lock(&kvm->slots_lock); - if (kvm->arch.apic_access_page) + if (kvm->arch.apic_access_page_done) goto out; kvm_userspace_mem.slot = APIC_ACCESS_PAGE_PRIVATE_MEMSLOT; kvm_userspace_mem.flags = 0; @@ -4049,7 +4049,12 @@ static int alloc_apic_access_page(struct kvm *kvm) goto out; } - kvm->arch.apic_access_page = page; + /* + * Do not pin the page in memory, so that memory hot-unplug + * is able to migrate it. + */ + put_page(page); + kvm->arch.apic_access_page_done = true; out: mutex_unlock(&kvm->slots_lock); return r; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c1412f5d93db..6857257f3810 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6028,19 +6028,31 @@ static void kvm_vcpu_flush_tlb(struct kvm_vcpu *vcpu) void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu) { + struct page *page = NULL; + if (!kvm_x86_ops->set_apic_access_page_addr) return; - vcpu->kvm->arch.apic_access_page = gfn_to_page(vcpu->kvm, - APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT); - kvm_x86_ops->set_apic_access_page_addr(vcpu, - page_to_phys(vcpu->kvm->arch.apic_access_page)); + page = gfn_to_page(vcpu->kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT); + kvm_x86_ops->set_apic_access_page_addr(vcpu, page_to_phys(page)); + + /* + * Do not pin apic access page in memory, the MMU notifier + * will call us again if it is migrated or swapped out. + */ + put_page(page); } EXPORT_SYMBOL_GPL(kvm_vcpu_reload_apic_access_page); void kvm_arch_mmu_notifier_invalidate_page(struct kvm *kvm, unsigned long address) { + /* + * The physical address of apic access page is stored in the VMCS. + * Update it when it becomes invalid. + */ + if (address == gfn_to_hva(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT)) + kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD); } /* @@ -7297,8 +7309,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm) kfree(kvm->arch.vpic); kfree(kvm->arch.vioapic); kvm_free_vcpus(kvm); - if (kvm->arch.apic_access_page) - put_page(kvm->arch.apic_access_page); kfree(rcu_dereference_check(kvm->arch.apic_map, 1)); } |