Commit a255d479 authored by Tang Chen's avatar Tang Chen Committed by Paolo Bonzini

kvm: Remove ept_identity_pagetable from struct kvm_arch.

kvm_arch->ept_identity_pagetable holds the ept identity pagetable page. But
it is never used to refer to the page at all.

In vcpu initialization, it indicates two things:
1. indicates if ept page is allocated
2. indicates if a memory slot for identity page is initialized

Actually, kvm_arch->ept_identity_pagetable_done is enough to tell if the ept
identity pagetable is initialized. So we can remove ept_identity_pagetable.

NOTE: In the original code, ept identity pagetable page is pinned in memroy.
      As a result, it cannot be migrated/hot-removed. After this patch, since
      kvm_arch->ept_identity_pagetable is removed, ept identity pagetable page
      is no longer pinned in memory. And it can be migrated/hot-removed.
Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: default avatarGleb Natapov <gleb@kernel.org>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 80ce1639
...@@ -578,7 +578,6 @@ struct kvm_arch { ...@@ -578,7 +578,6 @@ struct kvm_arch {
gpa_t wall_clock; gpa_t wall_clock;
struct page *ept_identity_pagetable;
bool ept_identity_pagetable_done; bool ept_identity_pagetable_done;
gpa_t ept_identity_map_addr; gpa_t ept_identity_map_addr;
......
...@@ -767,6 +767,7 @@ static u32 vmx_segment_access_rights(struct kvm_segment *var); ...@@ -767,6 +767,7 @@ static u32 vmx_segment_access_rights(struct kvm_segment *var);
static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu *vcpu); static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu *vcpu);
static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx); static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx);
static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx); static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx);
static int alloc_identity_pagetable(struct kvm *kvm);
static DEFINE_PER_CPU(struct vmcs *, vmxarea); static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs); static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
...@@ -3962,21 +3963,27 @@ static int init_rmode_tss(struct kvm *kvm) ...@@ -3962,21 +3963,27 @@ static int init_rmode_tss(struct kvm *kvm)
static int init_rmode_identity_map(struct kvm *kvm) static int init_rmode_identity_map(struct kvm *kvm)
{ {
int i, idx, r, ret; int i, idx, r, ret = 0;
pfn_t identity_map_pfn; pfn_t identity_map_pfn;
u32 tmp; u32 tmp;
if (!enable_ept) if (!enable_ept)
return 1; return 1;
if (unlikely(!kvm->arch.ept_identity_pagetable)) {
printk(KERN_ERR "EPT: identity-mapping pagetable " /* Protect kvm->arch.ept_identity_pagetable_done. */
"haven't been allocated!\n"); mutex_lock(&kvm->slots_lock);
return 0;
if (likely(kvm->arch.ept_identity_pagetable_done)) {
ret = 1;
goto out2;
} }
if (likely(kvm->arch.ept_identity_pagetable_done))
return 1;
ret = 0;
identity_map_pfn = kvm->arch.ept_identity_map_addr >> PAGE_SHIFT; identity_map_pfn = kvm->arch.ept_identity_map_addr >> PAGE_SHIFT;
r = alloc_identity_pagetable(kvm);
if (r)
goto out2;
idx = srcu_read_lock(&kvm->srcu); idx = srcu_read_lock(&kvm->srcu);
r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE); r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);
if (r < 0) if (r < 0)
...@@ -3994,6 +4001,9 @@ static int init_rmode_identity_map(struct kvm *kvm) ...@@ -3994,6 +4001,9 @@ static int init_rmode_identity_map(struct kvm *kvm)
ret = 1; ret = 1;
out: out:
srcu_read_unlock(&kvm->srcu, idx); srcu_read_unlock(&kvm->srcu, idx);
out2:
mutex_unlock(&kvm->slots_lock);
return ret; return ret;
} }
...@@ -4043,31 +4053,20 @@ static int alloc_apic_access_page(struct kvm *kvm) ...@@ -4043,31 +4053,20 @@ static int alloc_apic_access_page(struct kvm *kvm)
static int alloc_identity_pagetable(struct kvm *kvm) static int alloc_identity_pagetable(struct kvm *kvm)
{ {
struct page *page; /* Called with kvm->slots_lock held. */
struct kvm_userspace_memory_region kvm_userspace_mem; struct kvm_userspace_memory_region kvm_userspace_mem;
int r = 0; int r = 0;
mutex_lock(&kvm->slots_lock); BUG_ON(kvm->arch.ept_identity_pagetable_done);
if (kvm->arch.ept_identity_pagetable)
goto out;
kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT; kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
kvm_userspace_mem.flags = 0; kvm_userspace_mem.flags = 0;
kvm_userspace_mem.guest_phys_addr = kvm_userspace_mem.guest_phys_addr =
kvm->arch.ept_identity_map_addr; kvm->arch.ept_identity_map_addr;
kvm_userspace_mem.memory_size = PAGE_SIZE; kvm_userspace_mem.memory_size = PAGE_SIZE;
r = __kvm_set_memory_region(kvm, &kvm_userspace_mem); r = __kvm_set_memory_region(kvm, &kvm_userspace_mem);
if (r)
goto out;
page = gfn_to_page(kvm, kvm->arch.ept_identity_map_addr >> PAGE_SHIFT);
if (is_error_page(page)) {
r = -EFAULT;
goto out;
}
kvm->arch.ept_identity_pagetable = page;
out:
mutex_unlock(&kvm->slots_lock);
return r; return r;
} }
...@@ -7758,8 +7757,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) ...@@ -7758,8 +7757,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
kvm->arch.ept_identity_map_addr = kvm->arch.ept_identity_map_addr =
VMX_EPT_IDENTITY_PAGETABLE_ADDR; VMX_EPT_IDENTITY_PAGETABLE_ADDR;
err = -ENOMEM; err = -ENOMEM;
if (alloc_identity_pagetable(kvm) != 0)
goto free_vmcs;
if (!init_rmode_identity_map(kvm)) if (!init_rmode_identity_map(kvm))
goto free_vmcs; goto free_vmcs;
} }
......
...@@ -7273,8 +7273,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm) ...@@ -7273,8 +7273,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
kvm_free_vcpus(kvm); kvm_free_vcpus(kvm);
if (kvm->arch.apic_access_page) if (kvm->arch.apic_access_page)
put_page(kvm->arch.apic_access_page); put_page(kvm->arch.apic_access_page);
if (kvm->arch.ept_identity_pagetable)
put_page(kvm->arch.ept_identity_pagetable);
kfree(rcu_dereference_check(kvm->arch.apic_map, 1)); kfree(rcu_dereference_check(kvm->arch.apic_map, 1));
} }
......
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