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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/kvm/vmx.c | |
| parent | 38b9917350cb2946e368ba684cfc33d1672f104e (diff) | |
| download | lwn-c24ae0dcd3e8695efa43e71704d1fc4bc7e29e9b.tar.gz lwn-c24ae0dcd3e8695efa43e71704d1fc4bc7e29e9b.zip | |
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/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 9 |
1 files changed, 7 insertions, 2 deletions
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; |