Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

kvm: x86: Unpin and remove kvm_arch->apic_access_page

Browse source 
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>
This commit is contained in:
Tang Chen 2014-09-24 15:57:58 +08:00 committed by Paolo Bonzini
parent 38b9917350
commit c24ae0dcd3
3 changed files with 24 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
arch/x86/include/asm/kvm_host.h
View file

@ -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;

9
arch/x86/kvm/vmx.c
View file

@ -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;

22
arch/x86/kvm/x86.c
View file

@ -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));
}