[PATCH v7 0/9] kvm, mem-hotplug: Do not pin ept identity pagetable and apic access page.

From: Tang Chen
Date: Sat Sep 20 2014 - 06:46:20 EST


ept identity pagetable and apic access page in kvm are pinned in memory.
As a result, they cannot be migrated/hot-removed.

But actually they don't need to be pinned in memory.

[For ept identity page]
Just do not pin it. When it is migrated, guest will be able to find the
new page in the next ept violation.

[For apic access page]
The hpa of apic access page is stored in VMCS APIC_ACCESS_ADDR pointer.
When apic access page is migrated, we update VMCS APIC_ACCESS_ADDR pointer
for each vcpu in addition.

This patch-set is based on Linux 3.17.0-rc5.

NOTE: Tested with -cpu xxx,-x2apic option.
But since nested vm pins some other pages in memory, if user uses nested
vm, memory hot-remove will not work.

Change log v6 -> v7:
1. Patch 1/9~3/9 are applied to kvm/queue by Paolo Bonzini <pbonzini@xxxxxxxxxx>.
Just resend them, no changes.
2. In the new patch 4/9, add a new interface to check if secondary exec
virtualized apic access is enabled.
3. In new patch 6/9, rename make_all_cpus_request() to kvm_make_all_cpus_request()
and make it non-static so that we can use it in other patches.
4. In new patch 8/9, add arch specific function to make apic access page reload
request in mmu notifier.

Tang Chen (9):
kvm: Use APIC_DEFAULT_PHYS_BASE macro as the apic access page address.
kvm: Remove ept_identity_pagetable from struct kvm_arch.
kvm: Make init_rmode_identity_map() return 0 on success.
kvm: Add interface to check if secondary exec virtualzed apic accesses
is enabled.
kvm, mem-hotplug: Reload L1's apic access page in vcpu_enter_guest().
kvm: Rename make_all_cpus_request() to kvm_make_all_cpus_request() and
make it non-static.
kvm, mem-hotplug: Reload L1's apic access page on migration when L2 is
running.
kvm, mem-hotplug: Add arch specific mmu notifier to handle apic access
migration.
kvm, mem-hotplug: Unpin and remove kvm_arch->apic_access_page.

arch/x86/include/asm/kvm_host.h | 6 ++-
arch/x86/kvm/svm.c | 15 +++++-
arch/x86/kvm/vmx.c | 104 ++++++++++++++++++++++++----------------
arch/x86/kvm/x86.c | 47 ++++++++++++++++--
include/linux/kvm_host.h | 16 ++++++-
virt/kvm/kvm_main.c | 13 +++--
6 files changed, 146 insertions(+), 55 deletions(-)

--
1.8.3.1

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