Re: [PATCH v8 0/8] kvm, mem-hotplug: Do not pin ept identity pagetable and apic access page.

[Tang Chen]

Hi Paolo,

I'd like to help to test the patches.
Would you please tell me what is the best way to test this patch-set ?

I think ept page is being used by regular guest.
Is adding "-cpu xxx,-x2apic option" able to make sure guest is using
apic page ?

Thanks.

On 09/24/2014 04:20 PM, Paolo Bonzini wrote:
> Il 24/09/2014 09:57, Tang Chen ha scritto:
> > 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 v7->v8:
> > 1. Patch 1/9~3/9 were applied to kvm/queue by Paolo Bonzini <pbonzini@xxxxxxxxxx>.
> >     Just resend them, no changes.
> > 2. Removed previous patch 4/9, which added unnecessary hook has_secondary_apic_access().
> > 3. Set kvm_x86_ops->set_apic_access_page_addr to NULL when hardware had no flexpriority
> >     functionality which actually exists only on x86.
> > 4. Moved declaration of kvm_arch_mmu_notifier_invalidate_page() to arch/*/include/asm/kvm_host.h.
> > 5. Removed useless set_apic_access_page_addr() hook for svm.
> >
> > Tang Chen (8):
> >    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, 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/arm/include/asm/kvm_host.h     |   5 ++
> >   arch/arm64/include/asm/kvm_host.h   |   5 ++
> >   arch/ia64/include/asm/kvm_host.h    |   7 ++
> >   arch/mips/include/asm/kvm_host.h    |   6 ++
> >   arch/powerpc/include/asm/kvm_host.h |   5 ++
> >   arch/s390/include/asm/kvm_host.h    |   8 +++
> >   arch/x86/include/asm/kvm_host.h     |   7 +-
> >   arch/x86/kvm/svm.c                  |   3 +-
> >   arch/x86/kvm/vmx.c                  | 130 ++++++++++++++++++++++++------------
> >   arch/x86/kvm/x86.c                  |  45 +++++++++++--
> >   include/linux/kvm_host.h            |   2 +
> >   virt/kvm/kvm_main.c                 |  13 ++--
> >   12 files changed, 180 insertions(+), 56 deletions(-)
> Thanks for your persistence!  The patches look good, I'll test them and
> apply to kvm/queue.
>
> Paolo
> .

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/