On 04/03/2014 05:26 PM, Marc Zyngier wrote:
> Hi Eric,
>
> On 03/04/14 16:17, Eric Auger wrote:
>> Currently when a KVM region is removed using
>> kvm_vm_ioctl_set_memory_region (with memory region size equal to 0), the
>> corresponding intermediate physical memory is not unmapped.
>>
>> This patch unmaps the region's IPA range in
>> kvm_arch_commit_memory_region using unmap_stage2_range.
>>
>> The patch was tested on QEMU VFIO based use case where RAM memory region
>> creation/deletion frequently happens for IRQ handling.
>>
>> Notes:
>> - the KVM_MR_MOVE case shall request some similar addition but I cannot test
>> this currently
>
> I think you should try to handle it anyway. I'm sure you could hack QEMU
> to do this test it, but even if you don't, better plug that hole right now.
Hi Marc,
OK I will proceed
>
>> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
>> ---
>> arch/arm/include/asm/kvm_mmu.h | 2 ++
>> arch/arm/kvm/arm.c | 8 ++++++++
>> arch/arm/kvm/mmu.c | 2 +-
>> 3 files changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
>> index 2d122ad..a91c863 100644
>> --- a/arch/arm/include/asm/kvm_mmu.h
>> +++ b/arch/arm/include/asm/kvm_mmu.h
>> @@ -52,6 +52,8 @@ void kvm_free_stage2_pgd(struct kvm *kvm);
>> int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
>> phys_addr_t pa, unsigned long size);
>>
>> +void unmap_stage2_range(struct kvm *kvm, phys_addr_t guest_ipa, u64 size);
>> +
>> int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);
>>
>> void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);
>> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
>> index bd18bb8..9a4bc10 100644
>> --- a/arch/arm/kvm/arm.c
>> +++ b/arch/arm/kvm/arm.c
>> @@ -241,6 +241,14 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
>> const struct kvm_memory_slot *old,
>> enum kvm_mr_change change)
>> {
>> + if (change == KVM_MR_DELETE) {
>> + gpa_t gpa = old->base_gfn << PAGE_SHIFT;
>> + u64 size = old->npages << PAGE_SHIFT;
>> +
>> + spin_lock(&kvm->mmu_lock);
>> + unmap_stage2_range(kvm, gpa, size);
>> + spin_unlock(&kvm->mmu_lock);
>> + }
>> }
>
> Just move the whole function to mmu.c, as it makes more sense to have it
> there. And while you're at it, how about moving the other
> memslot/memory_region stubs?
OK I will move:
kvm_arch_free_memslot,
kvm_arch_create_memslot,
kvm_arch_prepare_memory_region,
kvm_arch_commit_memory_region,
kvm_arch_shadow_all and
kvm_arch_shadow_memslot then.
Best Regards
Eric
>
>> void kvm_arch_flush_shadow_all(struct kvm *kvm)
>> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
>> index 7789857..e8580e2 100644
>> --- a/arch/arm/kvm/mmu.c
>> +++ b/arch/arm/kvm/mmu.c
>> @@ -443,7 +443,7 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm)
>> * destroying the VM), otherwise another faulting VCPU may come in and mess
>> * with things behind our backs.
>> */
>> -static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
>> +void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
>> {
>> unmap_range(kvm, kvm->arch.pgd, start, size);
>> }
>>
>
> Looks sensible otherwise.
>
> Thanks!
>
> M.
>
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