2014-06-06 09:10:59

by Eric Auger

Subject: [PATCH v3] ARM: KVM: Unmap IPA on memslot delete/move

Currently when a KVM region is deleted or moved after
KVM_SET_USER_MEMORY_REGION ioctl, the corresponding
intermediate physical memory is not unmapped.

This patch corrects this and unmaps the region's IPA range
in kvm_arch_commit_memory_region using unmap_stage2_range.

Signed-off-by: Eric Auger <[email protected]>
---

The patch was tested with QEMU using the VFIO platform
device. In a specific IRQ handling case, the device regularly
deletes/creates some RAM regions.

v3:
- replace u64 by phys_addr_t in kvm_arch_commit_memory_region

v2:
- KVM_MR_MOVE case also handled and tested using a QEMU hack
- memslot and memory_region stubs moved from arm.c to mmu.c
following Marc Zyngier recommendations.
---
arch/arm/kvm/arm.c | 37 -------------------------------------
arch/arm/kvm/mmu.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 46 insertions(+), 37 deletions(-)

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index f0e50a0..bcc2929 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -155,16 +155,6 @@ int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
return VM_FAULT_SIGBUS;
}

-void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
- struct kvm_memory_slot *dont)
-{
-}
-
-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
- unsigned long npages)
-{
- return 0;
-}

/**
* kvm_arch_destroy_vm - destroy the VM data structure
@@ -224,33 +214,6 @@ long kvm_arch_dev_ioctl(struct file *filp,
return -EINVAL;
}

-void kvm_arch_memslots_updated(struct kvm *kvm)
-{
-}
-
-int kvm_arch_prepare_memory_region(struct kvm *kvm,
- struct kvm_memory_slot *memslot,
- struct kvm_userspace_memory_region *mem,
- enum kvm_mr_change change)
-{
- return 0;
-}
-
-void kvm_arch_commit_memory_region(struct kvm *kvm,
- struct kvm_userspace_memory_region *mem,
- const struct kvm_memory_slot *old,
- enum kvm_mr_change change)
-{
-}
-
-void kvm_arch_flush_shadow_all(struct kvm *kvm)
-{
-}
-
-void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
- struct kvm_memory_slot *slot)
-{
-}

struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
{
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 16f8049..cc5ca9e 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -1100,3 +1100,49 @@ out:
free_hyp_pgds();
return err;
}
+
+void kvm_arch_commit_memory_region(struct kvm *kvm,
+ struct kvm_userspace_memory_region *mem,
+ const struct kvm_memory_slot *old,
+ enum kvm_mr_change change)
+{
+ gpa_t gpa = old->base_gfn << PAGE_SHIFT;
+ phys_addr_t size = old->npages << PAGE_SHIFT;
+ if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) {
+ spin_lock(&kvm->mmu_lock);
+ unmap_stage2_range(kvm, gpa, size);
+ spin_unlock(&kvm->mmu_lock);
+ }
+}
+
+int kvm_arch_prepare_memory_region(struct kvm *kvm,
+ struct kvm_memory_slot *memslot,
+ struct kvm_userspace_memory_region *mem,
+ enum kvm_mr_change change)
+{
+ return 0;
+}
+
+void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
+ struct kvm_memory_slot *dont)
+{
+}
+
+int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
+ unsigned long npages)
+{
+ return 0;
+}
+
+void kvm_arch_memslots_updated(struct kvm *kvm)
+{
+}
+
+void kvm_arch_flush_shadow_all(struct kvm *kvm)
+{
+}
+
+void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
+ struct kvm_memory_slot *slot)
+{
+}
--
1.9.1

2014-06-06 09:16:10

by Christoffer Dall

Subject: Re: [PATCH v3] ARM: KVM: Unmap IPA on memslot delete/move

On Fri, Jun 06, 2014 at 11:10:23AM +0200, Eric Auger wrote:
> Currently when a KVM region is deleted or moved after
> KVM_SET_USER_MEMORY_REGION ioctl, the corresponding
> intermediate physical memory is not unmapped.
>
> This patch corrects this and unmaps the region's IPA range
> in kvm_arch_commit_memory_region using unmap_stage2_range.
>
> Signed-off-by: Eric Auger <[email protected]>

I think I already acked it in the last version, if Marc is ok with it, I
can queue it for next.

-Christoffer

2014-06-06 10:40:05

by Marc Zyngier

Subject: Re: [PATCH v3] ARM: KVM: Unmap IPA on memslot delete/move

On Fri, Jun 06 2014 at 10:16:03 am BST, Christoffer Dall <[email protected]> wrote:
> On Fri, Jun 06, 2014 at 11:10:23AM +0200, Eric Auger wrote:
>> Currently when a KVM region is deleted or moved after
>> KVM_SET_USER_MEMORY_REGION ioctl, the corresponding
>> intermediate physical memory is not unmapped.
>>
>> This patch corrects this and unmaps the region's IPA range
>> in kvm_arch_commit_memory_region using unmap_stage2_range.
>>
>> Signed-off-by: Eric Auger <[email protected]>
>
> I think I already acked it in the last version, if Marc is ok with it, I
> can queue it for next.

Yes, I'm quite happy for this to go in.

Acked-by: Marc Zyngier <[email protected]>

Thanks,

M.
--
Jazz is not dead. It just smells funny.