| Message ID | 1396538266-13245-1-git-send-email-eric.auger@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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. > Signed-off-by: Eric Auger <eric.auger@linaro.org> > --- > 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? > 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.
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@linaro.org> >> --- >> 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. >
On 3 April 2014 08:26, Marc Zyngier <marc.zyngier@arm.com> 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. > I don't think we want untested code in the kernel if we can avoid it, so I would say, either test it somehow (kvm-unit-tests ?) or print a warning...? -Christoffer
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); + } } 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); }
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 Signed-off-by: Eric Auger <eric.auger@linaro.org> --- 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(-)