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authorMarc Zyngier <maz@kernel.org>2021-03-11 10:00:16 +0000
committerMarc Zyngier <maz@kernel.org>2021-03-12 15:43:22 +0000
commit262b003d059c6671601a19057e9fe1a5e7f23722 (patch)
tree803d472f432af55bdb4ace9d13d8613c2a6915e8
parent7d717558dd5ef10d28866750d5c24ff892ea3778 (diff)
downloadlinux-262b003d059c6671601a19057e9fe1a5e7f23722.tar.gz
KVM: arm64: Fix exclusive limit for IPA size
When registering a memslot, we check the size and location of that memslot against the IPA size to ensure that we can provide guest access to the whole of the memory. Unfortunately, this check rejects memslot that end-up at the exact limit of the addressing capability for a given IPA size. For example, it refuses the creation of a 2GB memslot at 0x8000000 with a 32bit IPA space. Fix it by relaxing the check to accept a memslot reaching the limit of the IPA space. Fixes: c3058d5da222 ("arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZE") Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Reviewed-by: Andrew Jones <drjones@redhat.com> Link: https://lore.kernel.org/r/20210311100016.3830038-3-maz@kernel.org
-rw-r--r--arch/arm64/kvm/mmu.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 77cb2d28f2a43..8711894db8c22 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1312,8 +1312,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
* Prevent userspace from creating a memory region outside of the IPA
* space addressable by the KVM guest IPA space.
*/
- if (memslot->base_gfn + memslot->npages >=
- (kvm_phys_size(kvm) >> PAGE_SHIFT))
+ if ((memslot->base_gfn + memslot->npages) > (kvm_phys_size(kvm) >> PAGE_SHIFT))
return -EFAULT;
mmap_read_lock(current->mm);