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From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Will Deacon <will@kernel.org>, Andrew Jones <drjones@redhat.com>,
	Eric Auger <eric.auger@redhat.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	kernel-team@android.com, stable@vger.kernel.org
Subject: [PATCH v3 2/2] KVM: arm64: Fix exclusive limit for IPA size
Date: Thu, 11 Mar 2021 10:00:16 +0000	[thread overview]
Message-ID: <20210311100016.3830038-3-maz@kernel.org> (raw)
In-Reply-To: <20210311100016.3830038-1-maz@kernel.org>

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: e55cac5bf2a9 ("kvm: arm/arm64: Prepare for VM specific stage2 translations")
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
---
 arch/arm64/kvm/mmu.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 77cb2d28f2a4..8711894db8c2 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);
-- 
2.29.2


WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: kernel-team@android.com, stable@vger.kernel.org,
	Will Deacon <will@kernel.org>
Subject: [PATCH v3 2/2] KVM: arm64: Fix exclusive limit for IPA size
Date: Thu, 11 Mar 2021 10:00:16 +0000	[thread overview]
Message-ID: <20210311100016.3830038-3-maz@kernel.org> (raw)
In-Reply-To: <20210311100016.3830038-1-maz@kernel.org>

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: e55cac5bf2a9 ("kvm: arm/arm64: Prepare for VM specific stage2 translations")
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
---
 arch/arm64/kvm/mmu.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 77cb2d28f2a4..8711894db8c2 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);
-- 
2.29.2

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Will Deacon <will@kernel.org>, Andrew Jones <drjones@redhat.com>,
	Eric Auger <eric.auger@redhat.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	kernel-team@android.com, stable@vger.kernel.org
Subject: [PATCH v3 2/2] KVM: arm64: Fix exclusive limit for IPA size
Date: Thu, 11 Mar 2021 10:00:16 +0000	[thread overview]
Message-ID: <20210311100016.3830038-3-maz@kernel.org> (raw)
In-Reply-To: <20210311100016.3830038-1-maz@kernel.org>

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: e55cac5bf2a9 ("kvm: arm/arm64: Prepare for VM specific stage2 translations")
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
---
 arch/arm64/kvm/mmu.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 77cb2d28f2a4..8711894db8c2 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);
-- 
2.29.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2021-03-11 10:01 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-11 10:00 [PATCH v3 0/2] KVM: arm64: Assorted IPA size fixes Marc Zyngier
2021-03-11 10:00 ` Marc Zyngier
2021-03-11 10:00 ` Marc Zyngier
2021-03-11 10:00 ` [PATCH v3 1/2] KVM: arm64: Reject VM creation when the default IPA size is unsupported Marc Zyngier
2021-03-11 10:00   ` Marc Zyngier
2021-03-11 10:00   ` Marc Zyngier
2021-03-11 11:08   ` Andrew Jones
2021-03-11 11:08     ` Andrew Jones
2021-03-11 11:08     ` Andrew Jones
2021-03-11 14:05   ` Auger Eric
2021-03-11 14:05     ` Auger Eric
2021-03-11 14:05     ` Auger Eric
2021-03-11 10:00 ` Marc Zyngier [this message]
2021-03-11 10:00   ` [PATCH v3 2/2] KVM: arm64: Fix exclusive limit for IPA size Marc Zyngier
2021-03-11 10:00   ` Marc Zyngier
2021-03-11 11:15   ` Andrew Jones
2021-03-11 11:15     ` Andrew Jones
2021-03-11 11:15     ` Andrew Jones
2021-03-12 15:44     ` Marc Zyngier
2021-03-12 15:44       ` Marc Zyngier
2021-03-12 15:44       ` Marc Zyngier
2021-03-12 16:04 ` [PATCH v3 0/2] KVM: arm64: Assorted IPA size fixes Marc Zyngier
2021-03-12 16:04   ` Marc Zyngier
2021-03-12 16:04   ` Marc Zyngier

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