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| author | Joel Schopp <joel.schopp@amd.com> | 2014-07-09 11:17:04 -0500 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2014-09-26 14:39:13 +0200 |
| commit | dbff124e29fa24aff9705b354b5f4648cd96e0bb (patch) | |
| tree | 656027fb37f0866098281c7fb48accba6b47db66 | |
| parent | 0fea6d7628ed6e25a9ee1b67edf7c859718d39e8 (diff) | |
| download | lwn-dbff124e29fa24aff9705b354b5f4648cd96e0bb.tar.gz lwn-dbff124e29fa24aff9705b354b5f4648cd96e0bb.zip | |
arm/arm64: KVM: Fix VTTBR_BADDR_MASK and pgd alloc
The current aarch64 calculation for VTTBR_BADDR_MASK masks only 39 bits
and not all the bits in the PA range. This is clearly a bug that
manifests itself on systems that allocate memory in the higher address
space range.
[ Modified from Joel's original patch to be based on PHYS_MASK_SHIFT
instead of a hard-coded value and to move the alignment check of the
allocation to mmu.c. Also added a comment explaining why we hardcode
the IPA range and changed the stage-2 pgd allocation to be based on
the 40 bit IPA range instead of the maximum possible 48 bit PA range.
- Christoffer ]
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Joel Schopp <joel.schopp@amd.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| -rw-r--r-- | arch/arm/kvm/arm.c | 4 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_arm.h | 13 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 5 |
3 files changed, 16 insertions, 6 deletions
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 40bc3df6d87b..779605122f32 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -410,9 +410,9 @@ static void update_vttbr(struct kvm *kvm) /* update vttbr to be used with the new vmid */ pgd_phys = virt_to_phys(kvm->arch.pgd); + BUG_ON(pgd_phys & ~VTTBR_BADDR_MASK); vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) & VTTBR_VMID_MASK; - kvm->arch.vttbr = pgd_phys & VTTBR_BADDR_MASK; - kvm->arch.vttbr |= vmid; + kvm->arch.vttbr = pgd_phys | vmid; spin_unlock(&kvm_vmid_lock); } diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index cc83520459ed..7fd3e27e3ccc 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -122,6 +122,17 @@ #define VTCR_EL2_T0SZ_MASK 0x3f #define VTCR_EL2_T0SZ_40B 24 +/* + * We configure the Stage-2 page tables to always restrict the IPA space to be + * 40 bits wide (T0SZ = 24). Systems with a PARange smaller than 40 bits are + * not known to exist and will break with this configuration. + * + * Note that when using 4K pages, we concatenate two first level page tables + * together. + * + * The magic numbers used for VTTBR_X in this patch can be found in Tables + * D4-23 and D4-25 in ARM DDI 0487A.b. + */ #ifdef CONFIG_ARM64_64K_PAGES /* * Stage2 translation configuration: @@ -149,7 +160,7 @@ #endif #define VTTBR_BADDR_SHIFT (VTTBR_X - 1) -#define VTTBR_BADDR_MASK (((1LLU << (40 - VTTBR_X)) - 1) << VTTBR_BADDR_SHIFT) +#define VTTBR_BADDR_MASK (((1LLU << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) << VTTBR_BADDR_SHIFT) #define VTTBR_VMID_SHIFT (48LLU) #define VTTBR_VMID_MASK (0xffLLU << VTTBR_VMID_SHIFT) diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 737da742b293..a030d163840b 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -59,10 +59,9 @@ #define KERN_TO_HYP(kva) ((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET) /* - * Align KVM with the kernel's view of physical memory. Should be - * 40bit IPA, with PGD being 8kB aligned in the 4KB page configuration. + * We currently only support a 40bit IPA. */ -#define KVM_PHYS_SHIFT PHYS_MASK_SHIFT +#define KVM_PHYS_SHIFT (40) #define KVM_PHYS_SIZE (1UL << KVM_PHYS_SHIFT) #define KVM_PHYS_MASK (KVM_PHYS_SIZE - 1UL) |