From: Joel Schopp <joel.schopp@xxxxxxx> 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@xxxxxxx> Signed-off-by: Joel Schopp <joel.schopp@xxxxxxx> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> --- arch/arm/kvm/arm.c | 4 ++-- arch/arm64/include/asm/kvm_arm.h | 13 ++++++++++++- 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 40bc3df..7796051 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 cc83520..7fd3e27 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 737da74..a030d16 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) -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
