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arm/arm64: KVM: Fix VTTBR_BADDR_MASK and pgd alloc

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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>
This commit is contained in:
Joel Schopp 2014-07-09 11:17:04 -05:00 committed by Christoffer Dall
parent 0fea6d7628
commit dbff124e29
3 changed files with 16 additions and 6 deletions
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4
arch/arm/kvm/arm.c
View File

@ -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);
}

13
arch/arm64/include/asm/kvm_arm.h
View File

@ -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)

5
arch/arm64/include/asm/kvm_mmu.h
View File

@ -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)