diff options
| author | Marc Zyngier <marc.zyngier@arm.com> | 2016-06-30 18:40:50 +0100 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2016-07-03 23:41:27 +0200 |
| commit | eac378a9ceb7196b776a965d915e02995fb8ba55 (patch) | |
| tree | 207965331a3cb620ebcd081ac61b1580a2a7cf90 | |
| parent | f7bec68d2faed8180d7172cdbd69d99e3cad1387 (diff) | |
arm/arm64: KVM: Check that IDMAP doesn't intersect with VA range
This is more of a safety measure than anything else: If we end-up
with an idmap page that intersect with the range picked for the
the HYP VA space, abort the KVM setup, as it is unsafe to go
further.
I cannot imagine it happening on 64bit (we have a mechanism to
work around it), but could potentially occur on a 32bit system with
the kernel loaded high enough in memory so that in conflicts with
the kernel VA.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| -rw-r--r-- | arch/arm/kvm/mmu.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 0b36dd52af62..8a0aa37605c5 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1709,6 +1709,21 @@ int kvm_mmu_init(void) */ BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK); + kvm_info("IDMAP page: %lx\n", hyp_idmap_start); + kvm_info("HYP VA range: %lx:%lx\n", + KERN_TO_HYP(PAGE_OFFSET), KERN_TO_HYP(~0UL)); + + if (hyp_idmap_start >= KERN_TO_HYP(PAGE_OFFSET) && + hyp_idmap_start < KERN_TO_HYP(~0UL)) { + /* + * The idmap page is intersecting with the VA space, + * it is not safe to continue further. + */ + kvm_err("IDMAP intersecting with HYP VA, unable to continue\n"); + err = -EINVAL; + goto out; + } + hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order); if (!hyp_pgd) { kvm_err("Hyp mode PGD not allocated\n"); |