KVM: arm/arm64: Fix idmap size and alignment

Although the idmap section of KVM can only be at most 4kB and
must be aligned on a 4kB boundary, the rest of the code expects
it to be page aligned. Things get messy when tearing down the
HYP page tables when PAGE_SIZE is 64K, and the idmap section isn't
64K aligned.

Let's fix this by computing aligned boundaries that the HYP code
will use.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: James Morse <james.morse@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 52b0ee31ebee0d77a2f07775af9dd08783d02659..c41d03a8af9307c67919a3bc9f3253682a475404 100644 (file)
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1815,7 +1815,9 @@ int kvm_mmu_init(void)
        int err;
 
        hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);
+       hyp_idmap_start = ALIGN_DOWN(hyp_idmap_start, PAGE_SIZE);
        hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);
+       hyp_idmap_end = ALIGN(hyp_idmap_end, PAGE_SIZE);
        hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);
 
        /*