• Marc Zyngier's avatar
    arm64: KVM: Do not use pgd_index to index stage-2 pgd · 04b8dc85
    Marc Zyngier authored
    The kernel's pgd_index macro is designed to index a normal, page
    sized array. KVM is a bit diffferent, as we can use concatenated
    pages to have a bigger address space (for example 40bit IPA with
    4kB pages gives us an 8kB PGD.
    
    In the above case, the use of pgd_index will always return an index
    inside the first 4kB, which makes a guest that has memory above
    0x8000000000 rather unhappy, as it spins forever in a page fault,
    whist the host happilly corrupts the lower pgd.
    
    The obvious fix is to get our own kvm_pgd_index that does the right
    thing(tm).
    
    Tested on X-Gene with a hacked kvmtool that put memory at a stupidly
    high address.
    Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
    Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
    Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
    04b8dc85
mmu.c 48.1 KB