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| author |   Marc Zyngier <marc.zyngier@arm.com> | 2015-03-10 19:07:00 +0000 |
|---|---|---|
| committer |   Christoffer Dall <christoffer.dall@linaro.org> | 2015-03-11 14:24:36 +0100 |
| commit | 04b8dc85bf4a64517e3cf20e409eeaa503b15cc1 (patch) | |
| tree | ce074a61824c768147f911152c4af6dfa97ff9eb /arch/arm64/include | |
| parent | arm64: KVM: Fix stage-2 PGD allocation to have per-page refcounting (diff) | |
| download | linux-dev-04b8dc85bf4a64517e3cf20e409eeaa503b15cc1.tar.xz linux-dev-04b8dc85bf4a64517e3cf20e409eeaa503b15cc1.zip | |
arm64: KVM: Do not use pgd_index to index stage-2 pgd
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: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index a099cd9cdef8..bbfb600fa822 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -158,6 +158,8 @@ static inline bool kvm_s2pmd_readonly(pmd_t *pmd) #define PTRS_PER_S2_PGD (1 << PTRS_PER_S2_PGD_SHIFT) #define S2_PGD_ORDER get_order(PTRS_PER_S2_PGD * sizeof(pgd_t)) +#define kvm_pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_S2_PGD - 1)) + /* * If we are concatenating first level stage-2 page tables, we would have less * than or equal to 16 pointers in the fake PGD, because that's what the |