diff options
| author | Marc Zyngier <maz@kernel.org> | 2020-10-24 16:33:38 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2020-11-27 11:32:43 +0000 |
| commit | 68b824e428c5fb5c3dc5ef80b1543e767534b58e (patch) | |
| tree | 93f0cc373bf871d0eddcdef77fc5ca0d8bb17c8c /arch/arm64/include/asm/kvm_mmu.h | |
| parent | 7cd0aaafaadcaaf280887f8b478393a9fcfc69e3 (diff) | |
KVM: arm64: Patch kimage_voffset instead of loading the EL1 value
Directly using the kimage_voffset variable is fine for now, but
will become more problematic as we start distrusting EL1.
Instead, patch the kimage_voffset into the HYP text, ensuring
we don't have to load an untrusted value later on.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm/kvm_mmu.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 608c3a83e740..5633c5a27aad 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -72,6 +72,28 @@ alternative_cb kvm_update_va_mask alternative_cb_end .endm +/* + * Convert a kernel image address to a PA + * reg: kernel address to be converted in place + * tmp: temporary register + * + * The actual code generation takes place in kvm_get_kimage_voffset, and + * the instructions below are only there to reserve the space and + * perform the register allocation (kvm_get_kimage_voffset uses the + * specific registers encoded in the instructions). + */ +.macro kimg_pa reg, tmp +alternative_cb kvm_get_kimage_voffset + movz \tmp, #0 + movk \tmp, #0, lsl #16 + movk \tmp, #0, lsl #32 + movk \tmp, #0, lsl #48 +alternative_cb_end + + /* reg = __pa(reg) */ + sub \reg, \reg, \tmp +.endm + #else #include <linux/pgtable.h> |