diff options
| author | Marc Zyngier <maz@kernel.org> | 2020-10-24 17:33:38 +0200 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2020-11-27 12:32:43 +0100 |
| commit | 68b824e428c5fb5c3dc5ef80b1543e767534b58e (patch) | |
| tree | 93f0cc373bf871d0eddcdef77fc5ca0d8bb17c8c | |
| parent | KVM: arm64: Turn host HVC handling into a dispatch table (diff) | |
| download | linux-68b824e428c5fb5c3dc5ef80b1543e767534b58e.tar.xz linux-68b824e428c5fb5c3dc5ef80b1543e767534b58e.zip | |
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>
| -rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 22 | ||||
| -rw-r--r-- | arch/arm64/kernel/image-vars.h | 4 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/host.S | 5 | ||||
| -rw-r--r-- | arch/arm64/kvm/va_layout.c | 6 |
4 files changed, 30 insertions, 7 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> diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h index e8c194f8de88..4b32588918d9 100644 --- a/arch/arm64/kernel/image-vars.h +++ b/arch/arm64/kernel/image-vars.h @@ -65,13 +65,11 @@ __efistub__ctype = _ctype; KVM_NVHE_ALIAS(kvm_patch_vector_branch); KVM_NVHE_ALIAS(kvm_update_va_mask); KVM_NVHE_ALIAS(kvm_update_kimg_phys_offset); +KVM_NVHE_ALIAS(kvm_get_kimage_voffset); /* Global kernel state accessed by nVHE hyp code. */ KVM_NVHE_ALIAS(kvm_vgic_global_state); -/* Kernel constant needed to compute idmap addresses. */ -KVM_NVHE_ALIAS(kimage_voffset); - /* Kernel symbols used to call panic() from nVHE hyp code (via ERET). */ KVM_NVHE_ALIAS(__hyp_panic_string); KVM_NVHE_ALIAS(panic); diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S index ed27f06a31ba..4e207c1c5126 100644 --- a/arch/arm64/kvm/hyp/nvhe/host.S +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -115,10 +115,7 @@ SYM_FUNC_END(__hyp_do_panic) * Preserve x0-x4, which may contain stub parameters. */ ldr x5, =__kvm_handle_stub_hvc - ldr_l x6, kimage_voffset - - /* x5 = __pa(x5) */ - sub x5, x5, x6 + kimg_pa x5, x6 br x5 .L__vect_end\@: .if ((.L__vect_end\@ - .L__vect_start\@) > 0x80) diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c index 1d00d2cb93fd..d61117805de0 100644 --- a/arch/arm64/kvm/va_layout.c +++ b/arch/arm64/kvm/va_layout.c @@ -251,3 +251,9 @@ void kvm_update_kimg_phys_offset(struct alt_instr *alt, { generate_mov_q(kimage_voffset + PHYS_OFFSET, origptr, updptr, nr_inst); } + +void kvm_get_kimage_voffset(struct alt_instr *alt, + __le32 *origptr, __le32 *updptr, int nr_inst) +{ + generate_mov_q(kimage_voffset, origptr, updptr, nr_inst); +} |