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author | Marc Zyngier <maz@kernel.org> | 2020-10-21 20:48:02 +0100 |
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committer | Marc Zyngier <maz@kernel.org> | 2020-11-09 16:56:39 +0000 |
commit | 1db9d9ded771389aae5760d20dd1bac113451b9c (patch) | |
tree | 0b875630a1e300480e9532be817812633b5205b3 /arch/arm64/kvm/va_layout.c | |
parent | f8394f232b1eab649ce2df5c5f15b0e528c92091 (diff) | |
download | linux-stable-1db9d9ded771389aae5760d20dd1bac113451b9c.tar.gz linux-stable-1db9d9ded771389aae5760d20dd1bac113451b9c.tar.bz2 linux-stable-1db9d9ded771389aae5760d20dd1bac113451b9c.zip |
KVM: arm64: Add kimg_hyp_va() helper
KVM/arm64 is so far unable to deal with function pointers, as the compiler
will generate the kernel's runtime VA, and not the linear mapping address,
meaning that kern_hyp_va() will give the wrong result.
We so far have been able to use PC-relative addressing, but that's not
always easy to use, and prevents the implementation of things like
the mapping of an index to a pointer.
To allow this, provide a new helper that computes the required
translation from the kernel image to the HYP VA space.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/kvm/va_layout.c')
-rw-r--r-- | arch/arm64/kvm/va_layout.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c index e0404bcab019..1d00d2cb93fd 100644 --- a/arch/arm64/kvm/va_layout.c +++ b/arch/arm64/kvm/va_layout.c @@ -11,6 +11,7 @@ #include <asm/debug-monitors.h> #include <asm/insn.h> #include <asm/kvm_mmu.h> +#include <asm/memory.h> /* * The LSB of the HYP VA tag @@ -201,3 +202,52 @@ void kvm_patch_vector_branch(struct alt_instr *alt, AARCH64_INSN_BRANCH_NOLINK); *updptr++ = cpu_to_le32(insn); } + +static void generate_mov_q(u64 val, __le32 *origptr, __le32 *updptr, int nr_inst) +{ + u32 insn, oinsn, rd; + + BUG_ON(nr_inst != 4); + + /* Compute target register */ + oinsn = le32_to_cpu(*origptr); + rd = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RD, oinsn); + + /* movz rd, #(val & 0xffff) */ + insn = aarch64_insn_gen_movewide(rd, + (u16)val, + 0, + AARCH64_INSN_VARIANT_64BIT, + AARCH64_INSN_MOVEWIDE_ZERO); + *updptr++ = cpu_to_le32(insn); + + /* movk rd, #((val >> 16) & 0xffff), lsl #16 */ + insn = aarch64_insn_gen_movewide(rd, + (u16)(val >> 16), + 16, + AARCH64_INSN_VARIANT_64BIT, + AARCH64_INSN_MOVEWIDE_KEEP); + *updptr++ = cpu_to_le32(insn); + + /* movk rd, #((val >> 32) & 0xffff), lsl #32 */ + insn = aarch64_insn_gen_movewide(rd, + (u16)(val >> 32), + 32, + AARCH64_INSN_VARIANT_64BIT, + AARCH64_INSN_MOVEWIDE_KEEP); + *updptr++ = cpu_to_le32(insn); + + /* movk rd, #((val >> 48) & 0xffff), lsl #48 */ + insn = aarch64_insn_gen_movewide(rd, + (u16)(val >> 48), + 48, + AARCH64_INSN_VARIANT_64BIT, + AARCH64_INSN_MOVEWIDE_KEEP); + *updptr++ = cpu_to_le32(insn); +} + +void kvm_update_kimg_phys_offset(struct alt_instr *alt, + __le32 *origptr, __le32 *updptr, int nr_inst) +{ + generate_mov_q(kimage_voffset + PHYS_OFFSET, origptr, updptr, nr_inst); +} |