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| author | Geoff Levand <geoff@infradead.org> | 2016-04-27 19:47:03 +0300 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2016-04-28 14:05:46 +0300 |
| commit | ad72e59ff2bad55f6b9e7ac1fe5d824831ea2550 (patch) | |
| tree | ca5eca21b84288153c2ea778da81b9a5420afd95 /arch/arm64/kernel/hyp-stub.S | |
| parent | 00a44cdaba0900c63a003e0c431f506f49376a90 (diff) | |
| download | linux-ad72e59ff2bad55f6b9e7ac1fe5d824831ea2550.tar.xz | |
arm64: hyp/kvm: Make hyp-stub extensible
The existing arm64 hcall implementations are limited in that they only
allow for two distinct hcalls; with the x0 register either zero or not
zero. Also, the API of the hyp-stub exception vector routines and the
KVM exception vector routines differ; hyp-stub uses a non-zero value in
x0 to implement __hyp_set_vectors, whereas KVM uses it to implement
kvm_call_hyp.
To allow for additional hcalls to be defined and to make the arm64 hcall
API more consistent across exception vector routines, change the hcall
implementations to reserve all x0 values below 0xfff for hcalls such
as {s,g}et_vectors().
Define two new preprocessor macros HVC_GET_VECTORS, and HVC_SET_VECTORS
to be used as hcall type specifiers and convert the existing
__hyp_get_vectors() and __hyp_set_vectors() routines to use these new
macros when executing an HVC call. Also, change the corresponding
hyp-stub and KVM el1_sync exception vector routines to use these new
macros.
Signed-off-by: Geoff Levand <geoff@infradead.org>
[Merged two hcall patches, moved immediate value from esr to x0, use lr
as a scratch register, changed limit to 0xfff]
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/hyp-stub.S')
| -rw-r--r-- | arch/arm64/kernel/hyp-stub.S | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index 7eab8acbbbd9..894fb40fb378 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -22,6 +22,7 @@ #include <linux/irqchip/arm-gic-v3.h> #include <asm/assembler.h> +#include <asm/kvm_arm.h> #include <asm/ptrace.h> #include <asm/virt.h> @@ -53,15 +54,26 @@ ENDPROC(__hyp_stub_vectors) .align 11 el1_sync: - mrs x1, esr_el2 - lsr x1, x1, #26 - cmp x1, #0x16 - b.ne 2f // Not an HVC trap - cbz x0, 1f - msr vbar_el2, x0 // Set vbar_el2 - b 2f -1: mrs x0, vbar_el2 // Return vbar_el2 -2: eret + mrs x30, esr_el2 + lsr x30, x30, #ESR_ELx_EC_SHIFT + + cmp x30, #ESR_ELx_EC_HVC64 + b.ne 9f // Not an HVC trap + + cmp x0, #HVC_GET_VECTORS + b.ne 1f + mrs x0, vbar_el2 + b 9f + +1: cmp x0, #HVC_SET_VECTORS + b.ne 2f + msr vbar_el2, x1 + b 9f + + /* Unrecognised call type */ +2: mov x0, xzr + +9: eret ENDPROC(el1_sync) .macro invalid_vector label @@ -102,7 +114,7 @@ ENDPROC(\label) ENTRY(__hyp_get_vectors) str lr, [sp, #-16]! - mov x0, xzr + mov x0, #HVC_GET_VECTORS hvc #0 ldr lr, [sp], #16 ret @@ -110,6 +122,8 @@ ENDPROC(__hyp_get_vectors) ENTRY(__hyp_set_vectors) str lr, [sp, #-16]! + mov x1, x0 + mov x0, #HVC_SET_VECTORS hvc #0 ldr lr, [sp], #16 ret |