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authorMarc Zyngier <marc.zyngier@arm.com>2015-10-28 15:06:47 +0000
committerMarc Zyngier <marc.zyngier@arm.com>2016-02-29 18:34:18 +0000
commit5f05a72aed023e5824eebb2542b5397cb89188f4 (patch)
tree71166b529f6e077e7153119e09f30fac8ff2d815 /arch/arm64/kvm/hyp/hyp-entry.S
parent253dcbd39adb00890f3c350230ae310fcfeeb760 (diff)
arm64: KVM: Move most of the fault decoding to C
The fault decoding process (including computing the IPA in the case of a permission fault) would be much better done in C code, as we have a reasonable infrastructure to deal with the VHE/non-VHE differences. Let's move the whole thing to C, including the workaround for erratum 834220, and just patch the odd ESR_EL2 access remaining in hyp-entry.S. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64/kvm/hyp/hyp-entry.S')
-rw-r--r--arch/arm64/kvm/hyp/hyp-entry.S69
1 files changed, 5 insertions, 64 deletions
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index 1bdeee70833e..3488894397ff 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -19,7 +19,6 @@
#include <asm/alternative.h>
#include <asm/assembler.h>
-#include <asm/asm-offsets.h>
#include <asm/cpufeature.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
@@ -69,7 +68,11 @@ ENDPROC(__vhe_hyp_call)
el1_sync: // Guest trapped into EL2
save_x0_to_x3
+alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
mrs x1, esr_el2
+alternative_else
+ mrs x1, esr_el1
+alternative_endif
lsr x2, x1, #ESR_ELx_EC_SHIFT
cmp x2, #ESR_ELx_EC_HVC64
@@ -105,72 +108,10 @@ el1_trap:
cmp x2, #ESR_ELx_EC_FP_ASIMD
b.eq __fpsimd_guest_restore
- cmp x2, #ESR_ELx_EC_DABT_LOW
- mov x0, #ESR_ELx_EC_IABT_LOW
- ccmp x2, x0, #4, ne
- b.ne 1f // Not an abort we care about
-
- /* This is an abort. Check for permission fault */
-alternative_if_not ARM64_WORKAROUND_834220
- and x2, x1, #ESR_ELx_FSC_TYPE
- cmp x2, #FSC_PERM
- b.ne 1f // Not a permission fault
-alternative_else
- nop // Use the permission fault path to
- nop // check for a valid S1 translation,
- nop // regardless of the ESR value.
-alternative_endif
-
- /*
- * Check for Stage-1 page table walk, which is guaranteed
- * to give a valid HPFAR_EL2.
- */
- tbnz x1, #7, 1f // S1PTW is set
-
- /* Preserve PAR_EL1 */
- mrs x3, par_el1
- stp x3, xzr, [sp, #-16]!
-
- /*
- * Permission fault, HPFAR_EL2 is invalid.
- * Resolve the IPA the hard way using the guest VA.
- * Stage-1 translation already validated the memory access rights.
- * As such, we can use the EL1 translation regime, and don't have
- * to distinguish between EL0 and EL1 access.
- */
- mrs x2, far_el2
- at s1e1r, x2
- isb
-
- /* Read result */
- mrs x3, par_el1
- ldp x0, xzr, [sp], #16 // Restore PAR_EL1 from the stack
- msr par_el1, x0
- tbnz x3, #0, 3f // Bail out if we failed the translation
- ubfx x3, x3, #12, #36 // Extract IPA
- lsl x3, x3, #4 // and present it like HPFAR
- b 2f
-
-1: mrs x3, hpfar_el2
- mrs x2, far_el2
-
-2: mrs x0, tpidr_el2
- str w1, [x0, #VCPU_ESR_EL2]
- str x2, [x0, #VCPU_FAR_EL2]
- str x3, [x0, #VCPU_HPFAR_EL2]
-
+ mrs x0, tpidr_el2
mov x1, #ARM_EXCEPTION_TRAP
b __guest_exit
- /*
- * Translation failed. Just return to the guest and
- * let it fault again. Another CPU is probably playing
- * behind our back.
- */
-3: restore_x0_to_x3
-
- eret
-
el1_irq:
save_x0_to_x3
mrs x0, tpidr_el2