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| author | Dave Martin <Dave.Martin@arm.com> | 2018-05-02 13:36:48 +0100 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2018-05-25 12:28:30 +0100 |
| commit | 7846b3119e24fe8d726535d6aa7489253797700c (patch) | |
| tree | 8b9aa463a866e3048b29d184937b35c5734a614f /arch/arm64 | |
| parent | ba4f4cb0e661ed4c68057d4dd831f54b99770b09 (diff) | |
| download | op-kernel-dev-7846b3119e24fe8d726535d6aa7489253797700c.zip op-kernel-dev-7846b3119e24fe8d726535d6aa7489253797700c.tar.gz | |
KVM: arm64: Fold redundant exit code checks out of fixup_guest_exit()
The entire tail of fixup_guest_exit() is contained in if statements
of the form if (x && *exit_code == ARM_EXCEPTION_TRAP). As a result,
we can check just once and bail out of the function early, allowing
the remaining if conditions to be simplified.
The only awkward case is where *exit_code is changed to
ARM_EXCEPTION_EL1_SERROR in the case of an illegal GICv2 CPU
interface access: in that case, the GICv3 trap handling code is
skipped using a goto. This avoids pointlessly evaluating the
static branch check for the GICv3 case, even though we can't have
vgic_v2_cpuif_trap and vgic_v3_cpuif_trap true simultaneously
unless we have a GICv3 and GICv2 on the host: that sounds stupid,
but I haven't satisfied myself that it can't happen.
No functional change.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kvm/hyp/switch.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 18d0faa..4fbee95 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -387,11 +387,13 @@ static bool __hyp_text fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) * same PC once the SError has been injected, and replay the * trapping instruction. */ - if (*exit_code == ARM_EXCEPTION_TRAP && !__populate_fault_info(vcpu)) + if (*exit_code != ARM_EXCEPTION_TRAP) + goto exit; + + if (!__populate_fault_info(vcpu)) return true; - if (static_branch_unlikely(&vgic_v2_cpuif_trap) && - *exit_code == ARM_EXCEPTION_TRAP) { + if (static_branch_unlikely(&vgic_v2_cpuif_trap)) { bool valid; valid = kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_DABT_LOW && @@ -417,11 +419,12 @@ static bool __hyp_text fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) *vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS; *exit_code = ARM_EXCEPTION_EL1_SERROR; } + + goto exit; } } if (static_branch_unlikely(&vgic_v3_cpuif_trap) && - *exit_code == ARM_EXCEPTION_TRAP && (kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_SYS64 || kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_CP15_32)) { int ret = __vgic_v3_perform_cpuif_access(vcpu); @@ -430,6 +433,7 @@ static bool __hyp_text fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) return true; } +exit: /* Return to the host kernel and handle the exit */ return false; } |
