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| author |   Andre Przywara <andre.przywara@arm.com> | 2014-11-06 12:11:45 +0000 |
|---|---|---|
| committer |   Marc Zyngier <marc.zyngier@arm.com> | 2014-11-25 13:57:28 +0000 |
| commit | 5100f9833e1881c800bc088e70afa4b9a1409f51 (patch) | |
| tree | c4f34bbb05d281c623d7c0dbeba90ae4e8175ca3 /arch/arm/kvm | |
| parent | arm, arm64: KVM: handle potential incoherency of readonly memslots (diff) | |
| download | linux-dev-5100f9833e1881c800bc088e70afa4b9a1409f51.tar.xz linux-dev-5100f9833e1881c800bc088e70afa4b9a1409f51.zip | |
arm/arm64: KVM: avoid unnecessary guest register mangling on MMIO read
Currently we mangle the endianness of the guest's register even on an
MMIO _read_, where it is completely useless, because we will not use
the value of that register.
Rework the io_mem_abort() function to clearly separate between reads
and writes and only do the endianness mangling on MMIO writes.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm/kvm')
| -rw-r--r-- | arch/arm/kvm/mmio.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c index 4cb5a93182e9..5d3bfc0eb3f0 100644 --- a/arch/arm/kvm/mmio.c +++ b/arch/arm/kvm/mmio.c @@ -187,15 +187,18 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, } rt = vcpu->arch.mmio_decode.rt; - data = vcpu_data_guest_to_host(vcpu, *vcpu_reg(vcpu, rt), mmio.len); - trace_kvm_mmio((mmio.is_write) ? KVM_TRACE_MMIO_WRITE : - KVM_TRACE_MMIO_READ_UNSATISFIED, - mmio.len, fault_ipa, - (mmio.is_write) ? data : 0); + if (mmio.is_write) { + data = vcpu_data_guest_to_host(vcpu, *vcpu_reg(vcpu, rt), + mmio.len); - if (mmio.is_write) + trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, mmio.len, + fault_ipa, data); mmio_write_buf(mmio.data, mmio.len, data); + } else { + trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, mmio.len, + fault_ipa, 0); + } if (vgic_handle_mmio(vcpu, run, &mmio)) return 1; |