MMIO emulation for a realm cannot be done directly with the VM's registers as they are protected from the host. However, for emulatable data aborts, the RMM uses GPRS[0] to provide the read/written value. We can transfer this from/to the equivalent VCPU's register entry and then depend on the generic MMIO handling code in KVM. For a MMIO read, the value is placed in the shared RecExit structure during kvm_handle_mmio_return() rather than in the VCPU's register entry. Signed-off-by: Steven Price <steven.price@xxxxxxx> --- v3: Adapt to previous patch changes --- arch/arm64/kvm/mmio.c | 10 +++++++++- arch/arm64/kvm/rme-exit.c | 6 ++++++ 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c index cd6b7b83e2c3..dbd06ca368e8 100644 --- a/arch/arm64/kvm/mmio.c +++ b/arch/arm64/kvm/mmio.c @@ -6,6 +6,7 @@ #include <linux/kvm_host.h> #include <asm/kvm_emulate.h> +#include <asm/rmi_smc.h> #include <trace/events/kvm.h> #include "trace.h" @@ -90,6 +91,9 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu) vcpu->mmio_needed = 0; + if (vcpu_is_rec(vcpu)) + vcpu->arch.rec.run->enter.flags |= RMI_EMULATED_MMIO; + if (!kvm_vcpu_dabt_iswrite(vcpu)) { struct kvm_run *run = vcpu->run; @@ -108,7 +112,11 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu) trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr, &data); data = vcpu_data_host_to_guest(vcpu, data, len); - vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu), data); + + if (vcpu_is_rec(vcpu)) + vcpu->arch.rec.run->enter.gprs[0] = data; + else + vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu), data); } /* diff --git a/arch/arm64/kvm/rme-exit.c b/arch/arm64/kvm/rme-exit.c index f4e45d475798..03ed147f7926 100644 --- a/arch/arm64/kvm/rme-exit.c +++ b/arch/arm64/kvm/rme-exit.c @@ -25,6 +25,12 @@ static int rec_exit_reason_notimpl(struct kvm_vcpu *vcpu) static int rec_exit_sync_dabt(struct kvm_vcpu *vcpu) { + struct realm_rec *rec = &vcpu->arch.rec; + + if (kvm_vcpu_dabt_iswrite(vcpu) && kvm_vcpu_dabt_isvalid(vcpu)) + vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu), + rec->run->exit.gprs[0]); + return kvm_handle_guest_abort(vcpu); } -- 2.34.1