From b59d9d26becb8b32596f2eed6ce5a81d61f4f513 Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Thu, 24 Apr 2014 13:10:33 +0200 Subject: [PATCH] KVM: PPC: Book3S PR: PAPR: Access RTAS in big endian When the guest does an RTAS hypercall it keeps all RTAS variables inside a big endian data structure. To make sure we don't have to bother about endianness inside the actual RTAS handlers, let's just convert the whole structure to host endian before we call our RTAS handlers and back to big endian when we return to the guest. Signed-off-by: Alexander Graf --- arch/powerpc/kvm/book3s_rtas.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/arch/powerpc/kvm/book3s_rtas.c b/arch/powerpc/kvm/book3s_rtas.c index 7a053157483b..edb14ba992b3 100644 --- a/arch/powerpc/kvm/book3s_rtas.c +++ b/arch/powerpc/kvm/book3s_rtas.c @@ -205,6 +205,32 @@ int kvm_vm_ioctl_rtas_define_token(struct kvm *kvm, void __user *argp) return rc; } +static void kvmppc_rtas_swap_endian_in(struct rtas_args *args) +{ +#ifdef __LITTLE_ENDIAN__ + int i; + + args->token = be32_to_cpu(args->token); + args->nargs = be32_to_cpu(args->nargs); + args->nret = be32_to_cpu(args->nret); + for (i = 0; i < args->nargs; i++) + args->args[i] = be32_to_cpu(args->args[i]); +#endif +} + +static void kvmppc_rtas_swap_endian_out(struct rtas_args *args) +{ +#ifdef __LITTLE_ENDIAN__ + int i; + + for (i = 0; i < args->nret; i++) + args->args[i] = cpu_to_be32(args->args[i]); + args->token = cpu_to_be32(args->token); + args->nargs = cpu_to_be32(args->nargs); + args->nret = cpu_to_be32(args->nret); +#endif +} + int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu) { struct rtas_token_definition *d; @@ -223,6 +249,8 @@ int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu) if (rc) goto fail; + kvmppc_rtas_swap_endian_in(&args); + /* * args->rets is a pointer into args->args. Now that we've * copied args we need to fix it up to point into our copy, @@ -247,6 +275,7 @@ int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu) if (rc == 0) { args.rets = orig_rets; + kvmppc_rtas_swap_endian_out(&args); rc = kvm_write_guest(vcpu->kvm, args_phys, &args, sizeof(args)); if (rc) goto fail; -- 2.20.1