| Message ID | 1524657284-16706-4-git-send-email-wei.guo.simon@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | KVM: PPC: reconstruct mmio emulation with analyse_instr() | expand |
On Wed, Apr 25, 2018 at 07:54:36PM +0800, wei.guo.simon@gmail.com wrote: > From: Simon Guo <wei.guo.simon@gmail.com> > > When KVM emulates VMX store, it will invoke kvmppc_get_vmx_data() to > retrieve VMX reg val. kvmppc_get_vmx_data() will check mmio_host_swabbed > to decide which double word of vr[] to be used. But the > mmio_host_swabbed can be uninitiazed during VMX store procedure: > > kvmppc_emulate_loadstore > \- kvmppc_handle_store128_by2x64 > \- kvmppc_get_vmx_data > > This patch corrects this by using kvmppc_need_byteswap() to choose > double word of vr[] and initialized mmio_host_swabbed to avoid invisble > trouble. > > Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> The patch is correct, but I think the patch description needs to say that vcpu->arch.mmio_host_swabbed is not meant to be used at all for emulation of store instructions, and this patch makes that true for VMX stores. Paul. -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, May 03, 2018 at 03:48:26PM +1000, Paul Mackerras wrote: > On Wed, Apr 25, 2018 at 07:54:36PM +0800, wei.guo.simon@gmail.com wrote: > > From: Simon Guo <wei.guo.simon@gmail.com> > > > > When KVM emulates VMX store, it will invoke kvmppc_get_vmx_data() to > > retrieve VMX reg val. kvmppc_get_vmx_data() will check mmio_host_swabbed > > to decide which double word of vr[] to be used. But the > > mmio_host_swabbed can be uninitiazed during VMX store procedure: > > > > kvmppc_emulate_loadstore > > \- kvmppc_handle_store128_by2x64 > > \- kvmppc_get_vmx_data > > > > This patch corrects this by using kvmppc_need_byteswap() to choose > > double word of vr[] and initialized mmio_host_swabbed to avoid invisble > > trouble. > > > > Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> > > The patch is correct, but I think the patch description needs to say > that vcpu->arch.mmio_host_swabbed is not meant to be used at all for > emulation of store instructions, and this patch makes that true for > VMX stores. I will revise the commit message accordingly. > > Paul. Thanks, - Simon -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/powerpc/kvm/emulate_loadstore.c b/arch/powerpc/kvm/emulate_loadstore.c index a382e15..b8a3aef 100644 --- a/arch/powerpc/kvm/emulate_loadstore.c +++ b/arch/powerpc/kvm/emulate_loadstore.c @@ -111,6 +111,7 @@ int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu) vcpu->arch.mmio_sp64_extend = 0; vcpu->arch.mmio_sign_extend = 0; vcpu->arch.mmio_vmx_copy_nums = 0; + vcpu->arch.mmio_host_swabbed = 0; switch (get_op(inst)) { case 31: diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 4e38764..bef27b1 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -1374,7 +1374,7 @@ static inline int kvmppc_get_vmx_data(struct kvm_vcpu *vcpu, int rs, u64 *val) if (di > 1) return -1; - if (vcpu->arch.mmio_host_swabbed) + if (kvmppc_need_byteswap(vcpu)) di = 1 - di; w0 = vrs.u[di * 2];