From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from va3outboundpool.messaging.microsoft.com (va3ehsobe001.messaging.microsoft.com [216.32.180.11]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client CN "mail.global.frontbridge.com", Issuer "Microsoft Secure Server Authority" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 3BA64B6F5A for ; Wed, 27 Jun 2012 08:34:57 +1000 (EST) Message-ID: <4FEA3907.8080500@freescale.com> Date: Tue, 26 Jun 2012 17:34:47 -0500 From: Scott Wood MIME-Version: 1.0 To: Mihai Caraman Subject: Re: [RFC PATCH 03/17] KVM: PPC64: booke: Add EPCR support in sregs References: <1340627195-11544-1-git-send-email-mihai.caraman@freescale.com> <1340627195-11544-4-git-send-email-mihai.caraman@freescale.com> In-Reply-To: <1340627195-11544-4-git-send-email-mihai.caraman@freescale.com> Content-Type: text/plain; charset="UTF-8" Cc: qemu-ppc@nongnu.org, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 06/25/2012 07:26 AM, Mihai Caraman wrote: > Add KVM_SREGS_E_64 feature and EPCR spr support in get/set sregs > for 64-bit hosts. > > Signed-off-by: Mihai Caraman > --- > arch/powerpc/kvm/booke.c | 14 ++++++++++++++ > 1 files changed, 14 insertions(+), 0 deletions(-) > > diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c > index f9fa260..d15c4b5 100644 > --- a/arch/powerpc/kvm/booke.c > +++ b/arch/powerpc/kvm/booke.c > @@ -1052,6 +1052,9 @@ static void get_sregs_base(struct kvm_vcpu *vcpu, > u64 tb = get_tb(); > > sregs->u.e.features |= KVM_SREGS_E_BASE; > +#ifdef CONFIG_64BIT > + sregs->u.e.features |= KVM_SREGS_E_64;0 > +#endif > > sregs->u.e.csrr0 = vcpu->arch.csrr0; > sregs->u.e.csrr1 = vcpu->arch.csrr1; > @@ -1063,6 +1066,9 @@ static void get_sregs_base(struct kvm_vcpu *vcpu, > sregs->u.e.dec = kvmppc_get_dec(vcpu, tb); > sregs->u.e.tb = tb; > sregs->u.e.vrsave = vcpu->arch.vrsave; > +#ifdef CONFIG_64BIT > + sregs->u.e.epcr = vcpu->arch.epcr; > +#endif > } > > static int set_sregs_base(struct kvm_vcpu *vcpu, > @@ -1071,6 +1077,11 @@ static int set_sregs_base(struct kvm_vcpu *vcpu, > if (!(sregs->u.e.features & KVM_SREGS_E_BASE)) > return 0; > > +#ifdef CONFIG_64BIT > + if (!(sregs->u.e.features & KVM_SREGS_E_64)) > + return 0; > +#endif This means that a QEMU targeting a 32-bit guest won't be able to set any special registers, if it sets feature bits manually rather than getting them from GET_SREGS. This check should only qualify whether we look at sregs.u.e.epcr, not whether this function works at all. BTW, shouldn't the BASE check return an error rather than silently no-op? -Scott