From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hildenbrand Subject: Re: [PATCH v2 04/10] KVM: arm: guest debug, add stub KVM_SET_GUEST_DEBUG ioctl Date: Wed, 1 Apr 2015 17:55:29 +0200 Message-ID: <20150401175529.642f64af@thinkpad-w530> References: <1427814488-28467-1-git-send-email-alex.bennee@linaro.org> <1427814488-28467-5-git-send-email-alex.bennee@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1427814488-28467-5-git-send-email-alex.bennee@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: Alex =?UTF-8?B?QmVubsOpZQ==?= Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org, marc.zyngier@arm.com, peter.maydell@linaro.org, agraf@suse.de, drjones@redhat.com, pbonzini@redhat.com, zhichao.huang@linaro.org, jan.kiszka@siemens.com, r65777@freescale.com, bp@suse.de, Gleb Natapov , Jonathan Corbet , Russell King , "open list:DOCUMENTATION" , open list List-Id: kvmarm@lists.cs.columbia.edu > This commit adds a stub function to support the KVM_SET_GUEST_DEBUG > ioctl. Currently any operation flag will return EINVAL. Actual Well it won't return -EINVAL if you push in KVM_GUESTDBG_ENABLE or 0. "Any unsupported flag will return -EINVAL. For now, only KVM_GUESTDBG_E= NABLE is supported, although it won't have any effects." > functionality will be added with further patches. >=20 > Signed-off-by: Alex Benn=C3=A9e . >=20 > --- > v2 > - simplified form of the ioctl (stuff will go into setup_debug) >=20 > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtua= l/kvm/api.txt > index b112efc..06c5064 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -2604,7 +2604,7 @@ handled. > 4.87 KVM_SET_GUEST_DEBUG >=20 > Capability: KVM_CAP_SET_GUEST_DEBUG > -Architectures: x86, s390, ppc > +Architectures: x86, s390, ppc, arm64 > Type: vcpu ioctl > Parameters: struct kvm_guest_debug (in) > Returns: 0 on success; -1 on error > diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c > index 5560f74..445933d 100644 > --- a/arch/arm/kvm/arm.c > +++ b/arch/arm/kvm/arm.c > @@ -183,6 +183,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm,= long ext) > case KVM_CAP_ARM_PSCI: > case KVM_CAP_ARM_PSCI_0_2: > case KVM_CAP_READONLY_MEM: > + case KVM_CAP_SET_GUEST_DEBUG: > r =3D 1; > break; > case KVM_CAP_COALESCED_MMIO: > @@ -303,10 +304,21 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) > kvm_arm_set_running_vcpu(NULL); > } >=20 > +#define KVM_GUESTDBG_VALID (KVM_GUESTDBG_ENABLE) That makes me rather think that it is another flag. We(s390x) use VALID_GUESTDBG_FLAGS, what about that or KVM_GUESTDBG_VAL= ID_MASK? > + > int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, > struct kvm_guest_debug *dbg) > { > - return -EINVAL; > + if (dbg->control & KVM_GUESTDBG_ENABLE) { > + if (dbg->control & ~KVM_GUESTDBG_VALID) > + return -EINVAL; I'd move that check directly to the start of the function and bail out = on any unsupported flag. > + > + vcpu->guest_debug =3D dbg->control; > + } else { > + /* If not enabled clear all flags */ > + vcpu->guest_debug =3D 0; > + } > + return 0; > } >=20 >=20 David