From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38176) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dp9xa-0006ej-7J for qemu-devel@nongnu.org; Tue, 05 Sep 2017 05:15:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dp9xU-0005KE-DI for qemu-devel@nongnu.org; Tue, 05 Sep 2017 05:15:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51242) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dp9xT-0005GC-MG for qemu-devel@nongnu.org; Tue, 05 Sep 2017 05:15:48 -0400 Date: Tue, 5 Sep 2017 11:15:40 +0200 From: Cornelia Huck Message-ID: <20170905111540.027058d1.cohuck@redhat.com> In-Reply-To: <07ef5826-6b09-5ac8-7d51-d00db7170437@linux.vnet.ibm.com> References: <1504239778-29893-1-git-send-email-zyimin@linux.vnet.ibm.com> <1504239778-29893-2-git-send-email-zyimin@linux.vnet.ibm.com> <20170905102928.6b23a28a.cohuck@redhat.com> <0923f97e-4f69-0bf3-b9ab-8e5f69a56bbb@linux.vnet.ibm.com> <20170905105041.3409c8cd.cohuck@redhat.com> <07ef5826-6b09-5ac8-7d51-d00db7170437@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v2 1/3] s390x/pci: remove idx from msix msg data List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yi Min Zhao Cc: qemu-devel@nongnu.org, borntraeger@de.ibm.com, pasic@linux.vnet.ibm.com, pmorel@linux.vnet.ibm.com, agraf@suse.de, richard.henderson@linaro.org On Tue, 5 Sep 2017 17:08:14 +0800 Yi Min Zhao wrote: > =E5=9C=A8 2017/9/5 =E4=B8=8B=E5=8D=884:50, Cornelia Huck =E5=86=99=E9=81= =93: > > On Tue, 5 Sep 2017 16:44:37 +0800 > > Yi Min Zhao wrote: > > =20 > >> =E5=9C=A8 2017/9/5 =E4=B8=8B=E5=8D=884:29, Cornelia Huck =E5=86=99=E9= =81=93: =20 > >>> On Fri, 1 Sep 2017 06:22:56 +0200 > >>> Yi Min Zhao wrote: > >>> =20 > >>>> PCIDevice pointer has been a parameter of kvm_arch_fixup_msi_route(). > >>>> So we don't need to store zpci idx in msix message data to find out = the > >>>> specific zpci device. Instead, we could use pci device id to find its > >>>> corresponding zpci device. > >>>> > >>>> Signed-off-by: Yi Min Zhao > >>>> --- > >>>> hw/s390x/s390-pci-bus.c | 16 +++++----------- > >>>> hw/s390x/s390-pci-bus.h | 2 ++ > >>>> hw/s390x/s390-pci-inst.c | 24 ------------------------ > >>>> hw/s390x/s390-pci-stub.c | 6 ++++++ > >>>> target/s390x/kvm.c | 7 +++++-- > >>>> 5 files changed, 18 insertions(+), 37 deletions(-) > >>>> > >>>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c > >>>> index 1338c29528..3d490c5e4b 100644 > >>>> --- a/target/s390x/kvm.c > >>>> +++ b/target/s390x/kvm.c > >>>> @@ -2533,10 +2533,13 @@ int kvm_arch_fixup_msi_route(struct kvm_irq_= routing_entry *route, > >>>> uint64_t address, uint32_t data, PCI= Device *dev) > >>>> { > >>>> S390PCIBusDevice *pbdev; > >>>> - uint32_t idx =3D data >> ZPCI_MSI_VEC_BITS; > >>>> uint32_t vec =3D data & ZPCI_MSI_VEC_MASK; > >>>> =20 > >>>> - pbdev =3D s390_pci_find_dev_by_idx(s390_get_phb(), idx); > >>>> + if (!dev) { > >>>> + return -ENODEV; =20 > >>> Can this actually happen? =20 > >> I think this cannot happen. But I'm afraid that I miss something. > >> So I added this to avoid NULL pointer. But from the code and > >> my test, there has not been NULL pointer happened. =20 > > I'm wondering if that is in the same category as the instance I > > commented on above. Do you want to log something? > > =20 > For the case above, I ensure that zpci device must exist. But here, I'm=20 > not sure. > Because it's called from outside. I'm not sure if the caller might call > kvm_irqchip_add_msi_route() with NULL as pci device argument. >=20 > Although msix ctrl mr is accessed from outside. But its initialization > is controled by our code and the pointer to zpci device is saved as > mr's opaque. OK. Maybe add a DPRINTF as for the condition below? > >>> =20 > >>>> + } > >>>> + > >>>> + pbdev =3D s390_pci_find_dev_by_target(s390_get_phb(), DEVICE(de= v)->id); > >>>> if (!pbdev) { > >>>> DPRINTF("add_msi_route no dev\n"); > >>>> return -ENODEV; =20 > >>> =20 > > =20 >=20