| Message ID | 1372861854-23043-3-git-send-email-cornelia.huck@de.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Il 03/07/2013 16:30, Cornelia Huck ha scritto: > + /* > + * Return cookie in gpr 2, but don't overwrite the register if the > + * diagnose will be handled by userspace. > + */ > + if (ret != -EOPNOTSUPP) > + vcpu->run->s.regs.gprs[2] = ret; I think this should now be "if (ret >= 0)". > /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */ The comment is now obsolete. > return ret < 0 ? ret : 0; Otherwise looks good, thanks! Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 03 Jul 2013 17:30:40 +0200 Paolo Bonzini <pbonzini@redhat.com> wrote: > Il 03/07/2013 16:30, Cornelia Huck ha scritto: > > + /* > > + * Return cookie in gpr 2, but don't overwrite the register if the > > + * diagnose will be handled by userspace. > > + */ > > + if (ret != -EOPNOTSUPP) > > + vcpu->run->s.regs.gprs[2] = ret; > > I think this should now be "if (ret >= 0)". Hm, we don't want to kill gpr 2's old contents if userspace will do something, which means -EOPNOTSUPP. > > > /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */ > > The comment is now obsolete. s/kvm_io_bus_write/kvm_io_bus_write_cookie/ ? Otherwise, this is still true. > > > return ret < 0 ? ret : 0; > > Otherwise looks good, thanks! > > Paolo > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Il 03/07/2013 18:33, Cornelia Huck ha scritto: > On Wed, 03 Jul 2013 17:30:40 +0200 > Paolo Bonzini <pbonzini@redhat.com> wrote: > >> Il 03/07/2013 16:30, Cornelia Huck ha scritto: >>> + /* >>> + * Return cookie in gpr 2, but don't overwrite the register if the >>> + * diagnose will be handled by userspace. >>> + */ >>> + if (ret != -EOPNOTSUPP) >>> + vcpu->run->s.regs.gprs[2] = ret; >> >> I think this should now be "if (ret >= 0)". > > Hm, we don't want to kill gpr 2's old contents if userspace will do > something, which means -EOPNOTSUPP. In the end kvm_io_bus_write_cookie only returns -EOPNOTSUPP if there is an error, so it works. But if this were to change, the code would break. That's why I suggested testing "ret >= 0" rather than "ret != -EOPNOTSUPP". But in the end it is the same. >> >>> /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */ >> >> The comment is now obsolete. > > s/kvm_io_bus_write/kvm_io_bus_write_cookie/ ? Otherwise, this is still > true. True but somewhat misplaced, it is basically saying the same thing as the "Return cookie in gpr 2" comment just above. Anyhow, these are very small details. I changed kvm_io_bus_write to kvm_io_bus_write_cookie in the comment and applied the patches to kvm-queue. Paolo >> >>> return ret < 0 ? ret : 0; >> >> Otherwise looks good, thanks! >> >> Paolo >> > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jul 04, 2013 at 08:54:32AM +0200, Paolo Bonzini wrote: > Il 03/07/2013 18:33, Cornelia Huck ha scritto: > > On Wed, 03 Jul 2013 17:30:40 +0200 > > Paolo Bonzini <pbonzini@redhat.com> wrote: > > > >> Il 03/07/2013 16:30, Cornelia Huck ha scritto: > >>> + /* > >>> + * Return cookie in gpr 2, but don't overwrite the register if the > >>> + * diagnose will be handled by userspace. > >>> + */ > >>> + if (ret != -EOPNOTSUPP) > >>> + vcpu->run->s.regs.gprs[2] = ret; > >> > >> I think this should now be "if (ret >= 0)". > > > > Hm, we don't want to kill gpr 2's old contents if userspace will do > > something, which means -EOPNOTSUPP. > > In the end kvm_io_bus_write_cookie only returns -EOPNOTSUPP if there is > an error, so it works. But if this were to change, the code would > break. That's why I suggested testing "ret >= 0" rather than "ret != > -EOPNOTSUPP". But in the end it is the same. > > >> > >>> /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */ > >> > >> The comment is now obsolete. > > > > s/kvm_io_bus_write/kvm_io_bus_write_cookie/ ? Otherwise, this is still > > true. > > True but somewhat misplaced, it is basically saying the same thing as > the "Return cookie in gpr 2" comment just above. > > Anyhow, these are very small details. I changed kvm_io_bus_write to > kvm_io_bus_write_cookie in the comment and applied the patches to kvm-queue. > 1/2 broke x86. QEMU prints "Invalid read from memory region kvm-pic" and guest hangs. Looks like IO is forwarded to userspace instead of in kernel device for some reason. Un-applying for now. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" 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/s390/kvm/diag.c b/arch/s390/kvm/diag.c index 3074475..e88c76e 100644 --- a/arch/s390/kvm/diag.c +++ b/arch/s390/kvm/diag.c @@ -119,11 +119,20 @@ static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu) * The layout is as follows: * - gpr 2 contains the subchannel id (passed as addr) * - gpr 3 contains the virtqueue index (passed as datamatch) + * - gpr 4 contains the index on the bus (optionally) */ - ret = kvm_io_bus_write(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS, - vcpu->run->s.regs.gprs[2], - 8, &vcpu->run->s.regs.gprs[3]); + ret = kvm_io_bus_write_cookie(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS, + vcpu->run->s.regs.gprs[2], + 8, &vcpu->run->s.regs.gprs[3], + vcpu->run->s.regs.gprs[4]); srcu_read_unlock(&vcpu->kvm->srcu, idx); + + /* + * Return cookie in gpr 2, but don't overwrite the register if the + * diagnose will be handled by userspace. + */ + if (ret != -EOPNOTSUPP) + vcpu->run->s.regs.gprs[2] = ret; /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */ return ret < 0 ? ret : 0; }
Make use of cookies for the virtio ccw notification hypercall to speed up lookup of devices on the io bus. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> --- arch/s390/kvm/diag.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)