From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: Re: [RFC PATCH v2 1/2] KVM: kvm-vfio: User API for VT-d Posted-Interrupts Date: Tue, 25 Nov 2014 16:01:40 +0100 Message-ID: <547499D4.6000700@linaro.org> References: <1416918215-21878-1-git-send-email-feng.wu@intel.com> <1416918215-21878-2-git-send-email-feng.wu@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Feng Wu , alex.williamson@redhat.com, pbonzini@redhat.com, gleb@kernel.org Return-path: Received: from mail-wg0-f44.google.com ([74.125.82.44]:55440 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750902AbaKYPDD (ORCPT ); Tue, 25 Nov 2014 10:03:03 -0500 Received: by mail-wg0-f44.google.com with SMTP id b13so1107061wgh.17 for ; Tue, 25 Nov 2014 07:03:01 -0800 (PST) In-Reply-To: <1416918215-21878-2-git-send-email-feng.wu@intel.com> Sender: kvm-owner@vger.kernel.org List-ID: On 11/25/2014 01:23 PM, Feng Wu wrote: > This patch adds and documents a new attribute > KVM_DEV_VFIO_DEVICE_POSTING_IRQ in KVM_DEV_VFIO_DEVICE group. > This new attribute is used for VT-d Posted-Interrupts. > > When guest OS changes the interrupt configuration for an > assigned device, such as, MSI/MSIx data/address fields, > QEMU will use this IRQ attribute to tell KVM to update the > related IRTE according the VT-d Posted-Interrrupts Specification, > such as, the guest vector should be updated in the related IRTE. > > Signed-off-by: Feng Wu > --- > Documentation/virtual/kvm/devices/vfio.txt | 9 +++++++++ > include/uapi/linux/kvm.h | 10 ++++++++++ > 2 files changed, 19 insertions(+), 0 deletions(-) > > diff --git a/Documentation/virtual/kvm/devices/vfio.txt b/Documentation/virtual/kvm/devices/vfio.txt > index f7aff29..39dee86 100644 > --- a/Documentation/virtual/kvm/devices/vfio.txt > +++ b/Documentation/virtual/kvm/devices/vfio.txt > @@ -42,3 +42,12 @@ activated before VFIO_DEVICE_SET_IRQS has been called to trigger the IRQ > or associate an eventfd to it. Unforwarding can only be called while the > signaling has been disabled with VFIO_DEVICE_SET_IRQS. If this condition is > not satisfied, the command returns an -EBUSY. > + > + KVM_DEV_VFIO_DEVICE_POSTING_IRQ: Use posted interrtups mechanism to post > + the IRQ to guests. > +For this attribute, kvm_device_attr.addr points to a kvm_posted_intr struct. > + > +When guest OS changes the interrupt configuration for an assigned device, > +such as, MSI/MSIx data/address fields, QEMU will use this IRQ attribute > +to tell KVM to update the related IRTE according the VT-d Posted-Interrrupts > +Specification, such as, the guest vector should be updated in the related IRTE. > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index a269a42..e5f86ad 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -949,6 +949,7 @@ struct kvm_device_attr { > #define KVM_DEV_VFIO_DEVICE 2 > #define KVM_DEV_VFIO_DEVICE_FORWARD_IRQ 1 > #define KVM_DEV_VFIO_DEVICE_UNFORWARD_IRQ 2 > +#define KVM_DEV_VFIO_DEVICE_POSTING_IRQ 3 > > enum kvm_device_type { > KVM_DEV_TYPE_FSL_MPIC_20 = 1, > @@ -973,6 +974,15 @@ struct kvm_arch_forwarded_irq { > __u32 gsi; /* gsi, ie. virtual IRQ number */ > }; > > +struct kvm_posted_intr { > + __u32 argsz; > + __u32 fd; /* file descriptor of the VFIO device */ > + __u32 index; /* VFIO device IRQ index */ > + __u32 start; > + __u32 count; > + int virq[0]; /* gsi, ie. virtual IRQ number */ > +}; Hi Feng, This struct could be used by arm code too. If Alex agrees I could use that one instead. We just need to find a common sensible name Best Regards Eric > + > /* > * ioctls for VM fds > */ >