On Thu, Sep 11, 2014 at 07:03:32PM +0200, Christoffer Dall wrote: > On Thu, Sep 11, 2014 at 10:14:13AM +0200, Eric Auger wrote: > > On 09/11/2014 05:09 AM, Christoffer Dall wrote: > > > On Mon, Sep 01, 2014 at 10:53:04AM +0200, Eric Auger wrote: > > >> This patch enables irqfd on ARM. > > >> > > >> irqfd framework enables to inject a virtual IRQ into a guest upon an > > >> eventfd trigger. User-side uses KVM_IRQFD VM ioctl to provide KVM with > > >> a kvm_irqfd struct that associates a VM, an eventfd, a virtual IRQ number > > >> (aka. the gsi). When an actor signals the eventfd (typically a VFIO > > >> platform driver), the kvm irqfd subsystem injects the provided virtual > > >> IRQ into the guest. > > >> > > >> Resamplefd also is supported for level sensitive interrupts, ie. the > > >> user can provide another eventfd that is triggered when the completion > > >> of the virtual IRQ (gsi) is detected by the GIC. > > >> > > >> The gsi must correspond to a shared peripheral interrupt (SPI), ie the > > >> GIC interrupt ID is gsi+32. > > >> > > >> this patch enables CONFIG_HAVE_KVM_EVENTFD and CONFIG_HAVE_KVM_IRQFD. > > >> CONFIG_HAVE_KVM_IRQCHIP is removed. No IRQ routing table is used > > >> (irqchip.c and irqcomm.c are not used). > > >> > > >> Both KVM_CAP_IRQFD & KVM_CAP_IRQFD_RESAMPLE capabilities are exposed > > >> > > >> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> > > >> > > >> --- > > >> > > >> This patch serie deprecates the previous serie featuring GSI routing > > >> (https://patches.linaro.org/32261/) > > >> > > >> The patch serie has the following dependencies: > > >> - arm/arm64: KVM: Various VGIC cleanups and improvements > > >> https://lists.cs.columbia.edu/pipermail/kvmarm/2014-June/009979.html > > >> - "KVM: EVENTFD: remove inclusion of irq.h" > > >> > > >> All pieces can be found on git://git.linaro.org/people/eric.auger/linux.git > > >> branch irqfd_norouting_integ_v3 > > >> > > >> This work was tested with Calxeda Midway xgmac main interrupt with > > >> qemu-system-arm and QEMU VFIO platform device. > > >> > > >> v2 -> v3: > > >> - removal of irq.h from eventfd.c put in a separate patch to increase > > >> visibility > > >> - properly expose KVM_CAP_IRQFD capability in arm.c > > >> - remove CONFIG_HAVE_KVM_IRQCHIP meaningfull only if irq_comm.c is used > > >> > > >> v1 -> v2: > > >> - rebase on 3.17rc1 > > >> - move of the dist unlock in process_maintenance > > >> - remove of dist lock in __kvm_vgic_sync_hwstate > > >> - rewording of the commit message (add resamplefd reference) > > >> - remove irq.h > > >> --- > > >> Documentation/virtual/kvm/api.txt | 5 +++- > > >> arch/arm/include/uapi/asm/kvm.h | 3 +++ > > >> arch/arm/kvm/Kconfig | 4 +-- > > >> arch/arm/kvm/Makefile | 2 +- > > >> arch/arm/kvm/arm.c | 3 +++ > > >> virt/kvm/arm/vgic.c | 56 ++++++++++++++++++++++++++++++++++++--- > > >> 6 files changed, 65 insertions(+), 8 deletions(-) > > >> > > >> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > > >> index beae3fd..8118b12 100644 > > >> --- a/Documentation/virtual/kvm/api.txt > > >> +++ b/Documentation/virtual/kvm/api.txt > > >> @@ -2204,7 +2204,7 @@ into the hash PTE second double word). > > >> 4.75 KVM_IRQFD > > >> > > >> Capability: KVM_CAP_IRQFD > > >> -Architectures: x86 s390 > > >> +Architectures: x86 s390 arm > > >> Type: vm ioctl > > >> Parameters: struct kvm_irqfd (in) > > >> Returns: 0 on success, -1 on error > > >> @@ -2230,6 +2230,9 @@ Note that closing the resamplefd is not sufficient to disable the > > >> irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment > > >> and need not be specified with KVM_IRQFD_FLAG_DEASSIGN. > > >> > > >> +On ARM/arm64 the injected must be a shared peripheral interrupt (SPI). > > >> +This means the programmed GIC interrupt ID is gsi+32. > > >> + > > > > > > See above comment. > > Hi Christoffer, > > > > sorry which comment do you refer to? > > good question, I thought I had a comment above, just disregard. > > > wrt your last comment do you > > consider PPI injection support is a mandated feature for this patch to > > be upstreamable? > > well, right now, the only reason it's not supported is "we didn't bother > thinking about it or doing it" and I haven't heard a valid reason for > why we should be designing a new user space API etc. without supporting > PPIs. > > So yes, either argue why it's better to not include PPI support in the > first round, why we never need to, or just support it ;) > So we had a talk at Linaro Connect between Eric, Marc, and myself, and basically the reason not to support this is that any device using a PPI will be a private-to-the-CPU device (think about the timer), so it's state would have to be context-switched along with the VCPU and require in-kernel wiring anyhow, and is therefore simply not a relevant use case for irqfds. Therefore, you can ignore my comments about PPI support in this patch. Thanks, -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
