Il 05/08/2014 14:27, Paolo Bonzini ha scritto: > Il 30/06/2014 12:51, Paul Mackerras ha scritto: >> This series of patches provides a way to implement IRQFD support >> without having to implement IRQ routing, and adds IRQFD support for >> the XICS interrupt controller emulation. (XICS is the interrupt >> controller defined for the pSeries machine type, used on IBM POWER >> servers). >> >> The basic approach is to make it easy for code other than irqchip.c to >> provide a mapping from a global interrupt number (GSI) to an irq >> routing entry (struct kvm_kernel_irq_routing_entry). To make the >> lifetime of this routing entry easier to manage, we change the IRQFD >> code to keep a copy of the routing entry (for the MSI fast-path case) >> rather than a pointer to the routing entry. Since the copy can't be >> updated atomically, we add a seqcount_t to make sure that when reading >> it we get a copy that hasn't been half-way updated. >> >> Next we replace the hard-coded accesses outside irqchip.c to the >> fields of the kvm_irq_routing_table struct with calls to accessor >> functions in irqchip.c, namely kvm_irq_map_gsi() and >> kvm_irq_map_chip_pin(). That enables us to move all references to the >> kvm_irq_routing_table struct, and the definition of that struct, into >> irqchip.c. >> >> Then we move the irq notifier implementation from irqchip.c into >> eventfd.c and add a separate Kconfig option to enable IRQFD. With >> that we can enable IRQFD without irq routing, which we achieve by >> compiling in eventfd.c but not irqchip.c, and providing an alternative >> implementation of kvm_irq_map_gsi() and kvm_irq_map_chip_pin(). >> >> The last patch does that for XICS. With this series I can use >> vhost-net with KVM guests, and I see the TCP bandwidth between guest >> and host on a POWER8 machine go from around 700MB/s to over 2GB/s. >> >> I would like to see this go into 3.17. >> >> arch/ia64/kvm/Kconfig | 1 + >> arch/powerpc/kvm/Kconfig | 3 + >> arch/powerpc/kvm/book3s_hv_rm_xics.c | 5 ++ >> arch/powerpc/kvm/book3s_xics.c | 55 +++++++++++--- >> arch/powerpc/kvm/book3s_xics.h | 2 + >> arch/powerpc/kvm/mpic.c | 4 +- >> arch/s390/kvm/Kconfig | 1 + >> arch/s390/kvm/interrupt.c | 3 +- >> arch/x86/kvm/Kconfig | 1 + >> include/linux/kvm_host.h | 43 ++++------- >> virt/kvm/Kconfig | 3 + >> virt/kvm/eventfd.c | 134 ++++++++++++++++++++++++++--------- >> virt/kvm/irq_comm.c | 24 +++---- >> virt/kvm/irqchip.c | 98 ++++++++++--------------- >> virt/kvm/kvm_main.c | 2 +- >> 15 files changed, 227 insertions(+), 152 deletions(-) >> > > Applied for 3.17, thanks Eric and Cornelia for testing. > > Paolo > -- > 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 > This doesn't build without CONFIG_KVM_XICS, so I had to apply a fixup patch to move some code from being under CONFIG_HAVE_KVM_IRQCHIP or unconditional, to being conditional on CONFIG_HAVE_KVM_IRQFD. I'll send the patch shortly. Also, please look into adding a trace_kvm_set_irq call to kvm_set_irq in arch/powerpc/kvm/book3s_xics.c. I would have preferred these snags to be fixed before (especially since the breakage is simply with "make ppc64_defconfig"), but it's partly my fault for delaying the review for so long. And the series is good work and a very nice cleanup of the irqfd architecture. Assuming that the linux-next merge from tomorrow is fine, I'll send the second pull request to Linus. Paolo -- 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
