GITHUB======Latest git tree can be found at:http://github.com/ssuthiku/xen.git xen_avic_part1_v1
OVERVIEW========This patch set is the first of the two-part patch series to introduce the new AMD Advance Virtual Interrupt Controller (AVIC) support.Basically, SVM AVIC hardware virtualizes local APIC registers of eachvCPU via the virtual APIC (vAPIC) backing page. This allows guest accessto certain APIC registers without the need to emulate the hardware behaviorin the hypervisor. More information about AVIC can be found in theAMD64 Architecture Programmer???s Manual Volume 2 - System Programming.http://support.amd.com/TechDocs/24593.pdfFor SVM AVIC, we extend the existing kvm_amd driver to: * Check CPUID to detect AVIC support in the processor * Program new fields in VMCB to enable AVIC * Introduce new AVIC data structures and add code to manage them * Handle two new AVIC #VMEXITs * Add new interrupt injection code using vAPIC backing page instead of the existing V_IRQ, V_INTR_PRIO, V_INTR_VECTOR, and V_IGN_TPR fieldsCurrently, this patch series does not enable AVIC by default.Users can enable SVM AVIC by specifying Xen parameter svm-avic=1.Later, in part 2, we will introduce the IOMMU AVIC support, whichprovides speed up for PCI device pass-through use case by allowingthe IOMMU hardware to inject interrupt directly into the guest viathe vAPIC backing page.OVERALL PERFORMANCE===================Currently, AVIC is available on the AMD family 15h models 6Xh(Carrizo) processors and newer. Here, the Carizzo is used to collectperformance data shown below.Generally, SVM AVIC alone (w/o IOMMU AVIC) should provide overall speed upfor HVM guest since it does not require #vmexit into the hypervisor toemulate certain guest accesses to local APIC registers.It should also improve performance when hypervisor wants to injectinterrupts into a running vcpu by setting the corresponded IRRbit in the vAPIC backing page and trigger AVIC_DOORBELL MSR.For sending IPI interrupts between running vcpus in Linux guest,Xen is default to using event channel. However, in case ofnon-paravirtualize guest, AVIC can also provide performanceimprovements for sending IPI.BENCHMARK 1: HACKBENCH======================For measuring IPI performance used for scheduling workload, I have collectedsome performance number on 2 and 3 CPU running hackbech with the followingdetail: hackbench -p -l 100000 Running in process mode with 10 groups using 40 file descriptors each (== 400 tasks) Each sender will pass 100000 messages of 100 bytes | 2 vcpus (sec) | 3 vcpus (sec) -------------------------------------------------------- No AVIC w/o evtchn | 299.57 | 337.779 No AVIC w/ evtchn | 270.37 | 419.6064 AVIC w/ evtchn | 181.46 | 171.7957 AVIC w/o evtchn | 171.81 | 169.0858Note: In "w/o evtchn" case, the Linux guest is built w/o Xen guest support.CURRENT UNTESTED USE-CASES=========================== - Nested VMAny feedback and comments are very much appreciated.Thank you,SuraveeSuravee Suthikulpanit (9): x86/HVM: Introduce struct hvm_pi_ops x86/vLAPIC: Declare vlapic_read_aligned() and vlapic_reg_write() as non-static x86/HVM: Call vlapic_destroy after vcpu_destroy x86/SVM: Modify VMCB fields to add AVIC support x86/HVM/SVM: Add AVIC initialization code x86/SVM: Add AVIC vmexit handlers x86/SVM: Add vcpu scheduling support for AVIC x86/SVM: Add interrupt management code via AVIC x86/SVM: Hook up miscellaneous AVIC functions xen/arch/x86/hvm/hvm.c | 4 +- xen/arch/x86/hvm/svm/Makefile | 1 + xen/arch/x86/hvm/svm/avic.c | 609 +++++++++++++++++++++++++++++++++++++ xen/arch/x86/hvm/svm/intr.c | 4 + xen/arch/x86/hvm/svm/svm.c | 57 +++- xen/arch/x86/hvm/svm/vmcb.c | 9 +- xen/arch/x86/hvm/vlapic.c | 5 +- xen/arch/x86/hvm/vmx/vmx.c | 32 +- xen/include/asm-x86/hvm/domain.h | 63 ++++ xen/include/asm-x86/hvm/hvm.h | 4 +- xen/include/asm-x86/hvm/svm/avic.h | 49 +++ xen/include/asm-x86/hvm/svm/svm.h | 2 + xen/include/asm-x86/hvm/svm/vmcb.h | 35 ++- xen/include/asm-x86/hvm/vlapic.h | 4 + xen/include/asm-x86/hvm/vmx/vmcs.h | 59 ---- 15 files changed, 843 insertions(+), 94 deletions(-) create mode 100644 xen/arch/x86/hvm/svm/avic.c create mode 100644 xen/include/asm-x86/hvm/svm/avic.h-- 1.9.1
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