linux/arch/x86/pci
Boris Ostrovsky 14520c92cb xen/pci: Use APIC directly when APIC virtualization hardware is available
When hardware supports APIC/x2APIC virtualization we don't need to use
pirqs for MSI handling and instead use APIC since most APIC accesses
(MMIO or MSR) will now be processed without VMEXITs.

As an example, netperf on the original code produces this profile
(collected wih 'xentrace -e 0x0008ffff -T 5'):

    342 cpu_change
    260 CPUID
  34638 HLT
  64067 INJ_VIRQ
  28374 INTR
  82733 INTR_WINDOW
     10 NPF
  24337 TRAP
 370610 vlapic_accept_pic_intr
 307528 VMENTRY
 307527 VMEXIT
 140998 VMMCALL
    127 wrap_buffer

After applying this patch the same test shows

    230 cpu_change
    260 CPUID
  36542 HLT
    174 INJ_VIRQ
  27250 INTR
    222 INTR_WINDOW
     20 NPF
  24999 TRAP
 381812 vlapic_accept_pic_intr
 166480 VMENTRY
 166479 VMEXIT
  77208 VMMCALL
     81 wrap_buffer

ApacheBench results (ab -n 10000 -c 200) improve by about 10%

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 13:02:43 +00:00
..
Makefile x86, platforms: Remove NUMAQ 2014-02-27 08:07:39 -08:00
acpi.c x86, PCI, ACPI: Use kmalloc_node() to optimize for performance 2014-06-21 23:05:40 +02:00
amd_bus.c x86/PCI: Clean up and mark early_root_info_init() as deprecated 2014-05-27 10:47:49 -06:00
broadcom_bus.c x86/PCI: Fix Broadcom CNB20LE unintended sign extension 2014-04-25 11:01:08 -06:00
bus_numa.c x86/PCI: Remove unnecessary list_empty(&pci_root_infos) check 2014-02-03 10:38:52 -07:00
bus_numa.h x86/PCI: put busn resource in pci_root_info for native host bridge drivers 2012-06-13 15:42:24 -06:00
ce4100.c x86/ce4100: Fix PCI configuration register access for devices without interrupts 2012-10-30 10:16:47 +01:00
common.c x86/PCI: Mark DMI tables as initialization data 2014-09-22 14:24:41 -06:00
direct.c x86: constify PCI raw ops structures 2011-10-14 09:05:28 -07:00
early.c x86/PCI: remove early PCI pr_debug statements 2009-11-24 15:25:19 -08:00
fixup.c vgaarb: Don't default exclusively to first video device with mem+io 2014-09-16 13:06:18 -06:00
i386.c x86: remove the Xen-specific _PAGE_IOMAP PTE flag 2014-09-23 13:36:20 +00:00
init.c x86, olpc: Use pci subarch init for OLPC 2010-02-25 19:26:23 -08:00
intel_mid_pci.c x86, irq, PCI: Keep IRQ assignment for runtime power management 2014-08-29 13:38:00 +02:00
irq.c x86, irq, PCI: Keep IRQ assignment for runtime power management 2014-08-29 13:38:00 +02:00
legacy.c x86/PCI: Use pcibios_scan_root() instead of pci_scan_bus_on_node() 2014-02-03 10:38:18 -07:00
mmconfig-shared.c x86/PCI: Constify pci_mmcfg_probes[] array 2014-09-24 06:46:22 -06:00
mmconfig_32.c ACPI: Clean up inclusions of ACPI header files 2013-12-07 01:03:14 +01:00
mmconfig_64.c X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
numachip.c x86/PCI: Add NumaChip remote PCI support 2012-12-07 14:24:32 -07:00
olpc.c x86: constify PCI raw ops structures 2011-10-14 09:05:28 -07:00
pcbios.c x86/PCI: Mark PCI BIOS initialization code as such 2014-09-24 06:46:27 -06:00
sta2x11-fixup.c x86: enable DMA CMA with swiotlb 2014-06-04 16:53:57 -07:00
xen.c xen/pci: Use APIC directly when APIC virtualization hardware is available 2014-12-04 13:02:43 +00:00