[Xen-devel] [PATCH 0/2] Make the pcidevs_lock a recursive one

[Quan Xu <quan.xu@xxxxxxxxx>]

This patch set makes the pcidevs_lock a recursive one. It is a prereq
patch set for Patch:'VT-d Device-TLB flush issue', as the pcidevs_lock
may be recursively held for hiding the ATS device, when IOMMU Device-TLB
flush timed out.

In detail:
1. Fix a bug found in AMD IOMMU initialization.
Doing what we do serves as a fix for a bug found in AMD IOMMU initialization.

The current code is using spin_lock{_irqsave(), _irqrestore()} to
protect pci_get_dev() in the set_iommu_interrupt_handler(). However,
this can only be called during AMD IOMMU initialization, with interrupt
enabled, so at least it is not necessary to disable interrupts, or
save/restore interrupt flag.

In order to fix this, we can use just plain spin{_lock(),_unlock()},
instead of spin_lock{_irqsave(),_irqrestore()}.

2. Make the pcidevs_lock a recursive one.

CC: Keir Fraser <keir@xxxxxxx>
CC: Jan Beulich <jbeulich@xxxxxxxx>
CC: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CC: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
CC: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@xxxxxxx>
CC: Feng Wu <feng.wu@xxxxxxxxx>
CC: Kevin Tian <kevin.tian@xxxxxxxxx>
CC: Dario Faggioli <dario.faggioli@xxxxxxxxxx>

Quan Xu (2):
  IOMMU/spinlock: Fix a bug found in AMD IOMMU initialization.
  IOMMU/spinlock: Make the pcidevs_lock a recursive one

 xen/arch/x86/domctl.c                       |  8 +--
 xen/arch/x86/hvm/vmsi.c                     |  4 +-
 xen/arch/x86/irq.c                          |  8 +--
 xen/arch/x86/msi.c                          | 16 ++---
 xen/arch/x86/pci.c                          |  4 +-
 xen/arch/x86/physdev.c                      | 16 ++---
 xen/common/sysctl.c                         |  4 +-
 xen/drivers/passthrough/amd/iommu_init.c    |  9 ++-
 xen/drivers/passthrough/amd/iommu_map.c     |  2 +-
 xen/drivers/passthrough/amd/pci_amd_iommu.c |  4 +-
 xen/drivers/passthrough/pci.c               | 96 +++++++++++++++++------------
 xen/drivers/passthrough/vtd/iommu.c         | 14 ++---
 xen/drivers/video/vga.c                     |  4 +-
 xen/include/xen/pci.h                       |  5 +-
 14 files changed, 108 insertions(+), 86 deletions(-)

-- 
1.9.1


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