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OpenCloudOS-Kernel/drivers/xen/xen-pciback
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Konrad Rzeszutek Wilk 7681f31ec9 xen/pciback: Don't disable PCI_COMMAND on PCI device reset. 
There is no need for this at all. Worst it means that if
the guest tries to write to BARs it could lead (on certain
platforms) to PCI SERR errors.

Please note that with af6fc858a3
"xen-pciback: limit guest control of command register"
a guest is still allowed to enable those control bits (safely), but
is not allowed to disable them and that therefore a well behaved
frontend which enables things before using them will still
function correctly.

This is done via an write to the configuration register 0x4 which
triggers on the backend side:
command_write
  \- pci_enable_device
     \- pci_enable_device_flags
        \- do_pci_enable_device
           \- pcibios_enable_device
              \-pci_enable_resourcess
                [which enables the PCI_COMMAND_MEMORY|PCI_COMMAND_IO]

However guests (and drivers) which don't do this could cause
problems, including the security issues which XSA-120 sought
to address.

Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
 		2019-02-18 06:49:46 +01:00
..
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
conf_space.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
conf_space.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
conf_space_capability.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
conf_space_header.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
conf_space_quirks.c xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in xen_pcibk_config_quirks_init 2018-04-16 10:20:31 -04:00
conf_space_quirks.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
passthrough.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pci_stub.c xen/pciback: Check dev_data before using it 2018-12-17 10:29:50 -05:00
pciback.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pciback_ops.c xen/pciback: Don't disable PCI_COMMAND on PCI device reset. 2019-02-18 06:49:46 +01:00
vpci.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xenbus.c xen: mark expected switch fall-through 2019-02-18 06:48:35 +01:00