linux-stable.git/include/xen/interface, branch linux-3.10.y

xen: Add RING_COPY_REQUEST()

2017-02-06T08:04:07+00:00

commit 454d5d882c7e412b840e3c99010fe81a9862f6fb upstream.

Using RING_GET_REQUEST() on a shared ring is easy to use incorrectly
(i.e., by not considering that the other end may alter the data in the
shared ring while it is being inspected).  Safe usage of a request
generally requires taking a local copy.

Provide a RING_COPY_REQUEST() macro to use instead of
RING_GET_REQUEST() and an open-coded memcpy().  This takes care of
ensuring that the copy is done correctly regardless of any possible
compiler optimizations.

Use a volatile source to prevent the compiler from reordering or
omitting the copy.

This is part of XSA155.

Signed-off-by: David Vrabel 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Willy Tarreau

x86/xen: Support kexec/kdump in HVM guests by doing a soft reset

2015-10-22T21:37:50+00:00

commit 0b34a166f291d255755be46e43ed5497cdd194f2 upstream.

Currently there is a number of issues preventing PVHVM Xen guests from
doing successful kexec/kdump:

  - Bound event channels.
  - Registered vcpu_info.
  - PIRQ/emuirq mappings.
  - shared_info frame after XENMAPSPACE_shared_info operation.
  - Active grant mappings.

Basically, newly booted kernel stumbles upon already set up Xen
interfaces and there is no way to reestablish them. In Xen-4.7 a new
feature called 'soft reset' is coming. A guest performing kexec/kdump
operation is supposed to call SCHEDOP_shutdown hypercall with
SHUTDOWN_soft_reset reason before jumping to new kernel. Hypervisor
(with some help from toolstack) will do full domain cleanup (but
keeping its memory and vCPU contexts intact) returning the guest to
the state it had when it was first booted and thus allowing it to
start over.

Doing SHUTDOWN_soft_reset on Xen hypervisors which don't support it is
probably OK as by default all unknown shutdown reasons cause domain
destroy with a message in toolstack log: 'Unknown shutdown reason code
5. Destroying domain.'  which gives a clue to what the problem is and
eliminates false expectations.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: David Vrabel 
Signed-off-by: Greg Kroah-Hartman

xen-netback: coalesce slots in TX path and fix regressions

2013-04-22T19:37:01+00:00

This patch tries to coalesce tx requests when constructing grant copy
structures. It enables netback to deal with situation when frontend's
MAX_SKB_FRAGS is larger than backend's MAX_SKB_FRAGS.

With the help of coalescing, this patch tries to address two regressions
avoid reopening the security hole in XSA-39.

Regression 1. The reduction of the number of supported ring entries (slots)
per packet (from 18 to 17). This regression has been around for some time but
remains unnoticed until XSA-39 security fix. This is fixed by coalescing
slots.

Regression 2. The XSA-39 security fix turning "too many frags" errors from
just dropping the packet to a fatal error and disabling the VIF. This is fixed
by coalescing slots (handling 18 slots when backend's MAX_SKB_FRAGS is 17)
which rules out false positive (using 18 slots is legit) and dropping packets
using 19 to `max_skb_slots` slots.

To avoid reopening security hole in XSA-39, frontend sending packet using more
than max_skb_slots is considered malicious.

The behavior of netback for packet is thus:

    1-18            slots: valid
   19-max_skb_slots slots: drop and respond with an error
   max_skb_slots+   slots: fatal error

max_skb_slots is configurable by admin, default value is 20.

Also change variable name from "frags" to "slots" in netbk_count_requests.

Please note that RX path still has dependency on MAX_SKB_FRAGS. This will be
fixed with separate patch.

Signed-off-by: Wei Liu 
Acked-by: Ian Campbell 
Signed-off-by: David S. Miller

xen-netfront: reduce gso_max_size to account for max TCP header

2013-04-22T19:37:01+00:00

The maximum packet including header that can be handled by netfront / netback
wire format is 65535. Reduce gso_max_size accordingly.

Drop skb and print warning when skb->len > 65535. This can 1) save the effort
to send malformed packet to netback, 2) help spotting misconfiguration of
netfront in the future.

Signed-off-by: Wei Liu 
Acked-by: Ian Campbell 
Signed-off-by: David S. Miller

Merge tag 'for-linus-20130331' of git://git.kernel.dk/linux-block

2013-03-31T18:38:59+00:00

Pull block fixes from Jens Axboe:
 "Alright, this time from 10K up in the air.

  Collection of fixes that have been queued up since the merge window
  opened, hence postponed until later in the cycle.  The pull request
  contains:

   - A bunch of fixes for the xen blk front/back driver.

   - A round of fixes for the new IBM RamSan driver, fixing various
     nasty issues.

   - Fixes for multiple drives from Wei Yongjun, bad handling of return
     values and wrong pointer math.

   - A fix for loop properly killing partitions when being detached."

* tag 'for-linus-20130331' of git://git.kernel.dk/linux-block: (25 commits)
  mg_disk: fix error return code in mg_probe()
  rsxx: remove unused variable
  rsxx: enable error return of rsxx_eeh_save_issued_dmas()
  block: removes dynamic allocation on stack
  Block: blk-flush: Fixed indent code style
  cciss: fix invalid use of sizeof in cciss_find_cfgtables()
  loop: cleanup partitions when detaching loop device
  loop: fix error return code in loop_add()
  mtip32xx: fix error return code in mtip_pci_probe()
  xen-blkfront: remove frame list from blk_shadow
  xen-blkfront: pre-allocate pages for requests
  xen-blkback: don't store dev_bus_addr
  xen-blkfront: switch from llist to list
  xen-blkback: fix foreach_grant_safe to handle empty lists
  xen-blkfront: replace kmalloc and then memcpy with kmemdup
  xen-blkback: fix dispatch_rw_block_io() error path
  rsxx: fix missing unlock on error return in rsxx_eeh_remap_dmas()
  Adding in EEH support to the IBM FlashSystem 70/80 device driver
  block: IBM RamSan 70/80 error message bug fix.
  block: IBM RamSan 70/80 branding changes.
  ...

Merge branch 'stable/for-jens-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus

2013-03-22T14:56:32+00:00

Konrad writes:

[the branch] has a bunch of fixes. They vary from being able to deal
with unknown requests, overflow in statistics, compile warnings, bug in
the error path, removal of unnecessary logic. There is also one
performance fix - which is to allocate pages for requests when the
driver loads - instead of doing it per request

xen-pciback: notify hypervisor about devices intended to be assigned to guests

2013-03-22T14:20:55+00:00

For MSI-X capable devices the hypervisor wants to write protect the
MSI-X table and PBA, yet it can't assume that resources have been
assigned to their final values at device enumeration time. Thus have
pciback do that notification, as having the device controlled by it is
a prerequisite to assigning the device to guests anyway.

This is the kernel part of hypervisor side commit 4245d33 ("x86/MSI:
add mechanism to fully protect MSI-X table from PV guest accesses") on
the master branch of git://xenbits.xen.org/xen.git.

CC: stable@vger.kernel.org
Signed-off-by: Jan Beulich 
Signed-off-by: Konrad Rzeszutek Wilk

xen/blkback: correctly respond to unknown, non-native requests

2013-03-11T17:54:28+00:00

If the frontend is using a non-native protocol (e.g., a 64-bit
frontend with a 32-bit backend) and it sent an unrecognized request,
the request was not translated and the response would have the
incorrect ID.  This may cause the frontend driver to behave
incorrectly or crash.

Since the ID field in the request is always in the same place,
regardless of the request type we can get the correct ID and make a
valid response (which will report BLKIF_RSP_EOPNOTSUPP).

This bug affected 64-bit SLES 11 guests when using a 32-bit backend.
This guest does a BLKIF_OP_RESERVED_1 (BLKIF_OP_PACKET in the SLES
source) and would crash in blkif_int() as the ID in the response would
be invalid.

Signed-off-by: David Vrabel 
Cc: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk

xen: event channel arrays are xen_ulong_t and not unsigned long

2013-02-20T13:45:07+00:00

On ARM we want these to be the same size on 32- and 64-bit.

This is an ABI change on ARM. X86 does not change.

Signed-off-by: Ian Campbell 
Cc: Jan Beulich 
Cc: Keir (Xen.org) 
Cc: Tim Deegan 
Cc: Stefano Stabellini 
Cc: linux-arm-kernel@lists.infradead.org
Cc: xen-devel@lists.xen.org
Cc: Konrad Rzeszutek Wilk 
Signed-off-by: Konrad Rzeszutek Wilk

xen/acpi: ACPI cpu hotplug

2013-02-20T03:02:29+00:00

This patch implement real Xen ACPI cpu hotplug driver as module.
When loaded, it replaces Xen stub driver.

For booting existed cpus, the driver enumerates them.
For hotadded cpus, which added at runtime and notify OS via
device or container event, the driver is invoked to add them,
parsing cpu information, hypercalling to Xen hypervisor to add
them, and finally setting up new /sys interface for them.

Signed-off-by: Liu Jinsong 
Signed-off-by: Konrad Rzeszutek Wilk