iomem_access_permitted() wants an inclusive range as input.
Also use pfn_to_paddr() in nearby code instead of open coding it.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
master commit: afa65ddfd8
master date: 2013-05-15 14:34:05 +0200
This fixes two regressions from c/s 20143:a7de5bd776ca ("x86: Make the
hypercall PHYSDEVOP_alloc_irq_vector hypercall dummy"):
For one, IRQs that had their vector set up by Xen internally without a
handler ever having got set (e.g. via "com<n>=..." without a matching
consumer option like "console=com<n>") would wrongly call
add_pin_to_irq() here, triggering the BUG_ON() in that function.
Second, when assign_irq_vector() fails this addition to irq_2_pin[]
needs to be undone.
In the context of this I'm also surprised that the irq_2_pin[]
manipulations here occur without any lock, i.e. rely on Dom0 to do
some sort of serialization.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
master commit: 30256a0ff1
master date: 2013-05-15 10:52:02 +0200
This drops the "preemptible" parameters from various functions where
now they can't (or shouldn't, validated by assertions) be run in non-
preemptible mode anymore, to prove that manipulations of at least L3
and L4 page tables and page table entries are now always preemptible,
i.e. the earlier patches actually fulfill their purpose of fixing the
resulting security issue.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
master commit: b965b31a6b
master date: 2013-05-02 17:04:14 +0200
Only in cases where we don't know what to do we should leave the IRTE
blank (suppressing all validation), but we should always log a warning
in those cases (as being insecure).
This is CVE-2013-1952 / XSA-49.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: "Zhang, Xiantao" <xiantao.zhang@intel.com>
master commit: 63cec00679
master date: 2013-05-02 17:08:58 +0200
... as they may take significant amounts of time.
This requires cloning the tweaked continuation logic from
do_mmuext_op() to do_mmu_update().
Note that in mod_l[34]_entry() a negative "preemptible" value gets
passed to put_page_from_l[34]e() now, telling the callee to store the
respective page in current->arch.old_guest_table (for a hypercall
continuation to pick up), rather than carrying out the put right away.
This is going to be made a little more explicit by a subsequent cleanup
patch.
This is part of CVE-2013-1918 / XSA-45.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
master commit: b8efae696c
master date: 2013-05-02 16:39:37 +0200
... as it may take significant amounts of time.
Since we can't re-invoke the operation in a second attempt, the
continuation logic must be slightly tweaked so that we make sure
do_mmuext_op() gets run one more time even when the preempted unpin
operation was the last one in a batch.
This is part of CVE-2013-1918 / XSA-45.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
master commit: a3e049f8e8
master date: 2013-05-02 16:39:06 +0200
.. as the root page table validation (and the dropping of an eventual
old one) can require meaningful amounts of time.
This is part of CVE-2013-1918 / XSA-45.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
master commit: 99d2b14991
master date: 2013-05-02 16:38:30 +0200
... as dropping the old page tables may take significant amounts of
time.
This is part of CVE-2013-1918 / XSA-45.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
master commit: 4939f9a6de
master date: 2013-05-02 16:37:24 +0200
... as it may take significant amounts of time.
This is part of CVE-2013-1918 / XSA-45.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
master commit: 918a5f17b4
master date: 2013-05-02 16:36:44 +0200
... as it may take significant amounts of time.
This is part of CVE-2013-1918 / XSA-45.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
master commit: e2e6b7b627
master date: 2013-05-02 16:35:50 +0200
... as it may take significant amounts of time.
The function, being moved to mm.c as the better home for it anyway, and
to avoid having to make a new helper function there non-static, is
given a "preemptible" parameter temporarily (until, in a subsequent
patch, its other caller is also being made capable of dealing with
preemption).
This is part of CVE-2013-1918 / XSA-45.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
master commit: 6cdc9be2a5
master date: 2013-05-02 16:34:21 +0200
When acquiring a transitive grant for copy then the owning domain
needs to be locked down as well as the granting domain. This was being
done, but the unlocking was not. The acquire code now stores the
struct domain * of the owning domain (rather than the domid) in the
active entry in the granting domain. The release code then does the
unlock on the owning domain. Note that I believe I also fixed a bug
where, for non-transitive grants the active entry contained a
reference to the acquiring domain rather than the granting
domain. From my reading of the code this would stop the release code
for transitive grants from terminating its recursion correctly.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
master commit: f544bf377e
master date: 2011-03-08 16:30:30 +0000
Also, for non-transitive grants we now avoid incorrectly recursing
in __release_grant_for_copy.
This is CVE-2013-1964 / XSA-50.
Reported-by: Manuel Bouyer <bouyer@antioche.eu.org>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Manuel Bouyer <bouyer@antioche.eu.org>
- properly revoke IRQ access in map_domain_pirq() error path
- don't permit replacing an in use IRQ
- don't accept inputs in the GSI range for MAP_PIRQ_TYPE_MSI
- track IRQ access permission in host IRQ terms, not guest IRQ ones
(and with that, also disallow Dom0 access to IRQ0)
This is CVE-2013-1919 / XSA-46.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
master commit: 545607eb3c
master date: 2013-04-18 16:11:23 +0200
... as it causes problems if we happen to exit back via IRET: In the
course of trying to handle the fault, the hypervisor creates a stack
frame by hand, and uses PUSHFQ to set the respective EFLAGS field, but
expects to be able to IRET through that stack frame to the second
portion of the fixup code (which causes a #GP due to the stored EFLAGS
having NT set).
And even if this worked (e.g if we cleared NT in that path), it would
then (through the fail safe callback) cause a #GP in the guest with the
SYSENTER handler's first instruction as the source, which in turn would
allow guest user mode code to crash the guest kernel.
Inject a #GP on the fake (NULL) address of the SYSENTER instruction
instead, just like in the case where the guest kernel didn't register
a corresponding entry point.
On 32-bit we also need to make sure we clear SYSENTER_CS for all CPUs
(neither #RESET nor #INIT guarantee this).
This is CVE-2013-1917 / XSA-44.
Reported-by: Andrew Cooper <andrew.cooper3@citirx.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: fdac951560
master date: 2013-04-18 16:00:35 +0200
This fixes a regression side-effect caused by:
IOMMU: properly check whether interrupt remapping is enabled
git: fae0372140
hg: 26742:e1ec14bad0cb
On the crash path in nmi_shootdown_cpus(), we shut down the IOMMU, then
disable the IOAPIC.
On systems which support interrupt remapping, the variable iommu_intremap
remains set, meaning that disable_IO_APIC() issues interrupt remapping
invalidate requests.
IOAPIC interrupt remapping used to be conditional on iommu_enabled, but is now
conditional on iommu_intremap, following the above changeset.
This behaviour can be fixed by also indicating that interrupt remapping is not
enabled after shutting down the IOMMU.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 53fd1d8458
master date: 2013-04-16 10:34:32 +0200
scale_delta(), which is being called by that function, doesn't cope
with that.
Also print a warning message, so hopefully we can eventually figure why
occasionally a negative value results from the calculation in the first
place.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
master commit: eb60be3dd8
master date: 2013-04-11 12:07:55 +0200
commit e7dda8ec9f
VMX: disable SMEP feature when guest is in non-paging mode
disabled the SMEP bit if a guest VCPU was using HAP and was not
in paging mode. However I could observe VCPUs getting stuck in
the trampoline after the following patch in the Linux kernel
changed the way CR4 gets set up:
x86, realmode: read cr4 and EFER from kernel for 64-bit trampoline
The change will set CR4 from already set flags which includes the
SMEP bit. On bare metal this does not matter as the CPU is in non-
paging mode at that time. But Xen seems to use the emulated non-
paging mode regardless of HAP (I verified that on the guests I was
seeing the issue, HAP was not used).
Therefor it seems right to unset the SMEP bit for a VCPU that is
not in paging-mode, regardless of its HAP usage.
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Dongxiao Xu <dongxiao.xu@intel.com>
master commit: 0d2e673a76
master date: 2013-04-04 10:37:19 +0200
SMEP is disabled if CPU is in non-paging mode in hardware.
However Xen always uses paging mode to emulate guest non-paging
mode with HAP. To emulate this behavior, SMEP needs to be manually
disabled when guest switches to non-paging mode.
We met an issue that, SMP Linux guest with recent kernel (enable
SMEP support, for example, 3.5.3) would crash with triple fault if
setting unrestricted_guest=0 in grub. This is because Xen uses an
identity mapping page table to emulate the non-paging mode, where
the page table is set with USER flag. If SMEP is still enabled in
this case, guest will meet unhandlable page fault and then crash.
Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
master commit: e7dda8ec9f
master date: 2013-01-30 09:17:30 -0800
Xenheap pages will always have an extra typecount, taken in
share_xen_page_with_guest(), which doesn't come from a shadow PTE.
Adjust the warning in sh_remove_all_mappings() to account for it.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Tim Deegan <tim@xen.org>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: cfc515dabe
master date: 2013-04-04 10:14:30 +0100
When in SYS_STATE_suspend, and going through the cpu_disable_scheduler
path, save a copy of the current cpu affinity, and mark a flag to
restore it later.
Later, in the resume process, when enabling nonboot cpus restore these
affinities.
Signed-off-by: Ben Guthro <benjamin.guthro@citrix.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Keir Fraser <keir@xen.org>
master commit: 41e71c2607
master date: 2013-04-02 09:52:32 +0200
Since the main loop in the function includes legacy vectors, and since
vector_irq[] gets set up for legacy vectors regardless of whether those
get handled through the IO-APIC, it must not do anything on this vector
range. In fact, we should never get past the move_cleanup_count check
for IRQs not handled through the IO-APIC. Adding a respective assertion
woulkd make those iterations more expensive (due to the lock acquire).
For such an assertion to not have false positives we however ought to
suppress setting up IRQ2 as an 8259A interrupt (which wasn't correct
anyway), which is being done here despite the assertion not actually
getting added.
Furthermore, there's no point iterating over the vectors past
LAST_HIPRIORITY_VECTOR, so terminate the loop accordingly.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Keir Fraser <keir@xen.org>
master commit: af699220ad
master date: 2013-04-02 08:30:03 +0200
Otherwise a dangling pointer can be left, which would cause subsequent
memory corruption as soon as the space got re-allocated for some other
purpose.
This is CVE-2013-1920 / XSA-47.
Reported-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
master commit: 99b9ab0b3e
master date: 2013-04-05 09:59:03 +0200
On Huang Ying's machine:
erst_tab->header_length == sizeof(struct acpi_table_einj)
but Yinghai reported that on his machine,
erst_tab->header_length == sizeof(struct acpi_table_einj) -
sizeof(struct acpi_table_header)
To make erst table size checking code works on all systems, both
testing are treated as PASS.
Same situation applies to einj_tab->header_length, so corresponding
table size checking is changed in similar way too.
Originally-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Huang Ying <ying.huang@intel.com>
- use switch() for better readability
- add comment explaining why a formally invalid size it also being
accepted
- check erst_tab->header.length before even looking at
erst_tab->header_length
- prefer sizeof(*erst_tab) over sizeof(struct acpi_table_erst)
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
master commit: 915ef37d7c
master date: 2012-10-16 17:26:36 +0200
Some actions in APEI ERST and EINJ tables are optional, for example,
ACPI_EINJ_BEGIN_OPERATION action is used to do some preparation for
error injection, and firmware may choose to do nothing here. While
some other actions are mandatory, for example, firmware must provide
ACPI_EINJ_GET_ERROR_TYPE implementation.
Original implementation treats all actions as optional (that is, can
have no instructions), that may cause issue if firmware does not
provide some mandatory actions. To fix this, this patch adds
apei_exec_run_optional, which should be used for optional actions.
The original apei_exec_run should be used for mandatory actions.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 72af01bf6f
master date: 2013-03-22 12:46:25 +0100
This causes deadlocks during early boot on hardware with broken/buggy
APEI implementations, such as a Dell Poweredge 2950 with the latest
currently available BIOS.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Don't use goto or another special error path, as handling the error
case in normal flow is quite simple.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
master commit: 0611689d91
master date: 2013-03-22 09:43:38 +0100
The src_base and dst_base fields in apei_exec_context are physical
address, so they should be ioremaped before being used in ERST
MOVE_DATA instruction.
Reported-by: Javier Martinez Canillas <martinez.javier@gmail.com>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Replace use of ioremap() by __acpi_map_table()/set_fixmap(). Fix error
handling.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
master commit: df2cf6a726
master date: 2012-10-17 14:12:06 +0200
SNB graphics devices have a bug that prevent them from accessing certain
memory ranges, namely anything below 1M and in the pages listed in the
table.
Xen does not initialize below 1MB to heap, i.e. below 1MB pages don't be
allocated, so it's unnecessary to reserve memory below the 1 MB mark
that has not already been reserved.
So reserve those pages listed in the table at xen boot if set detect a
SNB gfx device on the CPU to avoid GPU hangs.
Signed-off-by: Xudong Hao <xudong.hao@intel.com>
Acked-by: Keir Fraser <keir@xen.org>
master commit: db537fe302
master date: 2013-03-26 14:22:07 +0100
After some more thought on the XSA-36 and specifically the comments we
got regarding disabling the IOMMU in this situation altogether making
things worse instead of better, I came to the conclusion that we can
actually restrict the action in affected cases to just disabling
interrupt remapping. That doesn't make the situation worse than prior
to the XSA-36 fixes (where interrupt remapping didn't really protect
domains from one another), but allows at least DMA isolation to still
be utilized.
To do so, disabling of interrupt remapping must be explicitly requested
on the command line - respective checks will then be skipped.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Suravee Suthikulanit <suravee.suthikulpanit@amd.com>
master changeset: 92b8bc03bd
master date: 2013-03-25 16:55:22 +0100
http://www.intel.com/content/www/us/en/chipsets/5520-and-5500-chipset-ioh-specification-update.html
Stepping B-3 has two errata (#47 and #53) related to Interrupt
remapping, to which the workaround is for the BIOS to completely disable
interrupt remapping. These errata are fixed in stepping C-2.
Unfortunately this chipset stepping is very common and many BIOSes are
not disabling interrupt remapping on this stepping . We can detect this in
Xen and prevent Xen from using the problematic interrupt remapping feature.
The Intel 5500/5520/X58 chipset does not support VT-d
Extended Interrupt Mode(EIM). This means the iommu_supports_eim() check
always fails and so x2apic mode cannot be enabled in Xen before this quirk
disables the interrupt remapping feature.
Signed-off-by: Malcolm Crossley <malcolm.crossley@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Gate the function call to check the quirk on interrupt remapping being
requested to get enabled, and upon failure disable the IOMMU to be in
line with what the changes for XSA-36 (plus follow-ups) did.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: "Zhang, Xiantao" <xiantao.zhang@intel.com>
master changeset: 6890cebc6a
master date: 2013-03-25 14:31:27 +0100
... rather than the IOMMU as a whole.
That in turn required to make sure iommu_intremap gets properly
cleared when the respective initialization fails (or isn't being
done at all).
Along with making sure interrupt remapping doesn't get inconsistently
enabled on some IOMMUs and not on others in the VT-d code, this in turn
allowed quite a bit of cleanup on the VT-d side (removed from the
backport).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: "Zhang, Xiantao" <xiantao.zhang@intel.com>
master changeset: fae0372140
master date: 2013-03-25 14:28:31 +0100
This saves N identical console log lines on a multi-iommu server.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
master changeset: 32861c5377
master date: 2013-03-20 10:02:26 +0100
Recent changes which have made their way into xen-4.2 stable have pushed the
runtime of construct_dom0() over 5 seconds, which has caused regressions in
XenServer testing because of our 5 second watchdog.
The root cause is that amd_iommu_dom0_init() does not process softirqs and in
particular the nmi_timer which causes the watchdog to decide that no useful
progress is being made.
This patch adds periodic calls to process_pending_softirqs() at the same
interval as the Intel variant of this function. The server which was failing
with the watchdog test now boots reliably with a timeout of 1 second.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
master changeset: 0f7b6f91ac
master date: 2013-03-20 10:00:01 +0100
As the bits indicating validity of the ADDR and MISC bank MSRs may be
injected in a way that isn't consistent with what the underlying
hardware implements (while the bank must be valid for injection to
work, the auxiliary MSRs may not be implemented - and hence cause #GP
upon access - if the hardware never sets the corresponding valid bits.
Consequently we need to do the clearing writes only if no value was
interposed for the respective MSR (which also makes sense the other way
around: there's no point in clearing a hardware register when all data
read came from software). Of course this all requires the injection
tool to do things in a consistent way (but that had been a requirement
before already).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Ren Yongjie <yongjie.ren@intel.com>
Acked-by: Liu Jinsong <jinsong.liu@intel.com>
master changeset: b0583c0e64
master date: 2013-03-12 15:53:30 +0100
In the Linux kernel, these two git commits:
- f594065faf4f9067c2283a34619fc0714e79a98d
ACPI: Add fixups for AMD P-state figures
- 9855d8ce41a7801548a05d844db2f46c3e810166
ACPI: Check MSR valid bit before using P-state frequencies
Try to fix the the issue that "some AMD systems may round the
frequencies in ACPI tables to 100MHz boundaries. We can obtain the real
frequencies from MSRs, so add a quirk to fix these frequencies up
on AMD systems." (from f594065..)
In discussion (around 9855d8..) "it turned out that indeed real
HW/BIOSes may choose to not set the valid bit and thus mark the
P-state as invalid. So this could be considered a fix for broken
BIOSes." (from 9855d8..)
which is great for Linux. Unfortunatly the Linux kernel, when
it tries to do the RDMSR under Xen it fails to get the right
value (it gets zero) as Xen traps it and returns zero. Hence
when dom0 uploads the P-states they will be unmodified and
we should take care of updating the frequencies with the right
values.
I've tested it under Dell Inc. PowerEdge T105 /0RR825, BIOS 1.3.2
08/20/2008 where this quirk can be observed (x86 == 0x10, model == 2).
Also on other AMD (x86 == 0x12, A8-3850; x86 = 0x14, AMD E-350) to
make sure the quirk is not applied there.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: stefan.bader@canonical.com
Do the MSR access here (and while at it, also the one reading
MSR_PSTATE_CUR_LIMIT) on the target CPU, and bound the loop over
amd_fixup_frequency() by max_hw_pstate (matching the one in
powernow_cpufreq_cpu_init()).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
master changeset: 1d80765b50
master date: 2013-03-12 15:34:22 +0100
Signed-off-by: Jan Beulich <jbeulich@novell.com>
xen-unstable changeset: 4afea3d653
xen-unstable date: Wed Mar 9 16:19:36 2011 +0000
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
[ This is byte-for-byte identical to Bastian Blank's backport of the
same changeset to xen-4.1, as found in Debian xen_4.1.4-2.*
patch debian/patches/upstream-23002:eb64b8f8eebb -iwj ]
This adds two new physdev operations for Dom0 to invoke when resource
allocation for devices is known to be complete, so that the hypervisor
can arrange for the respective MMIO ranges to be marked read-only
before an eventual guest getting such a device assigned even gets
started, such that it won't be able to set up writable mappings for
these MMIO ranges before Xen has a chance to protect them.
This also addresses another issue with the code being modified here,
in that so far write protection for the address ranges in question got
set up only once during the lifetime of a device (i.e. until either
system shutdown or device hot removal), while teardown happened when
the last interrupt was disposed of by the guest (which at least allowed
the tables to be writable when the device got assigned to a second
guest [instance] after the first terminated).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
master changeset: 4245d331e0
master date: 2013-03-08 14:05:34 +0100
The flags structure is not protected by locks (or more precisely,
it is protected using an inconsistent set of locks); we therefore need
to make sure that all accesses are atomic-safe. This is particulary
important in the case of the PARKED flag, which if clobbered while
changing the YIELD bit will leave a vcpu wedged in an offline state.
Using the atomic bitops also requires us to change the size of the "flags"
element.
Spotted-by: Igor Pavlikevich <ipavlikevich@gmail.com>
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
master changeset: be65075094
master date: 2013-03-04 13:37:39 +0100
Otherwise, we may end up in the scheduler, keeping NMIs masked for a
possibly unbounded period of time (until whenever the next IRET gets
executed). Enforce timely event processing by sending a self IPI.
Of course it's open for discussion whether to always use the straight
exit path from handle_ist_exception.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
master changeset: d463b005bb
master date: 2013-03-04 10:19:34 +0100
The introduction of vcpu_force_reschedule() in 14320:215b799fa181 was
incompatible with the SEDF scheduler: Any vCPU using
VCPUOP_stop_periodic_timer (e.g. any vCPU of half way modern PV Linux
guests) ends up on pCPU0 after that call. Obviously, running all PV
guests' (and namely Dom0's) vCPU-s on pCPU0 causes problems for those
guests rather sooner than later.
So the main thing that was clearly wrong (and bogus from the beginning)
was the use of cpumask_first() in sedf_pick_cpu(). It is being replaced
by a construct that prefers to put back the vCPU on the pCPU that it
got launched on.
However, there's one more glitch: When reducing the affinity of a vCPU
temporarily, and then widening it again to a set that includes the pCPU
that the vCPU was last running on, the generic scheduler code would not
force a migration of that vCPU, and hence it would forever stay on the
pCPU it last ran on. Since that can again create a load imbalance, the
SEDF scheduler wants a migration to happen regardless of it being
apparently unnecessary.
Of course, an alternative to checking for SEDF explicitly in
vcpu_set_affinity() would be to introduce a flags field in struct
scheduler, and have SEDF set a "always-migrate-on-affinity-change"
flag.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
master changeset: e6a6fd6365
master date: 2013-03-04 10:17:52 +0100
When a domain's shared info field "max_pfn" is zero,
domain_get_maximum_gpfn() so far returned ULONG_MAX, which
do_memory_op() in turn converted to -1 (i.e. -EPERM). Make the former
always return a sensible number (i.e. zero if the field was zero) and
have the latter no longer truncate return values.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
master changeset: 7ffc9779aa
master date: 2013-03-04 10:16:04 +0100
A shift with a negative count was erroneously used here, yielding
undefined behavior.
Reported-by: Xi Wang <xi@mit.edu>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
master changeset: 53decd3221
master date: 2013-03-01 16:59:49 +0100
Jan Beulich
Ian Jackson
Paul Durrant
Andrew Cooper
Stefan Bader
Dongxiao Xu
Keir Fraser
Tim Deegan
Ben Guthro
Huang Ying
Xudong Hao
Malcolm Crossley
Konrad Rzeszutek Wilk
George Dunlap