reset_stack_and_jump() is actually a macro, but can effectivly become noreturn
by giving it an unreachable() declaration.
Propagate the 'noreturn-ness' up through the direct and indirect callers.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
This includes:
* A stale comment in sh_skip_sync()
* A dead for ever loop in __bug()
* A prototype for machine_power_off() which unimplemented in any architecture
* Replacing a for(;;); loop with unreachable()
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
On an x86 build (GCC Debian 4.7.2-5), this substantially reduces the size of
.text and .init.text sections.
Experimentally, even in a non-debug build, GCC uses `call` rather than `jmp`
so there should be no impact on any stack trace generation.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Make a formal define for noreturn in compiler.h, and fix up opencoded uses of
__attribute__((noreturn)). This includes removing redundant uses with
function definitions which have a public declaration.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
... so it can correctly be annotated as noreturn. Move the declaration of
nmi_crash() to be effectively private in crash.c
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
Splitting this up into pieces signficantly speeds up building on multi-
CPU systems when making use of make's -j option.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
In Linux the improper use was found to cause problems with certain
distributed build environments. Even if not directly affecting us, be
on the safe side.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
At least one vendor is in the process of making systems available where
these live in MMIO, not in I/O port space.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
It's unclear why c/s 4850:923dd9975981 added this - Dom0 isn't
controlling the timer interrupt, and hence has no need to know.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
this_cpu() makes use of RELOC_HIDE() to prevent unsafe optimisations, forcing
a recalculation of the per-cpu data area. Don't use it needlessly.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Eliminate effectively unused variables mistakenly left in place by
9539:08aede767c63 ("Rename update_dom_time() to
update_vcpu_system_time()").
Drop the pointless casts.
Use SECONDS() instead of open coding it.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
c/s 21039:95f5a4ce8f24 ("VT-d: reduce default verbosity") having put a
call to process_pending_softirqs() in VT-d's domain_context_mapping()
was wrong in two ways: For one we shouldn't be doing this when setting
up a device during DomU assignment. And then - I didn't check whether
that was the case already back then - we shouldn't call that function
with the pcidevs_lock (or in fact any spin lock) held.
Move the "preemption" into generic code, at once dealing with further
actual (too much output elsewhere - particularly on systems with very
many host bridge like devices - having been observed to still cause the
watchdog to trigger when enabled) and potential (other IOMMU code may
also end up being too verbose) issues.
Do the "preemption" once per device actually being set up when in
verbose mode, and once per bus otherwise.
Note that dropping pcidevs_lock around the process_pending_softirqs()
invocation is specifically not a problem here: We're in an __init
function and aren't racing with potential additions/removals of PCI
devices. Not acquiring the lock in setup_dom0_pci_devices() otoh is not
an option, as there are too many places that assert the lock being
held.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Xiantao Zhang <xiantao.zhang@intel.com>
During my fun time playing with balloon driver I found that hypervisor's
preemption check kept decrease_reservation from doing any useful work
for 32 bit guests, resulting in hanging the guests.
As Andrew suggested, we can force the check to fail for the first
iteration to ensure progress. We did this in d3a55d7d9 "x86/mm: Ensure
useful progress in alloc_l2_table()" already.
After this change I cannot see the hang caused by continuation logic
anymore.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Keir Fraser <keir@xen.org>
The privileges being strongly ordered is better reflected by using fall
through within the respective switch statement.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
... which has been missing since the introduction of the new interface
in the 4.2 development cycle.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Keir Fraser <keir@xen.org>
We have run relinquish_shared_pages() already by the time this
teardown happens, and page_make_sharable() exits early if the owning
domain is dying.
Signed-off-by: Tim Deegan <tim@xen.org>
Acked-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
This avoids a potentially long loop populating the p2m table from the
m2p. Since there's no reason to turn on translate mode after the
domain is already running, this shouldn't be a problem.
Signed-off-by: Tim Deegan <tim@xen.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
This patch extends the information returned for CR0/CR3/CR4 register
write events with the previous value of the register. The old value
was already passed to the trap processing function, just never placed
into the returned request. By returning this value, applications
subscribing the CR events obtain additional context about the event.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Tim Deegan <tim@xen.org>
Since it is an MMIO device, the code has been modified to accept MMIO based
devices as well. MMIO device settings are populated in the 'uart_config' table.
It also advertises 64 bit BAR. Therefore, code is reworked to account for 64
bit BAR and 64 bit MMIO lengths.
Some more quirks are - the need to shift the register offset by a specific
value and we also need to verify (UART_LSR_THRE && UART_LSR_TEMT) bits before
transmitting data.
While testing, include com1=115200,8n1,pci,0 on the xen cmdline to observe
output on console using SoL.
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: Thomas Lendacky <Thomas.Lendacky@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
To save finding it repeatedly with cpuid instructions. The name
"extended_cpuid_level" is chosen to match Linux.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
RTC_ALWAYS_BCD is always defined by default, meaning that we will
unconditionally enter the if statement. Reordering the condition allows
short-circult evaluation to remove a redundant CMOS read.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
This patch introduces a generic MSRs save/restore mechanism, so that
in the future new MSRs' save/restore could be added w/ smaller change
than the full blown addition of a new save/restore type.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Liu Jinsong <jinsong.liu@intel.com>
Acked-by: Keir Fraser <keir@xen.org>
When MPX supported, a new guest-state field for IA32_BNDCFGS
is added to the VMCS. In addition, two new controls are added:
- a VM-exit control called "clear BNDCFGS"
- a VM-entry control called "load BNDCFGS."
VM exits always save IA32_BNDCFGS into BNDCFGS field of VMCS.
Signed-off-by: Xudong Hao <xudong.hao@intel.com>
Reviewed-by: Liu Jinsong <jinsong.liu@intel.com>
Unlikely, but in case VMX support is not available, not expose
MPX to hvm guest.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Intel has released a new version of Intel Architecture Instruction Set
Extensions Programming Reference, adding new features like AVX-512,
MPX, etc. Refer to
http://download-software.intel.com/sites/default/files/319433-015.pdf
This patch adds support for these new instruction set extensions
without enabling this support for guest use, yet.
It also adjusts XCR0 validation, at once fixing the definition of
XSTATE_ALL (which is not supposed to include bit 63).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Keir Fraser <keir@xen.org>
When booting with "no-mce", the user does not need to be told that "MCE
support [was] disabled by bootparam" for each cpu. Furthermore, a file:line
reference is unnecessary.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Even in no-ack mode, there's no reason to leave the line asserted
after an explicit ack of the interrupt.
Furthermore, rtc_update_irq() is an unconditional noop having just cleared
REG_C.
Signed-off-by: Tim Deegan <tim@xen.org>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Let the vpt code drive the RTC's timer interrupts directly, as it does
for other periodic time sources, and fix up the register state in a
vpt callback when the interrupt is injected.
This fixes a hang seen on Windows 2003 in no-missed-ticks mode, where
when a tick was pending, the early callback from the VPT code would
always set REG_C.PF on every VMENTER; meanwhile the guest was in its
interrupt handler reading REG_C in a loop and waiting to see it clear.
One drawback is that a guest that attempts to suppress RTC periodic
interrupts by failing to read REG_C will receive up to 10 spurious
interrupts, even in 'strict' mode. However:
- since all previous RTC models have had this property (including
the current one, since 'no-ack' mode is hard-coded on) we're
pretty sure that all guests can handle this; and
- we're already playing some other interesting games with this
interrupt in the vpt code.
One other corner case: a guest that enables the PF timer interrupt,
masks the interupt in the APIC and then polls REG_C looking for PF
will not see PF getting set. The more likely case of enabling the
timers and masking the interrupt with REG_B.PIE is already handled
correctly.
Signed-off-by: Tim Deegan <tim@xen.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
If the guest has not asked for interrupts, don't run the vpt timer
to generate them. This is a prerequisite for a patch to simplify how
the vpt interacts with the RTC, and also gets rid of a timer series in
Xen in a case where it's unlikely to be needed.
Instead, calculate the correct value for REG_C.PF whenever REG_C is
read or PIE is enabled. This allow a guest to poll for the PF bit
while not asking for actual timer interrupts. Such a guest would no
longer get the benefit of the vpt's timer modes.
Signed-off-by: Tim Deegan <tim@xen.org>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
libxl_postfork_child_noexec would nestedly reaquire the non-recursive
"no_forking" mutex: atfork_lock uses it, as does sigchld_user_remove.
The result on Linux is that the process always deadlocks before
returning from this function.
This is used by xl's console child. So, the ultimate effect is that
xl with pygrub does not manage to connect to the pygrub console.
This behaviour was reported by Michael Young in Xen 4.4.0 RC5.
Also, the use of sigchld_user_remove in libxl_postfork_child_noexec is
not correct with SIGCHLD sharing. libxl_postfork_child_noexec is
documented to suffice if called only on one ctx. So deregistering the
ctx it's called on is not sufficient. Instead, we need a new approach
which discards the whole sigchld_user list and unconditionally removes
our SIGCHLD handler if we had one.
Prompted by this, clarify the semantics of
libxl_postfork_child_noexec. Specifically, expand on the meaning of
"quickly" by explaining what operations are not permitted; and
document the fact that the function doesn't reclaim the resources in
the ctxs.
And add a comment in libxl_postfork_child_noexec explaining the
internal concurrency situation.
This is an important bugfix. IMO the bug is a blocker for Xen 4.4.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reported-by: M A Young <m.a.young@durham.ac.uk>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
Release-acked-by: George Dunlap <george.dunlap@eu.citrix.com>
(cherry picked from commit 5be1e95318)
Currently iommu_init_dom0 is browsing the page list and call map_page callback
on each page.
On both AMD and VTD drivers, the function will directly return if the page
table is shared with the processor. So Xen can safely avoid to run through
the page list.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
This patch explicitly exposes Intel new features to dom0, including
RDSEED and ADX. As for PREFETCHW, it doesn't need explicit exposing.
Signed-off-by: Xudong Hao <xudong.hao@intel.com>
Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The check in question is redundant with the one in the immediately
following if(), where dividing by zero gets carefully avoided.
Spotted-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Since SVM and VMX use different mechanism to emulate the virtual-vmentry
and virtual-vmexit, it's hard to update the nested paging mode correctly in
common code. So we need to update the nested paging mode in their respective
code path.
SVM already updates the nested paging mode on vmexit. This patch adds the same
logic in VMX side.
Previous discussion is here:
http://lists.xen.org/archives/html/xen-devel/2013-12/msg01759.html
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Christoph Egger <chegger@amazon.de>
vmce_amd_[rd|wr]msr functions can handle accesses to AMD thresholding
registers. But due to this statement here:
switch ( msr & (MSR_IA32_MC0_CTL | 3) )
we are wrongly masking off top two bits which meant the register
accesses never made it to vmce_amd_* functions.
Corrected this problem by modifying the mask in this patch to allow
AMD thresholding registers to fall to 'default' case which in turn
allows vmce_amd_* functions to handle access to the registers.
While at it, remove some clutter in the vmce_amd* functions. Retained
current policy of returning zero for reads and ignoring writes.
Signed-off-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Liu Jinsong <jinsong.liu@intel.com>
These lines (in mctelem_reserve)
newhead = oldhead->mcte_next;
if (cmpxchgptr(freelp, oldhead, newhead) == oldhead) {
are racy. After you read the newhead pointer it can happen that another
flow (thread or recursive invocation) change all the list but set head
with same value. So oldhead is the same as *freelp but you are setting
a new head that could point to whatever element (even already used).
This patch use instead a bit array and atomic bit operations.
Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
Reviewed-by: Liu Jinsong <jinsong.liu@intel.com>
QEMU_UPSTREAM_REVISION set back to master, to track the tip.
QEMU_TAG set to the specific changeset as is customary.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
GICH_VMCR register contains alias to important bits of GICV interface such as:
- priority mask of the CPU
- EOImode
- ...
We were safe because Linux guest always use the same value for this bits.
When new guests will handle priority or change EOI mode, VCPU interrupt
management will be in a wrong state.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Cc: George Dunlap <george.dunlap@citrix.com>
Andrew Cooper
Jan Beulich
Wei Liu
Tim Deegan
Tamas K Lengyel
Aravind Gopalakrishnan
Xudong Hao
Jan Beulich
Julien Grall
Ian Jackson
Fabio Fantoni
Yang Zhang
Frediano Ziglio