Commit Graph
16 Commits
Author SHA1 Message Date
Ross Lagerwall c5089fae0f x86: avoid tripping watchdog when constructing dom0
Constructing dom0 may take a few seconds, particularly if the slow VESA
graphics terminal is used. Process pending softirqs a few times to avoid
tripping a watchdog with a short timeout.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>

Move inclusion of xen/softirq.h (and at once clean up other includes).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
2015-06-12 12:07:05 +02:00
Ross Lagerwall d4300db3a0 efi: avoid calling boot services after ExitBootServices()
After the first call to ExitBootServices(), avoid calling any boot
services (except GetMemoryMap() and ExitBootServices()) by setting
setting efi_bs to NULL and halting in blexit(). Only GetMemoryMap() and
ExitBootServices() are explicitly allowed to be called after the first
call to ExitBootServices() and so are are called via
SystemTable->BootServices.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-06-10 12:00:10 +02:00
Ross Lagerwall 8a753b3f1c efi: fix allocation problems if ExitBootServices() fails
If calling ExitBootServices() fails, the required memory map size may
have increased. When initially allocating the memory map, allocate a
slightly larger buffer (by an arbitrary 8 entries) to fix this.

The ARM code path was already allocating a larger buffer than required,
so this moves the code to be common for all architectures.

This was seen on the following machine when using the iscsidxe UEFI
driver. The machine would consistently fail the first call to
ExitBootServices().
System Information
        Manufacturer: Supermicro
        Product Name: X10SLE-F/HF
BIOS Information
        Vendor: American Megatrends Inc.
        Version: 2.00
        Release Date: 04/24/2014

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-06-02 13:44:24 +02:00
Ross Lagerwall 591e1e357c x86: don't crash when mapping a page using EFI runtime page tables
When an interrupt is received during an EFI runtime service call, Xen
may call map_domain_page() while using the EFI runtime page tables.
This fails because, although the EFI runtime page tables are a
copy of the idle domain's page tables, current points at a different
domain's vCPU.

To fix this, return NULL from mapcache_current_vcpu() when using the EFI
runtime page tables which is treated equivalently to running in an idle
vCPU.

This issue can be reproduced by repeatedly calling GetVariable() from
dom0 while using VT-d, since VT-d frequently maps a page from interrupt
context.

Example call trace:
[<ffff82d0801615dc>] __find_next_zero_bit+0x28/0x60
[<ffff82d08016a10e>] map_domain_page+0x4c6/0x4eb
[<ffff82d080156ae6>] map_vtd_domain_page+0xd/0xf
[<ffff82d08015533a>] msi_msg_read_remap_rte+0xe3/0x1d8
[<ffff82d08014e516>] iommu_read_msi_from_ire+0x31/0x34
[<ffff82d08016ff6c>] set_msi_affinity+0x134/0x17a
[<ffff82d0801737b5>] move_masked_irq+0x5c/0x98
[<ffff82d080173816>] move_native_irq+0x25/0x36
[<ffff82d08016ffcb>] ack_nonmaskable_msi_irq+0x19/0x20
[<ffff82d08016ffdb>] ack_maskable_msi_irq+0x9/0x37
[<ffff82d080173e8b>] do_IRQ+0x251/0x635
[<ffff82d080234502>] common_interrupt+0x62/0x70
[<00000000df7ed2be>] 00000000df7ed2be

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
2015-06-01 11:59:14 +02:00
Ross Lagerwall bf68adcada x86/efi: Reserve SMBIOS table region when EFI booting
Some EFI firmware implementations may place the SMBIOS table in RAM
marked as BootServicesData, which Xen does not consider as reserved.
When dom0 tries to access the SMBIOS, the region is not contained in the
initial P2M and it crashes with a page fault. To fix this, reserve the
SMBIOS region.

Also, fix the memcmp checks for existence of the SMBIOS.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2015-04-17 10:44:48 +02:00
Ross Lagerwall 916735e181 tools/libxl: Restore errnoval behavior for datacopier callback
6d896e1357 ("tools/libxl: Extend datacopier to support reading into a
buffer") changed the semantics of the errnoval parameter for the datacopier
callback without updating all callers.  Restore the original behavior for now.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-03-20 16:16:14 +00:00
Ross Lagerwall 6d896e1357 tools/libxl: Extend datacopier to support reading into a buffer
Currently a datacopier may source its data from an fd or local buffer, but its
destination must be an fd.  For migration v2, libxl needs to read from the
migration stream into a local buffer.

Implement a "read into local buffer" mode, invoked when readbuf is set and
writefd is -1.  On success, the callback passes the number of bytes read.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
[Rewrite commit message]
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-03-18 11:31:58 +00:00
Ross Lagerwall c9f8db9b16 tools/libxl: Allow limiting amount copied by datacopier
Currently, a datacopier will unconditionally read until EOF on its read fd.

For migration v2, libxl needs to read records of a specific length out of the
migration stream, without reading any further data.

Introduce a parameter, bytes_to_read, which may be used to stop the datacopier
ahead of reaching EOF. If bytes_to_read is set to -1, then the datacopier will
read until EOF.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
[Rewrite commit message]
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2015-03-18 11:31:57 +00:00
Ross Lagerwall 8aaeef92c9 tools/libxl: Avoid overrunning static buffer with prefixdata
An individual datacopier_buf contains a static buffer of 1000 bytes.
Attempting to add prefixdata of more than 1000 bytes would overrun the buffer
and cause heap corruption.

Instead, split the prefixdata and chain together multiple datacopier buffers.
This allows for an arbitrary quantity of prefixdata to be added to a
datacopier.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
2015-03-18 11:31:57 +00:00
Ross Lagerwall 9832f5e8e3 x86: don't apply reboot quirks if reboot set by user
If reboot= is specified on the command-line, don't apply reboot quirks
to allow the command-line option to take precedence.

This is a port of Linux commit 5955633e91bf ("x86/reboot: Skip DMI
checks if reboot set by user").

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>

Leverage (and make apply on top of) c643fb110a ("x86/EFI: allow
reboot= overrides when running under EFI").

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2015-03-13 12:41:51 +01:00
Ross Lagerwall 1f4eb9d27d EFI: fix getting EFI variable list on some systems
Copy the entire output buffer to the guest because some firmwares update
size on successful calls (contrary to the spec) and the buffer may
contain data beyond the output size that the firmware requires on a
subsequent GetNextVariableName() call (e.g. a NULL character).

Note that this shouldn't change the amount of data copied because on success, a
compliant firmware does not change size and so the entire buffer is copied
anyway.  If size is changed, Xen does not copy the buffer.

Without this change, the following (simplified) sequence would occur:
GetNextVariableName: in \0, size 1024 || out AdminPw\0, size 7
GetNextVariableName: in AdminPw\0, size 1024 || out UserPw\0, size 6
GetNextVariableName: in UserPww\0, size 1024 || NOT FOUND

This was seen on an Intel S1200RP_SE with firmware
S1200RP.86B.02.02.0005.102320140911, version 4.6, date 2014-10-23.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2015-03-10 13:52:01 +01:00
Ross Lagerwall 96e0ee8386 tools/hotplug: systemd: Don't ever kill xenstored
Don't kill xenstored as part of the usual service shutdown process to
prevent hangs on shutdown where the kernel tries to unplug a VIF
after xenstored has exited.

In an ideal case with all guests cooperating, xendomains will have shut
down all guests before xenstored is killed.

However in the uncooperative case, malicious or crashed guests may still
be running after xendomains has exited and this should not block the
shutdown/reboot of dom0.

Xenstored has no state to sync to disk, and never used to be killed in
the sysvinit case; observe the warning in xencommons.  Our testing has
shown regressions caused by the change in behaviour between sysvinit and
systemd when it comes to killing xenstored.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
[ ijc -- added systemd to title ]
2015-02-24 16:06:22 +00:00
Ross Lagerwall 3ea2ba980a x86/NMI: allow processing unknown NMIs when watchdog is enabled
Change NMI processing so that if watchdog=force is passed on the
command-line and the NMI is not caused by a perf counter overflow (i.e.
likely not a watchdog "tick"), the NMI is handled by the unknown NMI
handler.

This allows injection of NMIs from IPMI controllers that don't set the
IOCK/SERR bits to trigger the unknown NMI handler rather than be
ignored.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

Fix command line parsing (don't enable the watchdog on e.g.
"watchdog=xyz").

Signed-off-by: Jan Beulich <jbeulich@suse.com>
2014-08-28 16:11:37 +02:00
Ross Lagerwall d17ac1d543 x86/mwait_idle: fix trace output
Use the C-state's type when tracing, not its index since the index is
not set by the mwait_idle driver.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
2014-06-20 10:37:21 +02:00
Ross Lagerwall 775c681db1 cpuidle: improve perf for certain workloads
The existing mechanism of using interrupt frequency as a heuristic does
not work well for certain workloads.  As an example, synchronous dd on a
small block size uses deep C-states because much of the time is spent
doing processing so the interrupt frequency is not too high, but when an
IOP is submitted, the interrupt occurs soon after going idle.  This
causes exit latency to be a significant factor.

To fix this, add a new factor which limits the exit latency to be no
more than 10% of the decaying measured idle time.  This improves
performance for workloads with a medium interrupt frequency but a short
idle duration.

In the workload given previously, throughput improves by 20% with this
patch.

This is not ported from the Linux menu governor since that uses load
average and number of IO wait processes to satisfy latency constraints.
If a process is in IO wait state, it compares the exit latency with the
predicted residency reduced by a factor of 10, which is somewhat similar
to what this patch does.

A side effect of this patch is to correctly limit the maximum idle time
used in the correction factor calculation. Previously data->measured_us
was used, and it was never set.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
2014-06-16 11:59:05 +02:00
Ross Lagerwall 054b6dfb61 timers: set the deadline more accurately
Program the timer to the deadline of the closest timer if it is further
than 50us ahead, otherwise set it 50us ahead.  This way a single event
fires on time rather than 50us late (as it would have previously) while
still preventing too many timer wakeups in the case of having many
timers scheduled close together.

(where 50us is the timer_slop)

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
2014-05-28 10:07:50 +02:00