on is level triggered rather than edge triggered, since it's a PCI device.
This is complicated by the possibility that another PCI device could be
on the same interrupt; the workaround is to have two irr registers
for the PIC and APIC, and have qemu and Xen generated interrupts go
into different ones.
This broke the alt_irq stuff. Fortunately, nobody uses that anymore, so
I've removed it.
Signed-off-by: Steven Smith <sos22@cam.ac.uk>
Also update the code in tools to create the device node if udev fails.
The tools now read the sysfs system to find the minor number needed.
Original patch from Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Keir Fraser <keir@xensource.com>
With Intel VT, VMXOFF needs to be executed before halting the
CPU. Without this fix Xen or Linux is unable to start up the CPU after
a kexec reboot.
Tested using x86_32 on a Pentium D 930.
Signed-Off-By: Magnus Damm <magnus@valinux.co.jp>
The current Xen code keeps X86_CR4_VMXE set even if VMXON has not been
executed. The stop_vmx() code assumes that it is possible to call
VMXOFF if X86_CR4_VMXE is set which is not always true. Calling VMXOFF
without VMXON results in an illegal opcode trap, and to avoid this condition
this patch makes sure that X86_CR4_VMXE is only set when VMXON has
been called.
Tested using x86_32 on a Pentium D 930.
Signed-Off-By: Magnus Damm <magnus@valinux.co.jp>
blktap_poll is calling tlb_flush_all() in its main ring buffer polling
loop. This seems to be superfluous: the hypervisor should be
performing
any necessary tlb flushes on grant table operations performed by the
back-end. Even a simple memory barrier is unnecessary here as the
RING_PUSH_REQUESTS() call performs a wmb() anyway.
And tlb_flush_all() is not exported to modules, so this call prevents
blktap from building as a module. Just remove it.
Signed-off-by: Stephen Tweedie <sct@redhat.com>
tapdisk was using a 1msec select() timeout in its main event loop. On
timeout, the loop does nothing except repeat, so the timeout achieves
nothing; worse, on a machine with HZ set to less than 1000, a msec
timeout returns immediately, sending tapdisk into a 100%-CPU-
utilisation loop.
Simply remove the timeout entirely; everything still works fine, and
much more efficiently when idle.
Signed-off-by: Stephen Tweedie <sct@redhat.com>
In vmx_assist, the copy for new/old context and vmx assist magic are
all using physical address, while hvm_copy will use the virtual address.
This may cause problem when guest jump directly from real mode to
paging mode.
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Keir Fraser <keir@xensource.com>
notifications during shutdown. When rootfs goes away this can
cause the system to hang, as we notify userspace etc.
Instead we forcibly reset the state machine back to state Closed
if we are a frontend driver, to get the backend to release
resources. Necessary if we are going to kexec.
Signed-off-by: Keir Fraser <keir@xensource.com>
This patch makes blktap Do The Right Thing(TM). It allows udev to
create the /dev/xen/blktap[0-9] devices.
It creates a sysfs class called "xen". This part may later be placed
someplace else, but currently blktap is the only user so it is placed in
the blktap code.
When blktap is initialized, a blktap0 sysfs class device is made. The
other devices blktapX (X > 0) are made when the BLKTAP_IOCTL_NEWINTF
ioctl is called. This way we don't flood the sysfs and /dev/xen with
unnecessary devices.
I added a rule in the xen-backend.rules to allow for udev to create the
blktap devices.
With this, we can really remove the code to search and create the
/dev/xen/blktap[0-9]*, but I'll leave it in for now. With the use of
udev, we really should remove that code as well as the code for creating
the evtchn device. udev works for both of these now. But that removal
will have to be in another patch.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
blktap currently uses a hardcoded major of 254 for the device. This is
not robust in anyway and needs to be dynamic.
Note: it is better not to have the daemon create the node, and have udev
create it instead. But since the daemon currently creates the node
anyway, it is still the way this is done. That change needs to be made
at another time.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
If a Xen guest has a bootloader configured, then it will fail to start
on a blktap image. The problem is blkdev_uname_to_file, which cannot
parse the "tap:aio:$filename" image strings: it tries to split the
string apart at ":" and assign the result to a 2-tuple, and this
results in a python error if the split results in three or more
strings.
The fix is to split only at the first ":", and then to split again
if we detect "tap:" as the image type.
Signed-off-by: Stephen Tweedie <sct@redhat.com>
blktap is calling non-atomic kernel functions with irqs disabled, which
hits various kernel debug traps if those are enabled. The problem is
req_increase(), which takes the pending_free_lock.
This function is currently only ever called from module initialiation,
where it is impossible for it to race against anything else. Its
companion, req_decrease(), is not called at all.
Fix by removing the offending locking from req_increase() and, while
we're at it, remove req_decrease() entirely.
Signed-off-by: Stephen Tweedie <sct@redhat.com>
This patch cleans up the blktap.c code to make it form to the Linux
coding style a little better.
It also removes the private data structure that is only used to store
the index of the tabfds descriptor. Instead the filp->private_data now
points to the descriptor itself.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
When a domain shuts down with a blktap-backed block device open, it can
easily cause a dom0 oops. The XenbusStateClosing event can occur while
the tapdisk userland thread is still processing IO requests (eg.
readaheads) from the domU. But the xenbus state handler calls
tap_blkif_unmap(), unmapping the blkif->blk_ring.sring rin buffer, so
when the tapdisk thread next calls the BLKTAP_IOCTL_KICK_FE to return
the completion event to the FE via that ring buffer, it oopses.
This can be fixed simply by not calling tap_blkif_unmap() in this case;
the ring buffer will still be unmapped later on when the blkif is
destroyed by blktap_remove(), only then it will properly wait for the
blkif refcnt to reach zero before doing so.
Signed-off-by: Stephen Tweedie <sct@redhat.com>
Remove try except blocks so that ACMError(s) are properly reported to
the user rather than silently fail.
Signed-off-by: Alastair Tse <atse@xensource.com>
Fixed built-in function name conflict.
Raise correct exceptions for when option is invalid to be properly
reported by xm.
Signed-off-by: Alastair Tse <atse@xensource.com>
Removing try,except block as cfgbootpolicy should allow exceptions to
propagate instead of printing traceback to stdout.
(http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=778)
Changed usage of string.join, string.split when creating security
policy path name.
Signed-off-by: Alastair Tse <atse@xensource.com>
parameters. Arguments on stack can be clobbered by
callee, since it owns them. But we require this doesn't
happen when we create hypercall continuations. Hence the
need to copy.
Signed-off-by: Keir Fraser <keir@xensource.com>
by passing a *pointer* to the register state, instead of
'passing by value'.
This should fix the bugs resulting in display of
"trying to set reserved bit in EFER"
on the Xen console.
Signed-off-by: Keir Fraser <keir@xensource.com>
to properly add cs<<4 to eip only when guest is in real
mode (or vm86 mode).
Remove bogus test-and-fail from hvm-mmio-insn-len decoder.
Signed-off-by: Keir Fraser <keir@xensource.com>
