If we set an msr via an ioctl() instead of by handling a guest exit, we
have the host state loaded, so reloading the msrs would clobber host
state instead of guest state.

This fixes a host oops (and loss of a cpu) on a guest reboot.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Simpifies things a bit.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Signed-off-by: NAvi Kivity <avi@qumranet.com>

Attempting to boot the default 'bsd' kernel of OpenBSD 4.1 i386 in a guest
fails early in the kernel init inside p3_get_bus_clock while trying to read
the IA32_EBL_CR_POWERON MSR.  KVM logs an 'unhandled MSR' message and the
guest kernel faults.

This patch is sufficient to allow OpenBSD to boot, after which it seems to
run fine.  I'm not sure if this is the correct solution for dealing with
this particular MSR, but it works for me.
Signed-off-by: NMatthew Gregan <kinetik@flim.org>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This allows fwait instructions to be trapped when the guest fpu is not
loaded.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Easier to keep track of where the fpu is this way.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Everyone owns a piece of the exception bitmap, but they happily write to
the entire thing like there's no tomorrow.  Centralize handling in
update_exception_bitmap() and have everyone call that.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Signed-off-by: NAvi Kivity <avi@qumranet.com>

The lightweight vmexit path avoids saving and reloading certain host
state.  However in certain cases lightweight vmexit handling can schedule()
which requires reloading the host state.

So we store the host state in the vcpu structure, and reloaded it if we
relinquish the vcpu.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This improves kbuild times by about 10%, bringing it within a respectable
25% of native.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

A typical demand page/copy on write pattern is:

- page fault on vaddr
- kvm propagates fault to guest
- guest handles fault, updates pte
- kvm traps write, clears shadow pte, resumes guest
- guest returns to userspace, re-faults on same vaddr
- kvm installs shadow pte, resumes guest
- guest continues

So, three vmexits for a single guest page fault.  But if instead of clearing
the page table entry, we update to correspond to the value that the guest
has just written, we eliminate the third vmexit.

This patch does exactly that, reducing kbuild time by about 10%.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

When a guest writes to a page that has an mmu shadow, we have to clear
the shadow pte corresponding to the memory location touched by the guest.

Now, in nonpae mode, a single guest page may have two or four shadow
pages (because a nonpae page maps 4MB or 4GB, whereas the pae shadow maps
2MB or 1GB), so we when we look up the page we find up to three additional
aliases for the page.  Since we _clear_ the shadow pte, it doesn't matter
except for a slight performance penalty, but if we want to _update_ the
shadow pte instead of clearing it, it is vital that we don't modify the
aliases.

Fortunately, exactly which page is needed (the "quadrant") is easily
computed, and is accessible in the shadow page header.  All we need is
to ignore shadow pages from the wrong quadrants.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Instead of calling two functions and repeating expensive checks, call one
function and provide it with before/after information.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

i386 wants fs for accessing the pda even on a lightweight exit, so ensure
we can always restore it.  This fixes a regression on i386 introduced by
the lightweight vmexit patch.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

The kvm mmu tries to detects forks by looking for repeated writes to a
page table.  If it sees a fork, it unshadows the page table so the page
table copying can proceed at native speed instead of being emulated.

However, the detector also triggered on simple demand paging access patterns:
a linear walk of memory would of course cause repeated writes to the same
pagetable page, causing it to unshadow prematurely.

Fix by resetting the fork detector if we detect a demand fault.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Signed-off-by: NAvi Kivity <avi@qumranet.com>

Many msrs and the like will only be used by the host if we schedule() or
return to userspace.  Therefore, we avoid saving them if we handle the
exit within the kernel, and if a reschedule is not requested.

Based on a patch from Eddie Dong <eddie.dong@intel.com> with a couple of
fixes by me.
Signed-off-by: NYaozu(Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This allows us to remove write protection earlier than otherwise.  Should
some mad OS choose to use byte writes to update pagetables, it will suffer
a performance hit, but still work correctly.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

The PC debug port is used for IO delay and does not require emulation.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This patch enables IO bitmaps control on vmx and unmask the 0x80 port to
avoid VMEXITs caused by accessing port 0x80. 0x80 is used as delays (see
include/asm/io.h), and handling VMEXITs on its access is unnecessary but
slows things down. This patch improves kernel build test at around
3%~5%.
	Because every VM uses the same io bitmap, it is shared between
all VMs rather than a per-VM data structure.
Signed-off-by: NQing He <qing.he@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

* git://git.infradead.org/battery-2.6:
  git-battery vs git-acpi
  Power supply class and drivers: remove non obligatory return statements
  pda_power: clean up irq, timer
  MAINTAINERS: Add maintainers for power supply subsystem and drivers

Fixed up trivial conflict in drivers/w1/slaves/w1_ds2760.c manually

* master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (166 commits)
  [SCSI] ibmvscsi: convert to use the data buffer accessors
  [SCSI] dc395x: convert to use the data buffer accessors
  [SCSI] ncr53c8xx: convert to use the data buffer accessors
  [SCSI] sym53c8xx: convert to use the data buffer accessors
  [SCSI] ppa: coding police and printk levels
  [SCSI] aic7xxx_old: remove redundant GFP_ATOMIC from kmalloc
  [SCSI] i2o: remove redundant GFP_ATOMIC from kmalloc from device.c
  [SCSI] remove the dead CYBERSTORMIII_SCSI option
  [SCSI] don't build scsi_dma_{map,unmap} for !HAS_DMA
  [SCSI] Clean up scsi_add_lun a bit
  [SCSI] 53c700: Remove printk, which triggers because of low scsi clock on SNI RMs
  [SCSI] sni_53c710: Cleanup
  [SCSI] qla4xxx: Fix underrun/overrun conditions
  [SCSI] megaraid_mbox: use mutex instead of semaphore
  [SCSI] aacraid: add 51245, 51645 and 52245 adapters to documentation.
  [SCSI] qla2xxx: update version to 8.02.00-k1.
  [SCSI] qla2xxx: add support for NPIV
  [SCSI] stex: use resid for xfer len information
  [SCSI] Add Brownie 1200U3P to blacklist
  [SCSI] scsi.c: convert to use the data buffer accessors
  ...

* 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6: (53 commits)
  [TCP]: Verify the presence of RETRANS bit when leaving FRTO
  [IPV6]: Call inet6addr_chain notifiers on link down
  [NET_SCHED]: Kill CONFIG_NET_CLS_POLICE
  [NET_SCHED]: act_api: qdisc internal reclassify support
  [NET_SCHED]: sch_dsmark: act_api support
  [NET_SCHED]: sch_atm: act_api support
  [NET_SCHED]: sch_atm: Lindent
  [IPV6]: MSG_ERRQUEUE messages do not pass to connected raw sockets
  [IPV4]: Cleanup call to __neigh_lookup()
  [NET_SCHED]: Revert "avoid transmit softirq on watchdog wakeup" optimization
  [NETFILTER]: nf_conntrack: UDPLITE support
  [NETFILTER]: nf_conntrack: mark protocols __read_mostly
  [NETFILTER]: x_tables: add connlimit match
  [NETFILTER]: Lower *tables printk severity
  [NETFILTER]: nf_conntrack: Don't track locally generated special ICMP error
  [NETFILTER]: nf_conntrack: Introduces nf_ct_get_tuplepr and uses it
  [NETFILTER]: nf_conntrack: make l3proto->prepare() generic and renames it
  [NETFILTER]: nf_conntrack: Increment error count on parsing IPv4 header
  [NET]: Add ethtool support for NETIF_F_IPV6_CSUM devices.
  [AF_IUCV]: Add lock when updating accept_q
  ...

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: fix a race condition bug in umount which caused a segfault
  9p: re-enable mount time debug option
  9p: cache meta-data when cache=loose
  net/9p: set error to EREMOTEIO if trans->write returns zero
  net/9p: change net/9p module name to 9pnet
  9p: Reorganization of 9p file system code

* 'for-linus' of git://oss.sgi.com:8090/xfs/xfs-2.6: (37 commits)
  [XFS] Fix lockdep annotations for xfs_lock_inodes
  [LIB]: export radix_tree_preload()
  [XFS] Fix XFS_IOC_FSBULKSTAT{,_SINGLE} & XFS_IOC_FSINUMBERS in compat mode
  [XFS] Compat ioctl handler for handle operations
  [XFS] Compat ioctl handler for XFS_IOC_FSGEOMETRY_V1.
  [XFS] Clean up function name handling in tracing code
  [XFS] Quota inode has no parent.
  [XFS] Concurrent Multi-File Data Streams
  [XFS] Use uninitialized_var macro to stop warning about rtx
  [XFS] XFS should not be looking at filp reference counts
  [XFS] Use is_power_of_2 instead of open coding checks
  [XFS] Reduce shouting by removing unnecessary macros from dir2 code.
  [XFS] Simplify XFS min/max macros.
  [XFS] Kill off xfs_count_bits
  [XFS] Cancel transactions on xfs_itruncate_start error.
  [XFS] Use do_div() on 64 bit types.
  [XFS] Fix remount,readonly path to flush everything correctly.
  [XFS] Cleanup inode extent size hint extraction
  [XFS] Prevent ENOSPC from aborting transactions that need to succeed
  [XFS] Prevent deadlock when flushing inodes on unmount
  ...

It depends on tristate I2C and it's trivial to make modular.  The
current Kconfig allows I2C=m, I2C_ACORN=y, which doesn't work at
all; alternatives are dependency on I2C=y and making I2C_ACORN
itself a tristate.  The latter is the right thing to do...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Fallout from commit 91a69029 ('sysfs:
add parameter "struct bin_attribute *" ...')
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

s390 is the only 32bit with unsigned long for size_t (usual for those
is unsigned int).  Tell sparse...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It returns __sum16, not unsigned int
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

... so all proud owners of s390-based PDAs will have to live without that one
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Going through the string and waiting for _pointer_ to become '\0'
is not what the authors meant...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NBen Collins <ben.collins@ubuntu.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Shows how many people are testing coda - the bug had been there for 5 years
and results of stepping on it are not subtle.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

still looks racy (and definitely leaks)
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>