KVM: MMU: gather remote tlb flush which occurs during page zapped

Using kvm_mmu_prepare_zap_page() and kvm_mmu_zap_page() instead of
kvm_mmu_zap_page() that can reduce remote tlb flush IPI

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: don't get free page number in the loop

In the later patch, we will modify sp's zapping way like below:

kvm_mmu_prepare_zap_page A
kvm_mmu_prepare_zap_page B
kvm_mmu_prepare_zap_page C
....
kvm_mmu_commit_zap_page

[ zaped multiple sps only need to call kvm_mmu_commit_zap_page once ]

In __kvm_mmu_free_some_pages() function, the free page number is
getted form 'vcpu->kvm->arch.n_free_mmu_pages' in loop, it will
hinders us to apply kvm_mmu_prepare_zap_page() and kvm_mmu_commit_zap_page()
since kvm_mmu_prepare_zap_page() not free sp.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: split the operations of kvm_mmu_zap_page()

Using kvm_mmu_prepare_zap_page() and kvm_mmu_commit_zap_page() to
split kvm_mmu_zap_page() function, then we can:

- traverse hlist safely
- easily to gather remote tlb flush which occurs during page zapped

Those feature can be used in the later patches

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: introduce some macros to cleanup hlist traverseing

Introduce for_each_gfn_sp() and for_each_gfn_indirect_valid_sp() to
cleanup hlist traverseing

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: skip invalid sp when unprotect page

In kvm_mmu_unprotect_page(), the invalid sp can be skipped

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: VMX: Make sure single type invvpid is supported before issuing invvpid instruction

According to SDM, we need check whether single-context INVVPID type is supported
before issuing invvpid instruction.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Reviewed-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: x86: use linux/uaccess.h instead of asm/uaccess.h

Should use linux/uaccess.h instead of asm/uaccess.h

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: cleanup "*new.rmap" type

The type of '*new.rmap' is not 'struct page *', fix it

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: VMX: Enforce EPT pagetable level checking

We only support 4 levels EPT pagetable now.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: Add Documentation/kvm/msr.txt

This patch adds a file that documents the usage of KVM-specific
MSRs.

Signed-off-by: Glauber Costa <glommer@redhat.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: PPC: elide struct thread_struct instances from stack

Instead of instantiating a whole thread_struct on the stack use only the
required parts of it.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Tested-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: VMX: Properly return error to userspace on vmentry failure

The vmexit handler returns KVM_EXIT_UNKNOWN since there is no handler
for vmentry failures. This intercepts vmentry failures and returns
KVM_FAIL_ENTRY to userspace instead.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: MMU: Don't calculate quadrant if tdp_enabled

There's no need to calculate quadrant if tdp is enabled.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: MMU: Document large pages

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: MMU: Document cr0.wp emulation

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: Allow spte.w=1 for gpte.w=0 and cr0.wp=0 only in shadow mode

When tdp is enabled, the guest's cr0.wp shouldn't have any effect on spte
permissions.

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86: Propagate fpu_alloc errors

Memory allocation may fail. Propagate such errors.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: SVM: Fix EFER.LME being stripped

Must set VCPU register to be the guest notion of EFER even if that
setting is not valid on hardware.  This was masked by the set in
set_efer until 7657fd5ace88e8092f5f3a84117e093d7b893f26 broke that.
Fix is simply to set the VCPU register before stripping bits.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: don't check PT_WRITABLE_MASK directly

Since we have is_writable_pte(), make use of it.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: calculate correct gfn for small host pages backing large guest pages

In Documentation/kvm/mmu.txt:
  gfn:
    Either the guest page table containing the translations shadowed by this
    page, or the base page frame for linear translations. See role.direct.

But in function FNAME(fetch)(), sp->gfn is incorrect when one of following
situations occurred:

 1) guest is 32bit paging and the guest PDE maps a 4-MByte page
    (backed by 4k host pages), FNAME(fetch)() miss handling the quadrant.

    And if guest use pse-36, "table_gfn = gpte_to_gfn(gw->ptes[level - delta]);"
    is incorrect.

 2) guest is long mode paging and the guest PDPTE maps a 1-GByte page
    (backed by 4k or 2M host pages).

So we fix it to suit to the document and suit to the code which
requires sp->gfn correct when sp->role.direct=1.

We use the goal mapping gfn(gw->gfn) to calculate the base page frame
for linear translations, it is simple and easy to be understood.

Reported-by: Marcelo Tosatti <mtosatti@redhat.com>
Reported-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: Calculate correct base gfn for direct non-DIR level

In Document/kvm/mmu.txt:
  gfn:
    Either the guest page table containing the translations shadowed by this
    page, or the base page frame for linear translations. See role.direct.

But in __direct_map(), the base gfn calculation is incorrect,
it does not calculate correctly when level=3 or 4.

Fix by using PT64_LVL_ADDR_MASK() which accounts for all levels correctly.

Reported-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: Don't allocate gfns page for direct mmu pages

When sp->role.direct is set, sp->gfns does not contain any essential
information, leaf sptes reachable from this sp are for a continuous
guest physical memory range (a linear range).
So sp->gfns[i] (if it was set) equals to sp->gfn + i. (PT_PAGE_TABLE_LEVEL)
Obviously, it is not essential information, we can calculate it when need.

It means we don't need sp->gfns when sp->role.direct=1,
Thus we can save one page usage for every kvm_mmu_page.

Note:
  Access to sp->gfns must be wrapped by kvm_mmu_page_get_gfn()
  or kvm_mmu_page_set_gfn().
  It is only exposed in FNAME(sync_page).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: VMX: Add constant for invalid guest state exit reason

For the sake of completeness, this patch adds a symbolic
constant for VMX exit reason 0x21 (invalid guest state).

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: allow more page become unsync at getting sp time

Allow more page become asynchronous at getting sp time, if need create new
shadow page for gfn but it not allow unsync(level > 1), we should unsync all
gfn's unsync page

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: allow more page become unsync at gfn mapping time

In current code, shadow page can become asynchronous only if one
shadow page for a gfn, this rule is too strict, in fact, we can
let all last mapping page(i.e, it's the pte page) become unsync,
and sync them at invlpg or flush tlb time.

This patch allow more page become asynchronous at gfn mapping time

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: Update Red Hat copyrights

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: SVM: correctly trace irq injection

On SVM interrupts are injected by svm_set_irq() not svm_inject_irq().
The later is used only to wait for irq window.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: only update unsync page in invlpg path

Only unsync pages need updated at invlpg time since other shadow
pages are write-protected

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: don't write-protect if have new mapping to unsync page

Two cases maybe happen in kvm_mmu_get_page() function:

- one case is, the goal sp is already in cache, if the sp is unsync,
  we only need update it to assure this mapping is valid, but not
  mark it sync and not write-protect sp->gfn since it not broke unsync
  rule(one shadow page for a gfn)

- another case is, the goal sp not existed, we need create a new sp
  for gfn, i.e, gfn (may)has another shadow page, to keep unsync rule,
  we should sync(mark sync and write-protect) gfn's unsync shadow page.
  After enabling multiple unsync shadows, we sync those shadow pages
  only when the new sp not allow to become unsync(also for the unsyc
  rule, the new rule is: allow all pte page become unsync)

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: split kvm_sync_page() function

Split kvm_sync_page() into kvm_sync_page() and kvm_sync_page_transient()
to clarify the code address Avi's suggestion

kvm_sync_page_transient() function only update shadow page but not mark
it sync and not write protect sp->gfn. it will be used by later patch

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86: Use FPU API

Convert KVM to use generic FPU API.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86: Use unlazy_fpu() for host FPU

We can avoid unnecessary fpu load when userspace process
didn't use FPU frequently.

Derived from Avi's idea.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

x86: Export FPU API for KVM use

Also add some constants.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: Consolidate arch specific vcpu ioctl locking

Now that all arch specific ioctls have centralized locking, it is easy to
move it to the central dispatcher.

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: PPC: Centralize locking of arch specific vcpu ioctls

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: s390: Centrally lock arch specific vcpu ioctls

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86: Lock arch specific vcpu ioctls centrally

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: move vcpu locking to dispatcher for generic vcpu ioctls

All vcpu ioctls need to be locked, so instead of locking each one specifically
we lock at the generic dispatcher.

This patch only updates generic ioctls and leaves arch specific ioctls alone.

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86: cleanup unused local variable

fix:
 arch/x86/kvm/x86.c: In function ‘handle_emulation_failure’:
 arch/x86/kvm/x86.c:3844: warning: unused variable ‘ctxt’

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: MMU: unalias gfn before sp->gfns[] comparison in sync_page

sp->gfns[] contain unaliased gfns, but gpte might contain pointer
to aliased region.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: MMU: remove rmap before clear spte

Remove rmap before clear spte otherwise it will trigger BUG_ON() in
some functions such as rmap_write_protect().

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: MMU: use proper cache object freeing function

Use kmem_cache_free to free objects allocated by kmem_cache_alloc.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: remove CAP_SYS_RAWIO requirement from kvm_vm_ioctl_assign_irq

Remove this check in an effort to allow kvm guests to run without
root privileges.  This capability check doesn't seem to add any
security since the device needs to have already been added via the
assign device ioctl and the io actually occurs through the pci
sysfs interface.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: VMX: Only reset MMU when necessary

Only modifying some bits of CR0/CR4 needs paging mode switch.

Modify EFER.NXE bit would result in reserved bit updates.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: x86: Clean up duplicate assignment

mmu.free() already set root_hpa to INVALID_PAGE, no need to do it again in the
destory_kvm_mmu().

kvm_x86_ops->set_cr4() and set_efer() already assign cr4/efer to
vcpu->arch.cr4/efer, no need to do it again later.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: x86 emulator: Add missing decoder flags for xor instructions

This adds missing decoder flags for xor instructions (opcodes 0x34 - 0x35)

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: x86 emulator: Add missing decoder flags for sub instruction

This adds missing decoder flags for sub instructions (opcodes 0x2c - 0x2d)

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: x86 emulator: Add test acc, imm instruction (opcodes 0xA8 - 0xA9)

This adds test acc, imm instruction to the x86 emulator

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: pass correct parameter to kvm_mmu_free_some_pages

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: VMX: VMXON/VMXOFF usage changes

SDM suggests VMXON should be called before VMPTRLD, and VMXOFF
should be called after doing VMCLEAR.

Therefore in vmm coexistence case, we should firstly call VMXON
before any VMCS operation, and then call VMXOFF after the
operation is done.

Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: VMX: VMCLEAR/VMPTRLD usage changes

Originally VMCLEAR/VMPTRLD is called on vcpu migration. To
support hosted VMM coexistance, VMCLEAR is executed on vcpu
schedule out, and VMPTRLD is executed on vcpu schedule in.
This could also eliminate the IPI when doing VMCLEAR.

Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: VMX: Some minor changes to code structure

Do some preparations for vmm coexistence support.

Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: VMX: Define new functions to wrapper direct call of asm code

Define vmcs_load() and kvm_cpu_vmxon() to avoid direct call of asm
code. Also move VMXE bit operation out of kvm_cpu_vmxoff().

Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: update mmu documetation for role.nxe

There's no member "cr4_nxe" in struct kvm_mmu_page_role, it names "nxe" now.
Update mmu document.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: MMU: Fix free memory accounting race in mmu_alloc_roots()

We drop the mmu lock between freeing memory and allocating the roots; this
allows some other vcpu to sneak in and allocate memory.

While the race is benign (resulting only in temporary overallocation, not oom)
it is simple and easy to fix by moving the freeing close to the allocation.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: inject #UD if instruction emulation fails and exit to userspace

Do not kill VM when instruction emulation fails. Inject #UD and report
failure to userspace instead. Userspace may choose to reenter guest if
vcpu is in userspace (cpl == 3) in which case guest OS will kill
offending process and continue running.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

KVM: Document KVM_SET_BOOT_CPU_ID

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: Document KVM_SET_IDENTITY_MAP ioctl

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: make kvm_mmu_zap_page() return the number of pages it actually freed

Currently, kvm_mmu_zap_page() returning the number of freed children sp.
This might confuse the caller, because caller don't know the actual freed
number. Let's make kvm_mmu_zap_page() return the number of pages it actually
freed.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: Fix debug output error in walk_addr()

Fix a debug output error in walk_addr

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: MMU: mark page table dirty when a pte is actually modified

Sometime cmpxchg_gpte doesn't modify gpte, in such case, don't mark
page table page as dirty.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: SVM: Allow EFER.LMSLE to be set with nested svm

This patch enables setting of efer bit 13 which is allowed
in all SVM capable processors. This is necessary for the
SLES11 version of Xen 4.0 to boot with nested svm.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: SVM: Dump vmcb contents on failed vmrun

This patch adds a function to dump the vmcb into the kernel
log and calls it after a failed vmrun to ease debugging.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: Get rid of KVM_REQ_KICK

KVM_REQ_KICK poisons vcpu->requests by having a bit set during normal
operation.  This causes the fast path check for a clear vcpu->requests
to fail all the time, triggering tons of atomic operations.

Fix by replacing KVM_REQ_KICK with a vcpu->guest_mode atomic.

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: do not inject exception directly into vcpu

Return exception as a result of instruction emulation and handle
injection in KVM code.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: move interruptibility state tracking out of emulator

Emulator shouldn't access vcpu directly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: handle shadowed registers outside emulator

Emulator shouldn't access vcpu directly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: use shadowed register in emulate_sysexit()

emulate_sysexit() should use shadowed registers copy instead of
looking into vcpu state directly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: set RFLAGS outside x86 emulator code

Removes the need for set_flags() callback.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: advance RIP outside x86 emulator code

Return new RIP as part of instruction emulation result instead of
updating KVM's RIP from x86 emulator code.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: handle emulation failure case first

If emulation failed return immediately.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: do not inject #PF in (read|write)_emulated() callbacks

Return error to x86 emulator instead of injection exception behind its back.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: remove export of emulator_write_emulated()

It is not called directly outside of the file it's defined in anymore.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: x86_emulate_insn() return -1 only in case of emulation failure

Currently emulator returns -1 when emulation failed or IO is needed.
Caller tries to guess whether emulation failed by looking at other
variables. Make it easier for caller to recognise error condition by
always returning -1 in case of failure. For this new emulator
internal return value X86EMUL_IO_NEEDED is introduced. It is used to
distinguish between error condition (which returns X86EMUL_UNHANDLEABLE)
and condition that requires IO exit to userspace to continue emulation.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: fill in run->mmio details in (read|write)_emulated function

Fill in run->mmio details in (read|write)_emulated function just like
pio does. There is no point in filling only vcpu fields there just to
copy them into vcpu->run a little bit later.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: fix X86EMUL_RETRY_INSTR and X86EMUL_CMPXCHG_FAILED values

Currently X86EMUL_PROPAGATE_FAULT, X86EMUL_RETRY_INSTR and
X86EMUL_CMPXCHG_FAILED have the same value so caller cannot
distinguish why function such as emulator_cmpxchg_emulated()
(which can return both X86EMUL_PROPAGATE_FAULT and
X86EMUL_CMPXCHG_FAILED) failed.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: make (get|set)_dr() callback return error if it fails

Make (get|set)_dr() callback return error if it fails instead of
injecting exception behind emulator's back.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: make set_cr() callback return error if it fails

Make set_cr() callback return error if it fails instead of injecting #GP
behind emulator's back.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: cleanup some direct calls into kvm to use existing callbacks

Use callbacks from x86_emulate_ops to access segments instead of calling
into kvm directly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: add get_cached_segment_base() callback to x86_emulate_ops

On VMX it is expensive to call get_cached_descriptor() just to get segment
base since multiple vmcs_reads are done instead of only one. Introduce
new call back get_cached_segment_base() for efficiency.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: add (set|get)_msr callbacks to x86_emulate_ops

Add (set|get)_msr callbacks to x86_emulate_ops instead of calling
them directly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: add (set|get)_dr callbacks to x86_emulate_ops

Add (set|get)_dr callbacks to x86_emulate_ops instead of calling
them directly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: handle "far address" source operand

ljmp/lcall instruction operand contains address and segment.
It can be 10 bytes long. Currently we decode it as two different
operands. Fix it by introducing new kind of operand that can hold
entire far address.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: cleanup nop emulation

Make it more explicit what we are checking for.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: cleanup xchg emulation

Dst operand is already initialized during decoding stage. No need to
reinitialize.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: fix Move r/m16 to segment register decoding

This instruction does not need generic decoding for its dst operand.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86 emulator: introduce read cache

Introduce read cache which is needed for instruction that require more
then one exit to userspace. After returning from userspace the instruction
will be re-executed with cached read value.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: VMX: Avoid writing HOST_CR0 every entry

cr0.ts may change between entries, so we copy cr0 to HOST_CR0 before each
entry.  That is slow, so instead, set HOST_CR0 to have TS set unconditionally
(which is a safe value), and issue a clts() just before exiting vcpu context
if the task indeed owns the fpu.

Saves ~50 cycles/exit.

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: kvm_pdptr_read() may sleep

Annotate it thusly.

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: x86: avoid unnecessary bitmap allocation when memslot is clean

Although we always allocate a new dirty bitmap in x86's get_dirty_log(),
it is only used as a zero-source of copy_to_user() and freed right after
that when memslot is clean. This patch uses clear_user() instead of doing
this unnecessary zero-source allocation.

Performance improvement: as we can expect easily, the time needed to
allocate a bitmap is completely reduced. In my test, the improved ioctl
was about 4 to 10 times faster than the original one for clean slots.
Furthermore, reducing memory allocations and copies will produce good
effects to caches too.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: VMX: Simplify vmx_get_nmi_mask()

!! is not needed due to the cast to bool.

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: Avoid killing userspace through guest SRAO MCE on unmapped pages

In common cases, guest SRAO MCE will cause corresponding poisoned page
be un-mapped and SIGBUS be sent to QEMU-KVM, then QEMU-KVM will relay
the MCE to guest OS.

But it is reported that if the poisoned page is accessed in guest
after unmapping and before MCE is relayed to guest OS, userspace will
be killed.

The reason is as follows. Because poisoned page has been un-mapped,
guest access will cause guest exit and kvm_mmu_page_fault will be
called. kvm_mmu_page_fault can not get the poisoned page for fault
address, so kernel and user space MMIO processing is tried in turn. In
user MMIO processing, poisoned page is accessed again, then userspace
is killed by force_sig_info.

To fix the bug, kvm_mmu_page_fault send HWPOISON signal to QEMU-KVM
and do not try kernel and user space MMIO processing for poisoned
page.

[xiao: fix warning introduced by avi]

Reported-by: Max Asbock <masbock@linux.vnet.ibm.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

Merge branch 'for_linus' of git://git./linux/kernel/git/jwessel/linux-2.6-kgdb

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  x86,kgdb: Fix hw breakpoint regression

Merge git://git./linux/kernel/git/jejb/scsi-rc-fixes-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
  [SCSI] ibmvscsi: Fix oops when an interrupt is pending during probe
  [SCSI] zfcp: Update status read mempool
  [SCSI] zfcp: Do not wait for SBALs on stopped queue
  [SCSI] zfcp: Fix check whether unchained ct_els is possible
  [SCSI] ipr: fix resource path display and formatting

Merge branch 'for-linus' of git://git./linux/kernel/git/lrg/voltage-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6:
  davinci: da850/omap-l138 evm: account for DEFDCDC{2,3} being tied high
  regulator: tps6507x: allow driver to use DEFDCDC{2,3}_HIGH register
  wm8350-regulator: fix wm8350_register_regulator error handling
  ab3100: fix off-by-one value range checking for voltage selector

ecryptfs: Bugfix for error related to ecryptfs_hash_buckets

The function ecryptfs_uid_hash wrongly assumes that the
second parameter to hash_long() is the number of hash
buckets instead of the number of hash bits.
This patch fixes that and renames the variable
ecryptfs_hash_buckets to ecryptfs_hash_bits to make it
clearer.

Fixes: CVE-2010-2492

Signed-off-by: Andre Osterhues <aosterhues@escrypt.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86,kgdb: Fix hw breakpoint regression

HW breakpoints events stopped working correctly with kgdb
as a result of commit: 018cbffe6819f6f8db20a0a3acd9bab9bfd667e4
(Merge commit 'v2.6.33' into perf/core).

The regression occurred because the behavior changed for setting
NOTIFY_STOP as the return value to the die notifier if the breakpoint
was known to the HW breakpoint API.  Because kgdb is using the HW
breakpoint API to register HW breakpoints slots, it must also now
implement the overflow_handler call back else kgdb does not get to see
the events from the die notifier.

The kgdb_ll_trap function will be changed to be general purpose code
which can allow an easy way to implement the hw_breakpoint API
overflow call back.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Dongdong Deng <dongdong.deng@windriver.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>

Merge branch 'for-linus' of git://git./linux/kernel/git/sage/ceph-client

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: use complete_all and wake_up_all
  ceph: Correct obvious typo of Kconfig variable "CRYPTO_AES"
  ceph: fix dentry lease release
  ceph: fix leak of dentry in ceph_init_dentry() error path
  ceph: fix pg_mapping leak on pg_temp updates
  ceph: fix d_release dop for snapdir, snapped dentries
  ceph: avoid dcache readdir for snapdir

GFS2: Use kmalloc when possible for ->readdir()

If we don't need a huge amount of memory in ->readdir() then
we can use kmalloc rather than vmalloc to allocate it. This
should cut down on the greater overheads associated with
vmalloc for smaller directories.

We may be able to eliminate vmalloc entirely at some stage,
but this is easy to do right away.

Also using GFP_NOFS to avoid any issues wrt to deleting inodes
while under a glock, and suggestion from Linus to factor out
the alloc/dealloc.

I've given this a test with a variety of different sized
directories and it seems to work ok.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

davinci: da850/omap-l138 evm: account for DEFDCDC{2,3} being tied high

Per the da850/omap-l138 Beta EVM SOM schematic, the DEFDCDC2 and
DEFDCDC3 lines are tied high. This leads to a 3.3V IO and 1.2V CVDD
voltage.

Pass the right platform data to the TPS6507x driver so it can operate
on the DEFDCDC{2,3}_HIGH register to read and change voltage levels.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>