Josh Triplett [Sun, 20 Oct 2013 14:29:57 +0000 (15:29 +0100)]
kvm: Delete prototype for non-existent function complete_pio
complete_pio ceased to exist in commit 7972995b0c346de76fe260ce0fd6bcc8ffab724a ("KVM: x86 emulator: Move
string pio emulation into emulator.c"), but the prototype remained.
Remove its prototype.
I noticed that srcu_read_lock/unlock both have a memory barrier,
so just by moving srcu_read_unlock earlier we can get rid of
one call to smp_mb() using smp_mb__after_srcu_read_unlock instead.
Unsurprisingly, the gain is small but measureable using the unit test
microbenchmark:
before
vmcall in the ballpark of 1410 cycles
after
vmcall in the ballpark of 1360 cycles
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
srcu read lock/unlock include a full memory barrier
but that's an implementation detail.
Add an API for make memory fencing explicit for
users that need this barrier, to make sure we
can change it as needed without breaking all users.
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
Gleb Natapov [Tue, 5 Nov 2013 14:04:18 +0000 (16:04 +0200)]
KVM: remove vm mmap method
It was used in conjunction with KVM_SET_MEMORY_REGION ioctl which was
removed by b74a07beed0 in 2010, QEMU stopped using it in 2008, so
it is time to remove the code finally.
Greg Edwards [Mon, 4 Nov 2013 16:08:12 +0000 (09:08 -0700)]
KVM: IOMMU: hva align mapping page size
When determining the page size we could use to map with the IOMMU, the
page size should also be aligned with the hva, not just the gfn. The
gfn may not reflect the real alignment within the hugetlbfs file.
Most of the time, this works fine. However, if the hugetlbfs file is
backed by non-contiguous huge pages, a multi-huge page memslot starts at
an unaligned offset within the hugetlbfs file, and the gfn is aligned
with respect to the huge page size, kvm_host_page_size() will return the
huge page size and we will use that to map with the IOMMU.
When we later unpin that same memslot, the IOMMU returns the unmap size
as the huge page size, and we happily unpin that many pfns in
monotonically increasing order, not realizing we are spanning
non-contiguous huge pages and partially unpin the wrong huge page.
Ensure the IOMMU mapping page size is aligned with the hva corresponding
to the gfn, which does reflect the alignment within the hugetlbfs file.
Paolo Bonzini [Thu, 31 Oct 2013 22:05:24 +0000 (23:05 +0100)]
KVM: x86: fix emulation of "movzbl %bpl, %eax"
When I was looking at RHEL5.9's failure to start with
unrestricted_guest=0/emulate_invalid_guest_state=1, I got it working with a
slightly older tree than kvm.git. I now debugged the remaining failure,
which was introduced by commit 660696d1 (KVM: X86 emulator: fix
source operand decoding for 8bit mov[zs]x instructions, 2013-04-24)
introduced a similar mis-emulation to the one in commit 8acb4207 (KVM:
fix sil/dil/bpl/spl in the mod/rm fields, 2013-05-30). The incorrect
decoding occurs in 8-bit movzx/movsx instructions whose 8-bit operand
is sil/dil/bpl/spl.
Needless to say, "movzbl %bpl, %eax" does occur in RHEL5.9's decompression
prolog, just a handful of instructions before finally giving control to
the decompressed vmlinux and getting out of the invalid guest state.
Because OpMem8 bypasses decode_modrm, the same handling of the REX prefix
must be applied to OpMem8.
Paolo Bonzini [Thu, 17 Oct 2013 14:50:47 +0000 (16:50 +0200)]
KVM: x86: fix KVM_SET_XCRS loop
The loop was always using 0 as the index. This means that
any rubbish after the first element of the array went undetected.
It seems reasonable to assume that no KVM userspace did that.
Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Thu, 17 Oct 2013 14:50:46 +0000 (16:50 +0200)]
KVM: x86: fix KVM_SET_XCRS for CPUs that do not support XSAVE
The KVM_SET_XCRS ioctl must accept anything that KVM_GET_XCRS
could return. XCR0's bit 0 is always 1 in real processors with
XSAVE, and KVM_GET_XCRS will always leave bit 0 set even if the
emulated processor does not have XSAVE. So, KVM_SET_XCRS must
ignore that bit when checking for attempts to enable unsupported
save states.
Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Alex Williamson [Wed, 30 Oct 2013 17:02:30 +0000 (11:02 -0600)]
kvm: Create non-coherent DMA registeration
We currently use some ad-hoc arch variables tied to legacy KVM device
assignment to manage emulation of instructions that depend on whether
non-coherent DMA is present. Create an interface for this, adapting
legacy KVM device assignment and adding VFIO via the KVM-VFIO device.
For now we assume that non-coherent DMA is possible any time we have a
VFIO group. Eventually an interface can be developed as part of the
VFIO external user interface to query the coherency of a group.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Alex Williamson [Wed, 30 Oct 2013 17:02:17 +0000 (11:02 -0600)]
kvm: Add VFIO device
So far we've succeeded at making KVM and VFIO mostly unaware of each
other, but areas are cropping up where a connection beyond eventfds
and irqfds needs to be made. This patch introduces a KVM-VFIO device
that is meant to be a gateway for such interaction. The user creates
the device and can add and remove VFIO groups to it via file
descriptors. When a group is added, KVM verifies the group is valid
and gets a reference to it via the VFIO external user interface.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Borislav Petkov [Tue, 29 Oct 2013 11:54:56 +0000 (12:54 +0100)]
kvm: Emulate MOVBE
This basically came from the need to be able to boot 32-bit Atom SMP
guests on an AMD host, i.e. a host which doesn't support MOVBE. As a
matter of fact, qemu has since recently received MOVBE support but we
cannot share that with kvm emulation and thus we have to do this in the
host. We're waay faster in kvm anyway. :-)
So, we piggyback on the #UD path and emulate the MOVBE functionality.
With it, an 8-core SMP guest boots in under 6 seconds.
Also, requesting MOVBE emulation needs to happen explicitly to work,
i.e. qemu -cpu n270,+movbe...
Just FYI, a fairly straight-forward boot of a MOVBE-enabled 3.9-rc6+
kernel in kvm executes MOVBE ~60K times.
Signed-off-by: Andre Przywara <andre@andrep.de> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a field to the current emulation context which contains the
instruction opcode length. This will streamline handling of opcodes of
different length.
Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a kvm ioctl which states which system functionality kvm emulates.
The format used is that of CPUID and we return the corresponding CPUID
bits set for which we do emulate functionality.
Make sure ->padding is being passed on clean from userspace so that we
can use it for something in the future, after the ioctl gets cast in
stone.
s/kvm_dev_ioctl_get_supported_cpuid/kvm_dev_ioctl_get_cpuid/ while at
it.
Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Mon, 28 Oct 2013 12:15:55 +0000 (13:15 +0100)]
Merge tag 'kvm-arm-for-3.13-2' of git://git.linaro.org/people/cdall/linux-kvm-arm into kvm-queue
Updates for KVM/ARM, take 2 including:
- Transparent Huge Pages and hugetlbfs support for KVM/ARM
- Yield CPU when guest executes WFE to speed up CPU overcommit
Yang Zhang [Thu, 24 Oct 2013 01:56:39 +0000 (09:56 +0800)]
KVM: Mapping IOMMU pages after updating memslot
In kvm_iommu_map_pages(), we need to know the page size via call
kvm_host_page_size(). And it will check whether the target slot
is valid before return the right page size.
Currently, we will map the iommu pages when creating a new slot.
But we call kvm_iommu_map_pages() during preparing the new slot.
At that time, the new slot is not visible by domain(still in preparing).
So we cannot get the right page size from kvm_host_page_size() and
this will break the IOMMU super page logic.
The solution is to map the iommu pages after we insert the new slot
into domain.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Tested-by: Patrick Lu <patrick.lu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Jan Kiszka [Wed, 23 Oct 2013 16:42:15 +0000 (17:42 +0100)]
nVMX: Fix pick-up of uninjected NMIs
__vmx_complete_interrupts stored uninjected NMIs in arch.nmi_injected,
not arch.nmi_pending. So we actually need to check the former field in
vmcs12_save_pending_event. This fixes the eventinj unit test when run
in nested KVM.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Support transparent huge pages in KVM/ARM and KVM/ARM64. The
transparent_hugepage_adjust is not very pretty, but this is also how
it's solved on x86 and seems to be simply an artifact on how THPs
behave. This should eventually be shared across architectures if
possible, but that can always be changed down the road.
Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Support huge pages in KVM/ARM and KVM/ARM64. The pud_huge checking on
the unmap path may feel a bit silly as the pud_huge check is always
defined to false, but the compiler should be smart about this.
Note: This deals only with VMAs marked as huge which are allocated by
users through hugetlbfs only. Transparent huge pages can only be
detected by looking at the underlying pages (or the page tables
themselves) and this patch so far simply maps these on a page-by-page
level in the Stage-2 page tables.
Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Marc Zyngier [Tue, 8 Oct 2013 17:38:13 +0000 (18:38 +0100)]
ARM: KVM: Yield CPU when vcpu executes a WFE
On an (even slightly) oversubscribed system, spinlocks are quickly
becoming a bottleneck, as some vcpus are spinning, waiting for a
lock to be released, while the vcpu holding the lock may not be
running at all.
This creates contention, and the observed slowdown is 40x for
hackbench. No, this isn't a typo.
The solution is to trap blocking WFEs and tell KVM that we're
now spinning. This ensures that other vpus will get a scheduling
boost, allowing the lock to be released more quickly. Also, using
CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT slightly improves the performance
when the VM is severely overcommited.
Quick test to estimate the performance: hackbench 1 process 1000
2xA15 host (baseline): 1.843s
2xA15 guest w/o patch: 2.083s
4xA15 guest w/o patch: 80.212s
8xA15 guest w/o patch: Could not be bothered to find out
kvm: powerpc: book3s: Allow the HV and PR selection per virtual machine
This moves the kvmppc_ops callbacks to be a per VM entity. This
enables us to select HV and PR mode when creating a VM. We also
allow both kvm-hv and kvm-pr kernel module to be loaded. To
achieve this we move /dev/kvm ownership to kvm.ko module. Depending on
which KVM mode we select during VM creation we take a reference
count on respective module
kvm: powerpc: book3s: Add is_hv_enabled to kvmppc_ops
This help us to identify whether we are running with hypervisor mode KVM
enabled. The change is needed so that we can have both HV and PR kvm
enabled in the same kernel.
If both HV and PR KVM are included, interrupts come in to the HV version
of the kvmppc_interrupt code, which then jumps to the PR handler,
renamed to kvmppc_interrupt_pr, if the guest is a PR guest.
Allowing both PR and HV in the same kernel required some changes to
kvm_dev_ioctl_check_extension(), since the values returned now can't
be selected with #ifdefs as much as previously. We look at is_hv_enabled
to return the right value when checking for capabilities.For capabilities that
are only provided by HV KVM, we return the HV value only if
is_hv_enabled is true. For capabilities provided by PR KVM but not HV,
we return the PR value only if is_hv_enabled is false.
NOTE: in later patch we replace is_hv_enabled with a static inline
function comparing kvm_ppc_ops
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
With this patch if HV is included, interrupts come in to the HV version
of the kvmppc_interrupt code, which then jumps to the PR handler,
renamed to kvmppc_interrupt_pr, if the guest is a PR guest. This helps
in enabling both HV and PR, which we do in later patch
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
This patch add a new callback kvmppc_ops. This will help us in enabling
both HV and PR KVM together in the same kernel. The actual change to
enable them together is done in the later patch in the series.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[agraf: squash in booke changes] Signed-off-by: Alexander Graf <agraf@suse.de>
kvm: powerpc: book3s: Add a new config variable CONFIG_KVM_BOOK3S_HV_POSSIBLE
This help ups to select the relevant code in the kernel code
when we later move HV and PR bits as seperate modules. The patch
also makes the config options for PR KVM selectable
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
kvm: powerpc: book3s: pr: Rename KVM_BOOK3S_PR to KVM_BOOK3S_PR_POSSIBLE
With later patches supporting PR kvm as a kernel module, the changes
that has to be built into the main kernel binary to enable PR KVM module
is now selected via KVM_BOOK3S_PR_POSSIBLE
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Mon, 7 Oct 2013 16:47:50 +0000 (22:17 +0530)]
kvm: powerpc: book3s: move book3s_64_vio_hv.c into the main kernel binary
Since the code in book3s_64_vio_hv.c is called from real mode with HV
KVM, and therefore has to be built into the main kernel binary, this
makes it always built-in rather than part of the KVM module. It gets
called from the KVM module by PR KVM, so this adds an EXPORT_SYMBOL_GPL().
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
This patch adds the debug stub support on booke/bookehv.
Now QEMU debug stub can use hw breakpoint, watchpoint and
software breakpoint to debug guest.
This is how we save/restore debug register context when switching
between guest, userspace and kernel user-process:
When QEMU is running
-> thread->debug_reg == QEMU debug register context.
-> Kernel will handle switching the debug register on context switch.
-> no vcpu_load() called
QEMU makes ioctls (except RUN)
-> This will call vcpu_load()
-> should not change context.
-> Some ioctls can change vcpu debug register, context saved in vcpu->debug_regs
QEMU Makes RUN ioctl
-> Save thread->debug_reg on STACK
-> Store thread->debug_reg == vcpu->debug_reg
-> load thread->debug_reg
-> RUN VCPU ( So thread points to vcpu context )
Context switch happens When VCPU running
-> makes vcpu_load() should not load any context
-> kernel loads the vcpu context as thread->debug_regs points to vcpu context.
On heavyweight_exit
-> Load the context saved on stack in thread->debug_reg
Currently we do not support debug resource emulation to guest,
On debug exception, always exit to user space irrespective of
user space is expecting the debug exception or not. If this is
unexpected exception (breakpoint/watchpoint event not set by
userspace) then let us leave the action on user space. This
is similar to what it was before, only thing is that now we
have proper exit state available to user space.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
KVM: PPC: E500: exit to user space on "ehpriv 1" instruction
"ehpriv 1" instruction is used for setting software breakpoints
by user space. This patch adds support to exit to user space
with "run->debug" have relevant information.
As this is the first point we are using run->debug, also defined
the run->debug structure.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
kvm: powerpc: allow guest control "E" attribute in mas2
"E" bit in MAS2 bit indicates whether the page is accessed
in Little-Endian or Big-Endian byte order.
There is no reason to stop guest setting "E", so allow him."
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
powerpc: book3e: _PAGE_LENDIAN must be _PAGE_ENDIAN
For booke3e _PAGE_ENDIAN is not defined. Infact what is defined
is "_PAGE_LENDIAN" which is wrong and that should be _PAGE_ENDIAN.
There are no compilation errors as
arch/powerpc/include/asm/pte-common.h defines _PAGE_ENDIAN to 0
as it is not defined anywhere.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 4 Oct 2013 11:45:04 +0000 (21:45 +1000)]
KVM: PPC: Book3S HV: Better handling of exceptions that happen in real mode
When an interrupt or exception happens in the guest that comes to the
host, the CPU goes to hypervisor real mode (MMU off) to handle the
exception but doesn't change the MMU context. After saving a few
registers, we then clear the "in guest" flag. If, for any reason,
we get an exception in the real-mode code, that then gets handled
by the normal kernel exception handlers, which turn the MMU on. This
is disastrous if the MMU is still set to the guest context, since we
end up executing instructions from random places in the guest kernel
with hypervisor privilege.
In order to catch this situation, we define a new value for the "in guest"
flag, KVM_GUEST_MODE_HOST_HV, to indicate that we are in hypervisor real
mode with guest MMU context. If the "in guest" flag is set to this value,
we branch off to an emergency handler. For the moment, this just does
a branch to self to stop the CPU from doing anything further.
While we're here, we define another new flag value to indicate that we
are in a HV guest, as distinct from a PR guest. This will be useful
when we have a kernel that can support both PR and HV guests concurrently.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:54 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Reduce number of shadow PTEs invalidated by MMU notifiers
Currently, whenever any of the MMU notifier callbacks get called, we
invalidate all the shadow PTEs. This is inefficient because it means
that we typically then get a lot of DSIs and ISIs in the guest to fault
the shadow PTEs back in. We do this even if the address range being
notified doesn't correspond to guest memory.
This commit adds code to scan the memslot array to find out what range(s)
of guest physical addresses corresponds to the host virtual address range
being affected. For each such range we flush only the shadow PTEs
for the range, on all cpus.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:53 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Mark pages accessed, and dirty if being written
The mark_page_dirty() function, despite what its name might suggest,
doesn't actually mark the page as dirty as far as the MM subsystem is
concerned. It merely sets a bit in KVM's map of dirty pages, if
userspace has requested dirty tracking for the relevant memslot.
To tell the MM subsystem that the page is dirty, we have to call
kvm_set_pfn_dirty() (or an equivalent such as SetPageDirty()).
This adds a call to kvm_set_pfn_dirty(), and while we are here, also
adds a call to kvm_set_pfn_accessed() to tell the MM subsystem that
the page has been accessed. Since we are now using the pfn in
several places, this adds a 'pfn' variable to store it and changes
the places that used hpaddr >> PAGE_SHIFT to use pfn instead, which
is the same thing.
This also changes a use of HPTE_R_PP to PP_RXRX. Both are 3, but
PP_RXRX is more informative as being the read-only page permission
bit setting.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:52 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Use mmu_notifier_retry() in kvmppc_mmu_map_page()
When the MM code is invalidating a range of pages, it calls the KVM
kvm_mmu_notifier_invalidate_range_start() notifier function, which calls
kvm_unmap_hva_range(), which arranges to flush all the existing host
HPTEs for guest pages. However, the Linux PTEs for the range being
flushed are still valid at that point. We are not supposed to establish
any new references to pages in the range until the ...range_end()
notifier gets called. The PPC-specific KVM code doesn't get any
explicit notification of that; instead, we are supposed to use
mmu_notifier_retry() to test whether we are or have been inside a
range flush notifier pair while we have been getting a page and
instantiating a host HPTE for the page.
This therefore adds a call to mmu_notifier_retry inside
kvmppc_mmu_map_page(). This call is inside a region locked with
kvm->mmu_lock, which is the same lock that is called by the KVM
MMU notifier functions, thus ensuring that no new notification can
proceed while we are in the locked region. Inside this region we
also create the host HPTE and link the corresponding hpte_cache
structure into the lists used to find it later. We cannot allocate
the hpte_cache structure inside this locked region because that can
lead to deadlock, so we allocate it outside the region and free it
if we end up not using it.
This also moves the updates of vcpu3s->hpte_cache_count inside the
regions locked with vcpu3s->mmu_lock, and does the increment in
kvmppc_mmu_hpte_cache_map() when the pte is added to the cache
rather than when it is allocated, in order that the hpte_cache_count
is accurate.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:51 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Better handling of host-side read-only pages
Currently we request write access to all pages that get mapped into the
guest, even if the guest is only loading from the page. This reduces
the effectiveness of KSM because it means that we unshare every page we
access. Also, we always set the changed (C) bit in the guest HPTE if
it allows writing, even for a guest load.
This fixes both these problems. We pass an 'iswrite' flag to the
mmu.xlate() functions and to kvmppc_mmu_map_page() to indicate whether
the access is a load or a store. The mmu.xlate() functions now only
set C for stores. kvmppc_gfn_to_pfn() now calls gfn_to_pfn_prot()
instead of gfn_to_pfn() so that it can indicate whether we need write
access to the page, and get back a 'writable' flag to indicate whether
the page is writable or not. If that 'writable' flag is clear, we then
make the host HPTE read-only even if the guest HPTE allowed writing.
This means that we can get a protection fault when the guest writes to a
page that it has mapped read-write but which is read-only on the host
side (perhaps due to KSM having merged the page). Thus we now call
kvmppc_handle_pagefault() for protection faults as well as HPTE not found
faults. In kvmppc_handle_pagefault(), if the access was allowed by the
guest HPTE and we thus need to install a new host HPTE, we then need to
remove the old host HPTE if there is one. This is done with a new
function, kvmppc_mmu_unmap_page(), which uses kvmppc_mmu_pte_vflush() to
find and remove the old host HPTE.
Since the memslot-related functions require the KVM SRCU read lock to
be held, this adds srcu_read_lock/unlock pairs around the calls to
kvmppc_handle_pagefault().
Finally, this changes kvmppc_mmu_book3s_32_xlate_pte() to not ignore
guest HPTEs that don't permit access, and to return -EPERM for accesses
that are not permitted by the page protections.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:50 +0000 (14:52 +1000)]
KVM: PPC: Book3S: Move skip-interrupt handlers to common code
Both PR and HV KVM have separate, identical copies of the
kvmppc_skip_interrupt and kvmppc_skip_Hinterrupt handlers that are
used for the situation where an interrupt happens when loading the
instruction that caused an exit from the guest. To eliminate this
duplication and make it easier to compile in both PR and HV KVM,
this moves this code to arch/powerpc/kernel/exceptions-64s.S along
with other kernel interrupt handler code.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:49 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Allocate kvm_vcpu structs from kvm_vcpu_cache
This makes PR KVM allocate its kvm_vcpu structs from the kvm_vcpu_cache
rather than having them embedded in the kvmppc_vcpu_book3s struct,
which is allocated with vzalloc. The reason is to reduce the
differences between PR and HV KVM in order to make is easier to have
them coexist in one kernel binary.
With this, the kvm_vcpu struct has a pointer to the kvmppc_vcpu_book3s
struct. The pointer to the kvmppc_book3s_shadow_vcpu struct has moved
from the kvmppc_vcpu_book3s struct to the kvm_vcpu struct, and is only
present for 32-bit, since it is only used for 32-bit.
Signed-off-by: Paul Mackerras <paulus@samba.org>
[agraf: squash in compile fix from Aneesh] Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:48 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Make HPT accesses and updates SMP-safe
This adds a per-VM mutex to provide mutual exclusion between vcpus
for accesses to and updates of the guest hashed page table (HPT).
This also makes the code use single-byte writes to the HPT entry
when updating of the reference (R) and change (C) bits. The reason
for doing this, rather than writing back the whole HPTE, is that on
non-PAPR virtual machines, the guest OS might be writing to the HPTE
concurrently, and writing back the whole HPTE might conflict with
that. Also, real hardware does single-byte writes to update R and C.
The new mutex is taken in kvmppc_mmu_book3s_64_xlate() when reading
the HPT and updating R and/or C, and in the PAPR HPT update hcalls
(H_ENTER, H_REMOVE, etc.). Having the mutex means that we don't need
to use a hypervisor lock bit in the HPT update hcalls, and we don't
need to be careful about the order in which the bytes of the HPTE are
updated by those hcalls.
The other change here is to make emulated TLB invalidations (tlbie)
effective across all vcpus. To do this we call kvmppc_mmu_pte_vflush
for all vcpus in kvmppc_ppc_book3s_64_tlbie().
For 32-bit, this makes the setting of the accessed and dirty bits use
single-byte writes, and makes tlbie invalidate shadow HPTEs for all
vcpus.
With this, PR KVM can successfully run SMP guests.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:47 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Correct errors in H_ENTER implementation
The implementation of H_ENTER in PR KVM has some errors:
* With H_EXACT not set, if the HPTEG is full, we return H_PTEG_FULL
as the return value of kvmppc_h_pr_enter, but the caller is expecting
one of the EMULATE_* values. The H_PTEG_FULL needs to go in the
guest's R3 instead.
* With H_EXACT set, if the selected HPTE is already valid, the H_ENTER
call should return a H_PTEG_FULL error.
This fixes these errors and also makes it write only the selected HPTE,
not the whole group, since only the selected HPTE has been modified.
This also micro-optimizes the calculations involving pte_index and i.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:46 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Handle PP0 page-protection bit in guest HPTEs
64-bit POWER processors have a three-bit field for page protection in
the hashed page table entry (HPTE). Currently we only interpret the two
bits that were present in older versions of the architecture. The only
defined combination that has the new bit set is 110, meaning read-only
for supervisor and no access for user mode.
This adds code to kvmppc_mmu_book3s_64_xlate() to interpret the extra
bit appropriately.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:45 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Use 64k host pages where possible
Currently, PR KVM uses 4k pages for the host-side mappings of guest
memory, regardless of the host page size. When the host page size is
64kB, we might as well use 64k host page mappings for guest mappings
of 64kB and larger pages and for guest real-mode mappings. However,
the magic page has to remain a 4k page.
To implement this, we first add another flag bit to the guest VSID
values we use, to indicate that this segment is one where host pages
should be mapped using 64k pages. For segments with this bit set
we set the bits in the shadow SLB entry to indicate a 64k base page
size. When faulting in host HPTEs for this segment, we make them
64k HPTEs instead of 4k. We record the pagesize in struct hpte_cache
for use when invalidating the HPTE.
For now we restrict the segment containing the magic page (if any) to
4k pages. It should be possible to lift this restriction in future
by ensuring that the magic 4k page is appropriately positioned within
a host 64k page.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:44 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Allow guest to use 64k pages
This adds the code to interpret 64k HPTEs in the guest hashed page
table (HPT), 64k SLB entries, and to tell the guest about 64k pages
in kvm_vm_ioctl_get_smmu_info(). Guest 64k pages are still shadowed
by 4k pages.
This also adds another hash table to the four we have already in
book3s_mmu_hpte.c to allow us to find all the PTEs that we have
instantiated that match a given 64k guest page.
The tlbie instruction changed starting with POWER6 to use a bit in
the RB operand to indicate large page invalidations, and to use other
RB bits to indicate the base and actual page sizes and the segment
size. 64k pages came in slightly earlier, with POWER5++.
We use one bit in vcpu->arch.hflags to indicate that the emulated
cpu supports 64k pages, and another to indicate that it has the new
tlbie definition.
The KVM_PPC_GET_SMMU_INFO ioctl presents a bit of a problem, because
the MMU capabilities depend on which CPU model we're emulating, but it
is a VM ioctl not a VCPU ioctl and therefore doesn't get passed a VCPU
fd. In addition, commonly-used userspace (QEMU) calls it before
setting the PVR for any VCPU. Therefore, as a best effort we look at
the first vcpu in the VM and return 64k pages or not depending on its
capabilities. We also make the PVR default to the host PVR on recent
CPUs that support 1TB segments (and therefore multiple page sizes as
well) so that KVM_PPC_GET_SMMU_INFO will include 64k page and 1TB
segment support on those CPUs.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:43 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu
Currently PR-style KVM keeps the volatile guest register values
(R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than
the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two
places, a kmalloc'd struct and in the PACA, and it gets copied back
and forth in kvmppc_core_vcpu_load/put(), because the real-mode code
can't rely on being able to access the kmalloc'd struct.
This changes the code to copy the volatile values into the shadow_vcpu
as one of the last things done before entering the guest. Similarly
the values are copied back out of the shadow_vcpu to the kvm_vcpu
immediately after exiting the guest. We arrange for interrupts to be
still disabled at this point so that we can't get preempted on 64-bit
and end up copying values from the wrong PACA.
This means that the accessor functions in kvm_book3s.h for these
registers are greatly simplified, and are same between PR and HV KVM.
In places where accesses to shadow_vcpu fields are now replaced by
accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs.
Finally, on 64-bit, we don't need the kmalloc'd struct at all any more.
With this, the time to read the PVR one million times in a loop went
from 567.7ms to 575.5ms (averages of 6 values), an increase of about
1.4% for this worse-case test for guest entries and exits. The
standard deviation of the measurements is about 11ms, so the
difference is only marginally significant statistically.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:42 +0000 (14:52 +1000)]
KVM: PPC: Book3S PR: Fix compilation without CONFIG_ALTIVEC
Commit 9d1ffdd8f3 ("KVM: PPC: Book3S PR: Don't corrupt guest state
when kernel uses VMX") added a call to kvmppc_load_up_altivec() that
isn't guarded by CONFIG_ALTIVEC, causing a link failure when building
a kernel without CONFIG_ALTIVEC set. This adds an #ifdef to fix this.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
If we come out of a guest with an interrupt that we don't know about,
instead of crashing the host with a BUG(), we now return to userspace
with the exit reason set to KVM_EXIT_UNKNOWN and the trap vector in
the hw.hardware_exit_reason field of the kvm_run structure, as is done
on x86. Note that run->exit_reason is already set to KVM_EXIT_UNKNOWN
at the beginning of kvmppc_handle_exit().
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Sat, 21 Sep 2013 04:35:02 +0000 (14:35 +1000)]
KVM: PPC: Book3S HV: Support POWER6 compatibility mode on POWER7
This enables us to use the Processor Compatibility Register (PCR) on
POWER7 to put the processor into architecture 2.05 compatibility mode
when running a guest. In this mode the new instructions and registers
that were introduced on POWER7 are disabled in user mode. This
includes all the VSX facilities plus several other instructions such
as ldbrx, stdbrx, popcntw, popcntd, etc.
To select this mode, we have a new register accessible through the
set/get_one_reg interface, called KVM_REG_PPC_ARCH_COMPAT. Setting
this to zero gives the full set of capabilities of the processor.
Setting it to one of the "logical" PVR values defined in PAPR puts
the vcpu into the compatibility mode for the corresponding
architecture level. The supported values are:
Since the PCR is per-core, the architecture compatibility level and
the corresponding PCR value are stored in the struct kvmppc_vcore, and
are therefore shared between all vcpus in a virtual core.
Signed-off-by: Paul Mackerras <paulus@samba.org>
[agraf: squash in fix to add missing break statements and documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:39 +0000 (14:52 +1000)]
KVM: PPC: Book3S HV: Add support for guest Program Priority Register
POWER7 and later IBM server processors have a register called the
Program Priority Register (PPR), which controls the priority of
each hardware CPU SMT thread, and affects how fast it runs compared
to other SMT threads. This priority can be controlled by writing to
the PPR or by use of a set of instructions of the form or rN,rN,rN
which are otherwise no-ops but have been defined to set the priority
to particular levels.
This adds code to context switch the PPR when entering and exiting
guests and to make the PPR value accessible through the SET/GET_ONE_REG
interface. When entering the guest, we set the PPR as late as
possible, because if we are setting a low thread priority it will
make the code run slowly from that point on. Similarly, the
first-level interrupt handlers save the PPR value in the PACA very
early on, and set the thread priority to the medium level, so that
the interrupt handling code runs at a reasonable speed.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:38 +0000 (14:52 +1000)]
KVM: PPC: Book3S HV: Store LPCR value for each virtual core
This adds the ability to have a separate LPCR (Logical Partitioning
Control Register) value relating to a guest for each virtual core,
rather than only having a single value for the whole VM. This
corresponds to what real POWER hardware does, where there is a LPCR
per CPU thread but most of the fields are required to have the same
value on all active threads in a core.
The per-virtual-core LPCR can be read and written using the
GET/SET_ONE_REG interface. Userspace can can only modify the
following fields of the LPCR value:
DPFD Default prefetch depth
ILE Interrupt little-endian
TC Translation control (secondary HPT hash group search disable)
We still maintain a per-VM default LPCR value in kvm->arch.lpcr, which
contains bits relating to memory management, i.e. the Virtualized
Partition Memory (VPM) bits and the bits relating to guest real mode.
When this default value is updated, the update needs to be propagated
to the per-vcore values, so we add a kvmppc_update_lpcr() helper to do
that.
Signed-off-by: Paul Mackerras <paulus@samba.org>
[agraf: fix whitespace] Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 20 Sep 2013 04:52:37 +0000 (14:52 +1000)]
KVM: PPC: BookE: Add GET/SET_ONE_REG interface for VRSAVE
This makes the VRSAVE register value for a vcpu accessible through
the GET/SET_ONE_REG interface on Book E systems (in addition to the
existing GET/SET_SREGS interface), for consistency with Book 3S.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
The yield count in the VPA is supposed to be incremented every time
we enter the guest, and every time we exit the guest, so that its
value is even when the vcpu is running in the guest and odd when it
isn't. However, it's currently possible that we increment the yield
count on the way into the guest but then find that other CPU threads
are already exiting the guest, so we go back to nap mode via the
secondary_too_late label. In this situation we don't increment the
yield count again, breaking the relationship between the LSB of the
count and whether the vcpu is in the guest.
To fix this, we move the increment of the yield count to a point
after we have checked whether other CPU threads are exiting.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 6 Sep 2013 03:24:13 +0000 (13:24 +1000)]
KVM: PPC: Book3S HV: Pull out interrupt-reading code into a subroutine
This moves the code in book3s_hv_rmhandlers.S that reads any pending
interrupt from the XICS interrupt controller, and works out whether
it is an IPI for the guest, an IPI for the host, or a device interrupt,
into a new function called kvmppc_read_intr. Later patches will
need this.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 6 Sep 2013 03:23:44 +0000 (13:23 +1000)]
KVM: PPC: Book3S HV: Restructure kvmppc_hv_entry to be a subroutine
We have two paths into and out of the low-level guest entry and exit
code: from a vcpu task via kvmppc_hv_entry_trampoline, and from the
system reset vector for an offline secondary thread on POWER7 via
kvm_start_guest. Currently both just branch to kvmppc_hv_entry to
enter the guest, and on guest exit, we test the vcpu physical thread
ID to detect which way we came in and thus whether we should return
to the vcpu task or go back to nap mode.
In order to make the code flow clearer, and to keep the code relating
to each flow together, this turns kvmppc_hv_entry into a subroutine
that follows the normal conventions for call and return. This means
that kvmppc_hv_entry_trampoline() and kvmppc_hv_entry() now establish
normal stack frames, and we use the normal stack slots for saving
return addresses rather than local_paca->kvm_hstate.vmhandler. Apart
from that this is mostly moving code around unchanged.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 6 Sep 2013 03:23:21 +0000 (13:23 +1000)]
KVM: PPC: Book3S HV: Implement H_CONFER
The H_CONFER hypercall is used when a guest vcpu is spinning on a lock
held by another vcpu which has been preempted, and the spinning vcpu
wishes to give its timeslice to the lock holder. We implement this
in the straightforward way using kvm_vcpu_yield_to().
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 6 Sep 2013 03:18:32 +0000 (13:18 +1000)]
KVM: PPC: Book3S: Add GET/SET_ONE_REG interface for VRSAVE
The VRSAVE register value for a vcpu is accessible through the
GET/SET_SREGS interface for Book E processors, but not for Book 3S
processors. In order to make this accessible for Book 3S processors,
this adds a new register identifier for GET/SET_ONE_REG, and adds
the code to implement it.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 6 Sep 2013 03:17:46 +0000 (13:17 +1000)]
KVM: PPC: Book3S HV: Implement timebase offset for guests
This allows guests to have a different timebase origin from the host.
This is needed for migration, where a guest can migrate from one host
to another and the two hosts might have a different timebase origin.
However, the timebase seen by the guest must not go backwards, and
should go forwards only by a small amount corresponding to the time
taken for the migration.
Therefore this provides a new per-vcpu value accessed via the one_reg
interface using the new KVM_REG_PPC_TB_OFFSET identifier. This value
defaults to 0 and is not modified by KVM. On entering the guest, this
value is added onto the timebase, and on exiting the guest, it is
subtracted from the timebase.
This is only supported for recent POWER hardware which has the TBU40
(timebase upper 40 bits) register. Writing to the TBU40 register only
alters the upper 40 bits of the timebase, leaving the lower 24 bits
unchanged. This provides a way to modify the timebase for guest
migration without disturbing the synchronization of the timebase
registers across CPU cores. The kernel rounds up the value given
to a multiple of 2^24.
Timebase values stored in KVM structures (struct kvm_vcpu, struct
kvmppc_vcore, etc.) are stored as host timebase values. The timebase
values in the dispatch trace log need to be guest timebase values,
however, since that is read directly by the guest. This moves the
setting of vcpu->arch.dec_expires on guest exit to a point after we
have restored the host timebase so that vcpu->arch.dec_expires is a
host timebase value.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Paul Mackerras [Fri, 6 Sep 2013 03:11:18 +0000 (13:11 +1000)]
KVM: PPC: Book3S HV: Save/restore SIAR and SDAR along with other PMU registers
Currently we are not saving and restoring the SIAR and SDAR registers in
the PMU (performance monitor unit) on guest entry and exit. The result
is that performance monitoring tools in the guest could get false
information about where a program was executing and what data it was
accessing at the time of a performance monitor interrupt. This fixes
it by saving and restoring these registers along with the other PMU
registers on guest entry/exit.
This also provides a way for userspace to access these values for a
vcpu via the one_reg interface.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Michael Neuling [Tue, 3 Sep 2013 01:13:12 +0000 (11:13 +1000)]
KVM: PPC: Book3S HV: Reserve POWER8 space in get/set_one_reg
This reserves space in get/set_one_reg ioctl for the extra guest state
needed for POWER8. It doesn't implement these at all, it just reserves
them so that the ABI is defined now.
A few things to note here:
- This add *a lot* state for transactional memory. TM suspend mode,
this is unavoidable, you can't simply roll back all transactions and
store only the checkpointed state. I've added this all to
get/set_one_reg (including GPRs) rather than creating a new ioctl
which returns a struct kvm_regs like KVM_GET_REGS does. This means we
if we need to extract the TM state, we are going to need a bucket load
of IOCTLs. Hopefully most of the time this will not be needed as we
can look at the MSR to see if TM is active and only grab them when
needed. If this becomes a bottle neck in future we can add another
ioctl to grab all this state in one go.
- The TM state is offset by 0x80000000.
- For TM, I've done away with VMX and FP and created a single 64x128 bit
VSX register space.
- I've left a space of 1 (at 0x9c) since Paulus needs to add a value
which applies to POWER7 as well.
Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Alexander Graf <agraf@suse.de>
Linus Torvalds [Wed, 16 Oct 2013 00:14:13 +0000 (17:14 -0700)]
Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux
Pull device tree fixes and reverts from Grant Likely:
"One bug fix and three reverts. The reverts back out the slightly
controversial feeding the entire device tree into the random pool and
the reserved-memory binding which isn't fully baked yet. Expect the
reserved-memory patches at least to resurface for v3.13.
The bug fixes removes a scary but harmless warning on SPARC that was
introduced in the v3.12 merge window. v3.13 will contain a proper fix
that makes the new code work on SPARC.
On the plus side, the diffstat looks *awesome*. I love removing lines
of code"
* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux:
Revert "drivers: of: add initialization code for dma reserved memory"
Revert "ARM: init: add support for reserved memory defined by device tree"
Revert "of: Feed entire flattened device tree into the random pool"
of: fix unnecessary warning on missing /cpus node
Linus Torvalds [Tue, 15 Oct 2013 23:22:11 +0000 (16:22 -0700)]
Merge tag 'stable/for-linus-3.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen fixes from Stefano Stabellini:
"A small fix for Xen on x86_32 and a build fix for xen-tpmfront on
arm64"
* tag 'stable/for-linus-3.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: Fix possible user space selector corruption
tpm: xen-tpmfront: fix missing declaration of xen_domain
Raghavendra K T [Wed, 9 Oct 2013 09:03:21 +0000 (14:33 +0530)]
KVM: Enable pvspinlock after jump_label_init() to avoid VM hang
We use jump label to enable pv-spinlock. With the changes in (442e0973e927
Merge branch 'x86/jumplabel'), the jump label behaviour has changed
that would result in eventual hang of the VM since we would end up in a
situation where slow path locks would halt the vcpus but we will not be
able to wakeup the vcpu by lock releaser using unlock kick.
Similar problem in Xen and more detailed description is available in a945928ea270 (xen: Do not enable spinlocks before jump_label_init()
has executed)
This patch splits kvm_spinlock_init to separate jump label changes with
pvops patching and also make jump label enabling after jump_label_init().
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Gleb Natapov <gleb@redhat.com>
chai wen [Mon, 14 Oct 2013 14:22:33 +0000 (22:22 +0800)]
KVM: Drop FOLL_GET in GUP when doing async page fault
Page pinning is not mandatory in kvm async page fault processing since
after async page fault event is delivered to a guest it accesses page once
again and does its own GUP. Drop the FOLL_GET flag in GUP in async_pf
code, and do some simplifying in check/clear processing.
Marek Szyprowski [Fri, 11 Oct 2013 07:27:28 +0000 (09:27 +0200)]
Revert "drivers: of: add initialization code for dma reserved memory"
This reverts commit 9d8eab7af79cb4ce2de5de39f82c455b1f796963. There is
still no consensus on the bindings for the reserved memory and various
drawbacks of the proposed solution has been shown, so the best now is to
revert it completely and start again from scratch later.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Grant Likely <grant.likely@linaro.org>
Marek Szyprowski [Fri, 11 Oct 2013 07:27:27 +0000 (09:27 +0200)]
Revert "ARM: init: add support for reserved memory defined by device tree"
This reverts commit 10bcdfb8ba24760f715f0a700c3812747eddddf5. There is
no consensus on the bindings for the reserved memory, so the code for
handing it will be reverted.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Grant Likely <grant.likely@linaro.org>