Commit Graph

954 Commits

Author SHA1 Message Date
Mark Rutland
236cf17c25 KVM: arm/arm64: vgic: Ensure bitmaps are long enough
When we allocate bitmaps in vgic_vcpu_init_maps, we divide the number of
bits we need by 8 to figure out how many bytes to allocate. However,
bitmap elements are always accessed as unsigned longs, and if we didn't
happen to allocate a size such that size % sizeof(unsigned long) == 0,
bitmap accesses may go past the end of the allocation.

When using KASAN (which does byte-granular access checks), this results
in a continuous stream of BUGs whenever these bitmaps are accessed:

=============================================================================
BUG kmalloc-128 (Tainted: G    B          ): kasan: bad access detected
-----------------------------------------------------------------------------

INFO: Allocated in vgic_init.part.25+0x55c/0x990 age=7493 cpu=3 pid=1730
INFO: Slab 0xffffffbde6d5da40 objects=16 used=15 fp=0xffffffc935769700 flags=0x4000000000000080
INFO: Object 0xffffffc935769500 @offset=1280 fp=0x          (null)

Bytes b4 ffffffc9357694f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Object ffffffc935769500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Object ffffffc935769510: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Object ffffffc935769520: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Object ffffffc935769530: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Object ffffffc935769540: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Object ffffffc935769550: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Object ffffffc935769560: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Object ffffffc935769570: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Padding ffffffc9357695b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Padding ffffffc9357695c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Padding ffffffc9357695d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Padding ffffffc9357695e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
Padding ffffffc9357695f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
CPU: 3 PID: 1740 Comm: kvm-vcpu-0 Tainted: G    B           4.4.0+ #17
Hardware name: ARM Juno development board (r1) (DT)
Call trace:
[<ffffffc00008e770>] dump_backtrace+0x0/0x280
[<ffffffc00008ea04>] show_stack+0x14/0x20
[<ffffffc000726360>] dump_stack+0x100/0x188
[<ffffffc00030d324>] print_trailer+0xfc/0x168
[<ffffffc000312294>] object_err+0x3c/0x50
[<ffffffc0003140fc>] kasan_report_error+0x244/0x558
[<ffffffc000314548>] __asan_report_load8_noabort+0x48/0x50
[<ffffffc000745688>] __bitmap_or+0xc0/0xc8
[<ffffffc0000d9e44>] kvm_vgic_flush_hwstate+0x1bc/0x650
[<ffffffc0000c514c>] kvm_arch_vcpu_ioctl_run+0x2ec/0xa60
[<ffffffc0000b9a6c>] kvm_vcpu_ioctl+0x474/0xa68
[<ffffffc00036b7b0>] do_vfs_ioctl+0x5b8/0xcb0
[<ffffffc00036bf34>] SyS_ioctl+0x8c/0xa0
[<ffffffc000086cb0>] el0_svc_naked+0x24/0x28
Memory state around the buggy address:
 ffffffc935769400: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffffffc935769480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffffffc935769500: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffffffc935769580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffffffc935769600: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Fix the issue by always allocating a multiple of sizeof(unsigned long),
as we do elsewhere in the vgic code.

Fixes: c1bfb577a ("arm/arm64: KVM: vgic: switch to dynamic allocation")
Cc: stable@vger.kernel.org
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-23 19:02:48 +00:00
Andre Przywara
b3aff6ccbb KVM: arm/arm64: Fix reference to uninitialised VGIC
Commit 4b4b4512da ("arm/arm64: KVM: Rework the arch timer to use
level-triggered semantics") brought the virtual architected timer
closer to the VGIC. There is one occasion were we don't properly
check for the VGIC actually having been initialized before, but
instead go on to check the active state of some IRQ number.
If userland hasn't instantiated a virtual GIC, we end up with a
kernel NULL pointer dereference:
=========
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = ffffffc9745c5000
[00000000] *pgd=00000009f631e003, *pud=00000009f631e003, *pmd=0000000000000000
Internal error: Oops: 96000006 [#2] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 2144 Comm: kvm_simplest-ar Tainted: G      D 4.5.0-rc2+ #1300
Hardware name: ARM Juno development board (r1) (DT)
task: ffffffc976da8000 ti: ffffffc976e28000 task.ti: ffffffc976e28000
PC is at vgic_bitmap_get_irq_val+0x78/0x90
LR is at kvm_vgic_map_is_active+0xac/0xc8
pc : [<ffffffc0000b7e28>] lr : [<ffffffc0000b972c>] pstate: 20000145
....
=========

Fix this by bailing out early of kvm_timer_flush_hwstate() if we don't
have a VGIC at all.

Reported-by: Cosmin Gorgovan <cosmin@linux-geek.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <stable@vger.kernel.org> # 4.4.x
2016-02-08 15:23:39 +00:00
Dan Williams
ba049e93ae kvm: rename pfn_t to kvm_pfn_t
To date, we have implemented two I/O usage models for persistent memory,
PMEM (a persistent "ram disk") and DAX (mmap persistent memory into
userspace).  This series adds a third, DAX-GUP, that allows DAX mappings
to be the target of direct-i/o.  It allows userspace to coordinate
DMA/RDMA from/to persistent memory.

The implementation leverages the ZONE_DEVICE mm-zone that went into
4.3-rc1 (also discussed at kernel summit) to flag pages that are owned
and dynamically mapped by a device driver.  The pmem driver, after
mapping a persistent memory range into the system memmap via
devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus
page-backed pmem-pfns via flags in the new pfn_t type.

The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the
resulting pte(s) inserted into the process page tables with a new
_PAGE_DEVMAP flag.  Later, when get_user_pages() is walking ptes it keys
off _PAGE_DEVMAP to pin the device hosting the page range active.
Finally, get_page() and put_page() are modified to take references
against the device driver established page mapping.

Finally, this need for "struct page" for persistent memory requires
memory capacity to store the memmap array.  Given the memmap array for a
large pool of persistent may exhaust available DRAM introduce a
mechanism to allocate the memmap from persistent memory.  The new
"struct vmem_altmap *" parameter to devm_memremap_pages() enables
arch_add_memory() to use reserved pmem capacity rather than the page
allocator.

This patch (of 18):

The core has developed a need for a "pfn_t" type [1].  Move the existing
pfn_t in KVM to kvm_pfn_t [2].

[1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html
[2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15 17:56:32 -08:00
Linus Torvalds
1baa5efbeb * s390: Support for runtime instrumentation within guests,
support of 248 VCPUs.
 
 * ARM: rewrite of the arm64 world switch in C, support for
 16-bit VM identifiers.  Performance counter virtualization
 missed the boat.
 
 * x86: Support for more Hyper-V features (synthetic interrupt
 controller), MMU cleanups
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "PPC changes will come next week.

   - s390: Support for runtime instrumentation within guests, support of
     248 VCPUs.

   - ARM: rewrite of the arm64 world switch in C, support for 16-bit VM
     identifiers.  Performance counter virtualization missed the boat.

   - x86: Support for more Hyper-V features (synthetic interrupt
     controller), MMU cleanups"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (115 commits)
  kvm: x86: Fix vmwrite to SECONDARY_VM_EXEC_CONTROL
  kvm/x86: Hyper-V SynIC timers tracepoints
  kvm/x86: Hyper-V SynIC tracepoints
  kvm/x86: Update SynIC timers on guest entry only
  kvm/x86: Skip SynIC vector check for QEMU side
  kvm/x86: Hyper-V fix SynIC timer disabling condition
  kvm/x86: Reorg stimer_expiration() to better control timer restart
  kvm/x86: Hyper-V unify stimer_start() and stimer_restart()
  kvm/x86: Drop stimer_stop() function
  kvm/x86: Hyper-V timers fix incorrect logical operation
  KVM: move architecture-dependent requests to arch/
  KVM: renumber vcpu->request bits
  KVM: document which architecture uses each request bit
  KVM: Remove unused KVM_REQ_KICK to save a bit in vcpu->requests
  kvm: x86: Check kvm_write_guest return value in kvm_write_wall_clock
  KVM: s390: implement the RI support of guest
  kvm/s390: drop unpaired smp_mb
  kvm: x86: fix comment about {mmu,nested_mmu}.gva_to_gpa
  KVM: x86: MMU: Use clear_page() instead of init_shadow_page_table()
  arm/arm64: KVM: Detect vGIC presence at runtime
  ...
2016-01-12 13:22:12 -08:00
Paolo Bonzini
2860c4b167 KVM: move architecture-dependent requests to arch/
Since the numbers now overlap, it makes sense to enumerate
them in asm/kvm_host.h rather than linux/kvm_host.h.  Functions
that refer to architecture-specific requests are also moved
to arch/.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-01-08 19:04:36 +01:00
Paolo Bonzini
def840ede3 KVM/ARM changes for Linux v4.5
- Complete rewrite of the arm64 world switch in C, hopefully
   paving the way for more sharing with the 32bit code, better
   maintainability and easier integration of new features.
   Also smaller and slightly faster in some cases...
 - Support for 16bit VM identifiers
 - Various cleanups
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Merge tag 'kvm-arm-for-4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next

KVM/ARM changes for Linux v4.5

- Complete rewrite of the arm64 world switch in C, hopefully
  paving the way for more sharing with the 32bit code, better
  maintainability and easier integration of new features.
  Also smaller and slightly faster in some cases...
- Support for 16bit VM identifiers
- Various cleanups
2016-01-07 11:00:57 +01:00
Marc Zyngier
9d8415d6c1 arm64: KVM: Turn system register numbers to an enum
Having the system register numbers as #defines has been a pain
since day one, as the ordering is pretty fragile, and moving
things around leads to renumbering and epic conflict resolutions.

Now that we're mostly acessing the sysreg file in C, an enum is
a much better type to use, and we can clean things up a bit.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:43 +00:00
Marc Zyngier
3c13b8f435 KVM: arm/arm64: vgic-v3: Make the LR indexing macro public
We store GICv3 LRs in reverse order so that the CPU can save/restore
them in rever order as well (don't ask why, the design is crazy),
and yet generate memory traffic that doesn't completely suck.

We need this macro to be available to the C version of save/restore.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14 11:30:38 +00:00
Jisheng Zhang
8cdb654abe KVM: arm/arm64: vgic: make vgic_io_ops static
vgic_io_ops is only referenced within vgic.c, so it can be declared
static.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:29:59 +00:00
Christoffer Dall
fdec12c12e KVM: arm/arm64: vgic: Fix kvm_vgic_map_is_active's dist check
External inputs to the vgic from time to time need to poke into the
state of a virtual interrupt, the prime example is the architected timer
code.

Since the IRQ's active state can be represented in two places; the LR or
the distributor, we first loop over the LRs but if not active in the LRs
we just return if *any* IRQ is active on the VCPU in question.

This is of course bogus, as we should check if the specific IRQ in
quesiton is active on the distributor instead.

Reported-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-11 16:33:31 +00:00
Janosch Frank
4bd33b5688 KVM: Remove unnecessary debugfs dentry references
KVM creates debugfs files to export VM statistics to userland. To be
able to remove them on kvm exit it tracks the files' dentries.

Since their parent directory is also tracked and since each parent
direntry knows its children we can easily remove them by using
debugfs_remove_recursive(kvm_debugfs_dir). Therefore we don't
need the extra tracking in the kvm_stats_debugfs_item anymore.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-By: Sascha Silbe <silbe@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-11-30 12:47:05 +01:00
David Hildenbrand
e09fefdeeb KVM: Use common function for VCPU lookup by id
Let's reuse the new common function for VPCU lookup by id.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
[split out the new function into a separate patch]
2015-11-30 12:47:04 +01:00
Yaowei Bai
33e9415479 KVM: kvm_is_visible_gfn can be boolean
This patch makes kvm_is_visible_gfn return bool due to this particular
function only using either one or zero as its return value.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-25 17:24:23 +01:00
Markus Elfring
4f52696a6c KVM-async_pf: Delete an unnecessary check before the function call "kmem_cache_destroy"
The kmem_cache_destroy() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-25 17:24:23 +01:00
Andrey Smetanin
abdb080f7a kvm/irqchip: kvm_arch_irq_routing_update renaming split
Actually kvm_arch_irq_routing_update() should be
kvm_arch_post_irq_routing_update() as it's called at the end
of irq routing update.

This renaming frees kvm_arch_irq_routing_update function name.
kvm_arch_irq_routing_update() weak function which will be used
to update mappings for arch-specific irq routing entries
(in particular, the upcoming Hyper-V synthetic interrupts).

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-25 17:24:21 +01:00
Christoffer Dall
9f958c11b7 KVM: arm/arm64: vgic: Trust the LR state for HW IRQs
We were probing the physial distributor state for the active state of a
HW virtual IRQ, because we had seen evidence that the LR state was not
cleared when the guest deactivated a virtual interrupted.

However, this issue turned out to be a software bug in the GIC, which
was solved by: 84aab5e68c2a5e1e18d81ae8308c3ce25d501b29
(KVM: arm/arm64: arch_timer: Preserve physical dist. active
state on LR.active, 2015-11-24)

Therefore, get rid of the complexities and just look at the LR.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 18:08:37 +01:00
Christoffer Dall
0e3dfda91d KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active
We were incorrectly removing the active state from the physical
distributor on the timer interrupt when the timer output level was
deasserted.  We shouldn't be doing this without considering the virtual
interrupt's active state, because the architecture requires that when an
LR has the HW bit set and the pending or active bits set, then the
physical interrupt must also have the corresponding bits set.

This addresses an issue where we have been observing an inconsistency
between the LR state and the physical distributor state where the LR
state was active and the physical distributor was not active, which
shouldn't happen.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 18:07:40 +01:00
Linus Torvalds
933425fb00 s390: A bunch of fixes and optimizations for interrupt and time
handling.
 
 PPC: Mostly bug fixes.
 
 ARM: No big features, but many small fixes and prerequisites including:
 - a number of fixes for the arch-timer
 - introducing proper level-triggered semantics for the arch-timers
 - a series of patches to synchronously halt a guest (prerequisite for
   IRQ forwarding)
 - some tracepoint improvements
 - a tweak for the EL2 panic handlers
 - some more VGIC cleanups getting rid of redundant state
 
 x86: quite a few changes:
 
 - support for VT-d posted interrupts (i.e. PCI devices can inject
 interrupts directly into vCPUs).  This introduces a new component (in
 virt/lib/) that connects VFIO and KVM together.  The same infrastructure
 will be used for ARM interrupt forwarding as well.
 
 - more Hyper-V features, though the main one Hyper-V synthetic interrupt
 controller will have to wait for 4.5.  These will let KVM expose Hyper-V
 devices.
 
 - nested virtualization now supports VPID (same as PCID but for vCPUs)
 which makes it quite a bit faster
 
 - for future hardware that supports NVDIMM, there is support for clflushopt,
 clwb, pcommit
 
 - support for "split irqchip", i.e. LAPIC in kernel + IOAPIC/PIC/PIT in
 userspace, which reduces the attack surface of the hypervisor
 
 - obligatory smattering of SMM fixes
 
 - on the guest side, stable scheduler clock support was rewritten to not
 require help from the hypervisor.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "First batch of KVM changes for 4.4.

  s390:
     A bunch of fixes and optimizations for interrupt and time handling.

  PPC:
     Mostly bug fixes.

  ARM:
     No big features, but many small fixes and prerequisites including:

      - a number of fixes for the arch-timer

      - introducing proper level-triggered semantics for the arch-timers

      - a series of patches to synchronously halt a guest (prerequisite
        for IRQ forwarding)

      - some tracepoint improvements

      - a tweak for the EL2 panic handlers

      - some more VGIC cleanups getting rid of redundant state

  x86:
     Quite a few changes:

      - support for VT-d posted interrupts (i.e. PCI devices can inject
        interrupts directly into vCPUs).  This introduces a new
        component (in virt/lib/) that connects VFIO and KVM together.
        The same infrastructure will be used for ARM interrupt
        forwarding as well.

      - more Hyper-V features, though the main one Hyper-V synthetic
        interrupt controller will have to wait for 4.5.  These will let
        KVM expose Hyper-V devices.

      - nested virtualization now supports VPID (same as PCID but for
        vCPUs) which makes it quite a bit faster

      - for future hardware that supports NVDIMM, there is support for
        clflushopt, clwb, pcommit

      - support for "split irqchip", i.e.  LAPIC in kernel +
        IOAPIC/PIC/PIT in userspace, which reduces the attack surface of
        the hypervisor

      - obligatory smattering of SMM fixes

      - on the guest side, stable scheduler clock support was rewritten
        to not require help from the hypervisor"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (123 commits)
  KVM: VMX: Fix commit which broke PML
  KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0()
  KVM: x86: allow RSM from 64-bit mode
  KVM: VMX: fix SMEP and SMAP without EPT
  KVM: x86: move kvm_set_irq_inatomic to legacy device assignment
  KVM: device assignment: remove pointless #ifdefs
  KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic
  KVM: x86: zero apic_arb_prio on reset
  drivers/hv: share Hyper-V SynIC constants with userspace
  KVM: x86: handle SMBASE as physical address in RSM
  KVM: x86: add read_phys to x86_emulate_ops
  KVM: x86: removing unused variable
  KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs
  KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()
  KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings
  KVM: arm/arm64: Optimize away redundant LR tracking
  KVM: s390: use simple switch statement as multiplexer
  KVM: s390: drop useless newline in debugging data
  KVM: s390: SCA must not cross page boundaries
  KVM: arm: Do not indent the arguments of DECLARE_BITMAP
  ...
2015-11-05 16:26:26 -08:00
Paolo Bonzini
b97e6de9c9 KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic
We do not want to do too much work in atomic context, in particular
not walking all the VCPUs of the virtual machine.  So we want
to distinguish the architecture-specific injection function for irqfd
from kvm_set_msi.  Since it's still empty, reuse the newly added
kvm_arch_set_irq and rename it to kvm_arch_set_irq_inatomic.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-04 16:24:35 +01:00
Jan Beulich
6956d8946d KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs
The symbol was missing a KVM dependency.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-04 16:24:30 +01:00
Paolo Bonzini
197a4f4b06 KVM/ARM Changes for v4.4-rc1
Includes a number of fixes for the arch-timer, introducing proper
 level-triggered semantics for the arch-timers, a series of patches to
 synchronously halt a guest (prerequisite for IRQ forwarding), some tracepoint
 improvements, a tweak for the EL2 panic handlers, some more VGIC cleanups
 getting rid of redundant state, and finally a stylistic change that gets rid of
 some ctags warnings.
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Merge tag 'kvm-arm-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/ARM Changes for v4.4-rc1

Includes a number of fixes for the arch-timer, introducing proper
level-triggered semantics for the arch-timers, a series of patches to
synchronously halt a guest (prerequisite for IRQ forwarding), some tracepoint
improvements, a tweak for the EL2 panic handlers, some more VGIC cleanups
getting rid of redundant state, and finally a stylistic change that gets rid of
some ctags warnings.

Conflicts:
	arch/x86/include/asm/kvm_host.h
2015-11-04 16:24:17 +01:00
Pavel Fedin
26caea7693 KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()
Now we see that vgic_set_lr() and vgic_sync_lr_elrsr() are always used
together. Merge them into one function, saving from second vgic_ops
dereferencing every time.

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-04 15:29:49 +01:00
Pavel Fedin
212c76545d KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings
1. Remove unnecessary 'irq' argument, because irq number can be retrieved
   from the LR.
2. Since cff9211eb1
   ("arm/arm64: KVM: Fix arch timer behavior for disabled interrupts ")
   LR_STATE_PENDING is queued back by vgic_retire_lr() itself. Also, it
   clears vlr.state itself. Therefore, we remove the same, now duplicated,
   check with all accompanying bit manipulations from vgic_unqueue_irqs().
3. vgic_retire_lr() is always accompanied by vgic_irq_clear_queued(). Since
   it already does more than just clearing the LR, move
   vgic_irq_clear_queued() inside of it.

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-04 15:29:49 +01:00
Pavel Fedin
c4cd4c168b KVM: arm/arm64: Optimize away redundant LR tracking
Currently we use vgic_irq_lr_map in order to track which LRs hold which
IRQs, and lr_used bitmap in order to track which LRs are used or free.

vgic_irq_lr_map is actually used only for piggy-back optimization, and
can be easily replaced by iteration over lr_used. This is good because in
future, when LPI support is introduced, number of IRQs will grow up to at
least 16384, while numbers from 1024 to 8192 are never going to be used.
This would be a huge memory waste.

In its turn, lr_used is also completely redundant since
ae705930fc ("arm/arm64: KVM: Keep elrsr/aisr
in sync with software model"), because together with lr_used we also update
elrsr. This allows to easily replace lr_used with elrsr, inverting all
conditions (because in elrsr '1' means 'free').

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-04 15:29:49 +01:00
Linus Torvalds
6aa2fdb87c Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "The irq departement delivers:

   - Rework the irqdomain core infrastructure to accomodate ACPI based
     systems.  This is required to support ARM64 without creating
     artificial device tree nodes.

   - Sanitize the ACPI based ARM GIC initialization by making use of the
     new firmware independent irqdomain core

   - Further improvements to the generic MSI management

   - Generalize the irq migration on CPU hotplug

   - Improvements to the threaded interrupt infrastructure

   - Allow the migration of "chained" low level interrupt handlers

   - Allow optional force masking of interrupts in disable_irq[_nosysnc]

   - Support for two new interrupt chips - Sigh!

   - A larger set of errata fixes for ARM gicv3

   - The usual pile of fixes, updates, improvements and cleanups all
     over the place"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  Document that IRQ_NONE should be returned when IRQ not actually handled
  PCI/MSI: Allow the MSI domain to be device-specific
  PCI: Add per-device MSI domain hook
  of/irq: Use the msi-map property to provide device-specific MSI domain
  of/irq: Split of_msi_map_rid to reuse msi-map lookup
  irqchip/gic-v3-its: Parse new version of msi-parent property
  PCI/MSI: Use of_msi_get_domain instead of open-coded "msi-parent" parsing
  of/irq: Use of_msi_get_domain instead of open-coded "msi-parent" parsing
  of/irq: Add support code for multi-parent version of "msi-parent"
  irqchip/gic-v3-its: Add handling of PCI requester id.
  PCI/MSI: Add helper function pci_msi_domain_get_msi_rid().
  of/irq: Add new function of_msi_map_rid()
  Docs: dt: Add PCI MSI map bindings
  irqchip/gic-v2m: Add support for multiple MSI frames
  irqchip/gic-v3: Fix translation of LPIs after conversion to irq_fwspec
  irqchip/mxs: Add Alphascale ASM9260 support
  irqchip/mxs: Prepare driver for hardware with different offsets
  irqchip/mxs: Panic if ioremap or domain creation fails
  irqdomain: Documentation updates
  irqdomain/msi: Use fwnode instead of of_node
  ...
2015-11-03 14:40:01 -08:00
Christoffer Dall
e21f091087 arm/arm64: KVM: Add tracepoints for vgic and timer
The VGIC and timer code for KVM arm/arm64 doesn't have any tracepoints
or tracepoint infrastructure defined.  Rewriting some of the timer code
handling showed me how much we need this, so let's add these simple
trace points once and for all and we can easily expand with additional
trace points in these files as we go along.

Cc: Wei Huang <wei@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22 23:01:48 +02:00
Christoffer Dall
8fe2f19e6e arm/arm64: KVM: Support edge-triggered forwarded interrupts
We mark edge-triggered interrupts with the HW bit set as queued to
prevent the VGIC code from injecting LRs with both the Active and
Pending bits set at the same time while also setting the HW bit,
because the hardware does not support this.

However, this means that we must also clear the queued flag when we sync
back a LR where the state on the physical distributor went from active
to inactive because the guest deactivated the interrupt.  At this point
we must also check if the interrupt is pending on the distributor, and
tell the VGIC to queue it again if it is.

Since these actions on the sync path are extremely close to those for
level-triggered interrupts, rename process_level_irq to
process_queued_irq, allowing it to cater for both cases.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22 23:01:44 +02:00
Christoffer Dall
4b4b4512da arm/arm64: KVM: Rework the arch timer to use level-triggered semantics
The arch timer currently uses edge-triggered semantics in the sense that
the line is never sampled by the vgic and lowering the line from the
timer to the vgic doesn't have any effect on the pending state of
virtual interrupts in the vgic.  This means that we do not support a
guest with the otherwise valid behavior of (1) disable interrupts (2)
enable the timer (3) disable the timer (4) enable interrupts.  Such a
guest would validly not expect to see any interrupts on real hardware,
but will see interrupts on KVM.

This patch fixes this shortcoming through the following series of
changes.

First, we change the flow of the timer/vgic sync/flush operations.  Now
the timer is always flushed/synced before the vgic, because the vgic
samples the state of the timer output.  This has the implication that we
move the timer operations in to non-preempible sections, but that is
fine after the previous commit getting rid of hrtimer schedules on every
entry/exit.

Second, we change the internal behavior of the timer, letting the timer
keep track of its previous output state, and only lower/raise the line
to the vgic when the state changes.  Note that in theory this could have
been accomplished more simply by signalling the vgic every time the
state *potentially* changed, but we don't want to be hitting the vgic
more often than necessary.

Third, we get rid of the use of the map->active field in the vgic and
instead simply set the interrupt as active on the physical distributor
whenever the input to the GIC is asserted and conversely clear the
physical active state when the input to the GIC is deasserted.

Fourth, and finally, we now initialize the timer PPIs (and all the other
unused PPIs for now), to be level-triggered, and modify the sync code to
sample the line state on HW sync and re-inject a new interrupt if it is
still pending at that time.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22 23:01:44 +02:00
Christoffer Dall
54723bb37f arm/arm64: KVM: Use appropriate define in VGIC reset code
We currently initialize the SGIs to be enabled in the VGIC code, but we
use the VGIC_NR_PPIS define for this purpose, instead of the the more
natural VGIC_NR_SGIS.  Change this slightly confusing use of the
defines.

Note: This should have no functional change, as both names are defined
to the number 16.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22 23:01:43 +02:00
Christoffer Dall
8bf9a701e1 arm/arm64: KVM: Implement GICD_ICFGR as RO for PPIs
The GICD_ICFGR allows the bits for the SGIs and PPIs to be read only.
We currently simulate this behavior by writing a hardcoded value to the
register for the SGIs and PPIs on every write of these bits to the
register (ignoring what the guest actually wrote), and by writing the
same value as the reset value to the register.

This is a bit counter-intuitive, as the register is RO for these bits,
and we can just implement it that way, allowing us to control the value
of the bits purely in the reset code.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22 23:01:42 +02:00
Christoffer Dall
9103617df2 arm/arm64: KVM: vgic: Factor out level irq processing on guest exit
Currently vgic_process_maintenance() processes dealing with a completed
level-triggered interrupt directly, but we are soon going to reuse this
logic for level-triggered mapped interrupts with the HW bit set, so
move this logic into a separate static function.

Probably the most scary part of this commit is convincing yourself that
the current flow is safe compared to the old one.  In the following I
try to list the changes and why they are harmless:

  Move vgic_irq_clear_queued after kvm_notify_acked_irq:
    Harmless because the only potential effect of clearing the queued
    flag wrt.  kvm_set_irq is that vgic_update_irq_pending does not set
    the pending bit on the emulated CPU interface or in the
    pending_on_cpu bitmask if the function is called with level=1.
    However, the point of kvm_notify_acked_irq is to call kvm_set_irq
    with level=0, and we set the queued flag again in
    __kvm_vgic_sync_hwstate later on if the level is stil high.

  Move vgic_set_lr before kvm_notify_acked_irq:
    Also, harmless because the LR are cpu-local operations and
    kvm_notify_acked only affects the dist

  Move vgic_dist_irq_clear_soft_pend after kvm_notify_acked_irq:
    Also harmless, because now we check the level state in the
    clear_soft_pend function and lower the pending bits if the level is
    low.

Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22 23:01:42 +02:00
Christoffer Dall
d35268da66 arm/arm64: KVM: arch_timer: Only schedule soft timer on vcpu_block
We currently schedule a soft timer every time we exit the guest if the
timer did not expire while running the guest.  This is really not
necessary, because the only work we do in the timer work function is to
kick the vcpu.

Kicking the vcpu does two things:
(1) If the vpcu thread is on a waitqueue, make it runnable and remove it
from the waitqueue.
(2) If the vcpu is running on a different physical CPU from the one
doing the kick, it sends a reschedule IPI.

The second case cannot happen, because the soft timer is only ever
scheduled when the vcpu is not running.  The first case is only relevant
when the vcpu thread is on a waitqueue, which is only the case when the
vcpu thread has called kvm_vcpu_block().

Therefore, we only need to make sure a timer is scheduled for
kvm_vcpu_block(), which we do by encapsulating all calls to
kvm_vcpu_block() with kvm_timer_{un}schedule calls.

Additionally, we only schedule a soft timer if the timer is enabled and
unmasked, since it is useless otherwise.

Note that theoretically userspace can use the SET_ONE_REG interface to
change registers that should cause the timer to fire, even if the vcpu
is blocked without a scheduled timer, but this case was not supported
before this patch and we leave it for future work for now.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22 23:01:42 +02:00
Christoffer Dall
3217f7c25b KVM: Add kvm_arch_vcpu_{un}blocking callbacks
Some times it is useful for architecture implementations of KVM to know
when the VCPU thread is about to block or when it comes back from
blocking (arm/arm64 needs to know this to properly implement timers, for
example).

Therefore provide a generic architecture callback function in line with
what we do elsewhere for KVM generic-arch interactions.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22 23:01:41 +02:00
Christoffer Dall
0d997491f8 arm/arm64: KVM: Fix disabled distributor operation
We currently do a single update of the vgic state when the distributor
enable/disable control register is accessed and then bypass updating the
state for as long as the distributor remains disabled.

This is incorrect, because updating the state does not consider the
distributor enable bit, and this you can end up in a situation where an
interrupt is marked as pending on the CPU interface, but not pending on
the distributor, which is an impossible state to be in, and triggers a
warning.  Consider for example the following sequence of events:

1. An interrupt is marked as pending on the distributor
   - the interrupt is also forwarded to the CPU interface
2. The guest turns off the distributor (it's about to do a reboot)
   - we stop updating the CPU interface state from now on
3. The guest disables the pending interrupt
   - we remove the pending state from the distributor, but don't touch
     the CPU interface, see point 2.

Since the distributor disable bit really means that no interrupts should
be forwarded to the CPU interface, we modify the code to keep updating
the internal VGIC state, but always set the CPU interface pending bits
to zero when the distributor is disabled.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20 18:09:13 +02:00
Christoffer Dall
544c572e03 arm/arm64: KVM: Clear map->active on pend/active clear
When a guest reboots or offlines/onlines CPUs, it is not uncommon for it
to clear the pending and active states of an interrupt through the
emulated VGIC distributor.  However, since the architected timers are
defined by the architecture to be level triggered and the guest
rightfully expects them to be that, but we emulate them as
edge-triggered, we have to mimic level-triggered behavior for an
edge-triggered virtual implementation.

We currently do not signal the VGIC when the map->active field is true,
because it indicates that the guest has already been signalled of the
interrupt as required.  Normally this field is set to false when the
guest deactivates the virtual interrupt through the sync path.

We also need to catch the case where the guest deactivates the interrupt
through the emulated distributor, again allowing guests to boot even if
the original virtual timer signal hit before the guest's GIC
initialization sequence is run.

Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20 18:06:34 +02:00
Christoffer Dall
cff9211eb1 arm/arm64: KVM: Fix arch timer behavior for disabled interrupts
We have an interesting issue when the guest disables the timer interrupt
on the VGIC, which happens when turning VCPUs off using PSCI, for
example.

The problem is that because the guest disables the virtual interrupt at
the VGIC level, we never inject interrupts to the guest and therefore
never mark the interrupt as active on the physical distributor.  The
host also never takes the timer interrupt (we only use the timer device
to trigger a guest exit and everything else is done in software), so the
interrupt does not become active through normal means.

The result is that we keep entering the guest with a programmed timer
that will always fire as soon as we context switch the hardware timer
state and run the guest, preventing forward progress for the VCPU.

Since the active state on the physical distributor is really part of the
timer logic, it is the job of our virtual arch timer driver to manage
this state.

The timer->map->active boolean field indicates whether we have signalled
this interrupt to the vgic and if that interrupt is still pending or
active.  As long as that is the case, the hardware doesn't have to
generate physical interrupts and therefore we mark the interrupt as
active on the physical distributor.

We also have to restore the pending state of an interrupt that was
queued to an LR but was retired from the LR for some reason, while
remaining pending in the LR.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Reported-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20 18:04:54 +02:00
Pavel Fedin
437f9963bc KVM: arm/arm64: Do not inject spurious interrupts
When lowering a level-triggered line from userspace, we forgot to lower
the pending bit on the emulated CPU interface and we also did not
re-compute the pending_on_cpu bitmap for the CPU affected by the change.

Update vgic_update_irq_pending() to fix the two issues above and also
raise a warning in vgic_quue_irq_to_lr if we encounter an interrupt
pending on a CPU which is neither marked active nor pending.

  [ Commit text reworked completely - Christoffer ]

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20 18:04:43 +02:00
Andrey Smetanin
f33143d809 kvm/irqchip: allow only multiple irqchip routes per GSI
Any other irq routing types (MSI, S390_ADAPTER, upcoming Hyper-V
SynIC) map one-to-one to GSI.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-16 10:34:30 +02:00
Andrey Smetanin
c9a5eccac1 kvm/eventfd: add arch-specific set_irq
Allow for arch-specific interrupt types to be set.  For that, add
kvm_arch_set_irq() which takes interrupt type-specific action if it
recognizes the interrupt type given, and -EWOULDBLOCK otherwise.

The default implementation always returns -EWOULDBLOCK.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-16 10:34:29 +02:00
Andrey Smetanin
ba1aefcd6d kvm/eventfd: factor out kvm_notify_acked_gsi()
Factor out kvm_notify_acked_gsi() helper to iterate over EOI listeners
and notify those matching the given gsi.

It will be reused in the upcoming Hyper-V SynIC implementation.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-16 10:34:29 +02:00
Andrey Smetanin
351dc6477c kvm/eventfd: avoid loop inside irqfd_update()
The loop(for) inside irqfd_update() is unnecessary
because any other value for irq_entry.type will just trigger
schedule_work(&irqfd->inject) in irqfd_wakeup.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-16 10:34:28 +02:00
Kosuke Tatsukawa
6003a42010 kvm: fix waitqueue_active without memory barrier in virt/kvm/async_pf.c
async_pf_execute() seems to be missing a memory barrier which might
cause the waker to not notice the waiter and miss sending a wake_up as
in the following figure.

        async_pf_execute                    kvm_vcpu_block
------------------------------------------------------------------------
spin_lock(&vcpu->async_pf.lock);
if (waitqueue_active(&vcpu->wq))
/* The CPU might reorder the test for
   the waitqueue up here, before
   prior writes complete */
                                    prepare_to_wait(&vcpu->wq, &wait,
                                      TASK_INTERRUPTIBLE);
                                    /*if (kvm_vcpu_check_block(vcpu) < 0) */
                                     /*if (kvm_arch_vcpu_runnable(vcpu)) { */
                                      ...
                                      return (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE &&
                                        !vcpu->arch.apf.halted)
                                        || !list_empty_careful(&vcpu->async_pf.done)
                                     ...
                                     return 0;
list_add_tail(&apf->link,
  &vcpu->async_pf.done);
spin_unlock(&vcpu->async_pf.lock);
                                    waited = true;
                                    schedule();
------------------------------------------------------------------------

The attached patch adds the missing memory barrier.

I found this issue when I was looking through the linux source code
for places calling waitqueue_active() before wake_up*(), but without
preceding memory barriers, after sending a patch to fix a similar
issue in drivers/tty/n_tty.c  (Details about the original issue can be
found here: https://lkml.org/lkml/2015/9/28/849).

Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-14 16:41:08 +02:00
Jean-Philippe Brucker
4f64cb65bf arm/arm64: KVM: Only allow 64bit hosts to build VGICv3
Hardware virtualisation of GICv3 is only supported by 64bit hosts for
the moment. Some VGICv3 bits are missing from the 32bit side, and this
patch allows to still be able to build 32bit hosts when CONFIG_ARM_GIC_V3
is selected.

To this end, we introduce a new option, CONFIG_KVM_ARM_VGIC_V3, that is
only enabled on the 64bit side. The selection is done unconditionally
because CONFIG_ARM_GIC_V3 is always enabled on arm64.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-10-09 23:11:57 +01:00
Feng Wu
bf9f6ac8d7 KVM: Update Posted-Interrupts Descriptor when vCPU is blocked
This patch updates the Posted-Interrupts Descriptor when vCPU
is blocked.

pre-block:
- Add the vCPU to the blocked per-CPU list
- Set 'NV' to POSTED_INTR_WAKEUP_VECTOR

post-block:
- Remove the vCPU from the per-CPU list

Signed-off-by: Feng Wu <feng.wu@intel.com>
[Concentrate invocation of pre/post-block hooks to vcpu_block. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:53 +02:00
Feng Wu
f70c20aaf1 KVM: Add an arch specific hooks in 'struct kvm_kernel_irqfd'
This patch adds an arch specific hooks 'arch_update' in
'struct kvm_kernel_irqfd'. On Intel side, it is used to
update the IRTE when VT-d posted-interrupts is used.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:47 +02:00
Eric Auger
9016cfb577 KVM: eventfd: add irq bypass consumer management
This patch adds the registration/unregistration of an
irq_bypass_consumer on irqfd assignment/deassignment.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:46 +02:00
Eric Auger
1a02b27035 KVM: introduce kvm_arch functions for IRQ bypass
This patch introduces
- kvm_arch_irq_bypass_add_producer
- kvm_arch_irq_bypass_del_producer
- kvm_arch_irq_bypass_stop
- kvm_arch_irq_bypass_start

They make possible to specialize the KVM IRQ bypass consumer in
case CONFIG_KVM_HAVE_IRQ_BYPASS is set.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
[Add weak implementations of the callbacks. - Feng]
Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:45 +02:00
Eric Auger
166c9775f1 KVM: create kvm_irqfd.h
Move _irqfd_resampler and _irqfd struct declarations in a new
public header: kvm_irqfd.h. They are respectively renamed into
kvm_kernel_irqfd_resampler and kvm_kernel_irqfd. Those datatypes
will be used by architecture specific code, in the context of
IRQ bypass manager integration.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:44 +02:00
Feng Wu
37d9fe4783 virt: Add virt directory to the top Makefile
We need to build files in virt/lib/, which are now used by
KVM and VFIO, so add virt directory to the top Makefile.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Acked-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:44 +02:00
Alex Williamson
f73f817312 virt: IRQ bypass manager
When a physical I/O device is assigned to a virtual machine through
facilities like VFIO and KVM, the interrupt for the device generally
bounces through the host system before being injected into the VM.
However, hardware technologies exist that often allow the host to be
bypassed for some of these scenarios.  Intel Posted Interrupts allow
the specified physical edge interrupts to be directly injected into a
guest when delivered to a physical processor while the vCPU is
running.  ARM IRQ Forwarding allows forwarded physical interrupts to
be directly deactivated by the guest.

The IRQ bypass manager here is meant to provide the shim to connect
interrupt producers, generally the host physical device driver, with
interrupt consumers, generally the hypervisor, in order to configure
these bypass mechanism.  To do this, we base the connection on a
shared, opaque token.  For KVM-VFIO this is expected to be an
eventfd_ctx since this is the connection we already use to connect an
eventfd to an irqfd on the in-kernel path.  When a producer and
consumer with matching tokens is found, callbacks via both registered
participants allow the bypass facilities to be automatically enabled.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Feng Wu <feng.wu@intel.com>
Signed-off-by: Feng Wu <feng.wu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:43 +02:00