Commit graph

100140 commits

Author SHA1 Message Date
Steve Capper
3d08c62924 arm: kvm: STRICT_MM_TYPECHECKS fix for user_mem_abort
Commit:
b886576 ARM: KVM: user_mem_abort: support stage 2 MMIO page mapping

introduced some code in user_mem_abort that failed to compile if
STRICT_MM_TYPECHECKS was enabled.

This patch fixes up the failing comparison.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Reviewed-by: Kim Phillips <kim.phillips@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-15 11:25:22 +02:00
Christoffer Dall
c3058d5da2 arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZE
When creating or moving a memslot, make sure the IPA space is within the
addressable range of the guest.  Otherwise, user space can create too
large a memslot and KVM would try to access potentially unallocated page
table entries when inserting entries in the Stage-2 page tables.

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>
2014-10-14 05:48:25 -07:00
Christoffer Dall
38f791a4e4 arm64: KVM: Implement 48 VA support for KVM EL2 and Stage-2
This patch adds the necessary support for all host kernel PGSIZE and
VA_SPACE configuration options for both EL2 and the Stage-2 page tables.

However, for 40bit and 42bit PARange systems, the architecture mandates
that VTCR_EL2.SL0 is maximum 1, resulting in fewer levels of stage-2
pagge tables than levels of host kernel page tables.  At the same time,
systems with a PARange > 42bit, we limit the IPA range by always setting
VTCR_EL2.T0SZ to 24.

To solve the situation with different levels of page tables for Stage-2
translation than the host kernel page tables, we allocate a dummy PGD
with pointers to our actual inital level Stage-2 page table, in order
for us to reuse the kernel pgtable manipulation primitives.  Reproducing
all these in KVM does not look pretty and unnecessarily complicates the
32-bit side.

Systems with a PARange < 40bits are not yet supported.

 [ I have reworked this patch from its original form submitted by
   Jungseok to take the architecture constraints into consideration.
   There were too many changes from the original patch for me to
   preserve the authorship.  Thanks to Catalin Marinas for his help in
   figuring out a good solution to this challenge.  I have also fixed
   various bugs and missing error code handling from the original
   patch. - Christoffer ]

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-14 05:48:19 -07:00
Ard Biesheuvel
8eef91239e arm/arm64: KVM: map MMIO regions at creation time
There is really no point in faulting in memory regions page by page
if they are not backed by demand paged system RAM but by a linear
passthrough mapping of a host MMIO region. So instead, detect such
regions at setup time and install the mappings for the backing all
at once.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-13 03:36:53 -07:00
Ard Biesheuvel
4a513fb009 arm64: kvm: define PAGE_S2_DEVICE as read-only by default
Now that we support read-only memslots, we need to make sure that
pass-through device mappings are not mapped writable if the guest
has requested them to be read-only. The existing implementation
already honours this by calling kvm_set_s2pte_writable() on the new
pte in case of writable mappings, so all we need to do is define
the default pgprot_t value used for devices to be PTE_S2_RDONLY.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-10 13:07:38 +02:00
Ard Biesheuvel
903ed3a54d ARM: kvm: define PAGE_S2_DEVICE as read-only by default
Now that we support read-only memslots, we need to make sure that
pass-through device mappings are not mapped writable if the guest
has requested them to be read-only. The existing implementation
already honours this by calling kvm_set_s2pte_writable() on the new
pte in case of writable mappings, so all we need to do is define
the default pgprot_t value used for devices to be PTE_S2_RDONLY.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-10 13:07:37 +02:00
Ard Biesheuvel
c40f2f8ff8 arm/arm64: KVM: add 'writable' parameter to kvm_phys_addr_ioremap
Add support for read-only MMIO passthrough mappings by adding a
'writable' parameter to kvm_phys_addr_ioremap. For the moment,
mappings will be read-write even if 'writable' is false, but once
the definition of PAGE_S2_DEVICE gets changed, those mappings will
be created read-only.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-10 13:07:37 +02:00
Ard Biesheuvel
37b544087e arm/arm64: KVM: fix potential NULL dereference in user_mem_abort()
Handle the potential NULL return value of find_vma_intersection()
before dereferencing it.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-10 13:07:37 +02:00
Ard Biesheuvel
e9e8578b6c arm/arm64: KVM: use __GFP_ZERO not memset() to get zeroed pages
Pass __GFP_ZERO to __get_free_pages() instead of calling memset()
explicitly.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-10-10 13:07:37 +02:00
Vladimir Murzin
37a34ac1d4 arm: kvm: fix CPU hotplug
On some platforms with no power management capabilities, the hotplug
implementation is allowed to return from a smp_ops.cpu_die() call as a
function return. Upon a CPU onlining event, the KVM CPU notifier tries
to reinstall the hyp stub, which fails on platform where no reset took
place following a hotplug event, with the message:

CPU1: smp_ops.cpu_die() returned, trying to resuscitate
CPU1: Booted secondary processor
Kernel panic - not syncing: unexpected prefetch abort in Hyp mode at: 0x80409540
unexpected data abort in Hyp mode at: 0x80401fe8
unexpected HVC/SVC trap in Hyp mode at: 0x805c6170

since KVM code is trying to reinstall the stub on a system where it is
already configured.

To prevent this issue, this patch adds a check in the KVM hotplug
notifier that detects if the HYP stub really needs re-installing when a
CPU is onlined and skips the installation call if the stub is already in
place, which means that the CPU has not been reset.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-09-29 16:02:34 +02:00
Christoffer Dall
0496daa5cf arm/arm64: KVM: Report correct FSC for unsupported fault types
When we catch something that's not a permission fault or a translation
fault, we log the unsupported FSC in the kernel log, but we were masking
off the bottom bits of the FSC which was not very helpful.

Also correctly report the FSC for data and instruction faults rather
than telling people it was a DFCS, which doesn't exist in the ARM ARM.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-09-26 14:39:45 +02:00
Joel Schopp
dbff124e29 arm/arm64: KVM: Fix VTTBR_BADDR_MASK and pgd alloc
The current aarch64 calculation for VTTBR_BADDR_MASK masks only 39 bits
and not all the bits in the PA range. This is clearly a bug that
manifests itself on systems that allocate memory in the higher address
space range.

 [ Modified from Joel's original patch to be based on PHYS_MASK_SHIFT
   instead of a hard-coded value and to move the alignment check of the
   allocation to mmu.c.  Also added a comment explaining why we hardcode
   the IPA range and changed the stage-2 pgd allocation to be based on
   the 40 bit IPA range instead of the maximum possible 48 bit PA range.
   - Christoffer ]

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Joel Schopp <joel.schopp@amd.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-09-26 14:39:13 +02:00
Marc Zyngier
a98f26f183 arm/arm64: KVM: vgic: make number of irqs a configurable attribute
In order to make the number of interrupts configurable, use the new
fancy device management API to add KVM_DEV_ARM_VGIC_GRP_NR_IRQS as
a VGIC configurable attribute.

Userspace can now specify the exact size of the GIC (by increments
of 32 interrupts).

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-09-18 18:48:58 -07:00
Marc Zyngier
4956f2bc1f arm/arm64: KVM: vgic: delay vgic allocation until init time
It is now quite easy to delay the allocation of the vgic tables
until we actually require it to be up and running (when the first
vcpu is kicking around, or someones tries to access the GIC registers).

This allow us to allocate memory for the exact number of CPUs we
have. As nobody configures the number of interrupts just yet,
use a fallback to VGIC_NR_IRQS_LEGACY.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-09-18 18:48:58 -07:00
Marc Zyngier
c1bfb577ad arm/arm64: KVM: vgic: switch to dynamic allocation
So far, all the VGIC data structures are statically defined by the
*maximum* number of vcpus and interrupts it supports. It means that
we always have to oversize it to cater for the worse case.

Start by changing the data structures to be dynamically sizeable,
and allocate them at runtime.

The sizes are still very static though.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-09-18 18:48:52 -07:00
Christoffer Dall
a875dafcf9 Merge remote-tracking branch 'kvm/next' into queue
Conflicts:
	arch/arm64/include/asm/kvm_host.h
	virt/kvm/arm/vgic.c
2014-09-18 18:15:32 -07:00
Tang Chen
f51770ed46 kvm: Make init_rmode_identity_map() return 0 on success.
In init_rmode_identity_map(), there two variables indicating the return
value, r and ret, and it return 0 on error, 1 on success. The function
is only called by vmx_create_vcpu(), and ret is redundant.

This patch removes the redundant variable, and makes init_rmode_identity_map()
return 0 on success, -errno on failure.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-17 13:10:12 +02:00
Tang Chen
a255d4795f kvm: Remove ept_identity_pagetable from struct kvm_arch.
kvm_arch->ept_identity_pagetable holds the ept identity pagetable page. But
it is never used to refer to the page at all.

In vcpu initialization, it indicates two things:
1. indicates if ept page is allocated
2. indicates if a memory slot for identity page is initialized

Actually, kvm_arch->ept_identity_pagetable_done is enough to tell if the ept
identity pagetable is initialized. So we can remove ept_identity_pagetable.

NOTE: In the original code, ept identity pagetable page is pinned in memroy.
      As a result, it cannot be migrated/hot-removed. After this patch, since
      kvm_arch->ept_identity_pagetable is removed, ept identity pagetable page
      is no longer pinned in memory. And it can be migrated/hot-removed.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-17 13:10:11 +02:00
Cornelia Huck
84877d9333 KVM: s390: register flic ops dynamically
Using the new kvm_register_device_ops() interface makes us get rid of
an #ifdef in common code.

Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-17 13:10:09 +02:00
Guo Hui Liu
105b21bbf6 KVM: x86: Use kvm_make_request when applicable
This patch replace the set_bit method by kvm_make_request
to make code more readable and consistent.

Signed-off-by: Guo Hui Liu <liuguohui@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-16 14:44:20 +02:00
Ard Biesheuvel
a7d079cea2 ARM/arm64: KVM: fix use of WnR bit in kvm_is_write_fault()
The ISS encoding for an exception from a Data Abort has a WnR
bit[6] that indicates whether the Data Abort was caused by a
read or a write instruction. While there are several fields
in the encoding that are only valid if the ISV bit[24] is set,
WnR is not one of them, so we can read it unconditionally.

Instead of fixing both implementations of kvm_is_write_fault()
in place, reimplement it just once using kvm_vcpu_dabt_iswrite(),
which already does the right thing with respect to the WnR bit.
Also fix up the callers to pass 'vcpu'

Acked-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-09-11 11:31:13 +01:00
Paolo Bonzini
a183b638b6 KVM: x86: make apic_accept_irq tracepoint more generic
Initially the tracepoint was added only to the APIC_DM_FIXED case,
also because it reported coalesced interrupts that only made sense
for that case.  However, the coalesced argument is not used anymore
and tracing other delivery modes is useful, so hoist the call out
of the switch statement.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-11 11:51:02 +02:00
Tang Chen
73a6d94162 kvm: Use APIC_DEFAULT_PHYS_BASE macro as the apic access page address.
We have APIC_DEFAULT_PHYS_BASE defined as 0xfee00000, which is also the address of
apic access page. So use this macro.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-11 11:10:22 +02:00
Paolo Bonzini
2c69c1a321 KVM: s390: Fixes and features for next (3.18)
1. Crypto/CPACF support: To enable the MSA4 instructions we have to
    provide a common control structure for each SIE control block
 2. Two cleanups found by a static code checker: one redundant assignment
    and one useless if
 3. Fix the page handling of the diag10 ballooning interface. If the
    guest freed the pages at absolute 0 some checks and frees were
    incorrect
 4. Limit guests to 16TB
 5. Add __must_check to interrupt injection code
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Merge tag 'kvm-s390-next-20140910' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next

KVM: s390: Fixes and features for next (3.18)

1. Crypto/CPACF support: To enable the MSA4 instructions we have to
   provide a common control structure for each SIE control block
2. Two cleanups found by a static code checker: one redundant assignment
   and one useless if
3. Fix the page handling of the diag10 ballooning interface. If the
   guest freed the pages at absolute 0 some checks and frees were
   incorrect
4. Limit guests to 16TB
5. Add __must_check to interrupt injection code
2014-09-11 11:09:33 +02:00
Christian Borntraeger
bfac1f59a1 KVM: s390/interrupt: remove double assignment
r is already initialized to 0.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
2014-09-10 12:19:45 +02:00
Christian Borntraeger
f7a960affc KVM: s390/cmm: Fix prefix handling for diag 10 balloon
The old handling of prefix pages was broken in the diag10 ballooner.
We now rely on gmap_discard to check for start > end and do a
slow path if the prefix swap pages are affected:
1. discard the pages from start to prefix
2. discard the absolute 0 pages
3. discard the pages after prefix swap to end

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
2014-09-10 12:19:42 +02:00
Christian Borntraeger
6b331952f1 KVM: s390: get rid of constant condition in ipte_unlock_simple
Due to the earlier check we know that ipte_lock_count must be 0.
No need to add a useless if. Let's make clear that we are going
to always wakeup when we execute that code.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2014-09-10 12:19:38 +02:00
Christian Borntraeger
f346026e55 KVM: s390: unintended fallthrough for external call
We must not fallthrough if the conditions for external call are not met.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
2014-09-10 12:19:30 +02:00
Christian Borntraeger
0349985add KVM: s390: Limit guest size to 16TB
Currently we fill up a full 5 level page table to hold the guest
mapping. Since commit "support gmap page tables with less than 5
levels" we can do better.
Having more than 4 TB might be useful for some testing scenarios,
so let's just limit ourselves to 16TB guest size.
Having more than that is totally untested as I do not have enough
swap space/memory.

We continue to allow ucontrol the full size.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-09-10 12:19:15 +02:00
Christian Borntraeger
614aeab4dc KVM: s390: add __must_check to interrupt deliver functions
We now propagate interrupt injection errors back to the ioctl. We
should mark functions that might fail with __must_check.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
2014-09-10 12:19:12 +02:00
Tony Krowiak
5102ee8795 KVM: CPACF: Enable MSA4 instructions for kvm guest
We have to provide a per guest crypto block for the CPUs to
enable MSA4 instructions. According to icainfo on z196 or
later this enables CCM-AES-128, CMAC-AES-128, CMAC-AES-192
and CMAC-AES-256.

Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
[split MSA4/protected key into two patches]
2014-09-10 12:19:05 +02:00
Paolo Bonzini
54987b7afa KVM: x86: propagate exception from permission checks on the nested page fault
Currently, if a permission error happens during the translation of
the final GPA to HPA, walk_addr_generic returns 0 but does not fill
in walker->fault.  To avoid this, add an x86_exception* argument
to the translate_gpa function, and let it fill in walker->fault.
The nested_page_fault field will be true, since the walk_mmu is the
nested_mmu and translate_gpu instead operates on the "outer" (NPT)
instance.

Reported-by: Valentine Sinitsyn <valentine.sinitsyn@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-05 12:01:13 +02:00
Paolo Bonzini
ef54bcfeea KVM: x86: skip writeback on injection of nested exception
If a nested page fault happens during emulation, we will inject a vmexit,
not a page fault.  However because writeback happens after the injection,
we will write ctxt->eip from L2 into the L1 EIP.  We do not write back
if an instruction caused an interception vmexit---do the same for page
faults.

Suggested-by: Gleb Natapov <gleb@kernel.org>
Reviewed-by: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-05 12:01:06 +02:00
Paolo Bonzini
5e35251951 KVM: nSVM: propagate the NPF EXITINFO to the guest
This is similar to what the EPT code does with the exit qualification.
This allows the guest to see a valid value for bits 33:32.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03 10:18:54 +02:00
Paolo Bonzini
a0c0feb579 KVM: x86: reserve bit 8 of non-leaf PDPEs and PML4Es in 64-bit mode on AMD
Bit 8 would be the "global" bit, which does not quite make sense for non-leaf
page table entries.  Intel ignores it; AMD ignores it in PDEs, but reserves it
in PDPEs and PML4Es.  The SVM test is relying on this behavior, so enforce it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03 10:04:11 +02:00
Tiejun Chen
d143148383 KVM: mmio: cleanup kvm_set_mmio_spte_mask
Just reuse rsvd_bits() inside kvm_set_mmio_spte_mask()
for slightly better code.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03 10:04:10 +02:00
David Matlack
56f17dd3fb kvm: x86: fix stale mmio cache bug
The following events can lead to an incorrect KVM_EXIT_MMIO bubbling
up to userspace:

(1) Guest accesses gpa X without a memory slot. The gfn is cached in
struct kvm_vcpu_arch (mmio_gfn). On Intel EPT-enabled hosts, KVM sets
the SPTE write-execute-noread so that future accesses cause
EPT_MISCONFIGs.

(2) Host userspace creates a memory slot via KVM_SET_USER_MEMORY_REGION
covering the page just accessed.

(3) Guest attempts to read or write to gpa X again. On Intel, this
generates an EPT_MISCONFIG. The memory slot generation number that
was incremented in (2) would normally take care of this but we fast
path mmio faults through quickly_check_mmio_pf(), which only checks
the per-vcpu mmio cache. Since we hit the cache, KVM passes a
KVM_EXIT_MMIO up to userspace.

This patch fixes the issue by using the memslot generation number
to validate the mmio cache.

Cc: stable@vger.kernel.org
Signed-off-by: David Matlack <dmatlack@google.com>
[xiaoguangrong: adjust the code to make it simpler for stable-tree fix.]
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Tested-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03 10:03:42 +02:00
David Matlack
ee3d1570b5 kvm: fix potentially corrupt mmio cache
vcpu exits and memslot mutations can run concurrently as long as the
vcpu does not aquire the slots mutex. Thus it is theoretically possible
for memslots to change underneath a vcpu that is handling an exit.

If we increment the memslot generation number again after
synchronize_srcu_expedited(), vcpus can safely cache memslot generation
without maintaining a single rcu_dereference through an entire vm exit.
And much of the x86/kvm code does not maintain a single rcu_dereference
of the current memslots during each exit.

We can prevent the following case:

   vcpu (CPU 0)                             | thread (CPU 1)
--------------------------------------------+--------------------------
1  vm exit                                  |
2  srcu_read_unlock(&kvm->srcu)             |
3  decide to cache something based on       |
     old memslots                           |
4                                           | change memslots
                                            | (increments generation)
5                                           | synchronize_srcu(&kvm->srcu);
6  retrieve generation # from new memslots  |
7  tag cache with new memslot generation    |
8  srcu_read_unlock(&kvm->srcu)             |
...                                         |
   <action based on cache occurs even       |
    though the caching decision was based   |
    on the old memslots>                    |
...                                         |
   <action *continues* to occur until next  |
    memslot generation change, which may    |
    be never>                               |
                                            |

By incrementing the generation after synchronizing with kvm->srcu readers,
we ensure that the generation retrieved in (6) will become invalid soon
after (8).

Keeping the existing increment is not strictly necessary, but we
do keep it and just move it for consistency from update_memslots to
install_new_memslots.  It invalidates old cached MMIOs immediately,
instead of having to wait for the end of synchronize_srcu_expedited,
which makes the code more clearly correct in case CPU 1 is preempted
right after synchronize_srcu() returns.

To avoid halving the generation space in SPTEs, always presume that the
low bit of the generation is zero when reconstructing a generation number
out of an SPTE.  This effectively disables MMIO caching in SPTEs during
the call to synchronize_srcu_expedited.  Using the low bit this way is
somewhat like a seqcount---where the protected thing is a cache, and
instead of retrying we can simply punt if we observe the low bit to be 1.

Cc: stable@vger.kernel.org
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03 10:03:41 +02:00
Paolo Bonzini
00f034a12f KVM: do not bias the generation number in kvm_current_mmio_generation
The next patch will give a meaning (a la seqcount) to the low bit of the
generation number.  Ensure that it matches between kvm->memslots->generation
and kvm_current_mmio_generation().

Cc: stable@vger.kernel.org
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03 10:03:35 +02:00
Paolo Bonzini
fd2752352b KVM: x86: use guest maxphyaddr to check MTRR values
The check introduced in commit d7a2a246a1 (KVM: x86: #GP when attempts to write reserved bits of Variable Range MTRRs, 2014-08-19)
will break if the guest maxphyaddr is higher than the host's (which
sometimes happens depending on your hardware and how QEMU is
configured).

To fix this, use cpuid_maxphyaddr similar to how the APIC_BASE MSR
does already.

Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 18:56:24 +02:00
Radim Krčmář
13a34e067e KVM: remove garbage arg to *hardware_{en,dis}able
In the beggining was on_each_cpu(), which required an unused argument to
kvm_arch_ops.hardware_{en,dis}able, but this was soon forgotten.

Remove unnecessary arguments that stem from this.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 16:35:55 +02:00
Radim Krčmář
0865e636ae KVM: static inline empty kvm_arch functions
Using static inline is going to save few bytes and cycles.
For example on powerpc, the difference is 700 B after stripping.
(5 kB before)

This patch also deals with two overlooked empty functions:
kvm_arch_flush_shadow was not removed from arch/mips/kvm/mips.c
  2df72e9bc KVM: split kvm_arch_flush_shadow
and kvm_arch_sched_in never made it into arch/ia64/kvm/kvm-ia64.c.
  e790d9ef6 KVM: add kvm_arch_sched_in

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 16:35:55 +02:00
Paolo Bonzini
656473003b KVM: forward declare structs in kvm_types.h
Opaque KVM structs are useful for prototypes in asm/kvm_host.h, to avoid
"'struct foo' declared inside parameter list" warnings (and consequent
breakage due to conflicting types).

Move them from individual files to a generic place in linux/kvm_types.h.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 16:35:53 +02:00
Paolo Bonzini
d5b7706970 KVM: x86: remove Aligned bit from movntps/movntpd
These are not explicitly aligned, and do not require alignment on AVX.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 14:57:59 +02:00
Alex Williamson
0a37027e83 KVM: x86 emulator: emulate MOVNTDQ
Windows 8.1 guest with NVIDIA driver and GPU fails to boot with an
emulation failure.  The KVM spew suggests the fault is with lack of
movntdq emulation (courtesy of Paolo):

Code=02 00 00 b8 08 00 00 00 f3 0f 6f 44 0a f0 f3 0f 6f 4c 0a e0 <66> 0f e7 41 f0 66 0f e7 49 e0 48 83 e9 40 f3 0f 6f 44 0a 10 f3 0f 6f 0c 0a 66 0f e7 41 10

$ as -o a.out
        .section .text
        .byte 0x66, 0x0f, 0xe7, 0x41, 0xf0
        .byte 0x66, 0x0f, 0xe7, 0x49, 0xe0
$ objdump -d a.out
    0:  66 0f e7 41 f0          movntdq %xmm0,-0x10(%rcx)
    5:  66 0f e7 49 e0          movntdq %xmm1,-0x20(%rcx)

Add the necessary emulation.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 14:57:59 +02:00
Nadav Amit
0f54a32130 KVM: vmx: VMXOFF emulation in vm86 should cause #UD
Unlike VMCALL, the instructions VMXOFF, VMLAUNCH and VMRESUME should cause a UD
exception in real-mode or vm86.  However, the emulator considers all these
instructions the same for the matter of mode checks, and emulation upon exit
due to #UD exception.

As a result, the hypervisor behaves incorrectly on vm86 mode. VMXOFF, VMLAUNCH
or VMRESUME cause on vm86 exit due to #UD. The hypervisor then emulates these
instruction and inject #GP to the guest instead of #UD.

This patch creates a new group for these instructions and mark only VMCALL as
an instruction which can be emulated.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 14:02:49 +02:00
Paolo Bonzini
48d89b9260 KVM: x86: fix some sparse warnings
Sparse reports the following easily fixed warnings:

   arch/x86/kvm/vmx.c:8795:48: sparse: Using plain integer as NULL pointer
   arch/x86/kvm/vmx.c:2138:5: sparse: symbol vmx_read_l1_tsc was not declared. Should it be static?
   arch/x86/kvm/vmx.c:6151:48: sparse: Using plain integer as NULL pointer
   arch/x86/kvm/vmx.c:8851:6: sparse: symbol vmx_sched_in was not declared. Should it be static?

   arch/x86/kvm/svm.c:2162:5: sparse: symbol svm_read_l1_tsc was not declared. Should it be static?

Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 14:02:49 +02:00
Wanpeng Li
a7c0b07d57 KVM: nVMX: nested TPR shadow/threshold emulation
This patch fix bug https://bugzilla.kernel.org/show_bug.cgi?id=61411

TPR shadow/threshold feature is important to speed up the Windows guest.
Besides, it is a must feature for certain VMM.

We map virtual APIC page address and TPR threshold from L1 VMCS. If
TPR_BELOW_THRESHOLD VM exit is triggered by L2 guest and L1 interested
in, we inject it into L1 VMM for handling.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
[Add PAGE_ALIGNED check, do not write useless virtual APIC page address
 if TPR shadowing is disabled. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 14:02:48 +02:00
Wanpeng Li
a2bcba5035 KVM: nVMX: introduce nested_get_vmcs12_pages
Introduce function nested_get_vmcs12_pages() to check the valid
of nested apic access page and virtual apic page earlier.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 14:02:48 +02:00
Christian Borntraeger
dc77d344b4 KVM: s390/mm: fix up indentation of set_guest_storage_key
commit ab3f285f22 ("KVM: s390/mm: try a cow on read only pages for
key ops")' misaligned a code block. Let's fixup the indentation.

Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 13:46:54 +02:00