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- Multiple stolen time fixes, with a new capability to match x86
- Fix for hugetlbfs mappings when PUD and PMD are the same level
- Fix for hugetlbfs mappings when PTE mappings are enforced
(dirty logging, for example)
- Fix tracing output of 64bit values
x86:
- nSVM state restore fixes
- Async page fault fixes
- Lots of small fixes everywhere
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"A bit on the bigger side, mostly due to me being on vacation, then
busy, then on parental leave, but there's nothing worrisome.
ARM:
- Multiple stolen time fixes, with a new capability to match x86
- Fix for hugetlbfs mappings when PUD and PMD are the same level
- Fix for hugetlbfs mappings when PTE mappings are enforced (dirty
logging, for example)
- Fix tracing output of 64bit values
x86:
- nSVM state restore fixes
- Async page fault fixes
- Lots of small fixes everywhere"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (25 commits)
KVM: emulator: more strict rsm checks.
KVM: nSVM: more strict SMM checks when returning to nested guest
SVM: nSVM: setup nested msr permission bitmap on nested state load
SVM: nSVM: correctly restore GIF on vmexit from nesting after migration
x86/kvm: don't forget to ACK async PF IRQ
x86/kvm: properly use DEFINE_IDTENTRY_SYSVEC() macro
KVM: VMX: Don't freeze guest when event delivery causes an APIC-access exit
KVM: SVM: avoid emulation with stale next_rip
KVM: x86: always allow writing '0' to MSR_KVM_ASYNC_PF_EN
KVM: SVM: Periodically schedule when unregistering regions on destroy
KVM: MIPS: Change the definition of kvm type
kvm x86/mmu: use KVM_REQ_MMU_SYNC to sync when needed
KVM: nVMX: Fix the update value of nested load IA32_PERF_GLOBAL_CTRL control
KVM: fix memory leak in kvm_io_bus_unregister_dev()
KVM: Check the allocation of pv cpu mask
KVM: nVMX: Update VMCS02 when L2 PAE PDPTE updates detected
KVM: arm64: Update page shift if stage 2 block mapping not supported
KVM: arm64: Fix address truncation in traces
KVM: arm64: Do not try to map PUDs when they are folded into PMD
arm64/x86: KVM: Introduce steal-time cap
...
When kvm_mmu_get_page() gets a page with unsynced children, the spt
pagetable is unsynchronized with the guest pagetable. But the
guest might not issue a "flush" operation on it when the pagetable
entry is changed from zero or other cases. The hypervisor has the
responsibility to synchronize the pagetables.
KVM behaved as above for many years, But commit 8c8560b833
("KVM: x86/mmu: Use KVM_REQ_TLB_FLUSH_CURRENT for MMU specific flushes")
inadvertently included a line of code to change it without giving any
reason in the changelog. It is clear that the commit's intention was to
change KVM_REQ_TLB_FLUSH -> KVM_REQ_TLB_FLUSH_CURRENT, so we don't
needlessly flush other contexts; however, one of the hunks changed
a nearby KVM_REQ_MMU_SYNC instead. This patch changes it back.
Link: https://lore.kernel.org/lkml/20200320212833.3507-26-sean.j.christopherson@intel.com/
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20200902135421.31158-1-jiangshanlai@gmail.com>
fixes: 8c8560b833 ("KVM: x86/mmu: Use KVM_REQ_TLB_FLUSH_CURRENT for MMU specific flushes")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The 'flags' field of 'struct mmu_notifier_range' is used to indicate
whether invalidate_range_{start,end}() are permitted to block. In the
case of kvm_mmu_notifier_invalidate_range_start(), this field is not
forwarded on to the architecture-specific implementation of
kvm_unmap_hva_range() and therefore the backend cannot sensibly decide
whether or not to block.
Add an extra 'flags' parameter to kvm_unmap_hva_range() so that
architectures are aware as to whether or not they are permitted to block.
Cc: <stable@vger.kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20200811102725.7121-2-will@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
x86:
* Report last CPU for debugging
* Emulate smaller MAXPHYADDR in the guest than in the host
* .noinstr and tracing fixes from Thomas
* nested SVM page table switching optimization and fixes
Generic:
* Unify shadow MMU cache data structures across architectures
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"s390:
- implement diag318
x86:
- Report last CPU for debugging
- Emulate smaller MAXPHYADDR in the guest than in the host
- .noinstr and tracing fixes from Thomas
- nested SVM page table switching optimization and fixes
Generic:
- Unify shadow MMU cache data structures across architectures"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits)
KVM: SVM: Fix sev_pin_memory() error handling
KVM: LAPIC: Set the TDCR settable bits
KVM: x86: Specify max TDP level via kvm_configure_mmu()
KVM: x86/mmu: Rename max_page_level to max_huge_page_level
KVM: x86: Dynamically calculate TDP level from max level and MAXPHYADDR
KVM: VXM: Remove temporary WARN on expected vs. actual EPTP level mismatch
KVM: x86: Pull the PGD's level from the MMU instead of recalculating it
KVM: VMX: Make vmx_load_mmu_pgd() static
KVM: x86/mmu: Add separate helper for shadow NPT root page role calc
KVM: VMX: Drop a duplicate declaration of construct_eptp()
KVM: nSVM: Correctly set the shadow NPT root level in its MMU role
KVM: Using macros instead of magic values
MIPS: KVM: Fix build error caused by 'kvm_run' cleanup
KVM: nSVM: remove nonsensical EXITINFO1 adjustment on nested NPF
KVM: x86: Add a capability for GUEST_MAXPHYADDR < HOST_MAXPHYADDR support
KVM: VMX: optimize #PF injection when MAXPHYADDR does not match
KVM: VMX: Add guest physical address check in EPT violation and misconfig
KVM: VMX: introduce vmx_need_pf_intercept
KVM: x86: update exception bitmap on CPUID changes
KVM: x86: rename update_bp_intercept to update_exception_bitmap
...
Capture the max TDP level during kvm_configure_mmu() instead of using a
kvm_x86_ops hook to do it at every vCPU creation.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200716034122.5998-10-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rename max_page_level to explicitly call out that it tracks the max huge
page level so as to avoid confusion when a future patch moves the max
TDP level, i.e. max root level, into the MMU and kvm_configure_mmu().
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200716034122.5998-9-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Calculate the desired TDP level on the fly using the max TDP level and
MAXPHYADDR instead of doing the same when CPUID is updated. This avoids
the hidden dependency on cpuid_maxphyaddr() in vmx_get_tdp_level() and
also standardizes the "use 5-level paging iff MAXPHYADDR > 48" behavior
across x86.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200716034122.5998-8-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Refactor the shadow NPT role calculation into a separate helper to
better differentiate it from the non-nested shadow MMU, e.g. the NPT
variant is never direct and derives its root level from the TDP level.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200716034122.5998-3-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move the initialization of shadow NPT MMU's shadow_root_level into
kvm_init_shadow_npt_mmu() and explicitly set the level in the shadow NPT
MMU's role to be the TDP level. This ensures the role and MMU levels
are synchronized and also initialized before __kvm_mmu_new_pgd(), which
consumes the level when attempting a fast PGD switch.
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Fixes: 9fa72119b2 ("kvm: x86: Introduce kvm_mmu_calc_root_page_role()")
Fixes: a506fdd223 ("KVM: nSVM: implement nested_svm_load_cr3() and use it for host->guest switch")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200716034122.5998-2-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.
In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:
git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
xargs perl -pi -e \
's/\buninitialized_var\(([^\)]+)\)/\1/g;
s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'
drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.
No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.
[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/
Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
Intel processors of various generations have supported 36, 39, 46 or 52
bits for physical addresses. Until IceLake introduced MAXPHYADDR==52,
running on a machine with higher MAXPHYADDR than the guest more or less
worked, because software that relied on reserved address bits (like KVM)
generally used bit 51 as a marker and therefore the page faults where
generated anyway.
Unfortunately this is not true anymore if the host MAXPHYADDR is 52,
and this can cause problems when migrating from a MAXPHYADDR<52
machine to one with MAXPHYADDR==52. Typically, the latter are machines
that support 5-level page tables, so they can be identified easily from
the LA57 CPUID bit.
When that happens, the guest might have a physical address with reserved
bits set, but the host won't see that and trap it. Hence, we need
to check page faults' physical addresses against the guest's maximum
physical memory and if it's exceeded, we need to add the PFERR_RSVD_MASK
bits to the page fault error code.
This patch does this for the MMU's page walks. The next patches will
ensure that the correct exception and error code is produced whenever
no host-reserved bits are set in page table entries.
Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200710154811.418214-4-mgamal@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Also no point of it being inline since it's always called through
function pointers. So remove that.
Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200710154811.418214-3-mgamal@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The mmu_check_root() check in fast_pgd_switch() seems to be
superfluous: when GPA is outside of the visible range
cached_root_available() will fail for non-direct roots
(as we can't have a matching one on the list) and we don't
seem to care for direct ones.
Also, raising #TF immediately when a non-existent GFN is written to CR3
doesn't seem to mach architectural behavior. Drop the check.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-10-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Undesired triple fault gets injected to L1 guest on SVM when L2 is
launched with certain CR3 values. #TF is raised by mmu_check_root()
check in fast_pgd_switch() and the root cause is that when
kvm_set_cr3() is called from nested_prepare_vmcb_save() with NPT
enabled CR3 points to a nGPA so we can't check it with
kvm_is_visible_gfn().
Using generic kvm_set_cr3() when switching to nested guest is not
a great idea as we'll have to distinguish between 'real' CR3s and
'nested' CR3s to e.g. not call kvm_mmu_new_pgd() with nGPA. Following
nVMX implement nested-specific nested_svm_load_cr3() doing the job.
To support the change, nested_svm_load_cr3() needs to be re-ordered
with nested_svm_init_mmu_context().
Note: the current implementation is sub-optimal as we always do TLB
flush/MMU sync but this is still an improvement as we at least stop doing
kvm_mmu_reset_context().
Fixes: 7c390d350f ("kvm: x86: Add fast CR3 switch code path")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-8-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_init_shadow_mmu() was actually the only function that could be called
with different vcpu->arch.mmu values. Now that kvm_init_shadow_npt_mmu()
is separated from kvm_init_shadow_mmu(), we always know the MMU context
we need to use and there is no need to dereference vcpu->arch.mmu pointer.
Based on a patch by Vitaly Kuznetsov <vkuznets@redhat.com>.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As a preparatory change for moving kvm_mmu_new_pgd() from
nested_prepare_vmcb_save() to nested_svm_init_mmu_context() split
kvm_init_shadow_npt_mmu() from kvm_init_shadow_mmu(). This also makes
the code look more like nVMX (kvm_init_shadow_ept_mmu()).
No functional change intended.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move x86's memory cache helpers to common KVM code so that they can be
reused by arm64 and MIPS in future patches.
Suggested-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-16-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rename the memory helpers that will soon be moved to common code and be
made globaly available via linux/kvm_host.h. "mmu" alone is not a
sufficient namespace for globally available KVM symbols.
Opportunistically add "nr_" in mmu_memory_cache_free_objects() to make
it clear the function returns the number of free objects, as opposed to
freeing existing objects.
Suggested-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-14-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Don't bother filling the gfn array cache when the caller is a fully
direct MMU, i.e. won't need a gfn array for shadow pages.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-13-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Set __GFP_ZERO for the shadow page memory cache and drop the explicit
clear_page() from kvm_mmu_get_page(). This moves the cost of zeroing a
page to the allocation time of the physical page, i.e. when topping up
the memory caches, and thus avoids having to zero out an entire page
while holding mmu_lock.
Cc: Peter Feiner <pfeiner@google.com>
Cc: Peter Shier <pshier@google.com>
Cc: Junaid Shahid <junaids@google.com>
Cc: Jim Mattson <jmattson@google.com>
Suggested-by: Ben Gardon <bgardon@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-12-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a gfp_zero flag to 'struct kvm_mmu_memory_cache' and use it to
control __GFP_ZERO instead of hardcoding a call to kmem_cache_zalloc().
A future patch needs such a flag for the __get_free_page() path, as
gfn arrays do not need/want the allocator to zero the memory. Convert
the kmem_cache paths to __GFP_ZERO now so as to avoid a weird and
inconsistent API in the future.
No functional change intended.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-11-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use separate caches for allocating shadow pages versus gfn arrays. This
sets the stage for specifying __GFP_ZERO when allocating shadow pages
without incurring extra cost for gfn arrays.
No functional change intended.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-10-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Clean up the minimums in mmu_topup_memory_caches() to document the
driving mechanisms behind the minimums. Now that encountering an empty
cache is unlikely to trigger BUG_ON(), it is less dangerous to be more
precise when defining the minimums.
For rmaps, the logic is 1 parent PTE per level, plus a single rmap, and
prefetched rmaps. The extra objects in the current '8 + PREFETCH'
minimum came about due to an abundance of paranoia in commit
c41ef344de ("KVM: MMU: increase per-vcpu rmap cache alloc size"),
i.e. it could have increased the minimum to 2 rmaps. Furthermore, the
unexpected extra rmap case was killed off entirely by commits
f759e2b4c7 ("KVM: MMU: avoid pte_list_desc running out in
kvm_mmu_pte_write") and f5a1e9f895 ("KVM: MMU: remove call to
kvm_mmu_pte_write from walk_addr").
For the so called page cache, replace '8' with 2*PT64_ROOT_MAX_LEVEL.
The 2x multiplier is needed because the cache is used for both shadow
pages and gfn arrays for indirect MMUs.
And finally, for page headers, replace '4' with PT64_ROOT_MAX_LEVEL.
Note, KVM now supports 5-level paging, i.e. the old minimums that used a
baseline derived from 4-level paging were technically wrong. But, KVM
always allocates roots in a separate flow, e.g. it's impossible in the
current implementation to actually need 5 new shadow pages in a single
flow. Use PT64_ROOT_MAX_LEVEL unmodified instead of subtracting 1, as
the direct usage is likely more intuitive to uninformed readers, and the
inflated minimum is unlikely to affect functionality in practice.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-9-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Topup memory caches after walking the GVA->GPA translation during a
shadow page fault, there is no need to ensure the caches are full when
walking the GVA. As of commit f5a1e9f895 ("KVM: MMU: remove call
to kvm_mmu_pte_write from walk_addr"), the FNAME(walk_addr) flow no
longer add rmaps via kvm_mmu_pte_write().
This avoids allocating memory in the case that the GVA is unmapped in
the guest, and also provides a paper trail of why/when the memory caches
need to be filled.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-8-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Avoid refilling the memory caches and potentially slow reclaim/swap when
handling a fast page fault, which does not need to allocate any new
objects.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-7-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Attempt to allocate a new object instead of crashing KVM (and likely the
kernel) if a memory cache is unexpectedly empty. Use GFP_ATOMIC for the
allocation as the caches are used while holding mmu_lock. The immediate
BUG_ON() makes the code unnecessarily explosive and led to confusing
minimums being used in the past, e.g. allocating 4 objects where 1 would
suffice.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-6-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Return errors directly from mmu_topup_memory_caches() instead of
branching to a label that does the same.
No functional change intended.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-5-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use "mc" for local variables to shorten line lengths and provide
consistent names, which will be especially helpful when some of the
helpers are moved to common KVM code in future patches.
No functional change intended.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Drop the "page" variants of the topup/free memory cache helpers, using
the existence of an associated kmem_cache to select the correct alloc
or free routine.
No functional change intended.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Track the kmem_cache used for non-page KVM MMU memory caches instead of
passing in the associated kmem_cache when filling the cache. This will
allow consolidating code and other cleanups.
No functional change intended.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
OVMF booted guest running on shadow pages crashes on TRIPLE FAULT after
enabling paging from SMM. The crash is triggered from mmu_check_root() and
is caused by kvm_is_visible_gfn() searching through memslots with as_id = 0
while vCPU may be in a different context (address space).
Introduce kvm_vcpu_is_visible_gfn() and use it from mmu_check_root().
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200708140023.1476020-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rename KVM's accessor for retrieving a 'struct kvm_mmu_page' from the
associated host physical address to better convey what the function is
doing.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200622202034.15093-7-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce sptep_to_sp() to reduce the boilerplate code needed to get the
shadow page associated with a spte pointer, and to improve readability
as it's not immediately obvious that "page_header" is a KVM-specific
accessor for retrieving a shadow page.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200622202034.15093-6-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make 'struct kvm_mmu_page' MMU-only, nothing outside of the MMU should
be poking into the gory details of shadow pages.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200622202034.15093-5-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add mmu/mmu_internal.h to hold declarations and definitions that need
to be shared between various mmu/ files, but should not be used by
anything outside of the MMU.
Begin populating mmu_internal.h with declarations of the helpers used by
page_track.c.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200622202034.15093-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move kvm_mmu_available_pages() from mmu.h to mmu.c, it has a single
caller and has no business being exposed via mmu.h.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200622202034.15093-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move mmu_audit.c and mmutrace.h under mmu/ where they belong.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200622202034.15093-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Propagate any error returned by make_mmu_pages_available() out to
userspace instead of resuming the guest if the error occurs while
handling a page fault. Now that zapping the oldest MMU pages skips
active roots, i.e. fails if and only if there are no zappable pages,
there is no chance for a false positive, i.e. no chance of returning a
spurious error to userspace.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200623193542.7554-5-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use the recently introduced kvm_mmu_zap_oldest_mmu_pages() to batch zap
MMU pages when shrinking a slab. This fixes a long standing issue where
KVM's shrinker implementation is completely ineffective due to zapping
only a single page. E.g. without batch zapping, forcing a scan via
drop_caches basically has no impact on a VM with ~2k shadow pages. With
batch zapping, the number of shadow pages can be reduced to a few
hundred pages in one or two runs of drop_caches.
Note, if the default batch size (currently 128) is problematic, e.g.
zapping 128 pages holds mmu_lock for too long, KVM can bound the batch
size by setting @batch in mmu_shrinker.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200623193542.7554-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Collect MMU pages for zapping in a loop when making MMU pages available,
and skip over active roots when doing so as zapping an active root can
never immediately free up a page. Batching the zapping avoids multiple
remote TLB flushes and remedies the issue where the loop would bail
early if an active root was encountered.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200623193542.7554-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Delete a shadow page from the invalidation list instead of throwing it
back on the list of active pages when it's a root shadow page with
active users. Invalid active root pages will be explicitly freed by
mmu_free_root_page() when the root_count hits zero, i.e. they don't need
to be put on the active list to avoid leakage.
Use sp->role.invalid to detect that a shadow page has already been
zapped, i.e. is not on a list.
WARN if an invalid page is encountered when zapping pages, as it should
now be impossible.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200623193542.7554-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Skip the unsync checks and the write flooding clearing for fully direct
MMUs, which are guaranteed to not have unsync'd or indirect pages (write
flooding detection only applies to indirect pages). For TDP, this
avoids unnecessary memory reads and writes, and for the write flooding
count will also avoid dirtying a cache line (unsync_child_bitmap itself
consumes a cache line, i.e. write_flooding_count is guaranteed to be in
a different cache line than parent_ptes).
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200623194027.23135-3-sean.j.christopherson@intel.com>
Reviewed-By: Jon Cargille <jcargill@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Refactor for_each_valid_sp() to take the list of shadow pages instead of
retrieving it from a gfn to avoid doing the gfn->list hash and lookup
multiple times during kvm_get_mmu_page().
Cc: Peter Feiner <pfeiner@google.com>
Cc: Jon Cargille <jcargill@google.com>
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200623194027.23135-2-sean.j.christopherson@intel.com>
Reviewed-By: Jon Cargille <jcargill@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move .write_log_dirty() into kvm_x86_nested_ops to help differentiate it
from the non-nested dirty log hooks. And because it's a nested-only
operation.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200622215832.22090-5-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Drop kvm_arch_write_log_dirty() in favor of invoking .write_log_dirty()
directly from FNAME(update_accessed_dirty_bits). "kvm_arch" is usually
used for x86 functions that are invoked from generic KVM, and implies
that there are external callers, neither of which is true.
Remove the check for a non-NULL kvm_x86_ops hook as the call is wrapped
in PTTYPE_EPT and is unconditionally set by VMX.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200622215832.22090-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Unlike normal 'int' functions returning '0' on success, kvm_setup_async_pf()/
kvm_arch_setup_async_pf() return '1' when a job to handle page fault
asynchronously was scheduled and '0' otherwise. To avoid the confusion
change return type to 'bool'.
No functional change intended.
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200615121334.91300-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM guest code in Linux enables APF only when KVM_FEATURE_ASYNC_PF_INT
is supported, this means we will never see KVM_PV_REASON_PAGE_READY
when handling page fault vmexit in KVM.
While on it, make sure we only follow genuine page fault path when
APF reason is zero. If we happen to see something else this means
that the underlying hypervisor is misbehaving. Leave WARN_ON_ONCE()
to catch that.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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 and PDPEs, but
reserves it in PML4Es.
Probably, earlier versions of the AMD manual documented it as reserved in PDPEs
as well, and that behavior made it into KVM as well as kvm-unit-tests; fix it.
Cc: stable@vger.kernel.org
Reported-by: Nadav Amit <namit@vmware.com>
Fixes: a0c0feb579 ("KVM: x86: reserve bit 8 of non-leaf PDPEs and PML4Es in 64-bit mode on AMD", 2014-09-03)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
