Commit Graph

1057254 Commits

Author SHA1 Message Date
Paolo Bonzini
817506df9d Merge branch 'kvm-5.16-fixes' into kvm-master
* Fixes for Xen emulation

* Kill kvm_map_gfn() / kvm_unmap_gfn() and broken gfn_to_pfn_cache

* Fixes for migration of 32-bit nested guests on 64-bit hypervisor

* Compilation fixes

* More SEV cleanups
2021-11-18 02:11:57 -05:00
Sean Christopherson
8e38e96a4e KVM: SEV: Fix typo in and tweak name of cmd_allowed_from_miror()
Rename cmd_allowed_from_miror() to is_cmd_allowed_from_mirror(), fixing
a typo and making it obvious that the result is a boolean where
false means "not allowed".

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:10:28 -05:00
Sean Christopherson
ea410ef4da KVM: SEV: Drop a redundant setting of sev->asid during initialization
Remove a fully redundant write to sev->asid during SEV/SEV-ES guest
initialization.  The ASID is set a few lines earlier prior to the call to
sev_platform_init(), which doesn't take "sev" as a param, i.e. can't
muck with the ASID barring some truly magical behind-the-scenes code.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:10:27 -05:00
Sean Christopherson
1bd00a4257 KVM: SEV: WARN if SEV-ES is marked active but SEV is not
WARN if the VM is tagged as SEV-ES but not SEV.  KVM relies on SEV and
SEV-ES being set atomically, and guards common flows with "is SEV", i.e.
observing SEV-ES without SEV means KVM has a fatal bug.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:10:27 -05:00
Sean Christopherson
a41fb26e61 KVM: SEV: Set sev_info.active after initial checks in sev_guest_init()
Set sev_info.active during SEV/SEV-ES activation before calling any code
that can potentially consume sev_info.es_active, e.g. set "active" and
"es_active" as a pair immediately after the initial sanity checks.  KVM
generally expects that es_active can be true if and only if active is
true, e.g. sev_asid_new() deliberately avoids sev_es_guest() so that it
doesn't get a false negative.  This will allow WARNing in sev_es_guest()
if the VM is tagged as SEV-ES but not SEV.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:10:27 -05:00
Sean Christopherson
79b1114276 KVM: SEV: Disallow COPY_ENC_CONTEXT_FROM if target has created vCPUs
Reject COPY_ENC_CONTEXT_FROM if the destination VM has created vCPUs.
KVM relies on SEV activation to occur before vCPUs are created, e.g. to
set VMCB flags and intercepts correctly.

Fixes: 54526d1fd5 ("KVM: x86: Support KVM VMs sharing SEV context")
Cc: stable@vger.kernel.org
Cc: Peter Gonda <pgonda@google.com>
Cc: Marc Orr <marcorr@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Nathan Tempelman <natet@google.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:10:27 -05:00
David Woodhouse
357a18ad23 KVM: Kill kvm_map_gfn() / kvm_unmap_gfn() and gfn_to_pfn_cache
In commit 7e2175ebd6 ("KVM: x86: Fix recording of guest steal time /
preempted status") I removed the only user of these functions because
it was basically impossible to use them safely.

There are two stages to the GFN->PFN mapping; first through the KVM
memslots to a userspace HVA and then through the page tables to
translate that HVA to an underlying PFN. Invalidations of the former
were being handled correctly, but no attempt was made to use the MMU
notifiers to invalidate the cache when the HVA->GFN mapping changed.

As a prelude to reinventing the gfn_to_pfn_cache with more usable
semantics, rip it out entirely and untangle the implementation of
the unsafe kvm_vcpu_map()/kvm_vcpu_unmap() functions from it.

All current users of kvm_vcpu_map() also look broken right now, and
will be dealt with separately. They broadly fall into two classes:

* Those which map, access the data and immediately unmap. This is
  mostly gratuitous and could just as well use the existing user
  HVA, and could probably benefit from a gfn_to_hva_cache as they
  do so.

* Those which keep the mapping around for a longer time, perhaps
  even using the PFN directly from the guest. These will need to
  be converted to the new gfn_to_pfn_cache and then kvm_vcpu_map()
  can be removed too.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-8-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:03:45 -05:00
David Woodhouse
cee66664dc KVM: nVMX: Use a gfn_to_hva_cache for vmptrld
And thus another call to kvm_vcpu_map() can die.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-7-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:03:43 -05:00
David Woodhouse
7d0172b3ca KVM: nVMX: Use kvm_read_guest_offset_cached() for nested VMCS check
Kill another mostly gratuitous kvm_vcpu_map() which could just use the
userspace HVA for it.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-6-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:03:43 -05:00
David Woodhouse
6a834754a5 KVM: x86/xen: Use sizeof_field() instead of open-coding it
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-4-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:03:43 -05:00
David Woodhouse
297d597a6d KVM: nVMX: Use kvm_{read,write}_guest_cached() for shadow_vmcs12
Using kvm_vcpu_map() for reading from the guest is entirely gratuitous,
when all we do is a single memcpy and unmap it again. Fix it up to use
kvm_read_guest()... but in fact I couldn't bring myself to do that
without also making it use a gfn_to_hva_cache for both that *and* the
copy in the other direction.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-5-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:03:42 -05:00
David Woodhouse
4e8436479a KVM: x86/xen: Fix get_attr of KVM_XEN_ATTR_TYPE_SHARED_INFO
In commit 319afe6856 ("KVM: xen: do not use struct gfn_to_hva_cache") we
stopped storing this in-kernel as a GPA, and started storing it as a GFN.
Which means we probably should have stopped calling gpa_to_gfn() on it
when userspace asks for it back.

Cc: stable@vger.kernel.org
Fixes: 319afe6856 ("KVM: xen: do not use struct gfn_to_hva_cache")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-2-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:03:42 -05:00
Maxim Levitsky
b8453cdcf2 KVM: x86/mmu: include EFER.LMA in extended mmu role
Incorporate EFER.LMA into kvm_mmu_extended_role, as it used to compute the
guest root level and is not reflected in kvm_mmu_page_role.level when TDP
is in use.  When simply running the guest, it is impossible for EFER.LMA
and kvm_mmu.root_level to get out of sync, as the guest cannot transition
from PAE paging to 64-bit paging without toggling CR0.PG, i.e. without
first bouncing through a different MMU context.  And stuffing guest state
via KVM_SET_SREGS{,2} also ensures a full MMU context reset.

However, if KVM_SET_SREGS{,2} is followed by KVM_SET_NESTED_STATE, e.g. to
set guest state when migrating the VM while L2 is active, the vCPU state
will reflect L2, not L1.  If L1 is using TDP for L2, then root_mmu will
have been configured using L2's state, despite not being used for L2.  If
L2.EFER.LMA != L1.EFER.LMA, and L2 is using PAE paging, then root_mmu will
be configured for guest PAE paging, but will match the mmu_role for 64-bit
paging and cause KVM to not reconfigure root_mmu on the next nested VM-Exit.

Alternatively, the root_mmu's role could be invalidated after a successful
KVM_SET_NESTED_STATE that yields vcpu->arch.mmu != vcpu->arch.root_mmu,
i.e. that switches the active mmu to guest_mmu, but doing so is unnecessarily
tricky, and not even needed if L1 and L2 do have the same role (e.g., they
are both 64-bit guests and run with the same CR4).

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20211115131837.195527-3-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:03:42 -05:00
Maxim Levitsky
af957eebfc KVM: nVMX: don't use vcpu->arch.efer when checking host state on nested state load
When loading nested state, don't use check vcpu->arch.efer to get the
L1 host's 64-bit vs. 32-bit state and don't check it for consistency
with respect to VM_EXIT_HOST_ADDR_SPACE_SIZE, as register state in vCPU
may be stale when KVM_SET_NESTED_STATE is called---and architecturally
does not exist.  When restoring L2 state in KVM, the CPU is placed in
non-root where nested VMX code has no snapshot of L1 host state: VMX
(conditionally) loads host state fields loaded on VM-exit, but they need
not correspond to the state before entry.  A simple case occurs in KVM
itself, where the host RIP field points to vmx_vmexit rather than the
instruction following vmlaunch/vmresume.

However, for the particular case of L1 being in 32- or 64-bit mode
on entry, the exit controls can be treated instead as the source of
truth regarding the state of L1 on entry, and can be used to check
that vmcs12.VM_EXIT_HOST_ADDR_SPACE_SIZE matches vmcs12.HOST_EFER if
vmcs12.VM_EXIT_LOAD_IA32_EFER is set.  The consistency check on CPU
EFER vs. vmcs12.VM_EXIT_HOST_ADDR_SPACE_SIZE, instead, happens only
on VM-Enter.  That's because, again, there's conceptually no "current"
L1 EFER to check on KVM_SET_NESTED_STATE.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20211115131837.195527-2-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:03:42 -05:00
David Woodhouse
964b7aa0b0 KVM: Fix steal time asm constraints
In 64-bit mode, x86 instruction encoding allows us to use the low 8 bits
of any GPR as an 8-bit operand. In 32-bit mode, however, we can only use
the [abcd] registers. For which, GCC has the "q" constraint instead of
the less restrictive "r".

Also fix st->preempted, which is an input/output operand rather than an
input.

Fixes: 7e2175ebd6 ("KVM: x86: Fix recording of guest steal time / preempted status")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <89bf72db1b859990355f9c40713a34e0d2d86c98.camel@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:03:41 -05:00
Paul Durrant
dc23a5110b cpuid: kvm_find_kvm_cpuid_features() should be declared 'static'
The lack a static declaration currently results in:

arch/x86/kvm/cpuid.c:128:26: warning: no previous prototype for function 'kvm_find_kvm_cpuid_features'

when compiling with "W=1".

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 760849b147 ("KVM: x86: Make sure KVM_CPUID_FEATURES really are KVM_CPUID_FEATURES")
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Message-Id: <20211115144131.5943-1-pdurrant@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:03:14 -05:00
Paolo Bonzini
e5bc4d4602 Merge branch 'kvm-selftest' into kvm-master
- Cleanups for the perf test infrastructure and mapping hugepages

- Avoid contention on mmap_sem when the guests start to run

- Add event channel upcall support to xen_shinfo_test
2021-11-16 13:21:13 -05:00
黄乐
c5adbb3af0 KVM: x86: Fix uninitialized eoi_exit_bitmap usage in vcpu_load_eoi_exitmap()
In vcpu_load_eoi_exitmap(), currently the eoi_exit_bitmap[4] array is
initialized only when Hyper-V context is available, in other path it is
just passed to kvm_x86_ops.load_eoi_exitmap() directly from on the stack,
which would cause unexpected interrupt delivery/handling issues, e.g. an
*old* linux kernel that relies on PIT to do clock calibration on KVM might
randomly fail to boot.

Fix it by passing ioapic_handled_vectors to load_eoi_exitmap() when Hyper-V
context is not available.

Fixes: f2bc14b69c ("KVM: x86: hyper-v: Prepare to meet unallocated Hyper-V context")
Cc: stable@vger.kernel.org
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Huang Le <huangle1@jd.com>
Message-Id: <62115b277dab49ea97da5633f8522daf@jd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:51:04 -05:00
David Matlack
e2bd936581 KVM: selftests: Use perf_test_destroy_vm in memslot_modification_stress_test
Change memslot_modification_stress_test to use perf_test_destroy_vm
instead of manually calling ucall_uninit and kvm_vm_free.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Message-Id: <20211111001257.1446428-5-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:28 -05:00
David Matlack
89d9a43c1d KVM: selftests: Wait for all vCPU to be created before entering guest mode
Thread creation requires taking the mmap_sem in write mode, which causes
vCPU threads running in guest mode to block while they are populating
memory. Fix this by waiting for all vCPU threads to be created and start
running before entering guest mode on any one vCPU thread.

This substantially improves the "Populate memory time" when using 1GiB
pages since it allows all vCPUs to zero pages in parallel rather than
blocking because a writer is waiting (which is waiting for another vCPU
that is busy zeroing a 1GiB page).

Before:

  $ ./dirty_log_perf_test -v256 -s anonymous_hugetlb_1gb
  ...
  Populate memory time: 52.811184013s

After:

  $ ./dirty_log_perf_test -v256 -s anonymous_hugetlb_1gb
  ...
  Populate memory time: 10.204573342s

Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20211111001257.1446428-4-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:28 -05:00
David Matlack
81bcb26172 KVM: selftests: Move vCPU thread creation and joining to common helpers
Move vCPU thread creation and joining to common helper functions. This
is in preparation for the next commit which ensures that all vCPU
threads are fully created before entering guest mode on any one
vCPU.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Message-Id: <20211111001257.1446428-3-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:28 -05:00
David Matlack
36c5ad73d7 KVM: selftests: Start at iteration 0 instead of -1
Start at iteration 0 instead of -1 to avoid having to initialize
vcpu_last_completed_iteration when setting up vCPU threads. This
simplifies the next commit where we move vCPU thread initialization
out to a common helper.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20211111001257.1446428-2-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:27 -05:00
Sean Christopherson
13bbc70329 KVM: selftests: Sync perf_test_args to guest during VM creation
Copy perf_test_args to the guest during VM creation instead of relying on
the caller to do so at their leisure.  Ideally, tests wouldn't even be
able to modify perf_test_args, i.e. they would have no motivation to do
the sync, but enforcing that is arguably a net negative for readability.

No functional change intended.

[Set wr_fract=1 by default and add helper to override it since the new
 access_tracking_perf_test needs to set it dynamically.]

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Message-Id: <20211111000310.1435032-13-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:27 -05:00
Sean Christopherson
cf1d59300a KVM: selftests: Fill per-vCPU struct during "perf_test" VM creation
Fill the per-vCPU args when creating the perf_test VM instead of having
the caller do so.  This helps ensure that any adjustments to the number
of pages (and thus vcpu_memory_bytes) are reflected in the per-VM args.
Automatically filling the per-vCPU args will also allow a future patch
to do the sync to the guest during creation.

Signed-off-by: Sean Christopherson <seanjc@google.com>
[Updated access_tracking_perf_test as well.]
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Message-Id: <20211111000310.1435032-12-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:27 -05:00
Sean Christopherson
f5e8fe2a92 KVM: selftests: Create VM with adjusted number of guest pages for perf tests
Use the already computed guest_num_pages when creating the so called
extra VM pages for a perf test, and add a comment explaining why the
pages are allocated as extra pages.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20211111000310.1435032-11-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:27 -05:00
Sean Christopherson
a5ac0fd1b9 KVM: selftests: Remove perf_test_args.host_page_size
Remove perf_test_args.host_page_size and instead use getpagesize() so
that it's somewhat obvious that, for tests that care about the host page
size, they care about the system page size, not the hardware page size,
e.g. that the logic is unchanged if hugepages are in play.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20211111000310.1435032-10-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:26 -05:00
Sean Christopherson
b91b637f4a KVM: selftests: Move per-VM GPA into perf_test_args
Move the per-VM GPA into perf_test_args instead of storing it as a
separate global variable.  It's not obvious that guest_test_phys_mem
holds a GPA, nor that it's connected/coupled with per_vcpu->gpa.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20211111000310.1435032-9-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:26 -05:00
Sean Christopherson
92e34c9974 KVM: selftests: Use perf util's per-vCPU GPA/pages in demand paging test
Grab the per-vCPU GPA and number of pages from perf_util in the demand
paging test instead of duplicating perf_util's calculations.

Note, this may or may not result in a functional change.  It's not clear
that the test's calculations are guaranteed to yield the same value as
perf_util, e.g. if guest_percpu_mem_size != vcpu_args->pages.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20211111000310.1435032-8-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:26 -05:00
Sean Christopherson
613d61182f KVM: selftests: Capture per-vCPU GPA in perf_test_vcpu_args
Capture the per-vCPU GPA in perf_test_vcpu_args so that tests can get
the GPA without having to calculate the GPA on their own.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20211111000310.1435032-7-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:26 -05:00
Sean Christopherson
b65e1051e4 KVM: selftests: Use shorthand local var to access struct perf_tests_args
Use 'pta' as a local pointer to the global perf_tests_args in order to
shorten line lengths and make the code borderline readable.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20211111000310.1435032-6-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:25 -05:00
Sean Christopherson
69cdcfa6f3 KVM: selftests: Require GPA to be aligned when backed by hugepages
Assert that the GPA for a memslot backed by a hugepage is aligned to
the hugepage size and fix perf_test_util accordingly.  Lack of GPA
alignment prevents KVM from backing the guest with hugepages, e.g. x86's
write-protection of hugepages when dirty logging is activated is
otherwise not exercised.

Add a comment explaining that guest_page_size is for non-huge pages to
try and avoid confusion about what it actually tracks.

Cc: Ben Gardon <bgardon@google.com>
Cc: Yanan Wang <wangyanan55@huawei.com>
Cc: Andrew Jones <drjones@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Aaron Lewis <aaronlewis@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
[Used get_backing_src_pagesz() to determine alignment dynamically.]
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20211111000310.1435032-5-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:25 -05:00
Sean Christopherson
f4870ef3e1 KVM: selftests: Assert mmap HVA is aligned when using HugeTLB
Manually padding and aligning the mmap region is only needed when using
THP. When using HugeTLB, mmap will always return an address aligned to
the HugeTLB page size. Add a comment to clarify this and assert the mmap
behavior for HugeTLB.

[Removed requirement that HugeTLB mmaps must be padded per Yanan's
 feedback and added assertion that mmap returns aligned addresses
 when using HugeTLB.]

Cc: Ben Gardon <bgardon@google.com>
Cc: Yanan Wang <wangyanan55@huawei.com>
Cc: Andrew Jones <drjones@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Aaron Lewis <aaronlewis@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20211111000310.1435032-4-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:25 -05:00
Sean Christopherson
c071ff41e1 KVM: selftests: Expose align() helpers to tests
Refactor align() to work with non-pointers and split into separate
helpers for aligning up vs. down. Add align_ptr_up() for use with
pointers. Expose all helpers so that they can be used by tests and/or
other utilities.  The align_down() helper in particular will be used to
ensure gpa alignment for hugepages.

No functional change intended.

[Added sepearate up/down helpers and replaced open-coded alignment
 bit math throughout the KVM selftests.]

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Message-Id: <20211111000310.1435032-3-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:24 -05:00
Sean Christopherson
531ca3d6d5 KVM: selftests: Explicitly state indicies for vm_guest_mode_params array
Explicitly state the indices when populating vm_guest_mode_params to
make it marginally easier to visualize what's going on.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
[Added indices for new guest modes.]
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20211111000310.1435032-2-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:24 -05:00
David Woodhouse
7c4de881f7 KVM: selftests: Add event channel upcall support to xen_shinfo_test
When I first looked at this, there was no support for guest exception
handling in the KVM selftests. In fact it was merged into 5.10 before
the Xen support got merged in 5.11, and I could have used it from the
start.

Hook it up now, to exercise the Xen upcall delivery. I'm about to make
things a bit more interesting by handling the full 2level event channel
stuff in-kernel on top of the basic vector injection that we already
have, and I'll want to build more tests on top.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211115165030.7422-3-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-16 07:43:24 -05:00
Paolo Bonzini
84886c262e KVM/arm64 fixes for 5.16, take #1
- Fix the host S2 finalization by solely iterating over the memblocks
   instead of the whole IPA space
 
 - Tighten the return value of kvm_vcpu_preferred_target() now that
   32bit support is long gone
 
 - Make sure the extraction of ESR_ELx.EC is limited to the architected
   bits
 
 - Comment fixups
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Merge tag 'kvmarm-fixes-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

KVM/arm64 fixes for 5.16, take #1

- Fix the host S2 finalization by solely iterating over the memblocks
  instead of the whole IPA space

- Tighten the return value of kvm_vcpu_preferred_target() now that
  32bit support is long gone

- Make sure the extraction of ESR_ELx.EC is limited to the architected
  bits

- Comment fixups
2021-11-12 16:01:55 -05:00
Paolo Bonzini
501cfe0679 KVM: SEV: unify cgroup cleanup code for svm_vm_migrate_from
Use the same cleanup code independent of whether the cgroup to be
uncharged and unref'd is the source or the destination cgroup.  Use a
bool to track whether the destination cgroup has been charged, which also
fixes a bug in the error case: the destination cgroup must be uncharged
only if it does not match the source.

Fixes: b56639318b ("KVM: SEV: Add support for SEV intra host migration")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-12 04:37:51 -05:00
Paolo Bonzini
3e067fd850 KVM: x86: move guest_pv_has out of user_access section
When UBSAN is enabled, the code emitted for the call to guest_pv_has
includes a call to __ubsan_handle_load_invalid_value.  objtool
complains that this call happens with UACCESS enabled; to avoid
the warning, pull the calls to user_access_begin into both arms
of the "if" statement, after the check for guest_pv_has.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-12 02:53:52 -05:00
Paolo Bonzini
f5396f2d82 Merge branch 'kvm-5.16-fixes' into kvm-master
* Fix misuse of gfn-to-pfn cache when recording guest steal time / preempted status

* Fix selftests on APICv machines

* Fix sparse warnings

* Fix detection of KVM features in CPUID

* Cleanups for bogus writes to MSR_KVM_PV_EOI_EN

* Fixes and cleanups for MSR bitmap handling

* Cleanups for INVPCID

* Make x86 KVM_SOFT_MAX_VCPUS consistent with other architectures
2021-11-11 11:03:05 -05:00
Paolo Bonzini
1f05833193 Merge branch 'kvm-sev-move-context' into kvm-master
Add support for AMD SEV and SEV-ES intra-host migration support.  Intra
host migration provides a low-cost mechanism for userspace VMM upgrades.

In the common case for intra host migration, we can rely on the normal
ioctls for passing data from one VMM to the next. SEV, SEV-ES, and other
confidential compute environments make most of this information opaque, and
render KVM ioctls such as "KVM_GET_REGS" irrelevant.  As a result, we need
the ability to pass this opaque metadata from one VMM to the next. The
easiest way to do this is to leave this data in the kernel, and transfer
ownership of the metadata from one KVM VM (or vCPU) to the next.  In-kernel
hand off makes it possible to move any data that would be
unsafe/impossible for the kernel to hand directly to userspace, and
cannot be reproduced using data that can be handed to userspace.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 11:02:58 -05:00
Vitaly Kuznetsov
da1bfd52b9 KVM: x86: Drop arbitrary KVM_SOFT_MAX_VCPUS
KVM_CAP_NR_VCPUS is used to get the "recommended" maximum number of
VCPUs and arm64/mips/riscv report num_online_cpus(). Powerpc reports
either num_online_cpus() or num_present_cpus(), s390 has multiple
constants depending on hardware features. On x86, KVM reports an
arbitrary value of '710' which is supposed to be the maximum tested
value but it's possible to test all KVM_MAX_VCPUS even when there are
less physical CPUs available.

Drop the arbitrary '710' value and return num_online_cpus() on x86 as
well. The recommendation will match other architectures and will mean
'no CPU overcommit'.

For reference, QEMU only queries KVM_CAP_NR_VCPUS to print a warning
when the requested vCPU number exceeds it. The static limit of '710'
is quite weird as smaller systems with just a few physical CPUs should
certainly "recommend" less.

Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211111134733.86601-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:24 -05:00
Vipin Sharma
796c83c58a KVM: Move INVPCID type check from vmx and svm to the common kvm_handle_invpcid()
Handle #GP on INVPCID due to an invalid type in the common switch
statement instead of relying on the callers (VMX and SVM) to manually
validate the type.

Unlike INVVPID and INVEPT, INVPCID is not explicitly documented to check
the type before reading the operand from memory, so deferring the
type validity check until after that point is architecturally allowed.

Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109174426.2350547-3-vipinsh@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:24 -05:00
Vipin Sharma
329bd56ce5 KVM: VMX: Add a helper function to retrieve the GPR index for INVPCID, INVVPID, and INVEPT
handle_invept(), handle_invvpid(), handle_invpcid() read the same reg2
field in vmcs.VMX_INSTRUCTION_INFO to get the index of the GPR that
holds the invalidation type. Add a helper to retrieve reg2 from VMX
instruction info to consolidate and document the shift+mask magic.

Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109174426.2350547-2-vipinsh@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:24 -05:00
Sean Christopherson
a5e0c25284 KVM: nVMX: Clean up x2APIC MSR handling for L2
Clean up the x2APIC MSR bitmap intereption code for L2, which is the last
holdout of open coded bitmap manipulations.  Freshen up the SDM/PRM
comment, rename the function to make it abundantly clear the funky
behavior is x2APIC specific, and explain _why_ vmcs01's bitmap is ignored
(the previous comment was flat out wrong for x2APIC behavior).

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109013047.2041518-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:23 -05:00
Sean Christopherson
0cacb80b98 KVM: VMX: Macrofy the MSR bitmap getters and setters
Add builder macros to generate the MSR bitmap helpers to reduce the
amount of copy-paste code, especially with respect to all the magic
numbers needed to calc the correct bit location.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109013047.2041518-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:23 -05:00
Sean Christopherson
67f4b9969c KVM: nVMX: Handle dynamic MSR intercept toggling
Always check vmcs01's MSR bitmap when merging L0 and L1 bitmaps for L2,
and always update the relevant bits in vmcs02.  This fixes two distinct,
but intertwined bugs related to dynamic MSR bitmap modifications.

The first issue is that KVM fails to enable MSR interception in vmcs02
for the FS/GS base MSRs if L1 first runs L2 with interception disabled,
and later enables interception.

The second issue is that KVM fails to honor userspace MSR filtering when
preparing vmcs02.

Fix both issues simultaneous as fixing only one of the issues (doesn't
matter which) would create a mess that no one should have to bisect.
Fixing only the first bug would exacerbate the MSR filtering issue as
userspace would see inconsistent behavior depending on the whims of L1.
Fixing only the second bug (MSR filtering) effectively requires fixing
the first, as the nVMX code only knows how to transition vmcs02's
bitmap from 1->0.

Move the various accessor/mutators that are currently buried in vmx.c
into vmx.h so that they can be shared by the nested code.

Fixes: 1a155254ff ("KVM: x86: Introduce MSR filtering")
Fixes: d69129b4e4 ("KVM: nVMX: Disable intercept for FS/GS base MSRs in vmcs02 when possible")
Cc: stable@vger.kernel.org
Cc: Alexander Graf <graf@amazon.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109013047.2041518-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:23 -05:00
Sean Christopherson
7dfbc624eb KVM: nVMX: Query current VMCS when determining if MSR bitmaps are in use
Check the current VMCS controls to determine if an MSR write will be
intercepted due to MSR bitmaps being disabled.  In the nested VMX case,
KVM will disable MSR bitmaps in vmcs02 if they're disabled in vmcs12 or
if KVM can't map L1's bitmaps for whatever reason.

Note, the bad behavior is relatively benign in the current code base as
KVM sets all bits in vmcs02's MSR bitmap by default, clears bits if and
only if L0 KVM also disables interception of an MSR, and only uses the
buggy helper for MSR_IA32_SPEC_CTRL.  Because KVM explicitly tests WRMSR
before disabling interception of MSR_IA32_SPEC_CTRL, the flawed check
will only result in KVM reading MSR_IA32_SPEC_CTRL from hardware when it
isn't strictly necessary.

Tag the fix for stable in case a future fix wants to use
msr_write_intercepted(), in which case a buggy implementation in older
kernels could prove subtly problematic.

Fixes: d28b387fb7 ("KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109013047.2041518-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:22 -05:00
Vitaly Kuznetsov
afd67ee3cb KVM: x86: Don't update vcpu->arch.pv_eoi.msr_val when a bogus value was written to MSR_KVM_PV_EOI_EN
When kvm_gfn_to_hva_cache_init() call from kvm_lapic_set_pv_eoi() fails,
MSR write to MSR_KVM_PV_EOI_EN results in #GP so it is reasonable to
expect that the value we keep internally in KVM wasn't updated.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211108152819.12485-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:22 -05:00
Vitaly Kuznetsov
77c3323f48 KVM: x86: Rename kvm_lapic_enable_pv_eoi()
kvm_lapic_enable_pv_eoi() is a misnomer as the function is also
used to disable PV EOI. Rename it to kvm_lapic_set_pv_eoi().

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211108152819.12485-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:22 -05:00
Paul Durrant
760849b147 KVM: x86: Make sure KVM_CPUID_FEATURES really are KVM_CPUID_FEATURES
Currently when kvm_update_cpuid_runtime() runs, it assumes that the
KVM_CPUID_FEATURES leaf is located at 0x40000001. This is not true,
however, if Hyper-V support is enabled. In this case the KVM leaves will
be offset.

This patch introdues as new 'kvm_cpuid_base' field into struct
kvm_vcpu_arch to track the location of the KVM leaves and function
kvm_update_kvm_cpuid_base() (called from kvm_set_cpuid()) to locate the
leaves using the 'KVMKVMKVM\0\0\0' signature (which is now given a
definition in kvm_para.h). Adjustment of KVM_CPUID_FEATURES will hence now
target the correct leaf.

NOTE: A new for_each_possible_hypervisor_cpuid_base() macro is intoduced
      into processor.h to avoid having duplicate code for the iteration
      over possible hypervisor base leaves.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Message-Id: <20211105095101.5384-3-pdurrant@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:21 -05:00