Commit Graph

1043942 Commits

Author SHA1 Message Date
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
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
Sean Christopherson
8b44b174f6 KVM: x86: Add helper to consolidate core logic of SET_CPUID{2} flows
Move the core logic of SET_CPUID and SET_CPUID2 to a common helper, the
only difference between the two ioctls() is the format of the userspace
struct.  A future fix will add yet more code to the core logic.

No functional change intended.

Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211105095101.5384-2-pdurrant@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:21 -05:00
Junaid Shahid
10c30de019 kvm: mmu: Use fast PF path for access tracking of huge pages when possible
The fast page fault path bails out on write faults to huge pages in
order to accommodate dirty logging. This change adds a check to do that
only when dirty logging is actually enabled, so that access tracking for
huge pages can still use the fast path for write faults in the common
case.

Signed-off-by: Junaid Shahid <junaids@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211104003359.2201967-1-junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:20 -05:00
Sean Christopherson
c435d4b7ba KVM: x86/mmu: Properly dereference rcu-protected TDP MMU sptep iterator
Wrap the read of iter->sptep in tdp_mmu_map_handle_target_level() with
rcu_dereference().  Shadow pages in the TDP MMU, and thus their SPTEs,
are protected by rcu.

This fixes a Sparse warning at tdp_mmu.c:900:51:
  warning: incorrect type in argument 1 (different address spaces)
  expected unsigned long long [usertype] *sptep
  got unsigned long long [noderef] [usertype] __rcu *[usertype] sptep

Fixes: 7158bee4b4 ("KVM: MMU: pass kvm_mmu_page struct to make_spte")
Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211103161833.3769487-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:20 -05:00
Maxim Levitsky
cae72dcc3b KVM: x86: inhibit APICv when KVM_GUESTDBG_BLOCKIRQ active
KVM_GUESTDBG_BLOCKIRQ relies on interrupts being injected using
standard kvm's inject_pending_event, and not via APICv/AVIC.

Since this is a debug feature, just inhibit APICv/AVIC while
KVM_GUESTDBG_BLOCKIRQ is in use on at least one vCPU.

Fixes: 61e5f69ef0 ("KVM: x86: implement KVM_GUESTDBG_BLOCKIRQ")

Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211108090245.166408-1-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:20 -05:00
Jim Mattson
e6cd31f1a8 kvm: x86: Convert return type of *is_valid_rdpmc_ecx() to bool
These function names sound like predicates, and they have siblings,
*is_valid_msr(), which _are_ predicates. Moreover, there are comments
that essentially warn that these functions behave unexpectedly.

Flip the polarity of the return values, so that they become
predicates, and convert the boolean result to a success/failure code
at the outer call site.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211105202058.1048757-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:19 -05:00
David Woodhouse
7e2175ebd6 KVM: x86: Fix recording of guest steal time / preempted status
In commit b043138246 ("x86/KVM: Make sure KVM_VCPU_FLUSH_TLB flag is
not missed") we switched to using a gfn_to_pfn_cache for accessing the
guest steal time structure in order to allow for an atomic xchg of the
preempted field. This has a couple of problems.

Firstly, kvm_map_gfn() doesn't work at all for IOMEM pages when the
atomic flag is set, which it is in kvm_steal_time_set_preempted(). So a
guest vCPU using an IOMEM page for its steal time would never have its
preempted field set.

Secondly, the gfn_to_pfn_cache is not invalidated in all cases where it
should have been. There are two stages to the GFN->PFN conversion;
first the GFN is converted to a userspace HVA, and then that HVA is
looked up in the process page tables to find the underlying host PFN.
Correct invalidation of the latter would require being hooked up to the
MMU notifiers, but that doesn't happen---so it just keeps mapping and
unmapping the *wrong* PFN after the userspace page tables change.

In the !IOMEM case at least the stale page *is* pinned all the time it's
cached, so it won't be freed and reused by anyone else while still
receiving the steal time updates. The map/unmap dance only takes care
of the KVM administrivia such as marking the page dirty.

Until the gfn_to_pfn cache handles the remapping automatically by
integrating with the MMU notifiers, we might as well not get a
kernel mapping of it, and use the perfectly serviceable userspace HVA
that we already have.  We just need to implement the atomic xchg on
the userspace address with appropriate exception handling, which is
fairly trivial.

Cc: stable@vger.kernel.org
Fixes: b043138246 ("x86/KVM: Make sure KVM_VCPU_FLUSH_TLB flag is not missed")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <3645b9b889dac6438394194bb5586a46b68d581f.camel@infradead.org>
[I didn't entirely agree with David's assessment of the
 usefulness of the gfn_to_pfn cache, and integrated the outcome
 of the discussion in the above commit message. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 10:56:19 -05:00
Paolo Bonzini
52cf891d8d Minor cocci warning fixes:
1) Bool return warning fix
 2) Unnedded semicolon warning fix
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Merge tag 'kvm-riscv-5.16-2' of https://github.com/kvm-riscv/linux into HEAD

Minor cocci warning fixes:
1) Bool return warning fix
2) Unnedded semicolon warning fix
2021-11-02 09:15:31 -04:00
Bixuan Cui
bbd5ba8db7 RISC-V: KVM: fix boolreturn.cocci warnings
Fix boolreturn.cocci warnings:
./arch/riscv/kvm/mmu.c:603:9-10: WARNING: return of 0/1 in function
'kvm_age_gfn' with return type bool
./arch/riscv/kvm/mmu.c:582:9-10: WARNING: return of 0/1 in function
'kvm_set_spte_gfn' with return type bool
./arch/riscv/kvm/mmu.c:621:9-10: WARNING: return of 0/1 in function
'kvm_test_age_gfn' with return type bool
./arch/riscv/kvm/mmu.c:568:9-10: WARNING: return of 0/1 in function
'kvm_unmap_gfn_range' with return type bool

Signed-off-by: Bixuan Cui <cuibixuan@linux.alibaba.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2021-11-01 17:35:17 +05:30
ran jianping
7b161d9cab RISC-V: KVM: remove unneeded semicolon
Elimate the following coccinelle check warning:
 ./arch/riscv/kvm/vcpu_sbi.c:169:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu_exit.c:397:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu_exit.c:687:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu_exit.c:645:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu.c:247:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu.c:284:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu_timer.c:123:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu_timer.c:170:2-3: Unneeded semicolon

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: ran jianping <ran.jianping@zte.com.cn>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2021-11-01 17:35:13 +05:30
Paolo Bonzini
9c6eb531e7 KVM: s390: Fixes and Features for 5.16
- SIGP Fixes
 - initial preparations for lazy destroy of secure VMs
 - storage key improvements/fixes
 - Log the guest CPNC
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Merge tag 'kvm-s390-next-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Fixes and Features for 5.16

- SIGP Fixes
- initial preparations for lazy destroy of secure VMs
- storage key improvements/fixes
- Log the guest CPNC
2021-10-31 09:01:25 -04:00
Anup Patel
7c8de080d4 RISC-V: KVM: Fix GPA passed to __kvm_riscv_hfence_gvma_xyz() functions
The parameter passed to HFENCE.GVMA instruction in rs1 register
is guest physical address right shifted by 2 (i.e. divided by 4).

Unfortunately, we overlooked the semantics of rs1 registers for
HFENCE.GVMA instruction and never right shifted guest physical
address by 2. This issue did not manifest for hypervisors till
now because:
  1) Currently, only __kvm_riscv_hfence_gvma_all() and SBI
     HFENCE calls are used to invalidate TLB.
  2) All H-extension implementations (such as QEMU, Spike,
     Rocket Core FPGA, etc) that we tried till now were
     conservatively flushing everything upon any HFENCE.GVMA
     instruction.

This patch fixes GPA passed to __kvm_riscv_hfence_gvma_vmid_gpa()
and __kvm_riscv_hfence_gvma_gpa() functions.

Fixes: fd7bb4a251 ("RISC-V: KVM: Implement VMID allocator")
Reported-by: Ian Huang <ihuang@ventanamicro.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Message-Id: <20211026170136.2147619-4-anup.patel@wdc.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-31 02:45:43 -04:00
Anup Patel
0a86512dc1 RISC-V: KVM: Factor-out FP virtualization into separate sources
The timer and SBI virtualization is already in separate sources.
In future, we will have vector and AIA virtualization also added
as separate sources.

To align with above described modularity, we factor-out FP
virtualization into separate sources.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Message-Id: <20211026170136.2147619-3-anup.patel@wdc.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-31 02:45:43 -04:00
Paolo Bonzini
4e33868433 KVM/arm64 updates for Linux 5.16
- More progress on the protected VM front, now with the full
   fixed feature set as well as the limitation of some hypercalls
   after initialisation.
 
 - Cleanup of the RAZ/WI sysreg handling, which was pointlessly
   complicated
 
 - Fixes for the vgic placement in the IPA space, together with a
   bunch of selftests
 
 - More memcg accounting of the memory allocated on behalf of a guest
 
 - Timer and vgic selftests
 
 - Workarounds for the Apple M1 broken vgic implementation
 
 - KConfig cleanups
 
 - New kvmarm.mode=none option, for those who really dislike us
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Merge tag 'kvmarm-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for Linux 5.16

- More progress on the protected VM front, now with the full
  fixed feature set as well as the limitation of some hypercalls
  after initialisation.

- Cleanup of the RAZ/WI sysreg handling, which was pointlessly
  complicated

- Fixes for the vgic placement in the IPA space, together with a
  bunch of selftests

- More memcg accounting of the memory allocated on behalf of a guest

- Timer and vgic selftests

- Workarounds for the Apple M1 broken vgic implementation

- KConfig cleanups

- New kvmarm.mode=none option, for those who really dislike us
2021-10-31 02:28:48 -04:00
Collin Walling
3fd8417f2c KVM: s390: add debug statement for diag 318 CPNC data
The diag 318 data contains values that denote information regarding the
guest's environment. Currently, it is unecessarily difficult to observe
this value (either manually-inserted debug statements, gdb stepping, mem
dumping etc). It's useful to observe this information to obtain an
at-a-glance view of the guest's environment, so lets add a simple VCPU
event that prints the CPNC to the s390dbf logs.

Signed-off-by: Collin Walling <walling@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20211027025451.290124-1-walling@linux.ibm.com
[borntraeger@de.ibm.com]: change debug level to 3
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-27 07:55:53 +02:00
Claudio Imbrenda
380d97bd02 KVM: s390: pv: properly handle page flags for protected guests
Introduce variants of the convert and destroy page functions that also
clear the PG_arch_1 bit used to mark them as secure pages.

The PG_arch_1 flag is always allowed to overindicate; using the new
functions introduced here allows to reduce the extent of overindication
and thus improve performance.

These new functions can only be called on pages for which a reference
is already being held.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210920132502.36111-7-imbrenda@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-27 07:55:53 +02:00
Janis Schoetterl-Glausch
85f517b294 KVM: s390: Fix handle_sske page fault handling
If handle_sske cannot set the storage key, because there is no
page table entry or no present large page entry, it calls
fixup_user_fault.
However, currently, if the call succeeds, handle_sske returns
-EAGAIN, without having set the storage key.
Instead, retry by continue'ing the loop without incrementing the
address.
The same issue in handle_pfmf was fixed by
a11bdb1a6b ("KVM: s390: Fix pfmf and conditional skey emulation").

Fixes: bd096f6443 ("KVM: s390: Add skey emulation fault handling")
Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20211022152648.26536-1-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-27 07:55:40 +02:00
Paolo Bonzini
e59f3e5d45 Merge branch 'kvm-pvclock-raw-spinlock' into HEAD
pvclock_gtod_sync_lock is completely gone in Linux 5.16.  Include this
fix into the kvm/next history to record that the syzkaller report is
not valid there.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-25 08:40:24 -04:00
David Woodhouse
8228c77d8b KVM: x86: switch pvclock_gtod_sync_lock to a raw spinlock
On the preemption path when updating a Xen guest's runstate times, this
lock is taken inside the scheduler rq->lock, which is a raw spinlock.
This was shown in a lockdep warning:

[   89.138354] =============================
[   89.138356] [ BUG: Invalid wait context ]
[   89.138358] 5.15.0-rc5+ #834 Tainted: G S        I E
[   89.138360] -----------------------------
[   89.138361] xen_shinfo_test/2575 is trying to lock:
[   89.138363] ffffa34a0364efd8 (&kvm->arch.pvclock_gtod_sync_lock){....}-{3:3}, at: get_kvmclock_ns+0x1f/0x130 [kvm]
[   89.138442] other info that might help us debug this:
[   89.138444] context-{5:5}
[   89.138445] 4 locks held by xen_shinfo_test/2575:
[   89.138447]  #0: ffff972bdc3b8108 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0x77/0x6f0 [kvm]
[   89.138483]  #1: ffffa34a03662e90 (&kvm->srcu){....}-{0:0}, at: kvm_arch_vcpu_ioctl_run+0xdc/0x8b0 [kvm]
[   89.138526]  #2: ffff97331fdbac98 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0xff/0xbd0
[   89.138534]  #3: ffffa34a03662e90 (&kvm->srcu){....}-{0:0}, at: kvm_arch_vcpu_put+0x26/0x170 [kvm]
...
[   89.138695]  get_kvmclock_ns+0x1f/0x130 [kvm]
[   89.138734]  kvm_xen_update_runstate+0x14/0x90 [kvm]
[   89.138783]  kvm_xen_update_runstate_guest+0x15/0xd0 [kvm]
[   89.138830]  kvm_arch_vcpu_put+0xe6/0x170 [kvm]
[   89.138870]  kvm_sched_out+0x2f/0x40 [kvm]
[   89.138900]  __schedule+0x5de/0xbd0

Cc: stable@vger.kernel.org
Reported-by: syzbot+b282b65c2c68492df769@syzkaller.appspotmail.com
Fixes: 30b5c851af ("KVM: x86/xen: Add support for vCPU runstate information")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <1b02a06421c17993df337493a68ba923f3bd5c0f.camel@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-25 08:14:38 -04:00
David Edmondson
0d7d84498f KVM: x86: SGX must obey the KVM_INTERNAL_ERROR_EMULATION protocol
When passing the failing address and size out to user space, SGX must
ensure not to trample on the earlier fields of the emulation_failure
sub-union of struct kvm_run.

Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210920103737.2696756-5-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-25 06:48:25 -04:00
David Edmondson
e615e35589 KVM: x86: On emulation failure, convey the exit reason, etc. to userspace
Should instruction emulation fail, include the VM exit reason, etc. in
the emulation_failure data passed to userspace, in order that the VMM
can report it as a debugging aid when describing the failure.

Suggested-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210920103737.2696756-4-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-25 06:48:24 -04:00
David Edmondson
0a62a0319a KVM: x86: Get exit_reason as part of kvm_x86_ops.get_exit_info
Extend the get_exit_info static call to provide the reason for the VM
exit. Modify relevant trace points to use this rather than extracting
the reason in the caller.

Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210920103737.2696756-3-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-25 06:48:24 -04:00
David Edmondson
a9d496d8e0 KVM: x86: Clarify the kvm_run.emulation_failure structure layout
Until more flags for kvm_run.emulation_failure flags are defined, it
is undetermined whether new payload elements corresponding to those
flags will be additive or alternative. As a hint to userspace that an
alternative is possible, wrap the current payload elements in a union.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210920103737.2696756-2-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-25 06:48:24 -04:00
Eric Farman
67cf68b6a5 KVM: s390: Add a routine for setting userspace CPU state
This capability exists, but we don't record anything when userspace
enables it. Let's refactor that code so that a note can be made in
the debug logs that it was enabled.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20211008203112.1979843-7-farman@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-25 09:20:39 +02:00
Eric Farman
8eeba194a3 KVM: s390: Simplify SIGP Set Arch handling
The Principles of Operations describe the various reasons that
each individual SIGP orders might be rejected, and the status
bit that are set for each condition.

For example, for the Set Architecture order, it states:

  "If it is not true that all other CPUs in the configu-
   ration are in the stopped or check-stop state, ...
   bit 54 (incorrect state) ... is set to one."

However, it also states:

  "... if the CZAM facility is installed, ...
   bit 55 (invalid parameter) ... is set to one."

Since the Configuration-z/Architecture-Architectural Mode (CZAM)
facility is unconditionally presented, there is no need to examine
each VCPU to determine if it is started/stopped. It can simply be
rejected outright with the Invalid Parameter bit.

Fixes: b697e435ae ("KVM: s390: Support Configuration z/Architecture Mode")
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20211008203112.1979843-2-farman@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-25 09:20:39 +02:00
Claudio Imbrenda
f0a1a0615a KVM: s390: pv: avoid stalls when making pages secure
Improve make_secure_pte to avoid stalls when the system is heavily
overcommitted. This was especially problematic in kvm_s390_pv_unpack,
because of the loop over all pages that needed unpacking.

Due to the locks being held, it was not possible to simply replace
uv_call with uv_call_sched. A more complex approach was
needed, in which uv_call is replaced with __uv_call, which does not
loop. When the UVC needs to be executed again, -EAGAIN is returned, and
the caller (or its caller) will try again.

When -EAGAIN is returned, the path is the same as when the page is in
writeback (and the writeback check is also performed, which is
harmless).

Fixes: 214d9bbcd3 ("s390/mm: provide memory management functions for protected KVM guests")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210920132502.36111-5-imbrenda@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-25 09:20:39 +02:00
Claudio Imbrenda
1e2aa46de5 KVM: s390: pv: avoid stalls for kvm_s390_pv_init_vm
When the system is heavily overcommitted, kvm_s390_pv_init_vm might
generate stall notifications.

Fix this by using uv_call_sched instead of just uv_call. This is ok because
we are not holding spinlocks.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Fixes: 214d9bbcd3 ("s390/mm: provide memory management functions for protected KVM guests")
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Message-Id: <20210920132502.36111-4-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-25 09:20:39 +02:00
Claudio Imbrenda
d4074324b0 KVM: s390: pv: avoid double free of sida page
If kvm_s390_pv_destroy_cpu is called more than once, we risk calling
free_page on a random page, since the sidad field is aliased with the
gbea, which is not guaranteed to be zero.

This can happen, for example, if userspace calls the KVM_PV_DISABLE
IOCTL, and it fails, and then userspace calls the same IOCTL again.
This scenario is only possible if KVM has some serious bug or if the
hardware is broken.

The solution is to simply return successfully immediately if the vCPU
was already non secure.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Fixes: 19e1227768 ("KVM: S390: protvirt: Introduce instruction data area bounce buffer")
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20210920132502.36111-3-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-25 09:20:38 +02:00
Claudio Imbrenda
57c5df13ec KVM: s390: pv: add macros for UVC CC values
Add macros to describe the 4 possible CC values returned by the UVC
instruction.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Message-Id: <20210920132502.36111-2-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-25 09:20:38 +02:00
David Hildenbrand
14ea40e22c s390/mm: optimize reset_guest_reference_bit()
We already optimize get_guest_storage_key() to assume that if we don't have
a PTE table and don't have a huge page mapped that the storage key is 0.

Similarly, optimize reset_guest_reference_bit() to simply do nothing if
there is no PTE table and no huge page mapped.

Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20210909162248.14969-10-david@redhat.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-25 09:20:38 +02:00
David Hildenbrand
7cb70266b0 s390/mm: optimize set_guest_storage_key()
We already optimize get_guest_storage_key() to assume that if we don't have
a PTE table and don't have a huge page mapped that the storage key is 0.

Similarly, optimize set_guest_storage_key() to simply do nothing in case
the key to set is 0.

Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20210909162248.14969-9-david@redhat.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-25 09:20:38 +02:00
David Hildenbrand
8318c404cf s390/mm: no need for pte_alloc_map_lock() if we know the pmd is present
pte_map_lock() is sufficient.

Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20210909162248.14969-8-david@redhat.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-25 09:20:38 +02:00
David Hildenbrand
46c22ffd27 s390/uv: fully validate the VMA before calling follow_page()
We should not walk/touch page tables outside of VMA boundaries when
holding only the mmap sem in read mode. Evil user space can modify the
VMA layout just before this function runs and e.g., trigger races with
page table removal code since commit dd2283f260 ("mm: mmap: zap pages
with read mmap_sem in munmap").

find_vma() does not check if the address is >= the VMA start address;
use vma_lookup() instead.

Fixes: 214d9bbcd3 ("s390/mm: provide memory management functions for protected KVM guests")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Link: https://lore.kernel.org/r/20210909162248.14969-6-david@redhat.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2021-10-25 09:20:38 +02:00