Oliver Upton [Fri, 9 Dec 2022 01:53:02 +0000 (01:53 +0000)]
KVM: selftests: Mark correct page as mapped in virt_map()
The loop marks vaddr as mapped after incrementing it by page size,
thereby marking the *next* page as mapped. Set the bit in vpages_mapped
first instead.
Fixes: 56fc7732031d ("KVM: selftests: Fill in vm->vpages_mapped bitmap in virt_map() too") Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Message-Id: <20221209015307.1781352-4-oliver.upton@linux.dev> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Oliver Upton [Fri, 9 Dec 2022 01:53:04 +0000 (01:53 +0000)]
KVM: arm64: selftests: Don't identity map the ucall MMIO hole
Currently the ucall MMIO hole is placed immediately after slot0, which
is a relatively safe address in the PA space. However, it is possible
that the same address has already been used for something else (like the
guest program image) in the VA space. At least in my own testing,
building the vgic_irq test with clang leads to the MMIO hole appearing
underneath gicv3_ops.
Stop identity mapping the MMIO hole and instead find an unused VA to map
to it. Yet another subtle detail of the KVM selftests library is that
virt_pg_map() does not update vm->vpages_mapped. Switch over to
virt_map() instead to guarantee that the chosen VA isn't to something
else.
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Message-Id: <20221209015307.1781352-6-oliver.upton@linux.dev> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Mon, 12 Dec 2022 10:36:53 +0000 (05:36 -0500)]
KVM: selftests: document the default implementation of vm_vaddr_populate_bitmap
Explain the meaning of the bit manipulations of vm_vaddr_populate_bitmap.
These correspond to the "canonical addresses" of x86 and other
architectures, but that is not obvious.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Use magic value to signal ucall_alloc() failure
Use a magic value to signal a ucall_alloc() failure instead of simply
doing GUEST_ASSERT(). GUEST_ASSERT() relies on ucall_alloc() and so a
failure puts the guest into an infinite loop.
Use -1 as the magic value, as a real ucall struct should never wrap.
Reported-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Disable gnu-variable-sized-type-not-at-end so that tests and libraries
can create overlays of variable sized arrays at the end of structs when
using a fixed number of entries, e.g. to get/set a single MSR.
It's possible to fudge around the warning, e.g. by defining a custom
struct that hardcodes the number of entries, but that is a burden for
both developers and readers of the code.
lib/x86_64/processor.c:664:19: warning: field 'header' with variable sized type 'struct kvm_msrs'
not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
struct kvm_msrs header;
^
lib/x86_64/processor.c:772:19: warning: field 'header' with variable sized type 'struct kvm_msrs'
not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
struct kvm_msrs header;
^
lib/x86_64/processor.c:787:19: warning: field 'header' with variable sized type 'struct kvm_msrs'
not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
struct kvm_msrs header;
^
3 warnings generated.
x86_64/hyperv_tlb_flush.c:54:18: warning: field 'hv_vp_set' with variable sized type 'struct hv_vpset'
not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
struct hv_vpset hv_vp_set;
^
1 warning generated.
x86_64/xen_shinfo_test.c:137:25: warning: field 'info' with variable sized type 'struct kvm_irq_routing'
not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
struct kvm_irq_routing info;
^
1 warning generated.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213001653.3852042-12-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Include lib.mk before consuming $(CC)
Include lib.mk before consuming $(CC) and document that lib.mk overwrites
$(CC) unless make was invoked with -e or $(CC) was specified after make
(which makes the environment override the Makefile). Including lib.mk
after using it for probing, e.g. for -no-pie, can lead to weirdness.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213001653.3852042-11-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Explicitly disable builtins for mem*() overrides
Explicitly disable the compiler's builtin memcmp(), memcpy(), and
memset(). Because only lib/string_override.c is built with -ffreestanding,
the compiler reserves the right to do what it wants and can try to link the
non-freestanding code to its own crud.
/usr/bin/x86_64-linux-gnu-ld: /lib/x86_64-linux-gnu/libc.a(memcmp.o): in function `memcmp_ifunc':
(.text+0x0): multiple definition of `memcmp'; tools/testing/selftests/kvm/lib/string_override.o:
tools/testing/selftests/kvm/lib/string_override.c:15: first defined here
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Fixes: 6b6f71484bf4 ("KVM: selftests: Implement memcmp(), memcpy(), and memset() for guest use") Reported-by: Aaron Lewis <aaronlewis@google.com> Reported-by: Raghavendra Rao Ananta <rananta@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213001653.3852042-10-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Probe -no-pie with actual CFLAGS used to compile
Probe -no-pie with the actual set of CFLAGS used to compile the tests,
clang whines about -no-pie being unused if the tests are compiled with
-static.
clang: warning: argument unused during compilation: '-no-pie'
[-Wunused-command-line-argument]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213001653.3852042-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Use proper function prototypes in probing code
Make the main() functions in the probing code proper prototypes so that
compiling the probing code with more strict flags won't generate false
negatives.
<stdin>:1:5: error: function declaration isn’t a prototype [-Werror=strict-prototypes]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213001653.3852042-8-seanjc@google.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Rename UNAME_M to ARCH_DIR, fill explicitly for x86
Rename UNAME_M to ARCH_DIR and explicitly set it directly for x86. At
this point, the name of the arch directory really doesn't have anything
to do with `uname -m`, and UNAME_M is unnecessarily confusing given that
its purpose is purely to identify the arch specific directory.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213001653.3852042-7-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Fix a typo in x86-64's kvm_get_cpu_address_width()
Fix a == vs. = typo in kvm_get_cpu_address_width() that results in
@pa_bits being left unset if the CPU doesn't support enumerating its
MAX_PHY_ADDR. Flagged by clang's unusued-value warning.
Fixes: 3bd396353d18 ("KVM: selftests: Add X86_FEATURE_PAE and use it calc "fallback" MAXPHYADDR") Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221213001653.3852042-6-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Use pattern matching in .gitignore
Use pattern matching to exclude everything except .c, .h, .S, and .sh
files from Git. Manually adding every test target has an absurd
maintenance cost, is comically error prone, and leads to bikeshedding
over whether or not the targets should be listed in alphabetical order.
Deliberately do not include the one-off assets, e.g. config, settings,
.gitignore itself, etc as Git doesn't ignore files that are already in
the repository. Adding the one-off assets won't prevent mistakes where
developers forget to --force add files that don't match the "allowed".
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213001653.3852042-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Fix divide-by-zero bug in memslot_perf_test
Check that the number of pages per slot is non-zero in get_max_slots()
prior to computing the remaining number of pages. clang generates code
that uses an actual DIV for calculating the remaining, which causes a #DE
if the total number of pages is less than the number of slots.
traps: memslot_perf_te[97611] trap divide error ip:4030c4 sp:7ffd18ae58f0
error:0 in memslot_perf_test[401000+cb000]
Fixes: a69170c65acd ("KVM: selftests: memslot_perf_test: Report optimal memory slots") Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221213001653.3852042-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Delete dead code in x86_64/vmx_tsc_adjust_test.c
Delete an unused struct definition in x86_64/vmx_tsc_adjust_test.c.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213001653.3852042-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Define literal to asm constraint in aarch64 as unsigned long
Define a literal '0' asm input constraint to aarch64/page_fault_test's
guest_cas() as an unsigned long to make clang happy.
tools/testing/selftests/kvm/aarch64/page_fault_test.c:120:16: error:
value size does not match register size specified by the constraint
and modifier [-Werror,-Wasm-operand-widths]
:: "r" (0), "r" (TEST_DATA), "r" (guest_test_memory));
^
tools/testing/selftests/kvm/aarch64/page_fault_test.c:119:15: note:
use constraint modifier "w"
"casal %0, %1, [%2]\n"
^~
%w0
Fixes: 35c581015712 ("KVM: selftests: aarch64: Add aarch64/page_fault_test") Cc: Ricardo Koller <ricarkol@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221213001653.3852042-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86/mmu: Don't install TDP MMU SPTE if SP has unexpected level
Don't install a leaf TDP MMU SPTE if the parent page's level doesn't
match the target level of the fault, and instead have the vCPU retry the
faulting instruction after warning. Continuing on is completely
unnecessary as the absolute worst case scenario of retrying is DoSing
the vCPU, whereas continuing on all but guarantees bigger explosions, e.g.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213033030.83345-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86/mmu: Re-check under lock that TDP MMU SP hugepage is disallowed
Re-check sp->nx_huge_page_disallowed under the tdp_mmu_pages_lock spinlock
when adding a new shadow page in the TDP MMU. To ensure the NX reclaim
kthread can't see a not-yet-linked shadow page, the page fault path links
the new page table prior to adding the page to possible_nx_huge_pages.
If the page is zapped by different task, e.g. because dirty logging is
disabled, between linking the page and adding it to the list, KVM can end
up triggering use-after-free by adding the zapped SP to the aforementioned
list, as the zapped SP's memory is scheduled for removal via RCU callback.
The bug is detected by the sanity checks guarded by CONFIG_DEBUG_LIST=y,
i.e. the below splat is just one possible signature.
Map the leaf SPTE when handling a TDP MMU page fault if and only if the
target level is reached. A recent commit reworked the retry logic and
incorrectly assumed that walking SPTEs would never "fail", as the loop
either bails (retries) or installs parent SPs. However, the iterator
itself will bail early if it detects a frozen (REMOVED) SPTE when
stepping down. The TDP iterator also rereads the current SPTE before
stepping down specifically to avoid walking into a part of the tree that
is being removed, which means it's possible to terminate the loop without
the guts of the loop observing the frozen SPTE, e.g. if a different task
zaps a parent SPTE between the initial read and try_step_down()'s refresh.
Mapping a leaf SPTE at the wrong level results in all kinds of badness as
page table walkers interpret the SPTE as a page table, not a leaf, and
walk into the weeds.
Fixes: 63d28a25e04c ("KVM: x86/mmu: simplify kvm_tdp_mmu_map flow when guest has to retry") Cc: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213033030.83345-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86/mmu: Don't attempt to map leaf if target TDP MMU SPTE is frozen
Hoist the is_removed_spte() check above the "level == goal_level" check
when walking SPTEs during a TDP MMU page fault to avoid attempting to map
a leaf entry if said entry is frozen by a different task/vCPU.
Fixes: 63d28a25e04c ("KVM: x86/mmu: simplify kvm_tdp_mmu_map flow when guest has to retry") Cc: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Robert Hoo <robert.hu@linux.intel.com>
Message-Id: <20221213033030.83345-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: nVMX: Don't stuff secondary execution control if it's not supported
When stuffing the allowed secondary execution controls for nested VMX in
response to CPUID updates, don't set the allowed-1 bit for a feature that
isn't supported by KVM, i.e. isn't allowed by the canonical vmcs_config.
WARN if KVM attempts to manipulate a feature that isn't supported. All
features that are currently stuffed are always advertised to L1 for
nested VMX if they are supported in KVM's base configuration, and no
additional features should ever be added to the CPUID-induced stuffing
(updating VMX MSRs in response to CPUID updates is a long-standing KVM
flaw that is slowly being fixed).
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213062306.667649-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: nVMX: Properly expose ENABLE_USR_WAIT_PAUSE control to L1
Set ENABLE_USR_WAIT_PAUSE in KVM's supported VMX MSR configuration if the
feature is supported in hardware and enabled in KVM's base, non-nested
configuration, i.e. expose ENABLE_USR_WAIT_PAUSE to L1 if it's supported.
This fixes a bug where saving/restoring, i.e. migrating, a vCPU will fail
if WAITPKG (the associated CPUID feature) is enabled for the vCPU, and
obviously allows L1 to enable the feature for L2.
KVM already effectively exposes ENABLE_USR_WAIT_PAUSE to L1 by stuffing
the allowed-1 control ina vCPU's virtual MSR_IA32_VMX_PROCBASED_CTLS2 when
updating secondary controls in response to KVM_SET_CPUID(2), but (a) that
depends on flawed code (KVM shouldn't touch VMX MSRs in response to CPUID
updates) and (b) runs afoul of vmx_restore_control_msr()'s restriction
that the guest value must be a strict subset of the supported host value.
Although no past commit explicitly enabled nested support for WAITPKG,
doing so is safe and functionally correct from an architectural
perspective as no additional KVM support is needed to virtualize TPAUSE,
UMONITOR, and UMWAIT for L2 relative to L1, and KVM already forwards
VM-Exits to L1 as necessary (commit bf653b78f960, "KVM: vmx: Introduce
handle_unexpected_vmexit and handle WAITPKG vmexit").
Note, KVM always keeps the hosts MSR_IA32_UMWAIT_CONTROL resident in
hardware, i.e. always runs both L1 and L2 with the host's power management
settings for TPAUSE and UMWAIT. See commit bf09fb6cba4f ("KVM: VMX: Stop
context switching MSR_IA32_UMWAIT_CONTROL") for more details.
Fixes: e69e72faa3a0 ("KVM: x86: Add support for user wait instructions") Cc: stable@vger.kernel.org Reported-by: Aaron Lewis <aaronlewis@google.com> Reported-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20221213062306.667649-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: nVMX: Document that ignoring memory failures for VMCLEAR is deliberate
Explicitly drop the result of kvm_vcpu_write_guest() when writing the
"launch state" as part of VMCLEAR emulation, and add a comment to call
out that KVM's behavior is architecturally valid. Intel's pseudocode
effectively says that VMCLEAR is a nop if the target VMCS address isn't
in memory, e.g. if the address points at MMIO.
Add a FIXME to call out that suppressing failures on __copy_to_user() is
wrong, as memory (a memslot) does exist in that case. Punt the issue to
the future as open coding kvm_vcpu_write_guest() just to make sure the
guest dies with -EFAULT isn't worth the extra complexity. The flaw will
need to be addressed if KVM ever does something intelligent on uaccess
failures, e.g. to support post-copy demand paging, but in that case KVM
will need a more thorough overhaul, i.e. VMCLEAR shouldn't need to open
code a core KVM helper.
No functional change intended.
Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1527765 ("Error handling issues") Fixes: 587d7e72aedc ("kvm: nVMX: VMCLEAR should not cause the vCPU to shut down") Cc: Jim Mattson <jmattson@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221220154224.526568-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Zero out valid_bank_mask for "all" case in Hyper-V IPI test
Zero out the valid_bank_mask when using the fast variant of
HVCALL_SEND_IPI_EX to send IPIs to all vCPUs. KVM requires the "var_cnt"
and "valid_bank_mask" inputs to be consistent even when targeting all
vCPUs. See commit bd1ba5732bb9 ("KVM: x86: Get the number of Hyper-V
sparse banks from the VARHEAD field").
KVM: x86: Sanity check inputs to kvm_handle_memory_failure()
Add a sanity check in kvm_handle_memory_failure() to assert that a valid
x86_exception structure is provided if the memory "failure" wants to
propagate a fault into the guest. If a memory failure happens during a
direct guest physical memory access, e.g. for nested VMX, KVM hardcodes
the failure to X86EMUL_IO_NEEDED and doesn't provide an exception pointer
(because the exception struct would just be filled with garbage).
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221220153427.514032-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In kvm_hv_flush_tlb(), 'data_offset' and 'consumed_xmm_halves' variables
are used in a mutually exclusive way: in 'hc->fast' we count in 'XMM
halves' and increase 'data_offset' otherwise. Coverity discovered, that in
one case both variables are incremented unconditionally. This doesn't seem
to cause any issues as the only user of 'data_offset'/'consumed_xmm_halves'
data is kvm_hv_get_tlb_flush_entries() -> kvm_hv_get_hc_data() which also
takes into account 'hc->fast' but is still worth fixing.
To make things explicit, put 'data_offset' and 'consumed_xmm_halves' to
'struct kvm_hv_hcall' as a union and use at call sites. This allows to
remove explicit 'data_offset'/'consumed_xmm_halves' parameters from
kvm_hv_get_hc_data()/kvm_get_sparse_vp_set()/kvm_hv_get_tlb_flush_entries()
helpers.
Note: 'struct kvm_hv_hcall' is allocated on stack in kvm_hv_hypercall() and
is not zeroed, consumers are supposed to initialize the appropriate field
if needed.
When scanning userspace I/OAPIC entries, intercept EOI for level-triggered
IRQs if the current vCPU has a pending and/or in-service IRQ for the
vector in its local API, even if the vCPU doesn't match the new entry's
destination. This fixes a race between userspace I/OAPIC reconfiguration
and IRQ delivery that results in the vector's bit being left set in the
remote IRR due to the eventual EOI not being forwarded to the userspace
I/OAPIC.
Commit 0fc5a36dd6b3 ("KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC
reconfigure race") fixed the in-kernel IOAPIC, but not the userspace
IOAPIC configuration, which has a similar race.
Fixes: 0fc5a36dd6b3 ("KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC reconfigure race") Signed-off-by: Adamos Ttofari <attofari@amazon.de> Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221208094415.12723-1-attofari@amazon.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Wed, 7 Dec 2022 07:15:05 +0000 (15:15 +0800)]
KVM: x86/pmu: Prevent zero period event from being repeatedly released
The current vPMU can reuse the same pmc->perf_event for the same
hardware event via pmc_pause/resume_counter(), but this optimization
does not apply to a portion of the TSX events (e.g., "event=0x3c,in_tx=1,
in_tx_cp=1"), where event->attr.sample_period is legally zero at creation,
thus making the perf call to perf_event_period() meaningless (no need to
adjust sample period in this case), and instead causing such reusable
perf_events to be repeatedly released and created.
Avoid releasing zero sample_period events by checking is_sampling_event()
to follow the previously enable/disable optimization.
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20221207071506.15733-2-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86: Add proper ReST tables for userspace MSR exits/flags
Add ReST formatting to the set of userspace MSR exits/flags so that the
resulting HTML docs generate a table instead of malformed gunk. This
also fixes a warning that was introduced by a recent cleanup of the
relevant documentation (yay copy+paste).
>> Documentation/virt/kvm/api.rst:7287: WARNING: Block quote ends
without a blank line; unexpected unindent.
Fixes: 1ae099540e8c ("KVM: x86: Allow deflecting unknown MSR accesses to user space") Fixes: 1f158147181b ("KVM: x86: Clean up KVM_CAP_X86_USER_SPACE_MSR documentation") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221207000959.2035098-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Tue, 6 Dec 2022 17:29:06 +0000 (12:29 -0500)]
Merge remote-tracking branch 'kvm/queue' into HEAD
x86 Xen-for-KVM:
* Allow the Xen runstate information to cross a page boundary
* Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured
* add support for 32-bit guests in SCHEDOP_poll
x86 fixes:
* One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0).
* Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few
years back when eliminating unnecessary barriers when switching between
vmcs01 and vmcs02.
* Clean up the MSR filter docs.
* Clean up vmread_error_trampoline() to make it more obvious that params
must be passed on the stack, even for x86-64.
* Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective
of the current guest CPUID.
* Fudge around a race with TSC refinement that results in KVM incorrectly
thinking a guest needs TSC scaling when running on a CPU with a
constant TSC, but no hardware-enumerated TSC frequency.
* Advertise (on AMD) that the SMM_CTL MSR is not supported
* Remove unnecessary exports
Selftests:
* Fix an inverted check in the access tracking perf test, and restore
support for asserting that there aren't too many idle pages when
running on bare metal.
* Fix an ordering issue in the AMX test introduced by recent conversions
to use kvm_cpu_has(), and harden the code to guard against similar bugs
in the future. Anything that tiggers caching of KVM's supported CPUID,
kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if
the caching occurs before the test opts in via prctl().
* Fix build errors that occur in certain setups (unsure exactly what is
unique about the problematic setup) due to glibc overriding
static_assert() to a variant that requires a custom message.
* Introduce actual atomics for clear/set_bit() in selftests
Oliver Upton [Wed, 7 Dec 2022 21:48:08 +0000 (21:48 +0000)]
KVM: selftests: Allocate ucall pool from MEM_REGION_DATA
MEM_REGION_TEST_DATA is meant to hold data explicitly used by a
selftest, not implicit allocations due to the selftests infrastructure.
Allocate the ucall pool from MEM_REGION_DATA much like the rest of the
selftests library allocations.
Fixes: 426729b2cf2e ("KVM: selftests: Add ucall pool based implementation") Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Message-Id: <20221207214809.489070-5-oliver.upton@linux.dev> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Oliver Upton [Wed, 7 Dec 2022 21:48:07 +0000 (21:48 +0000)]
KVM: arm64: selftests: Align VA space allocator with TTBR0
An interesting feature of the Arm architecture is that the stage-1 MMU
supports two distinct VA regions, controlled by TTBR{0,1}_EL1. As KVM
selftests on arm64 only uses TTBR0_EL1, the VA space is constrained to
[0, 2^(va_bits-1)). This is different from other architectures that
allow for addressing low and high regions of the VA space from a single
page table.
KVM selftests' VA space allocator presumes the valid address range is
split between low and high memory based the MSB, which of course is a
poor match for arm64's TTBR0 region.
Allow architectures to override the default VA space layout. Make use of
the override to align vpages_valid with the behavior of TTBR0 on arm64.
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Message-Id: <20221207214809.489070-4-oliver.upton@linux.dev> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Tue, 6 Dec 2022 17:27:39 +0000 (12:27 -0500)]
Merge tag 'kvmarm-6.2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 6.2
- Enable the per-vcpu dirty-ring tracking mechanism, together with an
option to keep the good old dirty log around for pages that are
dirtied by something other than a vcpu.
- Switch to the relaxed parallel fault handling, using RCU to delay
page table reclaim and giving better performance under load.
- Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
option, which multi-process VMMs such as crosvm rely on.
- Merge the pKVM shadow vcpu state tracking that allows the hypervisor
to have its own view of a vcpu, keeping that state private.
- Add support for the PMUv3p5 architecture revision, bringing support
for 64bit counters on systems that support it, and fix the
no-quite-compliant CHAIN-ed counter support for the machines that
actually exist out there.
- Fix a handful of minor issues around 52bit VA/PA support (64kB pages
only) as a prefix of the oncoming support for 4kB and 16kB pages.
- Add/Enable/Fix a bunch of selftests covering memslots, breakpoints,
stage-2 faults and access tracking. You name it, we got it, we
probably broke it.
- Pick a small set of documentation and spelling fixes, because no
good merge window would be complete without those.
As a side effect, this tag also drags:
- The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring
series
- A shared branch with the arm64 tree that repaints all the system
registers to match the ARM ARM's naming, and resulting in
interesting conflicts
Marc Zyngier [Mon, 5 Dec 2022 14:38:44 +0000 (14:38 +0000)]
Merge branch kvm-arm64/pmu-unchained into kvmarm-master/next
* kvm-arm64/pmu-unchained:
: .
: PMUv3 fixes and improvements:
:
: - Make the CHAIN event handling strictly follow the architecture
:
: - Add support for PMUv3p5 (64bit counters all the way)
:
: - Various fixes and cleanups
: .
KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow
KVM: arm64: PMU: Sanitise PMCR_EL0.LP on first vcpu run
KVM: arm64: PMU: Simplify PMCR_EL0 reset handling
KVM: arm64: PMU: Replace version number '0' with ID_AA64DFR0_EL1_PMUVer_NI
KVM: arm64: PMU: Make kvm_pmc the main data structure
KVM: arm64: PMU: Simplify vcpu computation on perf overflow notification
KVM: arm64: PMU: Allow PMUv3p5 to be exposed to the guest
KVM: arm64: PMU: Implement PMUv3p5 long counter support
KVM: arm64: PMU: Allow ID_DFR0_EL1.PerfMon to be set from userspace
KVM: arm64: PMU: Allow ID_AA64DFR0_EL1.PMUver to be set from userspace
KVM: arm64: PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creation
KVM: arm64: PMU: Do not let AArch32 change the counters' top 32 bits
KVM: arm64: PMU: Simplify setting a counter to a specific value
KVM: arm64: PMU: Add counter_index_to_*reg() helpers
KVM: arm64: PMU: Only narrow counters that are not 64bit wide
KVM: arm64: PMU: Narrow the overflow checking when required
KVM: arm64: PMU: Distinguish between 64bit counter and 64bit overflow
KVM: arm64: PMU: Always advertise the CHAIN event
KVM: arm64: PMU: Align chained counter implementation with architecture pseudocode
arm64: Add ID_DFR0_EL1.PerfMon values for PMUv3p7 and IMP_DEF
Marc Zyngier [Mon, 5 Dec 2022 14:38:24 +0000 (14:38 +0000)]
Merge branch kvm-arm64/mte-map-shared into kvmarm-master/next
* kvm-arm64/mte-map-shared:
: .
: Update the MTE support to allow the VMM to use shared mappings
: to back the memslots exposed to MTE-enabled guests.
:
: Patches courtesy of Catalin Marinas and Peter Collingbourne.
: .
: Fix a number of issues with MTE, such as races on the tags
: being initialised vs the PG_mte_tagged flag as well as the
: lack of support for VM_SHARED when KVM is involved.
:
: Patches from Catalin Marinas and Peter Collingbourne.
: .
Documentation: document the ABI changes for KVM_CAP_ARM_MTE
KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled
KVM: arm64: unify the tests for VMAs in memslots when MTE is enabled
arm64: mte: Lock a page for MTE tag initialisation
mm: Add PG_arch_3 page flag
KVM: arm64: Simplify the sanitise_mte_tags() logic
arm64: mte: Fix/clarify the PG_mte_tagged semantics
mm: Do not enable PG_arch_2 for all 64-bit architectures
Marc Zyngier [Mon, 5 Dec 2022 14:30:49 +0000 (14:30 +0000)]
Merge branch kvm-arm64/pkvm-vcpu-state into kvmarm-master/next
* kvm-arm64/pkvm-vcpu-state: (25 commits)
: .
: Large drop of pKVM patches from Will Deacon and co, adding
: a private vm/vcpu state at EL2, managed independently from
: the EL1 state. From the cover letter:
:
: "This is version six of the pKVM EL2 state series, extending the pKVM
: hypervisor code so that it can dynamically instantiate and manage VM
: data structures without the host being able to access them directly.
: These structures consist of a hyp VM, a set of hyp vCPUs and the stage-2
: page-table for the MMU. The pages used to hold the hypervisor structures
: are returned to the host when the VM is destroyed."
: .
KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()
KVM: arm64: Don't unnecessarily map host kernel sections at EL2
KVM: arm64: Explicitly map 'kvm_vgic_global_state' at EL2
KVM: arm64: Maintain a copy of 'kvm_arm_vmid_bits' at EL2
KVM: arm64: Unmap 'kvm_arm_hyp_percpu_base' from the host
KVM: arm64: Return guest memory from EL2 via dedicated teardown memcache
KVM: arm64: Instantiate guest stage-2 page-tables at EL2
KVM: arm64: Consolidate stage-2 initialisation into a single function
KVM: arm64: Add generic hyp_memcache helpers
KVM: arm64: Provide I-cache invalidation by virtual address at EL2
KVM: arm64: Initialise hypervisor copies of host symbols unconditionally
KVM: arm64: Add per-cpu fixmap infrastructure at EL2
KVM: arm64: Instantiate pKVM hypervisor VM and vCPU structures from EL1
KVM: arm64: Add infrastructure to create and track pKVM instances at EL2
KVM: arm64: Rename 'host_kvm' to 'host_mmu'
KVM: arm64: Add hyp_spinlock_t static initializer
KVM: arm64: Include asm/kvm_mmu.h in nvhe/mem_protect.h
KVM: arm64: Add helpers to pin memory shared with the hypervisor at EL2
KVM: arm64: Prevent the donation of no-map pages
KVM: arm64: Implement do_donate() helper for donating memory
...
Marc Zyngier [Mon, 5 Dec 2022 14:22:55 +0000 (14:22 +0000)]
Merge branch kvm-arm64/parallel-faults into kvmarm-master/next
* kvm-arm64/parallel-faults:
: .
: Parallel stage-2 fault handling, courtesy of Oliver Upton.
: From the cover letter:
:
: "Presently KVM only takes a read lock for stage 2 faults if it believes
: the fault can be fixed by relaxing permissions on a PTE (write unprotect
: for dirty logging). Otherwise, stage 2 faults grab the write lock, which
: predictably can pile up all the vCPUs in a sufficiently large VM.
:
: Like the TDP MMU for x86, this series loosens the locking around
: manipulations of the stage 2 page tables to allow parallel faults. RCU
: and atomics are exploited to safely build/destroy the stage 2 page
: tables in light of multiple software observers."
: .
KVM: arm64: Reject shared table walks in the hyp code
KVM: arm64: Don't acquire RCU read lock for exclusive table walks
KVM: arm64: Take a pointer to walker data in kvm_dereference_pteref()
KVM: arm64: Handle stage-2 faults in parallel
KVM: arm64: Make table->block changes parallel-aware
KVM: arm64: Make leaf->leaf PTE changes parallel-aware
KVM: arm64: Make block->table PTE changes parallel-aware
KVM: arm64: Split init and set for table PTE
KVM: arm64: Atomically update stage 2 leaf attributes in parallel walks
KVM: arm64: Protect stage-2 traversal with RCU
KVM: arm64: Tear down unlinked stage-2 subtree after break-before-make
KVM: arm64: Use an opaque type for pteps
KVM: arm64: Add a helper to tear down unlinked stage-2 subtrees
KVM: arm64: Don't pass kvm_pgtable through kvm_pgtable_walk_data
KVM: arm64: Pass mm_ops through the visitor context
KVM: arm64: Stash observed pte value in visitor context
KVM: arm64: Combine visitor arguments into a context structure
Marc Zyngier [Mon, 5 Dec 2022 14:19:50 +0000 (14:19 +0000)]
Merge branch kvm-arm64/dirty-ring into kvmarm-master/next
* kvm-arm64/dirty-ring:
: .
: Add support for the "per-vcpu dirty-ring tracking with a bitmap
: and sprinkles on top", courtesy of Gavin Shan.
:
: This branch drags the kvmarm-fixes-6.1-3 tag which was already
: merged in 6.1-rc4 so that the branch is in a working state.
: .
KVM: Push dirty information unconditionally to backup bitmap
KVM: selftests: Automate choosing dirty ring size in dirty_log_test
KVM: selftests: Clear dirty ring states between two modes in dirty_log_test
KVM: selftests: Use host page size to map ring buffer in dirty_log_test
KVM: arm64: Enable ring-based dirty memory tracking
KVM: Support dirty ring in conjunction with bitmap
KVM: Move declaration of kvm_cpu_dirty_log_size() to kvm_dirty_ring.h
KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL
Marc Zyngier [Mon, 5 Dec 2022 14:19:27 +0000 (14:19 +0000)]
Merge branch kvm-arm64/52bit-fixes into kvmarm-master/next
* kvm-arm64/52bit-fixes:
: .
: 52bit PA fixes, courtesy of Ryan Roberts. From the cover letter:
:
: "I've been adding support for FEAT_LPA2 to KVM and as part of that work have been
: testing various (84) configurations of HW, host and guest kernels on FVP. This
: has thrown up a couple of pre-existing bugs, for which the fixes are provided."
: .
KVM: arm64: Fix benign bug with incorrect use of VA_BITS
KVM: arm64: Fix PAR_TO_HPFAR() to work independently of PA_BITS.
KVM: arm64: Fix kvm init failure when mode!=vhe and VA_BITS=52.
Ryan Roberts [Mon, 5 Dec 2022 11:40:31 +0000 (11:40 +0000)]
KVM: arm64: Fix benign bug with incorrect use of VA_BITS
get_user_mapping_size() uses kvm's pgtable library to walk a user space
page table created by the kernel, and in doing so, passes metadata
that the library needs, including ia_bits, which defines the size of the
input address.
For the case where the kernel is compiled for 52 VA bits but runs on HW
that does not support LVA, it will fall back to 48 VA bits at runtime.
Therefore we must use vabits_actual rather than VA_BITS to get the true
address size.
This is benign in the current code base because the pgtable library only
uses it for error checking.
Marc Zyngier [Mon, 5 Dec 2022 14:16:55 +0000 (14:16 +0000)]
Merge branch kvm-arm64/selftest/access-tracking into kvmarm-master/next
* kvm-arm64/selftest/access-tracking:
: .
: Small series to add support for arm64 to access_tracking_perf_test and
: correct a couple bugs along the way.
:
: Patches courtesy of Oliver Upton.
: .
KVM: selftests: Build access_tracking_perf_test for arm64
KVM: selftests: Have perf_test_util signal when to stop vCPUs
Marc Zyngier [Mon, 5 Dec 2022 14:16:41 +0000 (14:16 +0000)]
Merge branch kvm-arm64/selftest/s2-faults into kvmarm-master/next
* kvm-arm64/selftest/s2-faults:
: .
: New KVM/arm64 selftests exercising various sorts of S2 faults, courtesy
: of Ricardo Koller. From the cover letter:
:
: "This series adds a new aarch64 selftest for testing stage 2 fault handling
: for various combinations of guest accesses (e.g., write, S1PTW), backing
: sources (e.g., anon), and types of faults (e.g., read on hugetlbfs with a
: hole, write on a readonly memslot). Each test tries a different combination
: and then checks that the access results in the right behavior (e.g., uffd
: faults with the right address and write/read flag). [...]"
: .
KVM: selftests: aarch64: Add mix of tests into page_fault_test
KVM: selftests: aarch64: Add readonly memslot tests into page_fault_test
KVM: selftests: aarch64: Add dirty logging tests into page_fault_test
KVM: selftests: aarch64: Add userfaultfd tests into page_fault_test
KVM: selftests: aarch64: Add aarch64/page_fault_test
KVM: selftests: Use the right memslot for code, page-tables, and data allocations
KVM: selftests: Fix alignment in virt_arch_pgd_alloc() and vm_vaddr_alloc()
KVM: selftests: Add vm->memslots[] and enum kvm_mem_region_type
KVM: selftests: Stash backing_src_type in struct userspace_mem_region
tools: Copy bitfield.h from the kernel sources
KVM: selftests: aarch64: Construct DEFAULT_MAIR_EL1 using sysreg.h macros
KVM: selftests: Add missing close and munmap in __vm_mem_region_delete()
KVM: selftests: aarch64: Add virt_get_pte_hva() library function
KVM: selftests: Add a userfaultfd library
Marc Zyngier [Mon, 5 Dec 2022 14:16:24 +0000 (14:16 +0000)]
Merge branch kvm-arm64/selftest/linked-bps into kvmarm-master/next
* kvm-arm64/selftest/linked-bps:
: .
: Additional selftests for the arm64 breakpoints/watchpoints,
: courtesy of Reiji Watanabe. From the cover letter:
:
: "This series adds test cases for linked {break,watch}points to the
: debug-exceptions test, and expands {break,watch}point tests to
: use non-zero {break,watch}points (the current test always uses
: {break,watch}point#0)."
: .
KVM: arm64: selftests: Test with every breakpoint/watchpoint
KVM: arm64: selftests: Add a test case for a linked watchpoint
KVM: arm64: selftests: Add a test case for a linked breakpoint
KVM: arm64: selftests: Change debug_version() to take ID_AA64DFR0_EL1
KVM: arm64: selftests: Stop unnecessary test stage tracking of debug-exceptions
KVM: arm64: selftests: Add helpers to enable debug exceptions
KVM: arm64: selftests: Remove the hard-coded {b,w}pn#0 from debug-exceptions
KVM: arm64: selftests: Add write_dbg{b,w}{c,v}r helpers in debug-exceptions
KVM: arm64: selftests: Use FIELD_GET() to extract ID register fields
Marc Zyngier [Mon, 5 Dec 2022 14:16:07 +0000 (14:16 +0000)]
Merge branch kvm-arm64/selftest/memslot-fixes into kvmarm-master/next
* kvm-arm64/selftest/memslot-fixes:
: .
: KVM memslot selftest fixes for non-4kB page sizes, courtesy
: of Gavin Shan. From the cover letter:
:
: "kvm/selftests/memslots_perf_test doesn't work with 64KB-page-size-host
: and 4KB-page-size-guest on aarch64. In the implementation, the host and
: guest page size have been hardcoded to 4KB. It's ovbiously not working
: on aarch64 which supports 4KB, 16KB, 64KB individually on host and guest.
:
: This series tries to fix it. After the series is applied, the test runs
: successfully with 64KB-page-size-host and 4KB-page-size-guest."
: .
KVM: selftests: memslot_perf_test: Report optimal memory slots
KVM: selftests: memslot_perf_test: Consolidate memory
KVM: selftests: memslot_perf_test: Support variable guest page size
KVM: selftests: memslot_perf_test: Probe memory slots for once
KVM: selftests: memslot_perf_test: Consolidate loop conditions in prepare_vm()
KVM: selftests: memslot_perf_test: Use data->nslots in prepare_vm()
Marc Zyngier [Mon, 5 Dec 2022 12:05:51 +0000 (12:05 +0000)]
KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow
Fix the bogus masking when computing the period of a 64bit counter
with 32bit overflow. It really should be treated like a 32bit counter
for the purpose of the period.
Jim Mattson [Fri, 7 Oct 2022 22:16:44 +0000 (15:16 -0700)]
KVM: x86: Advertise that the SMM_CTL MSR is not supported
CPUID.80000021H:EAX[bit 9] indicates that the SMM_CTL MSR (0xc0010116) is
not supported. This defeature can be advertised by KVM_GET_SUPPORTED_CPUID
regardless of whether or not the host enumerates it; currently it will be
included only if the host enumerates at least leaf 8000001DH, due to a
preexisting bug in QEMU that KVM has to work around (commit f751d8eac176,
"KVM: x86: work around QEMU issue with synthetic CPUID leaves", 2022-04-29).
Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20221007221644.138355-1-jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Fri, 2 Dec 2022 18:34:45 +0000 (13:34 -0500)]
KVM: x86: remove unnecessary exports
Several symbols are not used by vendor modules but still exported.
Removing them ensures that new coupling between kvm.ko and kvm-*.ko
is noticed and reviewed.
Co-developed-by: Sean Christopherson <seanjc@google.com> Co-developed-by: Like Xu <like.xu.linux@gmail.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Like Xu <like.xu.linux@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There is a spelling mistake in some help text. Fix it.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Message-Id: <20221201091354.1613652-1-colin.i.king@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
tools: KVM: selftests: Convert clear/set_bit() to actual atomics
Convert {clear,set}_bit() to atomics as KVM's ucall implementation relies
on clear_bit() being atomic, they are defined in atomic.h, and the same
helpers in the kernel proper are atomic.
KVM's ucall infrastructure is the only user of clear_bit() in tools/, and
there are no true set_bit() users. tools/testing/nvdimm/ does make heavy
use of set_bit(), but that code builds into a kernel module of sorts, i.e.
pulls in all of the kernel's header and so is already getting the kernel's
atomic set_bit().
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221119013450.2643007-10-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
tools: Drop "atomic_" prefix from atomic test_and_set_bit()
Drop the "atomic_" prefix from tools' atomic_test_and_set_bit() to
match the kernel nomenclature where test_and_set_bit() is atomic,
and __test_and_set_bit() provides the non-atomic variant.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221119013450.2643007-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
tools: Drop conflicting non-atomic test_and_{clear,set}_bit() helpers
Drop tools' non-atomic test_and_set_bit() and test_and_clear_bit() helpers
now that all users are gone. The names will be claimed in the future for
atomic versions.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221119013450.2643007-8-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Use non-atomic clear/set bit helpers in KVM tests
Use the dedicated non-atomic helpers for {clear,set}_bit() and their
test variants, i.e. the double-underscore versions. Depsite being
defined in atomic.h, and despite the kernel versions being atomic in the
kernel, tools' {clear,set}_bit() helpers aren't actually atomic. Move
to the double-underscore versions so that the versions that are expected
to be atomic (for kernel developers) can be made atomic without affecting
users that don't want atomic operations.
Leave the usage in ucall_free() as-is, it's the one place in tools/ that
actually wants/needs atomic behavior.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221119013450.2643007-7-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
perf tools: Use dedicated non-atomic clear/set bit helpers
Use the dedicated non-atomic helpers for {clear,set}_bit() and their
test variants, i.e. the double-underscore versions. Depsite being
defined in atomic.h, and despite the kernel versions being atomic in the
kernel, tools' {clear,set}_bit() helpers aren't actually atomic. Move
to the double-underscore versions so that the versions that are expected
to be atomic (for kernel developers) can be made atomic without affecting
users that don't want atomic operations.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org>
Message-Id: <20221119013450.2643007-6-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
tools: Take @bit as an "unsigned long" in {clear,set}_bit() helpers
Take @bit as an unsigned long instead of a signed int in clear_bit() and
set_bit() so that they match the double-underscore versions, __clear_bit()
and __set_bit(). This will allow converting users that really don't want
atomic operations to the double-underscores without introducing a
functional change, which will in turn allow making {clear,set}_bit()
atomic (as advertised).
Practically speaking, this _should_ have no functional impact. KVM's
selftests usage is either hardcoded (Hyper-V tests) or is artificially
limited (arch_timer test and dirty_log test). In KVM, dirty_log test is
the only mildly interesting case as it's use indirectly restricted to
unsigned 32-bit values, but in theory it could generate a negative value
when cast to a signed int. But in that case, taking an "unsigned long"
is actually a bug fix.
Perf's usage is more difficult to audit, but any code that is affected
by the switch is likely already broken. perf_header__{set,clear}_feat()
and perf_file_header__read() effectively use only hardcoded enums with
small, positive values, atom_new() passes an unsigned long, but its value
is capped at 128 via NR_ATOM_PER_PAGE, etc...
The only real potential for breakage is in the perf flows that take a
"cpu", but it's unlikely perf is subtly relying on a negative index into
bitmaps, e.g. "cpu" can be "-1", but only as "not valid" placeholder.
Note, tools/testing/nvdimm/ makes heavy use of set_bit(), but that code
builds into a kernel module of sorts, i.e. pulls in all of the kernel's
header and so is getting the kernel's atomic set_bit(). The NVDIMM test
usage of atomics is likely unnecessary, e.g. ndtest_dimm_register() sets
bits in a local variable, but that's neither here nor there as far as
this change is concerned.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221119013450.2643007-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: arm64: selftests: Enable single-step without a "full" ucall()
Add a new ucall hook, GUEST_UCALL_NONE(), to allow tests to make ucalls
without allocating a ucall struct, and use it to enable single-step
in ARM's debug-exceptions test. Like the disable single-step path, the
enabling path also needs to ensure that no exclusive access sequences are
attempted after enabling single-step, as the exclusive monitor is cleared
on ERET from the debug exception taken to EL2.
The test currently "works" because clear_bit() isn't actually an atomic
operation... yet.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221119013450.2643007-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Yuan ZhaoXiong [Fri, 2 Dec 2022 12:36:14 +0000 (20:36 +0800)]
KVM: x86: fix APICv/x2AVIC disabled when vm reboot by itself
When a VM reboots itself, the reset process will result in
an ioctl(KVM_SET_LAPIC, ...) to disable x2APIC mode and set
the xAPIC id of the vCPU to its default value, which is the
vCPU id.
When kvm_apic_set_state invokes kvm_lapic_set_base to disable
x2APIC mode, the old 32-bit x2APIC id is still present rather
than the 8-bit xAPIC id. kvm_lapic_xapic_id_updated will set the
APICV_INHIBIT_REASON_APIC_ID_MODIFIED bit and disable APICv/x2AVIC.
Instead, kvm_lapic_xapic_id_updated must be called after APIC_ID is
changed.
In fact, this fixes another small issue in the code in that
potential changes to a vCPU's xAPIC ID need not be tracked for
KVM_GET_LAPIC.
Fixes: 3743c2f02517 ("KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base") Signed-off-by: Yuan ZhaoXiong <yuanzhaoxiong@baidu.com>
Message-Id: <1669984574-32692-1-git-send-email-yuanzhaoxiong@baidu.com> Cc: stable@vger.kernel.org Reported-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Fri, 2 Dec 2022 17:56:25 +0000 (12:56 -0500)]
Merge tag 'kvm-x86-fixes-6.2-1' of https://github.com/kvm-x86/linux into HEAD
Misc KVM x86 fixes and cleanups for 6.2:
- One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0).
- Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few
years back when eliminating unnecessary barriers when switching between
vmcs01 and vmcs02.
- Clean up the MSR filter docs.
- Clean up vmread_error_trampoline() to make it more obvious that params
must be passed on the stack, even for x86-64.
- Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective
of the current guest CPUID.
- Fudge around a race with TSC refinement that results in KVM incorrectly
thinking a guest needs TSC scaling when running on a CPU with a
constant TSC, but no hardware-enumerated TSC frequency.
Paolo Bonzini [Fri, 2 Dec 2022 17:55:55 +0000 (12:55 -0500)]
Merge tag 'kvm-selftests-6.2-2' of https://github.com/kvm-x86/linux into HEAD
KVM selftests fixes for 6.2
- Fix an inverted check in the access tracking perf test, and restore
support for asserting that there aren't too many idle pages when
running on bare metal.
- Fix an ordering issue in the AMX test introduced by recent conversions
to use kvm_cpu_has(), and harden the code to guard against similar bugs
in the future. Anything that tiggers caching of KVM's supported CPUID,
kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if
the caching occurs before the test opts in via prctl().
- Fix build errors that occur in certain setups (unsure exactly what is
unique about the problematic setup) due to glibc overriding
static_assert() to a variant that requires a custom message.
KVM: Reference to kvm_userspace_memory_region in doc and comments
There are still references to the removed kvm_memory_region data structure
but the doc and comments should mention struct kvm_userspace_memory_region
instead, since that is what's used by the ioctl that replaced the old one
and this data structure support the same set of flags.
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Message-Id: <20221202105011.185147-4-javierm@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: Delete all references to removed KVM_SET_MEMORY_ALIAS ioctl
The documentation says that the ioctl has been deprecated, but it has been
actually removed and the remaining references are just left overs.
Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Message-Id: <20221202105011.185147-3-javierm@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: Delete all references to removed KVM_SET_MEMORY_REGION ioctl
The documentation says that the ioctl has been deprecated, but it has been
actually removed and the remaining references are just left overs.
Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Message-Id: <20221202105011.185147-2-javierm@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Define and use a custom static assert in lib headers
Define and use kvm_static_assert() in the common KVM selftests headers to
provide deterministic behavior, and to allow creating static asserts
without dummy messages.
The kernel's static_assert() makes the message param optional, and on the
surface, tools/include/linux/build_bug.h appears to follow suit. However,
glibc may override static_assert() and redefine it as a direct alias of
_Static_assert(), which makes the message parameter mandatory. This leads
to non-deterministic behavior as KVM selftests code that utilizes
static_assert() without a custom message may or not compile depending on
the order of includes. E.g. recently added asserts in
x86_64/processor.h fail on some systems with errors like
In file included from lib/memstress.c:11:0:
include/x86_64/processor.h: In function ‘this_cpu_has_p’:
include/x86_64/processor.h:193:34: error: expected ‘,’ before ‘)’ token
static_assert(low_bit < high_bit); \
^
due to _Static_assert() expecting a comma before a message. The "message
optional" version of static_assert() uses macro magic to strip away the
comma when presented with empty an __VA_ARGS__
which yields "_Static_assert(expr)" and thus fails as above.
KVM selftests don't actually care about using C11, but __USE_ISOC11 gets
defined because of _GNU_SOURCE, which many tests do #define. _GNU_SOURCE
triggers a massive pile of defines in /usr/include/features.h, including
_ISOC11_SOURCE:
/* If _GNU_SOURCE was defined by the user, turn on all the other features. */
#ifdef _GNU_SOURCE
# undef _ISOC95_SOURCE
# define _ISOC95_SOURCE 1
# undef _ISOC99_SOURCE
# define _ISOC99_SOURCE 1
# undef _ISOC11_SOURCE
# define _ISOC11_SOURCE 1
# undef _POSIX_SOURCE
# define _POSIX_SOURCE 1
# undef _POSIX_C_SOURCE
# define _POSIX_C_SOURCE 200809L
# undef _XOPEN_SOURCE
# define _XOPEN_SOURCE 700
# undef _XOPEN_SOURCE_EXTENDED
# define _XOPEN_SOURCE_EXTENDED 1
# undef _LARGEFILE64_SOURCE
# define _LARGEFILE64_SOURCE 1
# undef _DEFAULT_SOURCE
# define _DEFAULT_SOURCE 1
# undef _ATFILE_SOURCE
# define _ATFILE_SOURCE 1
#endif
which further down in /usr/include/features.h leads to:
/* This is to enable the ISO C11 extension. */
#if (defined _ISOC11_SOURCE \
|| (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L))
# define __USE_ISOC11 1
#endif
To make matters worse, /usr/include/assert.h doesn't guard against
multiple inclusion by turning itself into a nop, but instead #undefs a
few macros and continues on. As a result, it's all but impossible to
ensure the "message optional" version of static_assert() will actually be
used, e.g. explicitly including assert.h and #undef'ing static_assert()
doesn't work as a later inclusion of assert.h will again redefine its
version.
KVM: selftests: Do kvm_cpu_has() checks before creating VM+vCPU
Move the AMX test's kvm_cpu_has() checks before creating the VM+vCPU,
there are no dependencies between the two operations. Opportunistically
add a comment to call out that enabling off-by-default XSAVE-managed
features must be done before KVM_GET_SUPPORTED_CPUID is cached.
KVM: selftests: Disallow "get supported CPUID" before REQ_XCOMP_GUEST_PERM
Disallow using kvm_get_supported_cpuid() and thus caching KVM's supported
CPUID info before enabling XSAVE-managed features that are off-by-default
and must be enabled by ARCH_REQ_XCOMP_GUEST_PERM. Caching the supported
CPUID before all XSAVE features are enabled can result in false negatives
due to testing features that were cached before they were enabled.
Move __vm_xsave_require_permission() below the CPUID helpers so that a
future change can reference the cached result of KVM_GET_SUPPORTED_CPUID
while keeping the definition of the variable close to its intended user,
kvm_get_supported_cpuid().
Lei Wang [Mon, 28 Nov 2022 22:57:32 +0000 (22:57 +0000)]
KVM: selftests: Move XFD CPUID checking out of __vm_xsave_require_permission()
Move the kvm_cpu_has() check on X86_FEATURE_XFD out of the helper to
enable off-by-default XSAVE-managed features and into the one test that
currenty requires XFD (XFeature Disable) support. kvm_cpu_has() uses
kvm_get_supported_cpuid() and thus caches KVM_GET_SUPPORTED_CPUID, and so
using kvm_cpu_has() before ARCH_REQ_XCOMP_GUEST_PERM effectively results
in the test caching stale values, e.g. subsequent checks on AMX_TILE will
get false negatives.
Although off-by-default features are nonsensical without XFD, checking
for XFD virtualization prior to enabling such features isn't strictly
required.
KVM: selftests: Restore assert for non-nested VMs in access tracking test
Restore the assert (on x86-64) that <10% of pages are still idle when NOT
running as a nested VM in the access tracking test. The original assert
was converted to a "warning" to avoid false failures when running the
test in a VM, but the non-nested case does not suffer from the same
"infinite TLB size" issue.
Using the HYPERVISOR flag isn't infallible as VMMs aren't strictly
required to enumerate the "feature" in CPUID, but practically speaking
anyone that is running KVM selftests in VMs is going to be using a VMM
and hypervisor that sets the HYPERVISOR flag.
KVM: selftests: Fix inverted "warning" in access tracking perf test
Warn if the number of idle pages is greater than or equal to 10% of the
total number of pages, not if the percentage of idle pages is less than
10%. The original code asserted that less than 10% of pages were still
idle, but the check got inverted when the assert was converted to a
warning.
Opportunistically clean up the warning; selftests are 64-bit only, there
is no need to use "%PRIu64" instead of "%lu".
Fixes: 6336a810db5c ("KVM: selftests: replace assertion with warning in access_tracking_perf_test") Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221129175300.4052283-2-seanjc@google.com
James Morse [Wed, 30 Nov 2022 17:16:15 +0000 (17:16 +0000)]
arm64/sysreg: Extend the maximum width of a register and symbol name
32bit has multiple values for its id registers, as extra properties
were added to the CPUs. Some of these end up having long names, which
exceed the fixed 48 character column that the sysreg awk script generates.
For example, the ID_MMFR1_EL1.L1Hvd field has an encoding whose natural
name would be 'invalidate Iside only'. Using this causes compile errors
as the script generates the following:
#define ID_MMFR1_EL1_L1Hvd_INVALIDATE_ISIDE_ONLYUL(0b0001)
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