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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
Torture test the cases where the runstate crosses a page boundary, and
and especially the case where it's configured in 32-bit mode and doesn't,
but then switching to 64-bit mode makes it go onto the second page.
To simplify this, make the KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST ioctl
also update the guest runstate area. It already did so if the actual
runstate changed, as a side-effect of kvm_xen_update_runstate(). So
doing it in the plain adjustment case is making it more consistent, as
well as giving us a nice way to trigger the update without actually
running the vCPU again and changing the values.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Closer inspection of the Xen code shows that we aren't supposed to be
using the XEN_RUNSTATE_UPDATE flag unconditionally. It should be
explicitly enabled by guests through the HYPERVISOR_vm_assist hypercall.
If we randomly set the top bit of ->state_entry_time for a guest that
hasn't asked for it and doesn't expect it, that could make the runtimes
fail to add up and confuse the guest. Without the flag it's perfectly
safe for a vCPU to read its own vcpu_runstate_info; just not for one
vCPU to read *another's*.
I briefly pondered adding a word for the whole set of VMASST_TYPE_*
flags but the only one we care about for HVM guests is this, so it
seemed a bit pointless.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20221127122210.248427-3-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The guest runstate area can be arbitrarily byte-aligned. In fact, even
when a sane 32-bit guest aligns the overall structure nicely, the 64-bit
fields in the structure end up being unaligned due to the fact that the
32-bit ABI only aligns them to 32 bits.
So setting the ->state_entry_time field to something|XEN_RUNSTATE_UPDATE
is buggy, because if it's unaligned then we can't update the whole field
atomically; the low bytes might be observable before the _UPDATE bit is.
Xen actually updates the *byte* containing that top bit, on its own. KVM
should do the same.
In addition, we cannot assume that the runstate area fits within a single
page. One option might be to make the gfn_to_pfn cache cope with regions
that cross a page — but getting a contiguous virtual kernel mapping of a
discontiguous set of IOMEM pages is a distinctly non-trivial exercise,
and it seems this is the *only* current use case for the GPC which would
benefit from it.
An earlier version of the runstate code did use a gfn_to_hva cache for
this purpose, but it still had the single-page restriction because it
used the uhva directly — because it needs to be able to do so atomically
when the vCPU is being scheduled out, so it used pagefault_disable()
around the accesses and didn't just use kvm_write_guest_cached() which
has a fallback path.
So... use a pair of GPCs for the first and potential second page covering
the runstate area. We can get away with locking both at once because
nothing else takes more than one GPC lock at a time so we can invent
a trivial ordering rule.
The common case where it's all in the same page is kept as a fast path,
but in both cases, the actual guest structure (compat or not) is built
up from the fields in @vx, following preset pointers to the state and
times fields. The only difference is whether those pointers point to
the kernel stack (in the split case) or to guest memory directly via
the GPC. The fast path is also fixed to use a byte access for the
XEN_RUNSTATE_UPDATE bit, then the only real difference is the dual
memcpy.
Finally, Xen also does write the runstate area immediately when it's
configured. Flip the kvm_xen_update_runstate() and …_guest() functions
and call the latter directly when the runstate area is set. This means
that other ioctls which modify the runstate also write it immediately
to the guest when they do so, which is also intended.
Update the xen_shinfo_test to exercise the pathological case where the
XEN_RUNSTATE_UPDATE flag in the top byte of the state_entry_time is
actually in a different page to the rest of the 64-bit word.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Conform to the rest of Hyper-V emulation selftests which have 'hyperv'
prefix. Get rid of '_test' suffix as well as the purpose of this code
is fairly obvious.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-49-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Enable Hyper-V L2 TLB flush and check that Hyper-V TLB flush hypercalls
from L2 don't exit to L1 unless 'TlbLockCount' is set in the Partition
assist page.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-48-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Enable Hyper-V L2 TLB flush and check that Hyper-V TLB flush hypercalls
from L2 don't exit to L1 unless 'TlbLockCount' is set in the
Partition assist page.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-47-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Hyper-V MSR-Bitmap tests do RDMSR from L2 to exit to L1. While 'evmcs_test'
correctly clobbers all GPRs (which are not preserved), 'hyperv_svm_test'
does not. Introduce a more generic rdmsr_from_l2() to avoid code
duplication and remove hardcoding of MSRs. Do not put it in common code
because it is really just a selftests bug rather than a processor
feature that requires it.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-46-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
vmmcall()/vmcall() are used to exit from L2 to L1 and no concrete hypercall
ABI is currenty followed. With the introduction of Hyper-V L2 TLB flush
it becomes (theoretically) possible that L0 will take responsibility for
handling the call and no L1 exit will happen. Prevent this by stuffing RAX
(KVM ABI) and RCX (Hyper-V ABI) with 'safe' values.
While on it, convert vmmcall() to 'static inline', make it setup stack
frame and move to include/x86_64/svm_util.h.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-45-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There's no need to pollute VMX and SVM code with Hyper-V specific
stuff and allocate Hyper-V specific test pages for all test as only
few really need them. Create a dedicated struct and an allocation
helper.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-43-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In preparation to putting Hyper-V specific test pages to a dedicated
struct, move eVMCS load logic from load_vmcs(). Tests call load_vmcs()
directly and the only one which needs 'enlightened' version is
evmcs_test so there's not much gain in having this merged.
Temporary pass both GPA and HVA to load_evmcs().
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-42-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Hyper-V VP assist page is not eVMCS specific, it is also used for
enlightened nSVM. Move the code to vendor neutral place.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-41-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
'struct hv_vp_assist_page' definition doesn't match TLFS. Also, define
'struct hv_nested_enlightenments_control' and use it instead of opaque
'__u64'.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-40-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
'struct hv_enlightened_vmcs' definition in selftests is not '__packed'
and so we rely on the compiler doing the right padding. This is not
obvious so it seems beneficial to use the same definition as in kernel.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-39-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce a selftest for Hyper-V PV TLB flush hypercalls
(HvFlushVirtualAddressSpace/HvFlushVirtualAddressSpaceEx,
HvFlushVirtualAddressList/HvFlushVirtualAddressListEx).
The test creates one 'sender' vCPU and two 'worker' vCPU which do busy
loop reading from a certain GVA checking the observed value. Sender
vCPU swaos the data page with another page filled with a different value.
The expectation for workers is also altered. Without TLB flush on worker
vCPUs, they may continue to observe old value. To guard against accidental
TLB flushes for worker vCPUs the test is repeated 100 times.
Hyper-V TLB flush hypercalls are tested in both 'normal' and 'XMM
fast' modes.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-38-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently, tests can only request a new vaddr range by using
vm_vaddr_alloc()/vm_vaddr_alloc_page()/vm_vaddr_alloc_pages() but
these functions allocate and map physical pages too. Make it possible
to request unmapped range too.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-36-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Similar to vm_vaddr_alloc(), virt_map() needs to reflect the mapping
in vm->vpages_mapped.
While on it, remove unneeded code wrapping in vm_vaddr_alloc().
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-35-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce a selftest for Hyper-V PV IPI hypercalls
(HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx).
The test creates one 'sender' vCPU and two 'receiver' vCPU and then
issues various combinations of send IPI hypercalls in both 'normal'
and 'fast' (with XMM input where necessary) mode. Later, the test
checks whether IPIs were delivered to the expected destination vCPU[s].
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-34-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All Hyper-V specific tests issuing hypercalls need this.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-33-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
HYPERV_LINUX_OS_ID needs to be written to HV_X64_MSR_GUEST_OS_ID by
each Hyper-V specific selftest.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-32-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
set_xmm()/get_xmm() helpers are fairly useless as they only read 64 bits
from 128-bit registers. Moreover, these helpers are not used. Borrow
_kvm_read_sse_reg()/_kvm_write_sse_reg() from KVM limiting them to
XMM0-XMM8 for now.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-31-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that KVM isn't littered with "struct hv_enlightenments" casts, rename
the struct to "hv_vmcb_enlightenments" to highlight the fact that the
struct is specifically for SVM's VMCB.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a union to provide hv_enlightenments side-by-side with the sw_reserved
bytes that Hyper-V's enlightenments overlay. Casting sw_reserved
everywhere is messy, confusing, and unnecessarily unsafe.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move Hyper-V's VMCB "struct hv_enlightenments" to the svm.h header so
that the struct can be referenced in "struct vmcb_control_area".
Alternatively, a dedicated header for SVM+Hyper-V could be added, a la
x86_64/evmcs.h, but it doesn't appear that Hyper-V will end up needing
a wholesale replacement for the VMCB.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move Hyper-V's VMCB enlightenment definitions to the TLFS header; the
definitions come directly from the TLFS[*], not from KVM.
No functional change intended.
[*] https://learn.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/datatypes/hv_svm_enlightened_vmcb_fields
[vitaly: rename VMCB_HV_ -> HV_VMCB_ to match the rest of
hyperv-tlfs.h, keep svm/hyperv.h]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This fixes three issues in nested SVM:
1) in the shutdown_interception() vmexit handler we call kvm_vcpu_reset().
However, if running nested and L1 doesn't intercept shutdown, the function
resets vcpu->arch.hflags without properly leaving the nested state.
This leaves the vCPU in inconsistent state and later triggers a kernel
panic in SVM code. The same bug can likely be triggered by sending INIT
via local apic to a vCPU which runs a nested guest.
On VMX we are lucky that the issue can't happen because VMX always
intercepts triple faults, thus triple fault in L2 will always be
redirected to L1. Plus, handle_triple_fault() doesn't reset the vCPU.
INIT IPI can't happen on VMX either because INIT events are masked while
in VMX mode.
Secondarily, KVM doesn't honour SHUTDOWN intercept bit of L1 on SVM.
A normal hypervisor should always intercept SHUTDOWN, a unit test on
the other hand might want to not do so.
Finally, the guest can trigger a kernel non rate limited printk on SVM
from the guest, which is fixed as well.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a SVM implementation to triple_fault_test to test that
emulated/injected shutdown works.
Since instead of the VMX, the SVM allows the hypervisor to avoid
intercepting shutdown in guest, don't intercept shutdown to test that
KVM suports this correctly.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20221103141351.50662-9-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add test that tests that on SVM if L1 doesn't intercept SHUTDOWN,
then L2 crashes L1 and doesn't crash L2
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20221103141351.50662-7-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
struct idt_entry will be used for a test which will break IDT on purpose.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20221103141351.50662-6-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that a VM isn't needed to check for nEPT support, assert that KVM
supports nEPT in prepare_eptp() instead of skipping the test, and push
the TEST_REQUIRE() check out to individual tests. The require+assert are
somewhat redundant and will incur some amount of ongoing maintenance
burden, but placing the "require" logic in the test makes it easier to
find/understand a test's requirements and in this case, provides a very
strong hint that the test cares about nEPT.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20220927165209.930904-1-dmatlack@google.com
[sean: rebase on merged code, write changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
When checking for nEPT support in KVM, use kvm_get_feature_msr() instead
of vcpu_get_msr() to retrieve KVM's default TRUE_PROCBASED_CTLS and
PROCBASED_CTLS2 MSR values, i.e. don't require a VM+vCPU to query nEPT
support.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20220927165209.930904-1-dmatlack@google.com
[sean: rebase on merged code, write changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Drop kvm_get_supported_cpuid_entry() and its inner helper now that all
known usage can use X86_FEATURE_*, X86_PROPERTY_*, X86_PMU_FEATURE_*, or
the dedicated Family/Model helpers. Providing "raw" access to CPUID
leafs is undesirable as it encourages open coding CPUID checks, which is
often error prone and not self-documenting.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-13-seanjc@google.com
Add KVM variants of the x86 Family and Model helpers, and use them in the
PMU event filter test. Open code the retrieval of KVM's supported CPUID
entry 0x1.0 in anticipation of dropping kvm_get_supported_cpuid_entry().
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-12-seanjc@google.com
Add dedicated helpers for getting x86's Family and Model, which are the
last holdouts that "need" raw access to CPUID information. FMS info is
a mess and requires not only splicing together multiple values, but
requires doing so conditional in the Family case.
Provide wrappers to reduce the odds of copy+paste errors, but mostly to
allow for the eventual removal of kvm_get_supported_cpuid_entry().
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-11-seanjc@google.com
Add an X86_PMU_FEATURE_* framework to simplify probing architectural
events on Intel PMUs, which require checking the length of a bit vector
and the _absence_ of a "feature" bit. Add helpers for both KVM and
"this CPU", and use the newfangled magic (along with X86_PROPERTY_*)
to clean up pmu_event_filter_test.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-10-seanjc@google.com
Add X86_PROPERTY_PMU_VERSION and use it in vmx_pmu_caps_test to replace
open coded versions of the same functionality.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-9-seanjc@google.com
Add and use x86 "properties" for the myriad AMX CPUID values that are
validated by the AMX test. Drop most of the test's single-usage
helpers so that the asserts more precisely capture what check failed.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-8-seanjc@google.com
Extent X86_PROPERTY_* support to KVM, i.e. add kvm_cpu_property() and
kvm_cpu_has_p(), and use the new helpers in kvm_get_cpu_address_width().
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-7-seanjc@google.com
Use X86_PROPERTY_MAX_KVM_LEAF to replace the equivalent open coded check
on KVM's maximum paravirt CPUID leaf.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-5-seanjc@google.com
Introduce X86_PROPERTY_* to allow retrieving values/properties from CPUID
leafs, e.g. MAXPHYADDR from CPUID.0x80000008. Use the same core code as
X86_FEATURE_*, the primary difference is that properties are multi-bit
values, whereas features enumerate a single bit.
Add this_cpu_has_p() to allow querying whether or not a property exists
based on the maximum leaf associated with the property, e.g. MAXPHYADDR
doesn't exist if the max leaf for 0x8000_xxxx is less than 0x8000_0008.
Use the new property infrastructure in vm_compute_max_gfn() to prove
that the code works as intended. Future patches will convert additional
selftests code.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-4-seanjc@google.com
Refactor the X86_FEATURE_* framework to prepare for extending the core
logic to support "properties". The "feature" framework allows querying a
single CPUID bit to detect the presence of a feature; the "property"
framework will extend the idea to allow querying a value, i.e. to get a
value that is a set of contiguous bits in a CPUID leaf.
Opportunistically add static asserts to ensure features are fully defined
at compile time, and to try and catch mistakes in the definition of
features.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-3-seanjc@google.com
Add X86_FEATURE_PAE and use it to guesstimate the MAXPHYADDR when the
MAXPHYADDR CPUID entry isn't supported.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006005125.680782-2-seanjc@google.com
Add a selftest to exercise the KVM_CAP_EXIT_ON_EMULATION_FAILURE
capability.
This capability is also exercised through
smaller_maxphyaddr_emulation_test, but that test requires
allow_smaller_maxphyaddr=Y, which is off by default on Intel when ept=Y
and unconditionally disabled on AMD when npt=Y. This new test ensures
that KVM_CAP_EXIT_ON_EMULATION_FAILURE is exercised independent of
allow_smaller_maxphyaddr.
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-11-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Change smaller_maxphyaddr_emulation_test to expect a #PF(RSVD), rather
than an emulation failure, when TDP is disabled. KVM only needs to
emulate instructions to emulate a smaller guest.MAXPHYADDR when TDP is
enabled.
Fixes: 39bbcc3a4e39 ("selftests: kvm: Allows userspace to handle emulation errors.")
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-10-dmatlack@google.com
[sean: massage comment to talk about having to emulate due to MAXPHYADDR]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Provide the error code on a fault in KVM_ASM_SAFE(), e.g. to allow tests
to assert that #PF generates the correct error code without needing to
manually install a #PF handler. Use r10 as the scratch register for the
error code, as it's already clobbered by the asm blob (loaded with the
RIP of the to-be-executed instruction). Deliberately load the output
"error_code" even in the non-faulting path so that error_code is always
initialized with deterministic data (the aforementioned RIP), i.e to
ensure a selftest won't end up with uninitialized consumption regardless
of how KVM_ASM_SAFE() is used.
Don't clear r10 in the non-faulting case and instead load error code with
the RIP (see above). The error code is valid if and only if an exception
occurs, and '0' isn't necessarily a better "invalid" value, e.g. '0'
could result in false passes for a buggy test.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-9-dmatlack@google.com
Clear R9 in the non-faulting path of KVM_ASM_SAFE() and fall through to
to a common load of "vector" to effectively load "vector" with '0' to
reduce the code footprint of the asm blob, to reduce the runtime overhead
of the non-faulting path (when "vector" is stored in a register), and so
that additional output constraints that are valid if and only if a fault
occur are loaded even in the non-faulting case.
A future patch will add a 64-bit output for the error code, and if its
output is not explicitly loaded with _something_, the user of the asm
blob can end up technically consuming uninitialized data. Using a
common path to load the output constraints will allow using an existing
scratch register, e.g. r10, to hold the error code in the faulting path,
while also guaranteeing the error code is initialized with deterministic
data in the non-faulting patch (r10 is loaded with the RIP of
to-be-executed instruction).
Consuming the error code when a fault doesn't occur would obviously be a
test bug, but there's no guarantee the compiler will detect uninitialized
consumption. And conversely, it's theoretically possible that the
compiler might throw a false positive on uninitialized data, e.g. if the
compiler can't determine that the non-faulting path won't touch the error
code.
Alternatively, the error code could be explicitly loaded in the
non-faulting path, but loading a 64-bit memory|register output operand
with an explicitl value requires a sign-extended "MOV imm32, r/m64",
which isn't exactly straightforward and has a largish code footprint.
And loading the error code with what is effectively garbage (from a
scratch register) avoids having to choose an arbitrary value for the
non-faulting case.
Opportunistically remove a rogue asterisk in the block comment.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-8-dmatlack@google.com
Copy KVM's macros for page fault error masks into processor.h so they
can be used in selftests.
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-7-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Move the flds instruction emulation failure handling code to a header
so it can be re-used in an upcoming test.
No functional change intended.
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-5-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
