kernel/tools/testing/selftests/kvm/include/x86_64, branch linux-6.2.y

Merge tag 'kvm-x86-fixes-6.2-1' of https://github.com/kvm-x86/linux into HEAD

2022-12-02T17:56:25Z

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.

KVM: selftests: Define and use a custom static assert in lib headers

2022-12-01T23:31:46Z

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__ #ifndef static_assert #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr) #define __static_assert(expr, msg, ...) _Static_assert(expr, msg) #endif // static_assert and effectively generates "_Static_assert(expr, #expr)". The incompatible version of static_assert() gets defined by this snippet in /usr/include/assert.h: #if defined __USE_ISOC11 && !defined __cplusplus # undef static_assert # define static_assert _Static_assert #endif 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. #ifdef _ASSERT_H # undef _ASSERT_H # undef assert # undef __ASSERT_VOID_CAST # ifdef __USE_GNU # undef assert_perror # endif #endif /* assert.h */ #define _ASSERT_H 1 #include Fixes: fcba483e8246 ("KVM: selftests: Sanity check input to ioctls() at build time") Fixes: ee3795536664 ("KVM: selftests: Refactor X86_FEATURE_* framework to prep for X86_PROPERTY_*") Fixes: 53a7dc0f215e ("KVM: selftests: Add X86_PROPERTY_* framework to retrieve CPUID values") Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20221122013309.1872347-1-seanjc@google.com

KVM: selftests: Restore assert for non-nested VMs in access tracking test

2022-12-01T23:31:39Z

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. Cc: David Matlack Reviewed-by: Emanuele Giuseppe Esposito Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20221129175300.4052283-3-seanjc@google.com

KVM: selftests: Verify userspace can stuff IA32_FEATURE_CONTROL at will

2022-12-01T00:29:54Z

Verify the KVM allows userspace to set all supported bits in the IA32_FEATURE_CONTROL MSR irrespective of the current guest CPUID, and that all unsupported bits are rejected. Throw the testcase into vmx_msrs_test even though it's not technically a VMX MSR; it's close enough, and the most frequently feature controlled by the MSR is VMX. Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20220607232353.3375324-4-seanjc@google.com

KVM: selftests: hyperv_svm_test: Introduce L2 TLB flush test

2022-11-21T11:42:43Z

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 Signed-off-by: Paolo Bonzini Message-Id: <20221101145426.251680-48-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini

KVM: selftests: evmcs_test: Introduce L2 TLB flush test

2022-11-21T11:42:41Z

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 Signed-off-by: Paolo Bonzini Message-Id: <20221101145426.251680-47-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini

KVM: selftests: Stuff RAX/RCX with 'safe' values in vmmcall()/vmcall()

2022-11-21T11:42:38Z

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 Reviewed-by: Sean Christopherson Signed-off-by: Paolo Bonzini Message-Id: <20221101145426.251680-45-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini

KVM: selftests: Allocate Hyper-V partition assist page

2022-11-21T11:41:59Z

In preparation to testing Hyper-V L2 TLB flush hypercalls, allocate so-called Partition assist page. Reviewed-by: Sean Christopherson Signed-off-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini Message-Id: <20221101145426.251680-44-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini

KVM: selftests: Create a vendor independent helper to allocate Hyper-V specific test pages

2022-11-21T11:41:22Z

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 Signed-off-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini Message-Id: <20221101145426.251680-43-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini

KVM: selftests: Split off load_evmcs() from load_vmcs()

2022-11-21T11:40:42Z

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 Signed-off-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini Message-Id: <20221101145426.251680-42-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini