kernel/linux.git/tools/testing/selftests/kvm/x86, branch linux-7.0.y

KVM: selftests: Fix reserved value WRMSR testcase for multi-feature MSRs

2026-05-07T04:13:49+00:00

commit 9396cc1e282a280bcba2e932e03994e0aada4cd8 upstream. When determining whether or not a WRMSR with reserved bits will #GP or succeed due to the WRMSR not existing per the guest virtual CPU model, expect failure if and only if _all_ features associated with the MSR are unsupported. Checking only the primary feature results in false failures when running on AMD and Hygon CPUs with only one of RDPID or RDTSCP, as AMD/Hygon CPUs ignore MSR_TSC_AUX[63:32], i.e. don't treat the bits as reserved, and so #GP only if the MSR is unsupported. Fixes: 9c38ddb3df94 ("KVM: selftests: Add an MSR test to exercise guest/host and read/write") Reported-by: Zhiquan Li Closes: https://lore.kernel.org/all/20260209041305.64906-6-zhiquan_li@163.com Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260212103841.171459-5-zhiquan_li@163.com Signed-off-by: Sean Christopherson Signed-off-by: Greg Kroah-Hartman

KVM: selftests: Remove duplicate LAUNCH_UPDATE_VMSA call in SEV-ES migrate test

2026-04-22T11:32:20+00:00

commit 25a642b6abc98bbbabbf2baef9fc498bbea6aee6 upstream. Drop the explicit KVM_SEV_LAUNCH_UPDATE_VMSA call when creating an SEV-ES VM in the SEV migration test, as sev_vm_create() automatically updates the VMSA pages for SEV-ES guests. The only reason the duplicate call doesn't cause visible problems is because the test doesn't actually try to run the vCPUs. That will change when KVM adds a check to prevent userspace from re-launching a VMSA (which corrupts the VMSA page due to KVM writing encrypted private memory). Fixes: 69f8e15ab61f ("KVM: selftests: Use the SEV library APIs in the intra-host migration test") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260310234829.2608037-2-seanjc@google.com Signed-off-by: Sean Christopherson Signed-off-by: Greg Kroah-Hartman

KVM: selftests: Verify SEV+ guests can read and write EFER, CR0, CR4, and CR8

2026-03-12T16:31:53+00:00

Add "do no harm" testing of EFER, CR0, CR4, and CR8 for SEV+ guests to verify that the guest can read and write the registers, without hitting e.g. a #VC on SEV-ES guests due to KVM incorrectly trying to intercept a register. Signed-off-by: Sean Christopherson Message-ID: <20260310211841.2552361-3-seanjc@google.com> Signed-off-by: Paolo Bonzini

selftests: kvm: add a test that VMX validates controls on RSM

2026-03-11T17:41:12+00:00

Add a test checking that invalid eVMCS contents are validated after an RSM instruction is emulated. The failure mode is simply that the RSM succeeds, because KVM virtualizes NMIs anyway while running L2; the two pin-based execution controls used by the test are entirely handled by KVM and not by the processor. Signed-off-by: Paolo Bonzini

selftests: kvm: extract common functionality out of smm_test.c

2026-03-11T17:41:12+00:00

Signed-off-by: Paolo Bonzini

Merge tag 'kvm-x86-apic-6.20' of https://github.com/kvm-x86/linux into HEAD

2026-02-11T17:45:32+00:00

KVM x86 APIC-ish changes for 6.20 - Fix a benign bug where KVM could use the wrong memslots (ignored SMM) when creating a vCPU-specific mapping of guest memory. - Clean up KVM's handling of marking mapped vCPU pages dirty. - Drop a pile of *ancient* sanity checks hidden behind in KVM's unused ASSERT() macro, most of which could be trivially triggered by the guest and/or user, and all of which were useless. - Fold "struct dest_map" into its sole user, "struct rtc_status", to make it more obvious what the weird parameter is used for, and to allow burying the RTC shenanigans behind CONFIG_KVM_IOAPIC=y. - Bury all of ioapic.h and KVM_IRQCHIP_KERNEL behind CONFIG_KVM_IOAPIC=y. - Add a regression test for recent APICv update fixes. - Rework KVM's handling of VMCS updates while L2 is active to temporarily switch to vmcs01 instead of deferring the update until the next nested VM-Exit. The deferred updates approach directly contributed to several bugs, was proving to be a maintenance burden due to the difficulty in auditing the correctness of deferred updates, and was polluting "struct nested_vmx" with a growing pile of booleans. - Handle "hardware APIC ISR", a.k.a. SVI, updates in kvm_apic_update_apicv() to consolidate the updates, and to co-locate SVI updates with the updates for KVM's own cache of ISR information. - Drop a dead function declaration.

Merge tag 'kvm-x86-svm-6.20' of https://github.com/kvm-x86/linux into HEAD

2026-02-09T17:51:37+00:00

KVM SVM changes for 6.20 - Drop a user-triggerable WARN on nested_svm_load_cr3() failure. - Add support for virtualizing ERAPS. Note, correct virtualization of ERAPS relies on an upcoming, publicly announced change in the APM to reduce the set of conditions where hardware (i.e. KVM) *must* flush the RAP. - Ignore nSVM intercepts for instructions that are not supported according to L1's virtual CPU model. - Add support for expedited writes to the fast MMIO bus, a la VMX's fastpath for EPT Misconfig. - Don't set GIF when clearing EFER.SVME, as GIF exists independently of SVM, and allow userspace to restore nested state with GIF=0. - Treat exit_code as an unsigned 64-bit value through all of KVM. - Add support for fetching SNP certificates from userspace. - Fix a bug where KVM would use vmcb02 instead of vmcb01 when emulating VMLOAD or VMSAVE on behalf of L2. - Misc fixes and cleanups.

Merge tag 'kvm-x86-selftests-6.20' of https://github.com/kvm-x86/linux into HEAD

2026-02-09T17:38:54+00:00

KVM selftests changes for 6.20 - Add a regression test for TPR<=>CR8 synchronization and IRQ masking. - Overhaul selftest's MMU infrastructure to genericize stage-2 MMU support, and extend x86's infrastructure to support EPT and NPT (for L2 guests). - Extend several nested VMX tests to also cover nested SVM. - Add a selftest for nested VMLOAD/VMSAVE. - Rework the nested dirty log test, originally added as a regression test for PML where KVM logged L2 GPAs instead of L1 GPAs, to improve test coverage and to hopefully make the test easier to understand and maintain.

KVM: selftests: Test READ=>WRITE dirty logging behavior for shadow MMU

2026-01-16T15:48:54+00:00

Update the nested dirty log test to validate KVM's handling of READ faults when dirty logging is enabled. Specifically, set the Dirty bit in the guest PTEs used to map L2 GPAs, so that KVM will create writable SPTEs when handling L2 read faults. When handling read faults in the shadow MMU, KVM opportunistically creates a writable SPTE if the mapping can be writable *and* the gPTE is dirty (or doesn't support the Dirty bit), i.e. if KVM doesn't need to intercept writes in order to emulate Dirty-bit updates. To actually test the L2 READ=>WRITE sequence, e.g. without masking a false pass by other test activity, route the READ=>WRITE and WRITE=>WRITE sequences to separate L1 pages, and differentiate between "marked dirty due to a WRITE access/fault" and "marked dirty due to creating a writable SPTE for a READ access/fault". The updated sequence exposes the bug fixed by KVM commit 1f4e5fc83a42 ("KVM: x86: fix nested guest live migration with PML") when the guest performs a READ=>WRITE sequence with dirty guest PTEs. Opportunistically tweak and rename the address macros, and add comments, to make it more obvious what the test is doing. E.g. NESTED_TEST_MEM1 vs. GUEST_TEST_MEM doesn't make it all that obvious that the test is creating aliases in both the L2 GPA and GVA address spaces, but only when L1 is using TDP to run L2. Cc: Yosry Ahmed Reviewed-by: Yosry Ahmed Link: https://patch.msgid.link/20260115172154.709024-1-seanjc@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Add a selftests for nested VMLOAD/VMSAVE

2026-01-14T22:09:10+00:00

Add a test for VMLOAD/VMSAVE in an L2 guest. The test verifies that L1 intercepts for VMSAVE/VMLOAD always work regardless of VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK. Then, more interestingly, it makes sure that when L1 does not intercept VMLOAD/VMSAVE, they work as intended in L2. When VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK is enabled by L1, VMSAVE/VMLOAD from L2 should interpret the GPA as an L2 GPA and translate it through the NPT. When VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK is disabled by L1, VMSAVE/VMLOAD from L2 should interpret the GPA as an L1 GPA. To test this, put two VMCBs (0 and 1) in L1's physical address space, and have a single L2 GPA where: - L2 VMCB GPA == L1 VMCB(0) GPA - L2 VMCB GPA maps to L1 VMCB(1) via the NPT in L1. This setup allows detecting how the GPA is interpreted based on which L1 VMCB is actually accessed. In both cases, L2 sets KERNEL_GS_BASE (one of the fields handled by VMSAVE/VMLOAD), and executes VMSAVE to write its value to the VMCB. The test userspace code then checks that the write was made to the correct VMCB (based on whether VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK is set by L1), and writes a new value to that VMCB. L2 then executes VMLOAD to load the new value and makes sure it's reflected correctly in KERNERL_GS_BASE. Signed-off-by: Yosry Ahmed Link: https://patch.msgid.link/20260110004821.3411245-4-yosry.ahmed@linux.dev Signed-off-by: Sean Christopherson