| d2ea4ff1 | 10-Mar-2026 |
Sean Christopherson <seanjc@google.com> |
KVM: selftests: Verify SEV+ guests can read and write EFER, CR0, CR4, and CR8
Add "do no harm" testing of EFER, CR0, CR4, and CR8 for SEV+ guests to
verify that the guest can read and write the regi
KVM: selftests: Verify SEV+ guests can read and write EFER, CR0, CR4, and CR8
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 <seanjc@google.com>
Message-ID: <20260310211841.2552361-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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| 3e745694 | 09-Mar-2026 |
Paolo Bonzini <pbonzini@redhat.com> |
selftests: kvm: add a test that VMX validates controls on RSM
Add a test checking that invalid eVMCS contents are validated after an
RSM instruction is emulated.
The failure mode is simply that the
selftests: kvm: add a test that VMX validates controls on RSM
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 <pbonzini@redhat.com>
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| 1b13885e | 09-Feb-2026 |
Paolo Bonzini <pbonzini@redhat.com> |
Merge tag 'kvm-x86-apic-6.20' of https://github.com/kvm-x86/linux into HEAD
KVM x86 APIC-ish changes for 6.20
- Fix a benign bug where KVM could use the wrong memslots (ignored SMM) when
creati
Merge tag 'kvm-x86-apic-6.20' of https://github.com/kvm-x86/linux into HEAD
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.
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| 4215ee0d | 09-Feb-2026 |
Paolo Bonzini <pbonzini@redhat.com> |
Merge tag 'kvm-x86-svm-6.20' of https://github.com/kvm-x86/linux into HEAD
KVM SVM changes for 6.20
- Drop a user-triggerable WARN on nested_svm_load_cr3() failure.
- Add support for virtualizin
Merge tag 'kvm-x86-svm-6.20' of https://github.com/kvm-x86/linux into HEAD
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.
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| a91cc482 | 15-Jan-2026 |
Sean Christopherson <seanjc@google.com> |
KVM: selftests: Test READ=>WRITE dirty logging behavior for shadow MMU
Update the nested dirty log test to validate KVM's handling of READ faults
when dirty logging is enabled. Specifically, set th
KVM: selftests: Test READ=>WRITE dirty logging behavior for shadow MMU
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 <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20260115172154.709024-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| 55058e32 | 10-Jan-2026 |
Yosry Ahmed <yosry.ahmed@linux.dev> |
KVM: selftests: Add a selftests for nested VMLOAD/VMSAVE
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_
KVM: selftests: Add a selftests for nested VMLOAD/VMSAVE
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 <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20260110004821.3411245-4-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| 3611ca7c | 29-Dec-2025 |
Sean Christopherson <seanjc@google.com> |
selftests: kvm: Verify TILELOADD actually #NM faults when XFD[18]=1
Rework the AMX test's #NM handling to use kvm_asm_safe() to verify an #NM
actually occurs. As is, a completely missing #NM could
selftests: kvm: Verify TILELOADD actually #NM faults when XFD[18]=1
Rework the AMX test's #NM handling to use kvm_asm_safe() to verify an #NM
actually occurs. As is, a completely missing #NM could go unnoticed.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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| 0383a8ed | 31-Dec-2025 |
Paolo Bonzini <pbonzini@redhat.com> |
selftests: kvm: try getting XFD and XSAVE state out of sync
The host is allowed to set FPU state that includes a disabled
xstate component. Check that this does not cause bad effects.
Cc: stable@v
selftests: kvm: try getting XFD and XSAVE state out of sync
The host is allowed to set FPU state that includes a disabled
xstate component. Check that this does not cause bad effects.
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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| ca2eccb9 | 21-Nov-2025 |
Yosry Ahmed <yosry.ahmed@linux.dev> |
KVM: selftests: Extend vmx_set_nested_state_test to cover SVM
Add test cases for the validation checks in svm_set_nested_state(), and
allow the test to run with SVM as well as VMX. The SVM test also
KVM: selftests: Extend vmx_set_nested_state_test to cover SVM
Add test cases for the validation checks in svm_set_nested_state(), and
allow the test to run with SVM as well as VMX. The SVM test also makes
sure that KVM_SET_NESTED_STATE accepts GIF being set or cleared if
EFER.SVME is cleared, verifying a recently fixed bug where GIF was
incorrectly expected to always be set when EFER.SVME is cleared.
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251121204803.991707-5-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| e3538504 | 31-Dec-2025 |
Sean Christopherson <seanjc@google.com> |
KVM: selftests: Rename vm_get_page_table_entry() to vm_get_pte()
Shorten the API to get a PTE as the "PTE" acronym is ubiquitous, and the
"page table entry" makes it unnecessarily difficult to quick
KVM: selftests: Rename vm_get_page_table_entry() to vm_get_pte()
Shorten the API to get a PTE as the "PTE" acronym is ubiquitous, and the
"page table entry" makes it unnecessarily difficult to quickly understand
what callers are doing.
No functional change intended.
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230230150.4150236-21-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| 6794d916 | 31-Dec-2025 |
Yosry Ahmed <yosry.ahmed@linux.dev> |
KVM: selftests: Extend vmx_dirty_log_test to cover SVM
Generalize the code in vmx_dirty_log_test.c by adding SVM-specific L1
code, doing some renaming (e.g. EPT -> TDP), and having setup code for
bo
KVM: selftests: Extend vmx_dirty_log_test to cover SVM
Generalize the code in vmx_dirty_log_test.c by adding SVM-specific L1
code, doing some renaming (e.g. EPT -> TDP), and having setup code for
both SVM and VMX in test_dirty_log().
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230230150.4150236-19-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| 753c0d5a | 31-Dec-2025 |
Yosry Ahmed <yosry.ahmed@linux.dev> |
KVM: selftests: Add support for nested NPTs
Implement nCR3 and NPT initialization functions, similar to the EPT
equivalents, and create common TDP helpers for enablement checking and
initialization.
KVM: selftests: Add support for nested NPTs
Implement nCR3 and NPT initialization functions, similar to the EPT
equivalents, and create common TDP helpers for enablement checking and
initialization. Enable NPT for nested guests by default if the TDP MMU
was initialized, similar to VMX.
Reuse the PTE masks from the main MMU in the NPT MMU, except for the C
and S bits related to confidential VMs.
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230230150.4150236-17-seanjc@google.com
[sean: apply Yosry's fixup for ncr3_gpa]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| e40e72fe | 31-Dec-2025 |
Yosry Ahmed <yosry.ahmed@linux.dev> |
KVM: selftests: Stop passing VMX metadata to TDP mapping functions
The root GPA is now retrieved from the nested MMU, stop passing VMX
metadata. This is in preparation for making these functions wor
KVM: selftests: Stop passing VMX metadata to TDP mapping functions
The root GPA is now retrieved from the nested MMU, stop passing VMX
metadata. This is in preparation for making these functions work for
NPTs as well.
Opportunistically drop tdp_pg_map() since it's unused.
No functional change intended.
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230230150.4150236-12-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| f00f519c | 31-Dec-2025 |
Yosry Ahmed <yosry.ahmed@linux.dev> |
KVM: selftests: Use a TDP MMU to share EPT page tables between vCPUs
prepare_eptp() currently allocates new EPTs for each vCPU. memstress has
its own hack to share the EPTs between vCPUs. Currentl
KVM: selftests: Use a TDP MMU to share EPT page tables between vCPUs
prepare_eptp() currently allocates new EPTs for each vCPU. memstress has
its own hack to share the EPTs between vCPUs. Currently, there is no
reason to have separate EPTs for each vCPU, and the complexity is
significant. The only reason it doesn't matter now is because memstress
is the only user with multiple vCPUs.
Add vm_enable_ept() to allocate EPT page tables for an entire VM, and use
it everywhere to replace prepare_eptp(). Drop 'eptp' and 'eptp_hva' from
'struct vmx_pages' as they serve no purpose (e.g. the EPTP can be built
from the PGD), but keep 'eptp_gpa' so that the MMU structure doesn't need
to be passed in along with vmx_pages. Dynamically allocate the TDP MMU
structure to avoid a cyclical dependency between kvm_util_arch.h and
kvm_util.h.
Remove the workaround in memstress to copy the EPT root between vCPUs
since that's now the default behavior.
Name the MMU tdp_mmu instead of e.g. nested_mmu or nested.mmu to avoid
recreating the same mess that KVM has with respect to "nested" MMUs, e.g.
does nested refer to the stage-2 page tables created by L1, or the stage-1
page tables created by L2?
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Link: https://patch.msgid.link/20251230230150.4150236-11-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| 9f073ac2 | 31-Dec-2025 |
Sean Christopherson <seanjc@google.com> |
KVM: selftests: Add "struct kvm_mmu" to track a given MMU instance
Add a "struct kvm_mmu" to track a given MMU instance, e.g. a VM's stage-1
MMU versus a VM's stage-2 MMU, so that x86 can share MMU
KVM: selftests: Add "struct kvm_mmu" to track a given MMU instance
Add a "struct kvm_mmu" to track a given MMU instance, e.g. a VM's stage-1
MMU versus a VM's stage-2 MMU, so that x86 can share MMU functionality for
both stage-1 and stage-2 MMUs, without creating the potential for subtle
bugs, e.g. due to consuming on vm->pgtable_levels when operating a stage-2
MMU.
Encapsulate the existing de facto MMU in "struct kvm_vm", e.g instead of
burying the MMU details in "struct kvm_vm_arch", to avoid more #ifdefs in
____vm_create(), and in the hopes that other architectures can utilize the
formalized MMU structure if/when they too support stage-2 page tables.
No functional change intended.
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230230150.4150236-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| 97dfbdfe | 31-Dec-2025 |
Yosry Ahmed <yosry.ahmed@linux.dev> |
KVM: selftests: Stop passing a memslot to nested_map_memslot()
On x86, KVM selftests use memslot 0 for all the default regions used by
the test infrastructure. This is an implementation detail.
nest
KVM: selftests: Stop passing a memslot to nested_map_memslot()
On x86, KVM selftests use memslot 0 for all the default regions used by
the test infrastructure. This is an implementation detail.
nested_map_memslot() is currently used to map the default regions by
explicitly passing slot 0, which leaks the library implementation into
the caller.
Rename the function to a very verbose
nested_identity_map_default_memslots() to reflect what it actually does.
Add an assertion that only memslot 0 is being used so that the
implementation does not change from under us.
No functional change intended.
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230230150.4150236-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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