| dfd2a8b0 | 20-Apr-2026 |
Sean Christopherson <seanjc@google.com> |
KVM: selftests: Replace "paddr" with "gpa" throughout
Replace all variations of "paddr" variables in KVM selftests with "gpa",
with the exception of the ELF structures, as those fields are not speci
KVM: selftests: Replace "paddr" with "gpa" throughout
Replace all variations of "paddr" variables in KVM selftests with "gpa",
with the exception of the ELF structures, as those fields are not specific
to guest virtual addresses, to complete the conversion from vm_paddr_t to
gpa_t.
No functional change intended.
Link: https://patch.msgid.link/20260420212004.3938325-20-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| ea8bc95f | 13-Apr-2026 |
Paolo Bonzini <pbonzini@redhat.com> |
Merge tag 'kvm-x86-nested-7.1' of https://github.com/kvm-x86/linux into HEAD
KVM nested SVM changes for 7.1 (with one common x86 fix)
- To minimize the probability of corrupting guest state, defer
Merge tag 'kvm-x86-nested-7.1' of https://github.com/kvm-x86/linux into HEAD
KVM nested SVM changes for 7.1 (with one common x86 fix)
- To minimize the probability of corrupting guest state, defer KVM's
non-architectural delivery of exception payloads (e.g. CR2 and DR6) until
consumption of the payload is imminent, and force delivery of the payload
in all paths where userspace saves relevant state.
- Use vcpu->arch.cr2 when updating vmcb12's CR2 on nested #VMEXIT to fix a
bug where L2's CR2 can get corrupted after a save/restore, e.g. if the VM
is migrated while L2 is faulting in memory.
- Fix a class of nSVM bugs where some fields written by the CPU are not
synchronized from vmcb02 to cached vmcb12 after VMRUN, and so are not
up-to-date when saved by KVM_GET_NESTED_STATE.
- Fix a class of bugs where the ordering between KVM_SET_NESTED_STATE and
KVM_SET_{S}REGS could cause vmcb02 to be incorrectly initialized after
save+restore.
- Add a variety of missing nSVM consistency checks.
- Fix several bugs where KVM failed to correctly update VMCB fields on nested
#VMEXIT.
- Fix several bugs where KVM failed to correctly synthesize #UD or #GP for
SVM-related instructions.
- Add support for save+restore of virtualized LBRs (on SVM).
- Refactor various helpers and macros to improve clarity and (hopefully) make
the code easier to maintain.
- Aggressively sanitize fields when copying from vmcb12 to guard against
unintentionally allowing L1 to utilize yet-to-be-defined features.
- Fix several bugs where KVM botched rAX legality checks when emulating SVM
instructions. Note, KVM is still flawed in that KVM doesn't address size
prefix overrides for 64-bit guests; this should probably be documented as a
KVM erratum.
- Fail emulation of VMRUN/VMLOAD/VMSAVE if mapping vmcb12 fails instead of
somewhat arbitrarily synthesizing #GP (i.e. don't bastardize AMD's already-
sketchy behavior of generating #GP if for "unsupported" addresses).
- Cache all used vmcb12 fields to further harden against TOCTOU bugs.
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| 53b28692 | 12-Feb-2026 |
Zhiquan Li <zhiquan_li@163.com> |
KVM: selftests: Add a flag to identify AMD compatible test cases
Most of KVM x86 selftests for AMD are compatible with Hygon architecture
(but not all), add a flag "host_cpu_is_amd_compatible" to fi
KVM: selftests: Add a flag to identify AMD compatible test cases
Most of KVM x86 selftests for AMD are compatible with Hygon architecture
(but not all), add a flag "host_cpu_is_amd_compatible" to figure out
these cases.
Following test failures on Hygon platform can be fixed:
* Fix hypercall test: Hygon architecture also uses VMMCALL as guest
hypercall instruction.
* Following test failures due to access reserved memory address regions:
- access_tracking_perf_test
- demand_paging_test
- dirty_log_perf_test
- dirty_log_test
- kvm_page_table_test
- memslot_modification_stress_test
- pre_fault_memory_test
- x86/dirty_log_page_splitting_test
Hygon CSV also makes the "physical address space width reduction", the
reduced physical address bits are reported by bits 11:6 of
CPUID[0x8000001f].EBX as well, so the existed logic is totally
applicable for Hygon processors. Mapping memory into these regions and
accessing to them results in a #PF.
Signed-off-by: Zhiquan Li <zhiquan_li@163.com>
Link: https://patch.msgid.link/20260212103841.171459-3-zhiquan_li@163.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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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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| f756ed82 | 13-Jan-2026 |
Yosry Ahmed <yosry.ahmed@linux.dev> |
KVM: selftests: Slightly simplify memstress_setup_nested()
Instead of calling memstress_setup_ept_mappings() only in the first
iteration in the loop, move it before the loop.
The call needed to hap
KVM: selftests: Slightly simplify memstress_setup_nested()
Instead of calling memstress_setup_ept_mappings() only in the first
iteration in the loop, move it before the loop.
The call needed to happen within the loop before commit e40e72fec0de
("KVM: selftests: Stop passing VMX metadata to TDP mapping functions"),
as memstress_setup_ept_mappings() used to take in a pointer to vmx_pages
and pass it into tdp_identity_map_1g() (to get the EPT root GPA). This
is no longer the case, as tdp_identity_map_1g() gets the EPT root
through stage2 MMU.
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20260113171456.2097312-1-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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| 251e4849 | 31-Dec-2025 |
Yosry Ahmed <yosry.ahmed@linux.dev> |
KVM: selftests: Set the user bit on nested NPT PTEs
According to the APM, NPT walks are treated as user accesses. In
preparation for supporting NPT mappings, set the 'user' bit on NPTs by
adding a m
KVM: selftests: Set the user bit on nested NPT PTEs
According to the APM, NPT walks are treated as user accesses. In
preparation for supporting NPT mappings, set the 'user' bit on NPTs by
adding a mask of bits to always be set on PTEs in kvm_mmu.
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230230150.4150236-18-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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| 9cb1944f | 31-Dec-2025 |
Yosry Ahmed <yosry.ahmed@linux.dev> |
KVM: selftests: Allow kvm_cpu_has_ept() to be called on AMD CPUs
In preparation for generalizing the nested dirty logging test, checking
if either EPT or NPT is enabled will be needed. To avoid need
KVM: selftests: Allow kvm_cpu_has_ept() to be called on AMD CPUs
In preparation for generalizing the nested dirty logging test, checking
if either EPT or NPT is enabled will be needed. To avoid needing to gate
the kvm_cpu_has_ept() call by the CPU type, make sure the function
returns false if VMX is not available instead of trying to read VMX-only
MSRs.
No functional change intended.
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230230150.4150236-16-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| 07676c04 | 31-Dec-2025 |
Sean Christopherson <seanjc@google.com> |
KVM: selftests: Move TDP mapping functions outside of vmx.c
Now that the functions are no longer VMX-specific, move them to
processor.c. Do a minor comment tweak replacing 'EPT' with 'TDP'.
No func
KVM: selftests: Move TDP mapping functions outside of vmx.c
Now that the functions are no longer VMX-specific, move them to
processor.c. Do a minor comment tweak replacing 'EPT' with 'TDP'.
No functional change intended.
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230230150.4150236-15-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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