KVM: x86: Fill kvm_run exit fields in common get_nested_state_pages() error paths

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Fill kvm_run with "internal error, emulation" in the common error handling
paths for getting nested state pages, as requiring each check to manually
fill kvm_run is error prone and requires a non-trivial amount of copy+paste.

Specifically, both SVM and VMX fail to fill kvm_run if load_pdptrs() fails,
and SVM fails to fill kvm_run if kvm_hv_verify_vp_assist() fails.  If those
flows fail, the *best* case scenario is that KVM will exit to userspace
with KVM_EXIT_UNKNOWN.  The worst case scenario is that KVM exits with a
stale exit_reason and confuses userspace.

Note, SVM never exits to userspace if something goes sideways when dealing
with vmcb12 assets while emulating VMRUN, i.e. lack of SVM-specific code is
not a bug.

Fixes: 0f85722341 ("KVM: nVMX: delay loading of PDPTRs to KVM_REQ_GET_NESTED_STATE_PAGES")
Fixes: 232f75d3b4 ("KVM: nSVM: call nested_svm_load_cr3 on nested state load")
Fixes: 3f4a812edf ("KVM: nSVM: hyper-v: Enable L2 TLB flush")
Cc: stable@vger.kernel.org
Reported-by: Jinwoo Lee <rkskek9254@gmail.com>
Closes: https://lore.kernel.org/all/20260813043932.3214460-1-rkskek9254@gmail.com
Reported-by: Stefan Teodorescu <fane@google.com>
Link: https://patch.msgid.link/20260921211608.1030158-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

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This commit is contained in:

Sean Christopherson 2026-09-21 14:16:08 -07:00

parent 10180a2775

commit c1214f293d

3 changed files with 9 additions and 16 deletions

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7

arch/x86/kvm/svm/nested.c

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15

arch/x86/kvm/vmx/nested.c

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3

arch/x86/kvm/x86.c

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