[PATCH 6.12 226/567] KVM: SVM: Mark VMCB_PERM_MAP as dirty on nested VMRUN

Greg Kroah-Hartman
2026-01-06T17:26:40Z

From: Jim Mattson <jmattson@google.com>

commit 93c9e107386dbe1243287a5b14ceca894de372b9 upstream.

Mark the VMCB_PERM_MAP bit as dirty in nested_vmcb02_prepare_control()
on every nested VMRUN.

If L1 changes MSR interception (INTERCEPT_MSR_PROT) between two VMRUN
instructions on the same L1 vCPU, the msrpm_base_pa in the associated
vmcb02 will change, and the VMCB_PERM_MAP clean bit should be cleared.

Fixes: 4bb170a5430b ("KVM: nSVM: do not mark all VMCB02 fields dirty on nested vmexit")
Reported-by: Matteo Rizzo <matteorizzo@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20250922162935.621409-2-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kvm/svm/nested.c | 1 +
1 file changed, 1 insertion(+)

--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -677,6 +677,7 @@ static void nested_vmcb02_prepare_contro
vmcb02->control.nested_ctl = vmcb01->control.nested_ctl;
vmcb02->control.iopm_base_pa = vmcb01->control.iopm_base_pa;
vmcb02->control.msrpm_base_pa = vmcb01->control.msrpm_base_pa;
+ vmcb_mark_dirty(vmcb02, VMCB_PERM_MAP);

/* Done at vmrun: asid. */