From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
commit e9f2a760b158551bfbef6db31d2cae45ab8072e5 upstream.
Note that in such a case it is quite likely that KVM will BUG_ON
in __pte_list_remove when the VM is closed. However, there is no
immediate risk of memory corruption in the host so a WARN_ON is
enough and it lets you gather traces for debugging.
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -781,10 +781,16 @@ static gfn_t kvm_mmu_page_get_gfn(struct
static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn)
{
- if (sp->role.direct)
- BUG_ON(gfn != kvm_mmu_page_get_gfn(sp, index));
- else
+ if (!sp->role.direct) {
sp->gfns[index] = gfn;
+ return;
+ }
+
+ if (WARN_ON(gfn != kvm_mmu_page_get_gfn(sp, index)))
+ pr_err_ratelimited("gfn mismatch under direct page %llx "
+ "(expected %llx, got %llx)\n",
+ sp->gfn,
+ kvm_mmu_page_get_gfn(sp, index), gfn);
}
/*
