Commit 9ef1fae2 authored Jun 30, 2019 by Paolo Bonzini Committed by Greg Kroah-Hartman Nov 12, 2019

KVM: x86: change kvm_mmu_page_get_gfn BUG_ON to WARN_ON



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@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent b182093d

arch/x86/kvm/mmu.c

+9 −3

Original line number	Diff line number	Diff line
		@@ -1027,10 +1027,16 @@ static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index)

		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);
		}

		/*