[PATCH 2/5] KVM: x86/mmu: WARN if TDP MMU's set_tdp_spte() sees multiple GFNs

From: Sean Christopherson
Date: Thu Feb 25 2021 - 20:04:58 EST


WARN if set_tdp_spte() is invoked with multipel GFNs. It is specifically
a callback to handle a single host PTE being changed. Consuming the
@end parameter also eliminates the confusing 'unused' parameter.

Cc: Ben Gardon <bgardon@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/mmu/tdp_mmu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 3290e53fb850..020f2e573f44 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1022,7 +1022,7 @@ int kvm_tdp_mmu_test_age_hva(struct kvm *kvm, unsigned long hva)
* Returns non-zero if a flush is needed before releasing the MMU lock.
*/
static int set_tdp_spte(struct kvm *kvm, struct kvm_memory_slot *slot,
- struct kvm_mmu_page *root, gfn_t gfn, gfn_t unused,
+ struct kvm_mmu_page *root, gfn_t gfn, gfn_t end,
unsigned long data)
{
struct tdp_iter iter;
@@ -1033,7 +1033,7 @@ static int set_tdp_spte(struct kvm *kvm, struct kvm_memory_slot *slot,

rcu_read_lock();

- WARN_ON(pte_huge(*ptep));
+ WARN_ON(pte_huge(*ptep) || (gfn + 1) != end);

new_pfn = pte_pfn(*ptep);

--
2.30.1.766.gb4fecdf3b7-goog