diff options
| author | Lai Jiangshan <jiangshan.ljs@antgroup.com> | 2022-12-12 17:01:06 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-12-27 06:02:56 -0500 |
| commit | 641e6808586d76b477c00de804358982b95c8d50 (patch) | |
| tree | 3d4eda2f15bbcd06b3ead647ed658c5de9a1d1fc | |
| parent | 1567037614af5f078c2361ca21d9b1a1cd42b8aa (diff) | |
| download | linux-641e6808586d76b477c00de804358982b95c8d50.tar.gz linux-641e6808586d76b477c00de804358982b95c8d50.zip | |
kvm: x86/mmu: Warn on linking when sp->unsync_children
Since the commit 65855ed8b034 ("KVM: X86: Synchronize the shadow
pagetable before link it"), no sp would be linked with
sp->unsync_children = 1.
So make it WARN if it is the case.
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Message-Id: <20221212090106.378206-1-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 4736d7849c60..26b32ae6b526 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -2355,7 +2355,16 @@ static void __link_shadow_page(struct kvm *kvm, mmu_page_add_parent_pte(cache, sp, sptep); - if (sp->unsync_children || sp->unsync) + /* + * The non-direct sub-pagetable must be updated before linking. For + * L1 sp, the pagetable is updated via kvm_sync_page() in + * kvm_mmu_find_shadow_page() without write-protecting the gfn, + * so sp->unsync can be true or false. For higher level non-direct + * sp, the pagetable is updated/synced via mmu_sync_children() in + * FNAME(fetch)(), so sp->unsync_children can only be false. + * WARN_ON_ONCE() if anything happens unexpectedly. + */ + if (WARN_ON_ONCE(sp->unsync_children) || sp->unsync) mark_unsync(sptep); } |